Testing is an integral part of enterprise software development. This chapter focuses on the value-add of the IoC principle to unit testing and on the benefits of the Spring Framework’s support for integration testing. (A thorough treatment of testing in the enterprise is beyond the scope of this reference manual.)
Dependency Injection should make your code less dependent on the container than it would
be with traditional Java EE development. The POJOs that make up your application should
be testable in JUnit or TestNG tests, with objects simply instantiated using the new
operator, without Spring or any other container. You can use mock
objects (in conjunction with other valuable testing techniques) to test your code in
isolation. If you follow the architecture recommendations for Spring, the resulting
clean layering and componentization of your codebase will facilitate easier unit
testing. For example, you can test service layer objects by stubbing or mocking DAO or
Repository interfaces, without needing to access persistent data while running unit
tests.
True unit tests typically run extremely quickly, as there is no runtime infrastructure to set up. Emphasizing true unit tests as part of your development methodology will boost your productivity. You may not need this section of the testing chapter to help you write effective unit tests for your IoC-based applications. For certain unit testing scenarios, however, the Spring Framework provides the following mock objects and testing support classes.
The org.springframework.mock.env
package contains mock implementations of the
Environment
and PropertySource
abstractions (see Section 4.13, “Bean definition profiles and environment abstraction”
and Section 4.14, “PropertySource Abstraction”). MockEnvironment
and
MockPropertySource
are useful for developing out-of-container tests for code that
depends on environment-specific properties.
The org.springframework.mock.jndi
package contains an implementation of the JNDI SPI,
which you can use to set up a simple JNDI environment for test suites or stand-alone
applications. If, for example, JDBC DataSource
s get bound to the same JNDI names in
test code as within a Java EE container, you can reuse both application code and
configuration in testing scenarios without modification.
The org.springframework.mock.web
package contains a comprehensive set of Servlet API
mock objects, targeted at usage with Spring’s Web MVC framework, which are useful for
testing web contexts and controllers. These mock objects are generally more convenient
to use than dynamic mock objects such as EasyMock or existing
Servlet API mock objects such as MockObjects.
The org.springframework.test.util
package contains ReflectionTestUtils
, which is a
collection of reflection-based utility methods. Developers use these methods in unit and
integration testing scenarios in which they need to set a non- public
field or invoke
a non- public
setter method when testing application code involving, for example:
private
or protected
field
access as opposed to public
setter methods for properties in a domain entity.
@Autowired
, @Inject
, and @Resource,
which provides dependency injection for private
or protected
fields, setter
methods, and configuration methods.
The org.springframework.test.web
package contains ModelAndViewAssert
, which you can
use in combination with JUnit, TestNG, or any other testing framework for unit tests
dealing with Spring MVC ModelAndView
objects.
Unit testing Spring MVC Controllers | |
---|---|
To test your Spring MVC Note: As of Spring 4.0, the set of mocks in the |
It is important to be able to perform some integration testing without requiring deployment to your application server or connecting to other enterprise infrastructure. This will enable you to test things such as:
The Spring Framework provides first-class support for integration testing in the
spring-test
module. The name of the actual JAR file might include the release version
and might also be in the long org.springframework.test
form, depending on where you
get it from (see the section on Dependency Management for an
explanation). This library includes the org.springframework.test
package, which
contains valuable classes for integration testing with a Spring container. This testing
does not rely on an application server or other deployment environment. Such tests are
slower to run than unit tests but much faster than the equivalent Selenium tests or remote
tests that rely on deployment to an application server.
In Spring 2.5 and later, unit and integration testing support is provided in the form of the annotation-driven Spring TestContext Framework. The TestContext framework is agnostic of the actual testing framework in use, thus allowing instrumentation of tests in various environments including JUnit, TestNG, and so on.
Spring’s integration testing support has the following primary goals:
The next few sections describe each goal and provide links to implementation and configuration details.
The Spring TestContext Framework provides consistent loading of Spring
ApplicationContext
s and WebApplicationContext
s as well as caching of those
contexts. Support for the caching of loaded contexts is important, because startup time
can become an issue — not because of the overhead of Spring itself, but because the
objects instantiated by the Spring container take time to instantiate. For example, a
project with 50 to 100 Hibernate mapping files might take 10 to 20 seconds to load the
mapping files, and incurring that cost before running every test in every test fixture
leads to slower overall test runs that reduce developer productivity.
Test classes typically declare either an array of resource locations for XML
configuration metadata — often in the classpath — or an array of annotated classes
that is used to configure the application. These locations or classes are the same as or
similar to those specified in web.xml
or other deployment configuration files.
By default, once loaded, the configured ApplicationContext
is reused for each test.
Thus the setup cost is incurred only once per test suite, and subsequent test execution
is much faster. In this context, the term test suite means all tests run in the same
JVM — for example, all tests run from an Ant, Maven, or Gradle build for a given
project or module. In the unlikely case that a test corrupts the application context and
requires reloading — for example, by modifying a bean definition or the state of an
application object — the TestContext framework can be configured to reload the
configuration and rebuild the application context before executing the next test.
See the section called “Context management” and the section called “Context caching” with the TestContext framework.
When the TestContext framework loads your application context, it can optionally
configure instances of your test classes via Dependency Injection. This provides a
convenient mechanism for setting up test fixtures using preconfigured beans from your
application context. A strong benefit here is that you can reuse application contexts
across various testing scenarios (e.g., for configuring Spring-managed object graphs,
transactional proxies, DataSource
s, etc.), thus avoiding the need to duplicate
complex test fixture setup for individual test cases.
As an example, consider the scenario where we have a class, HibernateTitleRepository
,
that implements data access logic for a Title
domain entity. We want to write
integration tests that test the following areas:
HibernateTitleRepository
bean correct and present?
HibernateTitleRepository
: does the configured instance of this
class perform as anticipated?
See dependency injection of test fixtures with the TestContext framework.
One common issue in tests that access a real database is their effect on the state of the persistence store. Even when you’re using a development database, changes to the state may affect future tests. Also, many operations — such as inserting or modifying persistent data — cannot be performed (or verified) outside a transaction.
The TestContext framework addresses this issue. By default, the framework will create
and roll back a transaction for each test. You simply write code that can assume the
existence of a transaction. If you call transactionally proxied objects in your tests,
they will behave correctly, according to their configured transactional semantics. In
addition, if a test method deletes the contents of selected tables while running within
the transaction managed for the test, the transaction will roll back by default, and the
database will return to its state prior to execution of the test. Transactional support
is provided to a test via a PlatformTransactionManager
bean defined in the test’s
application context.
If you want a transaction to commit — unusual, but occasionally useful when you want a
particular test to populate or modify the database — the TestContext framework can be
instructed to cause the transaction to commit instead of roll back via the
@TransactionConfiguration
and
@Rollback
annotations.
See transaction management with the TestContext framework.
The Spring TestContext Framework provides several abstract
support classes that
simplify the writing of integration tests. These base test classes provide well-defined
hooks into the testing framework as well as convenient instance variables and methods,
which enable you to access:
ApplicationContext
, for performing explicit bean lookups or testing the state of
the context as a whole.
JdbcTemplate
, for executing SQL statements to query the database. Such queries can
be used to confirm database state both prior to and after execution of
database-related application code, and Spring ensures that such queries run in the
scope of the same transaction as the application code. When used in conjunction with
an ORM tool, be sure to avoid false positives.
In addition, you may want to create your own custom, application-wide superclass with instance variables and methods specific to your project.
See support classes for the TestContext framework.
The org.springframework.test.jdbc
package contains JdbcTestUtils
, which is a
collection of JDBC related utility functions intended to simplify standard database
testing scenarios. Note that AbstractTransactionalJUnit4SpringContextTests
and
AbstractTransactionalTestNGSpringContextTests
provide convenience methods which delegate to JdbcTestUtils
internally.
The spring-jdbc
module provides support for configuring and launching an embedded
database which can be used in integration tests that interact with a database. For
details, see Section 13.8, “Embedded database support” and
Section 13.8.8, “Testing data access logic with an embedded database”.
The Spring Framework provides the following set of Spring-specific annotations that you can use in your unit and integration tests in conjunction with the TestContext framework. Refer to the corresponding javadocs for further information, including default attribute values, attribute aliases, and so on.
@ContextConfiguration
Defines class-level metadata that is used to determine how to load and configure an
ApplicationContext
for integration tests. Specifically, @ContextConfiguration
declares the application context resource locations
or the annotated classes
that will be used to load the context.
Resource locations are typically XML configuration files located in the classpath;
whereas, annotated classes are typically @Configuration
classes. However, resource
locations can also refer to files in the file system, and annotated classes can be
component classes, etc.
@ContextConfiguration("/test-config.xml") public class XmlApplicationContextTests { // class body... }
@ContextConfiguration(classes = TestConfig.class) public class ConfigClassApplicationContextTests { // class body... }
As an alternative or in addition to declaring resource locations or annotated classes,
@ContextConfiguration
may be used to declare ApplicationContextInitializer
classes.
@ContextConfiguration(initializers = CustomContextIntializer.class) public class ContextInitializerTests { // class body... }
@ContextConfiguration
may optionally be used to declare the ContextLoader
strategy
as well. Note, however, that you typically do not need to explicitly configure the
loader since the default loader supports either resource locations
or annotated
classes
as well as initializers
.
@ContextConfiguration(locations = "/test-context.xml", loader = CustomContextLoader.class) public class CustomLoaderXmlApplicationContextTests { // class body... }
Note | |
---|---|
|
See the section called “Context management” and the @ContextConfiguration
javadocs for
further details.
@WebAppConfiguration
A class-level annotation that is used to declare that the ApplicationContext
loaded
for an integration test should be a WebApplicationContext
. The mere presence of
@WebAppConfiguration
on a test class ensures that a WebApplicationContext
will be
loaded for the test, using the default value of "file:src/main/webapp"
for the path to
the root of the web application (i.e., the resource base path). The resource base
path is used behind the scenes to create a MockServletContext
which serves as the
ServletContext
for the test’s WebApplicationContext
.
@ContextConfiguration @WebAppConfiguration public class WebAppTests { // class body... }
To override the default, specify a different base resource path via the implicit
value
attribute. Both classpath:
and file:
resource prefixes are supported. If no
resource prefix is supplied the path is assumed to be a file system resource.
@ContextConfiguration @WebAppConfiguration("classpath:test-web-resources") public class WebAppTests { // class body... }
Note that @WebAppConfiguration
must be used in conjunction with
@ContextConfiguration
, either within a single test class or within a test class
hierarchy. See the @WebAppConfiguration
javadocs for further details.
@ContextHierarchy
A class-level annotation that is used to define a hierarchy of ApplicationContext
s
for integration tests. @ContextHierarchy
should be declared with a list of one or more
@ContextConfiguration
instances, each of which defines a level in the context
hierarchy. The following examples demonstrate the use of @ContextHierarchy
within a
single test class; however, @ContextHierarchy
can also be used within a test class
hierarchy.
@ContextHierarchy({ @ContextConfiguration("/parent-config.xml"), @ContextConfiguration("/child-config.xml") }) public class ContextHierarchyTests { // class body... }
@WebAppConfiguration @ContextHierarchy({ @ContextConfiguration(classes = AppConfig.class), @ContextConfiguration(classes = WebConfig.class) }) public class WebIntegrationTests { // class body... }
If you need to merge or override the configuration for a given level of the context
hierarchy within a test class hierarchy, you must explicitly name that level by
supplying the same value to the name
attribute in @ContextConfiguration
at each
corresponding level in the class hierarchy. See
the section called “Context hierarchies” and the @ContextHierarchy
javadocs
for further examples.
@ActiveProfiles
A class-level annotation that is used to declare which bean definition profiles
should be active when loading an ApplicationContext
for test classes.
@ContextConfiguration @ActiveProfiles("dev") public class DeveloperTests { // class body... }
@ContextConfiguration @ActiveProfiles({"dev", "integration"}) public class DeveloperIntegrationTests { // class body... }
Note | |
---|---|
|
See the section called “Context configuration with environment profiles” and the @ActiveProfiles
javadocs
for examples and further details.
@DirtiesContext
Indicates that the underlying Spring ApplicationContext
has been dirtied during
the execution of a test (i.e., modified or corrupted in some manner — for example, by
changing the state of a singleton bean) and should be closed, regardless of whether the
test passed. When an application context is marked dirty, it is removed from the
testing framework’s cache and closed. As a consequence, the underlying Spring container
will be rebuilt for any subsequent test that requires a context with the same
configuration metadata.
@DirtiesContext
can be used as both a class-level and method-level annotation within
the same test class. In such scenarios, the ApplicationContext
is marked as dirty
after any such annotated method as well as after the entire class. If the ClassMode
is
set to AFTER_EACH_TEST_METHOD
, the context is marked dirty after each test method in
the class.
The following examples explain when the context would be dirtied for various configuration scenarios:
After the current test class, when declared on a class with class mode set to
AFTER_CLASS
(i.e., the default class mode).
@DirtiesContext public class ContextDirtyingTests { // some tests that result in the Spring container being dirtied }
After each test method in the current test class, when declared on a class with class
mode set to AFTER_EACH_TEST_METHOD.
@DirtiesContext(classMode = ClassMode.AFTER_EACH_TEST_METHOD) public class ContextDirtyingTests { // some tests that result in the Spring container being dirtied }
After the current test, when declared on a method.
@DirtiesContext @Test public void testProcessWhichDirtiesAppCtx() { // some logic that results in the Spring container being dirtied }
If @DirtiesContext
is used in a test whose context is configured as part of a context
hierarchy via @ContextHierarchy
, the hierarchyMode
flag can be used to control how
the context cache is cleared. By default an exhaustive algorithm will be used that
clears the context cache including not only the current level but also all other context
hierarchies that share an ancestor context common to the current test; all
ApplicationContext
s that reside in a sub-hierarchy of the common ancestor context
will be removed from the context cache and closed. If the exhaustive algorithm is
overkill for a particular use case, the simpler current level algorithm can be
specified instead, as seen below.
@ContextHierarchy({ @ContextConfiguration("/parent-config.xml"), @ContextConfiguration("/child-config.xml") }) public class BaseTests { // class body... } public class ExtendedTests extends BaseTests { @Test @DirtiesContext(hierarchyMode = HierarchyMode.CURRENT_LEVEL) public void test() { // some logic that results in the child context being dirtied } }
For further details regarding the EXHAUSTIVE
and CURRENT_LEVEL
algorithms see the
DirtiesContext.HierarchyMode
javadocs.
@TestExecutionListeners
Defines class-level metadata for configuring which TestExecutionListener
s should be
registered with the TestContextManager
. Typically, @TestExecutionListeners
is used
in conjunction with @ContextConfiguration
.
@ContextConfiguration @TestExecutionListeners({CustomTestExecutionListener.class, AnotherTestExecutionListener.class}) public class CustomTestExecutionListenerTests { // class body... }
@TestExecutionListeners
supports inherited listeners by default. See the javadocs
for an example and further details.
@TransactionConfiguration
Defines class-level metadata for configuring transactional tests. Specifically, the bean
name of the PlatformTransactionManager
that should be used to drive transactions can
be explicitly specified if there are multiple beans of type PlatformTransactionManager
in the test’s ApplicationContext
and if the bean name of the desired
PlatformTransactionManager
is not "transactionManager". In addition, you can change
the defaultRollback
flag to false
. Typically, @TransactionConfiguration
is used in
conjunction with @ContextConfiguration
.
@ContextConfiguration @TransactionConfiguration(transactionManager = "txMgr", defaultRollback = false) public class CustomConfiguredTransactionalTests { // class body... }
Note | |
---|---|
If the default conventions are sufficient for your test configuration, you can avoid
using |
@Rollback
Indicates whether the transaction for the annotated test method should be rolled
back after the test method has completed. If true
, the transaction is rolled back;
otherwise, the transaction is committed. Use @Rollback
to override the default
rollback flag configured at the class level.
@Rollback(false) @Test public void testProcessWithoutRollback() { // ... }
@BeforeTransaction
Indicates that the annotated public void
method should be executed before a
transaction is started for test methods configured to run within a transaction via the
@Transactional
annotation.
@BeforeTransaction public void beforeTransaction() { // logic to be executed before a transaction is started }
@AfterTransaction
Indicates that the annotated public void
method should be executed after a
transaction has ended for test methods configured to run within a transaction via the
@Transactional
annotation.
@AfterTransaction public void afterTransaction() { // logic to be executed after a transaction has ended }
The following annotations are supported with standard semantics for all configurations of the Spring TestContext Framework. Note that these annotations are not specific to tests and can be used anywhere in the Spring Framework.
@Autowired
@Qualifier
@Resource
(javax.annotation) if JSR-250 is present
@Inject
(javax.inject) if JSR-330 is present
@Named
(javax.inject) if JSR-330 is present
@PersistenceContext
(javax.persistence) if JPA is present
@PersistenceUnit
(javax.persistence) if JPA is present
@Required
@Transactional
JSR-250 Lifecycle Annotations | |
---|---|
In the Spring TestContext Framework If a method within a test class is annotated with |
The following annotations are only supported when used in conjunction with the SpringJUnit4ClassRunner or the JUnit support classes.
@IfProfileValue
Indicates that the annotated test is enabled for a specific testing environment. If the
configured ProfileValueSource
returns a matching value
for the provided name
, the
test is enabled. This annotation can be applied to an entire class or to individual
methods. Class-level usage overrides method-level usage.
@IfProfileValue(name="java.vendor", value="Oracle Corporation") @Test public void testProcessWhichRunsOnlyOnOracleJvm() { // some logic that should run only on Java VMs from Oracle Corporation }
Alternatively, you can configure @IfProfileValue
with a list of values
(with OR
semantics) to achieve TestNG-like support for test groups in a JUnit environment.
Consider the following example:
@IfProfileValue(name="test-groups", values={"unit-tests", "integration-tests"}) @Test public void testProcessWhichRunsForUnitOrIntegrationTestGroups() { // some logic that should run only for unit and integration test groups }
@ProfileValueSourceConfiguration
Class-level annotation that specifies what type of ProfileValueSource
to use when
retrieving profile values configured through the @IfProfileValue
annotation. If
@ProfileValueSourceConfiguration
is not declared for a test,
SystemProfileValueSource
is used by default.
@ProfileValueSourceConfiguration(CustomProfileValueSource.class) public class CustomProfileValueSourceTests { // class body... }
@Timed
Indicates that the annotated test method must finish execution in a specified time period (in milliseconds). If the text execution time exceeds the specified time period, the test fails.
The time period includes execution of the test method itself, any repetitions of the
test (see @Repeat
), as well as any set up or tear down of the test fixture.
@Timed(millis=1000) public void testProcessWithOneSecondTimeout() { // some logic that should not take longer than 1 second to execute }
Spring’s @Timed
annotation has different semantics than JUnit’s @Test(timeout=...)
support. Specifically, due to the manner in which JUnit handles test execution timeouts
(that is, by executing the test method in a separate Thread
), @Test(timeout=...)
applies to each iteration in the case of repetitions and preemptively fails the test
if the test takes too long. Spring’s @Timed
, on the other hand, times the total
test execution time (including all repetitions) and does not preemptively fail the test
but rather waits for the test to complete before failing.
@Repeat
Indicates that the annotated test method must be executed repeatedly. The number of times that the test method is to be executed is specified in the annotation.
The scope of execution to be repeated includes execution of the test method itself as well as any set up or tear down of the test fixture.
@Repeat(10) @Test public void testProcessRepeatedly() { // ... }
As of Spring Framework 4.0, it is now possible to use test-related annotations as meta-annotations in order to create custom composed annotations and reduce configuration duplication across a test suite.
Each of the following may be used as meta-annotations in conjunction with the TestContext framework.
@ContextConfiguration
@ContextHierarchy
@ActiveProfiles
@DirtiesContext
@WebAppConfiguration
@TestExecutionListeners
@Transactional
@BeforeTransaction
@AfterTransaction
@TransactionConfiguration
@Rollback
@Repeat
@Timed
@IfProfileValue
@ProfileValueSourceConfiguration
For example, if we discover that we are repeating the following configuration across our JUnit-based test suite…
@RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration({"/app-config.xml", "/test-data-access-config.xml"}) @ActiveProfiles("dev") @Transactional public class OrderRepositoryTests { } @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration({"/app-config.xml", "/test-data-access-config.xml"}) @ActiveProfiles("dev") @Transactional public class UserRepositoryTests { }
We can reduce the above duplication by introducing a custom composed annotation that centralizes the common test configuration like this:
@Target(ElementType.TYPE) @Retention(RetentionPolicy.RUNTIME) @ContextConfiguration({"/app-config.xml", "/test-data-access-config.xml"}) @ActiveProfiles("dev") @Transactional public @interface TransactionalDevTest { }
Then we can use our custom @TransactionalDevTest
annotation to simplify the
configuration of individual test classes as follows:
@RunWith(SpringJUnit4ClassRunner.class) @TransactionalDevTest public class OrderRepositoryTests { } @RunWith(SpringJUnit4ClassRunner.class) @TransactionalDevTest public class UserRepositoryTests { }
The Spring TestContext Framework (located in the
org.springframework.test.context
package) provides generic, annotation-driven unit and
integration testing support that is agnostic of the testing framework in use. The
TestContext framework also places a great deal of importance on convention over
configuration with reasonable defaults that can be overridden through annotation-based
configuration.
In addition to generic testing infrastructure, the TestContext framework provides
explicit support for JUnit and TestNG in the form of abstract
support classes. For
JUnit, Spring also provides a custom JUnit Runner
that allows one to write so-called
POJO test classes. POJO test classes are not required to extend a particular class
hierarchy.
The following section provides an overview of the internals of the TestContext framework. If you are only interested in using the framework and not necessarily interested in extending it with your own custom listeners or custom loaders, feel free to go directly to the configuration (context management, dependency injection, transaction management), support classes, and annotation support sections.
The core of the framework consists of the TestContext
and TestContextManager
classes
and the TestExecutionListener
, ContextLoader
, and SmartContextLoader
interfaces. A
TestContextManager
is created on a per-test basis (e.g., for the execution of a single
test method in JUnit). The TestContextManager
in turn manages a TestContext
that
holds the context of the current test. The TestContextManager
also updates the state
of the TestContext
as the test progresses and delegates to TestExecutionListener
s,
which instrument the actual test execution by providing dependency injection, managing
transactions, and so on. A ContextLoader
(or SmartContextLoader
) is responsible for
loading an ApplicationContext
for a given test class. Consult the javadocs and the
Spring test suite for further information and examples of various implementations.
TestContext
: Encapsulates the context in which a test is executed, agnostic of the
actual testing framework in use, and provides context management and caching support
for the test instance for which it is responsible. The TestContext
also delegates to
a ContextLoader
(or SmartContextLoader
) to load an ApplicationContext
if
requested.
TestContextManager
: The main entry point into the Spring TestContext Framework,
which manages a single TestContext
and signals events to all registered
TestExecutionListener
s at well-defined test execution points:
TestExecutionListener
: Defines a listener API for reacting to test execution
events published by the TestContextManager
with which the listener is registered.
Spring provides four TestExecutionListener
implementations that are configured by
default: ServletTestExecutionListener
, DependencyInjectionTestExecutionListener
,
DirtiesContextTestExecutionListener
, and TransactionalTestExecutionListener
.
Respectively, they support Servlet API mocks for a WebApplicationContext
, dependency
injection of the test instance, handling of the @DirtiesContext
annotation, and
transactional test execution with default rollback semantics.
ContextLoader
: Strategy interface introduced in Spring 2.5 for loading an
ApplicationContext
for an integration test managed by the Spring TestContext
Framework.
As of Spring 3.1, implement SmartContextLoader
instead of this interface in order to
provide support for annotated classes and active bean definition profiles.
SmartContextLoader
: Extension of the ContextLoader
interface introduced in Spring
3.1.
The SmartContextLoader
SPI supersedes the ContextLoader
SPI that was introduced in
Spring 2.5. Specifically, a SmartContextLoader
can choose to process resource
locations
, annotated classes
, or context initializers
. Furthermore, a
SmartContextLoader
can set active bean definition profiles in the context that it
loads.
Spring provides the following implementations:
DelegatingSmartContextLoader
: one of two default loaders which delegates internally
to an AnnotationConfigContextLoader
or a GenericXmlContextLoader
depending either on
the configuration declared for the test class or on the presence of default locations or
default configuration classes.
WebDelegatingSmartContextLoader
: one of two default loaders which delegates
internally to an AnnotationConfigWebContextLoader
or a GenericXmlWebContextLoader
depending either on the configuration declared for the test class or on the presence of
default locations or default configuration classes. A web ContextLoader
will only be
used if @WebAppConfiguration
is present on the test class.
AnnotationConfigContextLoader
: loads a standard ApplicationContext
from
annotated classes.
AnnotationConfigWebContextLoader
: loads a WebApplicationContext
from annotated
classes.
GenericXmlContextLoader
: loads a standard ApplicationContext
from XML resource
locations.
GenericXmlWebContextLoader
: loads a WebApplicationContext
from XML resource
locations.
GenericPropertiesContextLoader
: loads a standard ApplicationContext
from Java
Properties files.
The following sections explain how to configure the TestContext framework through annotations and provide working examples of how to write unit and integration tests with the framework.
Each TestContext
provides context management and caching support for the test instance
it is responsible for. Test instances do not automatically receive access to the
configured ApplicationContext
. However, if a test class implements the
ApplicationContextAware
interface, a reference to the ApplicationContext
is supplied
to the test instance. Note that AbstractJUnit4SpringContextTests
and
AbstractTestNGSpringContextTests
implement ApplicationContextAware
and therefore
provide access to the ApplicationContext
automatically.
@Autowired ApplicationContext | |
---|---|
As an alternative to implementing the @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration public class MyTest { @Autowired private ApplicationContext applicationContext; // class body... } Similarly, if your test is configured to load a @RunWith(SpringJUnit4ClassRunner.class) @WebAppConfiguration @ContextConfiguration public class MyWebAppTest { @Autowired private WebApplicationContext wac; // class body... } Dependency injection via |
Test classes that use the TestContext framework do not need to extend any particular
class or implement a specific interface to configure their application context. Instead,
configuration is achieved simply by declaring the @ContextConfiguration
annotation at
the class level. If your test class does not explicitly declare application context
resource locations
or annotated classes
, the configured ContextLoader
determines
how to load a context from a default location or default configuration classes. In
addition to context resource locations
and annotated classes
, an application context
can also be configured via application context initializers
.
The following sections explain how to configure an ApplicationContext
via XML
configuration files, annotated classes (typically @Configuration
classes), or context
initializers using Spring’s @ContextConfiguration
annotation. Alternatively, you can
implement and configure your own custom SmartContextLoader
for advanced use cases.
To load an ApplicationContext
for your tests using XML configuration files, annotate
your test class with @ContextConfiguration
and configure the locations
attribute
with an array that contains the resource locations of XML configuration metadata. A
plain or relative path — for example "context.xml"
— will be treated as a classpath
resource that is relative to the package in which the test class is defined. A path
starting with a slash is treated as an absolute classpath location, for example
"/org/example/config.xml"
. A path which represents a resource URL (i.e., a path
prefixed with classpath:
, file:
, http:
, etc.) will be used as is.
@RunWith(SpringJUnit4ClassRunner.class) // ApplicationContext will be loaded from "/app-config.xml" and // "/test-config.xml" in the root of the classpath @ContextConfiguration(locations={"/app-config.xml", "/test-config.xml"}) public class MyTest { // class body... }
@ContextConfiguration
supports an alias for the locations
attribute through the
standard Java value
attribute. Thus, if you do not need to declare additional
attributes in @ContextConfiguration
, you can omit the declaration of the locations
attribute name and declare the resource locations by using the shorthand format
demonstrated in the following example.
@RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration({"/app-config.xml", "/test-config.xml"}) public class MyTest { // class body... }
If you omit both the locations
and value
attributes from the @ContextConfiguration
annotation, the TestContext framework will attempt to detect a default XML resource
location. Specifically, GenericXmlContextLoader
detects a default location based on
the name of the test class. If your class is named com.example.MyTest
,
GenericXmlContextLoader
loads your application context from
"classpath:/com/example/MyTest-context.xml"
.
package com.example; @RunWith(SpringJUnit4ClassRunner.class) // ApplicationContext will be loaded from // "classpath:/com/example/MyTest-context.xml" @ContextConfiguration public class MyTest { // class body... }
To load an ApplicationContext
for your tests using annotated classes (see
Section 4.12, “Java-based container configuration”), annotate your test class with @ContextConfiguration
and configure the
classes
attribute with an array that contains references to annotated classes.
@RunWith(SpringJUnit4ClassRunner.class) // ApplicationContext will be loaded from AppConfig and TestConfig @ContextConfiguration(classes = {AppConfig.class, TestConfig.class}) public class MyTest { // class body... }
Annotated Classes | |
---|---|
The term annotated class can refer to any of the following.
Consult the javadocs of |
If you omit the classes
attribute from the @ContextConfiguration
annotation, the
TestContext framework will attempt to detect the presence of default configuration
classes. Specifically, AnnotationConfigContextLoader
will detect all static inner
classes of the test class that meet the requirements for configuration class
implementations as specified in the @Configuration
javadocs. In the following
example, the OrderServiceTest
class declares a static inner configuration class named
Config
that will be automatically used to load the ApplicationContext
for the test
class. Note that the name of the configuration class is arbitrary. In addition, a test
class can contain more than one static inner configuration class if desired.
@RunWith(SpringJUnit4ClassRunner.class) // ApplicationContext will be loaded from the // static inner Config class @ContextConfiguration public class OrderServiceTest { @Configuration static class Config { // this bean will be injected into the OrderServiceTest class @Bean public OrderService orderService() { OrderService orderService = new OrderServiceImpl(); // set properties, etc. return orderService; } } @Autowired private OrderService orderService; @Test public void testOrderService() { // test the orderService } }
It may sometimes be desirable to mix XML resources and annotated classes (i.e.,
typically @Configuration
classes) to configure an ApplicationContext
for your tests.
For example, if you use XML configuration in production, you may decide that you want to
use @Configuration
classes to configure specific Spring-managed components for your
tests, or vice versa.
Furthermore, some third-party frameworks (like Spring Boot) provide first-class
support for loading an ApplicationContext
from different types of resources
simultaneously (e.g., XML configuration files and @Configuration
classes). The Spring
Framework historically has not supported this for standard deployments. Consequently,
each of the SmartContextLoader
implementations that the Spring Framework delivers in
the spring-test
module supports only one resource type per test context;
however, this does not mean that you cannot use both. Third-party frameworks may
choose to support the declaration of both locations
and classes
via
@ContextConfiguration
, and with the standard testing support in the TestContext
framework, you have the following options.
If you want to use XML and @Configuration
classes to configure your tests, you
will have to pick one as the entry point, and that one will have to include or
import the other. For example, in XML you can include @Configuration
classes via
component scanning or define them as normal Spring beans in XML; whereas, in a
@Configuration
class you can use @ImportResource
to import XML configuration files.
Note that this behavior is semantically equivalent to how you configure your application
in production: in production configuration you will define either a set of XML resource
locations or a set of @Configuration
classes that your production ApplicationContext
will be loaded from, but you still have the freedom to include or import the other type
of configuration.
To configure an ApplicationContext
for your tests using context initializers, annotate
your test class with @ContextConfiguration
and configure the initializers
attribute
with an array that contains references to classes that implement
ApplicationContextInitializer
. The declared context initializers will then be used to
initialize the ConfigurableApplicationContext
that is loaded for your tests. Note that
the concrete ConfigurableApplicationContext
type supported by each declared
initializer must be compatible with the type of ApplicationContext
created by the
SmartContextLoader
in use (i.e., typically a GenericApplicationContext
).
Furthermore, the order in which the initializers are invoked depends on whether they
implement Spring’s Ordered
interface or are annotated with Spring’s @Order
annotation.
@RunWith(SpringJUnit4ClassRunner.class) // ApplicationContext will be loaded from TestConfig // and initialized by TestAppCtxInitializer @ContextConfiguration( classes = TestConfig.class, initializers = TestAppCtxInitializer.class) public class MyTest { // class body... }
It is also possible to omit the declaration of XML configuration files or annotated
classes in @ContextConfiguration
entirely and instead declare only
ApplicationContextInitializer
classes which are then responsible for registering beans
in the context — for example, by programmatically loading bean definitions from XML
files or configuration classes.
@RunWith(SpringJUnit4ClassRunner.class) // ApplicationContext will be initialized by EntireAppInitializer // which presumably registers beans in the context @ContextConfiguration(initializers = EntireAppInitializer.class) public class MyTest { // class body... }
@ContextConfiguration
supports boolean inheritLocations
and inheritInitializers
attributes that denote whether resource locations or annotated classes and context
initializers declared by superclasses should be inherited. The default value for
both flags is true
. This means that a test class inherits the resource locations or
annotated classes as well as the context initializers declared by any superclasses.
Specifically, the resource locations or annotated classes for a test class are appended
to the list of resource locations or annotated classes declared by superclasses.
Similarly, the initializers for a given test class will be added to the set of
initializers defined by test superclasses. Thus, subclasses have the option
of extending the resource locations, annotated classes, or context initializers.
If @ContextConfiguration
's inheritLocations
or inheritInitializers
attribute is
set to false
, the resource locations or annotated classes and the context
initializers, respectively, for the test class shadow and effectively replace the
configuration defined by superclasses.
In the following example that uses XML resource locations, the ApplicationContext
for
ExtendedTest
will be loaded from "base-config.xml" and
"extended-config.xml", in that order. Beans defined in "extended-config.xml" may
therefore override (i.e., replace) those defined in "base-config.xml".
@RunWith(SpringJUnit4ClassRunner.class) // ApplicationContext will be loaded from "/base-config.xml" // in the root of the classpath @ContextConfiguration("/base-config.xml") public class BaseTest { // class body... } // ApplicationContext will be loaded from "/base-config.xml" and // "/extended-config.xml" in the root of the classpath @ContextConfiguration("/extended-config.xml") public class ExtendedTest extends BaseTest { // class body... }
Similarly, in the following example that uses annotated classes, the
ApplicationContext
for ExtendedTest
will be loaded from the BaseConfig
and
ExtendedConfig
classes, in that order. Beans defined in ExtendedConfig
may therefore
override (i.e., replace) those defined in BaseConfig
.
@RunWith(SpringJUnit4ClassRunner.class) // ApplicationContext will be loaded from BaseConfig @ContextConfiguration(classes = BaseConfig.class) public class BaseTest { // class body... } // ApplicationContext will be loaded from BaseConfig and ExtendedConfig @ContextConfiguration(classes = ExtendedConfig.class) public class ExtendedTest extends BaseTest { // class body... }
In the following example that uses context initializers, the ApplicationContext
for
ExtendedTest
will be initialized using BaseInitializer
and
ExtendedInitializer
. Note, however, that the order in which the initializers are
invoked depends on whether they implement Spring’s Ordered
interface or are annotated
with Spring’s @Order
annotation.
@RunWith(SpringJUnit4ClassRunner.class) // ApplicationContext will be initialized by BaseInitializer @ContextConfiguration(initializers = BaseInitializer.class) public class BaseTest { // class body... } // ApplicationContext will be initialized by BaseInitializer // and ExtendedInitializer @ContextConfiguration(initializers = ExtendedInitializer.class) public class ExtendedTest extends BaseTest { // class body... }
Spring 3.1 introduced first-class support in the framework for the notion of
environments and profiles (a.k.a., bean definition profiles), and integration tests
can be configured to activate particular bean definition profiles for various testing
scenarios. This is achieved by annotating a test class with the @ActiveProfiles
annotation and supplying a list of profiles that should be activated when loading the
ApplicationContext
for the test.
Note | |
---|---|
|
Let’s take a look at some examples with XML configuration and @Configuration
classes.
<!-- app-config.xml --> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee" xsi:schemaLocation="..."> <bean id="transferService" class="com.bank.service.internal.DefaultTransferService"> <constructor-arg ref="accountRepository"/> <constructor-arg ref="feePolicy"/> </bean> <bean id="accountRepository" class="com.bank.repository.internal.JdbcAccountRepository"> <constructor-arg ref="dataSource"/> </bean> <bean id="feePolicy" class="com.bank.service.internal.ZeroFeePolicy"/> <beans profile="dev"> <jdbc:embedded-database id="dataSource"> <jdbc:script location="classpath:com/bank/config/sql/schema.sql"/> <jdbc:script location="classpath:com/bank/config/sql/test-data.sql"/> </jdbc:embedded-database> </beans> <beans profile="production"> <jee:jndi-lookup id="dataSource" jndi-name="java:comp/env/jdbc/datasource"/> </beans> <beans profile="default"> <jdbc:embedded-database id="dataSource"> <jdbc:script location="classpath:com/bank/config/sql/schema.sql"/> </jdbc:embedded-database> </beans> </beans>
package com.bank.service; @RunWith(SpringJUnit4ClassRunner.class) // ApplicationContext will be loaded from "classpath:/app-config.xml" @ContextConfiguration("/app-config.xml") @ActiveProfiles("dev") public class TransferServiceTest { @Autowired private TransferService transferService; @Test public void testTransferService() { // test the transferService } }
When TransferServiceTest
is run, its ApplicationContext
will be loaded from the
app-config.xml
configuration file in the root of the classpath. If you inspect
app-config.xml
you’ll notice that the accountRepository
bean has a dependency on a
dataSource
bean; however, dataSource
is not defined as a top-level bean. Instead,
dataSource
is defined three times: in the production profile, the
dev profile, and the default profile.
By annotating TransferServiceTest
with @ActiveProfiles("dev")
we instruct the Spring
TestContext Framework to load the ApplicationContext
with the active profiles set to
{"dev"}
. As a result, an embedded database will be created and populated with test data,
and the accountRepository
bean will be wired with a reference to the development
DataSource
. And that’s likely what we want in an integration test.
It is sometimes useful to assign beans to a default
profile. Beans within the default profile
are only included when no other profile is specifically activated. This can be used to define
fallback beans to be used in the application’s default state. For example, you may
explicitly provide a data source for dev
and production
profiles, but define an in-memory
data source as a default when neither of these is active.
The following code listings demonstrate how to implement the same configuration and
integration test but using @Configuration
classes instead of XML.
@Configuration @Profile("dev") public class StandaloneDataConfig { @Bean public DataSource dataSource() { return new EmbeddedDatabaseBuilder() .setType(EmbeddedDatabaseType.HSQL) .addScript("classpath:com/bank/config/sql/schema.sql") .addScript("classpath:com/bank/config/sql/test-data.sql") .build(); } }
@Configuration @Profile("production") public class JndiDataConfig { @Bean public DataSource dataSource() throws Exception { Context ctx = new InitialContext(); return (DataSource) ctx.lookup("java:comp/env/jdbc/datasource"); } }
@Configuration @Profile("default") public class DefaultDataConfig { @Bean public DataSource dataSource() { return new EmbeddedDatabaseBuilder() .setType(EmbeddedDatabaseType.HSQL) .addScript("classpath:com/bank/config/sql/schema.sql") .build(); } }
@Configuration public class TransferServiceConfig { @Autowired DataSource dataSource; @Bean public TransferService transferService() { return new DefaultTransferService(accountRepository(), feePolicy()); } @Bean public AccountRepository accountRepository() { return new JdbcAccountRepository(dataSource); } @Bean public FeePolicy feePolicy() { return new ZeroFeePolicy(); } }
package com.bank.service; @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(classes = { TransferServiceConfig.class, StandaloneDataConfig.class, JndiDataConfig.class, DefaultDataConfig.class}) @ActiveProfiles("dev") public class TransferServiceTest { @Autowired private TransferService transferService; @Test public void testTransferService() { // test the transferService } }
In this variation, we have split the XML configuration into four independent
@Configuration
classes:
TransferServiceConfig
: acquires a dataSource
via dependency injection using
@Autowired
StandaloneDataConfig
: defines a dataSource
for an embedded database suitable for
developer tests
JndiDataConfig
: defines a dataSource
that is retrieved from JNDI in a production
environment
DefaultDataConfig
: defines a dataSource
for a default embedded database in case
no profile is active
As with the XML-based configuration example, we still annotate TransferServiceTest
with @ActiveProfiles("dev")
, but this time we specify all four configuration classes
via the @ContextConfiguration
annotation. The body of the test class itself remains
completely unchanged.
It is often the case that a single set of profiles is used across multiple test classes
within a given project. Thus, to avoid duplicate declarations of the @ActiveProfiles
annotation it is possible to declare @ActiveProfiles
once on a base class, and
subclasses will automatically inherit the @ActiveProfiles
configuration from the base
class. In the following example, the declaration of @ActiveProfiles
(as well as other
annotations) has been moved to an abstract superclass, AbstractIntegrationTest
.
package com.bank.service; @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(classes = { TransferServiceConfig.class, StandaloneDataConfig.class, JndiDataConfig.class, DefaultDataConfig.class}) @ActiveProfiles("dev") public abstract class AbstractIntegrationTest { }
package com.bank.service; // "dev" profile inherited from superclass public class TransferServiceTest extends AbstractIntegrationTest { @Autowired private TransferService transferService; @Test public void testTransferService() { // test the transferService } }
@ActiveProfiles
also supports an inheritProfiles
attribute that can be used to
disable the inheritance of active profiles.
package com.bank.service; // "dev" profile overridden with "production" @ActiveProfiles(profiles = "production", inheritProfiles = false) public class ProductionTransferServiceTest extends AbstractIntegrationTest { // test body }
Furthermore, it is sometimes necessary to resolve active profiles for tests programmatically instead of declaratively — for example, based on:
To resolve active bean definition profiles programmatically, simply implement a custom
ActiveProfilesResolver
and register it via the resolver
attribute of
@ActiveProfiles
. The following example demonstrates how to implement and register a
custom OperatingSystemActiveProfilesResolver
. For further information, refer to the
corresponding javadocs.
package com.bank.service; // "dev" profile overridden programmatically via a custom resolver @ActiveProfiles( resolver = OperatingSystemActiveProfilesResolver.class, inheritProfiles = false) public class TransferServiceTest extends AbstractIntegrationTest { // test body }
package com.bank.service.test; public class OperatingSystemActiveProfilesResolver implements ActiveProfilesResolver { @Override String[] resolve(Class<?> testClass) { String profile = ...; // determine the value of profile based on the operating system return new String[] {profile}; } }
Spring 3.2 introduced support for loading a WebApplicationContext
in integration
tests. To instruct the TestContext framework to load a WebApplicationContext
instead
of a standard ApplicationContext
, simply annotate the respective test class with
@WebAppConfiguration
.
The presence of @WebAppConfiguration
on your test class instructs the TestContext
framework (TCF) that a WebApplicationContext
(WAC) should be loaded for your
integration tests. In the background the TCF makes sure that a MockServletContext
is
created and supplied to your test’s WAC. By default the base resource path for your
MockServletContext
will be set to "src/main/webapp". This is interpreted as a path
relative to the root of your JVM (i.e., normally the path to your project). If you’re
familiar with the directory structure of a web application in a Maven project, you’ll
know that "src/main/webapp" is the default location for the root of your WAR. If you
need to override this default, simply provide an alternate path to the
@WebAppConfiguration
annotation (e.g., @WebAppConfiguration("src/test/webapp")
). If
you wish to reference a base resource path from the classpath instead of the file
system, just use Spring’s classpath: prefix.
Please note that Spring’s testing support for WebApplicationContexts
is on par with
its support for standard ApplicationContexts
. When testing with a
WebApplicationContext
you are free to declare either XML configuration files or
@Configuration
classes via @ContextConfiguration
. You are of course also free to use
any other test annotations such as @TestExecutionListeners
,
@TransactionConfiguration
, @ActiveProfiles
, etc.
The following examples demonstrate some of the various configuration options for loading
a WebApplicationContext
.
Conventions.
@RunWith(SpringJUnit4ClassRunner.class) // defaults to "file:src/main/webapp" @WebAppConfiguration // detects "WacTests-context.xml" in same package // or static nested @Configuration class @ContextConfiguration public class WacTests { //... }
The above example demonstrates the TestContext framework’s support for convention over
configuration. If you annotate a test class with @WebAppConfiguration
without
specifying a resource base path, the resource path will effectively default
to "file:src/main/webapp". Similarly, if you declare @ContextConfiguration
without
specifying resource locations
, annotated classes
, or context initializers
, Spring
will attempt to detect the presence of your configuration using conventions
(i.e., "WacTests-context.xml" in the same package as the WacTests
class or static
nested @Configuration
classes).
Default resource semantics.
@RunWith(SpringJUnit4ClassRunner.class) // file system resource @WebAppConfiguration("webapp") // classpath resource @ContextConfiguration("/spring/test-servlet-config.xml") public class WacTests { //... }
This example demonstrates how to explicitly declare a resource base path with
@WebAppConfiguration
and an XML resource location with @ContextConfiguration
. The
important thing to note here is the different semantics for paths with these two
annotations. By default, @WebAppConfiguration
resource paths are file system based;
whereas, @ContextConfiguration
resource locations are classpath based.
Explicit resource semantics.
@RunWith(SpringJUnit4ClassRunner.class) // classpath resource @WebAppConfiguration("classpath:test-web-resources") // file system resource @ContextConfiguration("file:src/main/webapp/WEB-INF/servlet-config.xml") public class WacTests { //... }
In this third example, we see that we can override the default resource semantics for both annotations by specifying a Spring resource prefix. Contrast the comments in this example with the previous example.
To provide comprehensive web testing support, Spring 3.2 introduced a
ServletTestExecutionListener
that is enabled by default. When testing against a
WebApplicationContext
this TestExecutionListener sets
up default thread-local state via Spring Web’s RequestContextHolder
before each test
method and creates a MockHttpServletRequest
, MockHttpServletResponse
, and
ServletWebRequest
based on the base resource path configured via
@WebAppConfiguration
. ServletTestExecutionListener
also ensures that the
MockHttpServletResponse
and ServletWebRequest
can be injected into the test
instance, and once the test is complete it cleans up thread-local state.
Once you have a WebApplicationContext
loaded for your test you might find that you
need to interact with the web mocks — for example, to set up your test fixture or to
perform assertions after invoking your web component. The following example demonstrates
which mocks can be autowired into your test instance. Note that the
WebApplicationContext
and MockServletContext
are both cached across the test suite;
whereas, the other mocks are managed per test method by the
ServletTestExecutionListener
.
Injecting mocks.
@WebAppConfiguration @ContextConfiguration public class WacTests { @Autowired WebApplicationContext wac; // cached @Autowired MockServletContext servletContext; // cached @Autowired MockHttpSession session; @Autowired MockHttpServletRequest request; @Autowired MockHttpServletResponse response; @Autowired ServletWebRequest webRequest; //... }
Once the TestContext framework loads an ApplicationContext
(or
WebApplicationContext
) for a test, that context will be cached and reused for all
subsequent tests that declare the same unique context configuration within the same test
suite. To understand how caching works, it is important to understand what is meant by
unique and test suite.
An ApplicationContext
can be uniquely identified by the combination of
configuration parameters that are used to load it. Consequently, the unique combination
of configuration parameters are used to generate a key under which the context is
cached. The TestContext framework uses the following configuration parameters to build
the context cache key:
locations
(from @ContextConfiguration)
classes
(from @ContextConfiguration)
contextInitializerClasses
(from @ContextConfiguration)
contextLoader
(from @ContextConfiguration)
activeProfiles
(from @ActiveProfiles)
resourceBasePath
(from @WebAppConfiguration)
For example, if TestClassA
specifies {"app-config.xml", "test-config.xml"}
for the
locations
(or value
) attribute of @ContextConfiguration
, the TestContext framework
will load the corresponding ApplicationContext
and store it in a static
context
cache under a key that is based solely on those locations. So if TestClassB
also
defines {"app-config.xml", "test-config.xml"}
for its locations (either explicitly or
implicitly through inheritance) but does not define @WebAppConfiguration
, a different
ContextLoader
, different active profiles, or different context initializers, then the
same ApplicationContext
will be shared by both test classes. This means that the setup
cost for loading an application context is incurred only once (per test suite), and
subsequent test execution is much faster.
Test suites and forked processes | |
---|---|
The Spring TestContext framework stores application contexts in a static cache. This
means that the context is literally stored in a To benefit from the caching mechanism, all tests must run within the same process or
test suite. This can be achieved by executing all tests as a group within an IDE.
Similarly, when executing tests with a build framework such as Ant, Maven, or Gradle it
is important to make sure that the build framework does not fork between tests. For
example, if the
forkMode
for the Maven Surefire plug-in is set to |
Since having a large number of application contexts loaded within a given test suite can
cause the suite to take an unnecessarily long time to execute, it is often beneficial to
know exactly how many contexts have been loaded and cached. To view the statistics for
the underlying context cache, simply set the log level for the
org.springframework.test.context.cache
logging category to DEBUG
.
In the unlikely case that a test corrupts the application context and requires reloading — for example, by modifying a bean definition or the state of an application object — you can annotate your test class or test method with @DirtiesContext
(see the
discussion of @DirtiesContext
in the section called “Spring Testing Annotations”). This
instructs Spring to remove the context from the cache and rebuild the application
context before executing the next test. Note that support for the @DirtiesContext
annotation is provided by the DirtiesContextTestExecutionListener
which is enabled by
default.
When writing integration tests that rely on a loaded Spring ApplicationContext
, it is
often sufficient to test against a single context; however, there are times when it is
beneficial or even necessary to test against a hierarchy of ApplicationContext
s. For
example, if you are developing a Spring MVC web application you will typically have a
root WebApplicationContext
loaded via Spring’s ContextLoaderListener
and a child
WebApplicationContext
loaded via Spring’s DispatcherServlet
. This results in a
parent-child context hierarchy where shared components and infrastructure configuration
are declared in the root context and consumed in the child context by web-specific
components. Another use case can be found in Spring Batch applications where you often
have a parent context that provides configuration for shared batch infrastructure and a
child context for the configuration of a specific batch job.
As of Spring Framework 3.2.2, it is possible to write integration tests that use context
hierarchies by declaring context configuration via the @ContextHierarchy
annotation,
either on an individual test class or within a test class hierarchy. If a context
hierarchy is declared on multiple classes within a test class hierarchy it is also
possible to merge or override the context configuration for a specific, named level in
the context hierarchy. When merging configuration for a given level in the hierarchy the
configuration resource type (i.e., XML configuration files or annotated classes) must be
consistent; otherwise, it is perfectly acceptable to have different levels in a context
hierarchy configured using different resource types.
The following JUnit-based examples demonstrate common configuration scenarios for integration tests that require the use of context hierarchies.
ControllerIntegrationTests
represents a typical integration testing scenario for a
Spring MVC web application by declaring a context hierarchy consisting of two levels,
one for the root WebApplicationContext (loaded using the TestAppConfig
@Configuration
class) and one for the dispatcher servlet WebApplicationContext
(loaded using the WebConfig
@Configuration
class). The WebApplicationContext
that
is autowired into the test instance is the one for the child context (i.e., the
lowest context in the hierarchy).
@RunWith(SpringJUnit4ClassRunner.class) @WebAppConfiguration @ContextHierarchy({ @ContextConfiguration(classes = TestAppConfig.class), @ContextConfiguration(classes = WebConfig.class) }) public class ControllerIntegrationTests { @Autowired private WebApplicationContext wac; // ... }
The following test classes define a context hierarchy within a test class hierarchy.
AbstractWebTests
declares the configuration for a root WebApplicationContext
in a
Spring-powered web application. Note, however, that AbstractWebTests
does not declare
@ContextHierarchy
; consequently, subclasses of AbstractWebTests
can optionally
participate in a context hierarchy or simply follow the standard semantics for
@ContextConfiguration
. SoapWebServiceTests
and RestWebServiceTests
both extend
AbstractWebTests
and define a context hierarchy via @ContextHierarchy
. The result is
that three application contexts will be loaded (one for each declaration of
@ContextConfiguration
), and the application context loaded based on the configuration
in AbstractWebTests
will be set as the parent context for each of the contexts loaded
for the concrete subclasses.
@RunWith(SpringJUnit4ClassRunner.class) @WebAppConfiguration @ContextConfiguration("file:src/main/webapp/WEB-INF/applicationContext.xml") public abstract class AbstractWebTests {} @ContextHierarchy(@ContextConfiguration("/spring/soap-ws-config.xml") public class SoapWebServiceTests extends AbstractWebTests {} @ContextHierarchy(@ContextConfiguration("/spring/rest-ws-config.xml") public class RestWebServiceTests extends AbstractWebTests {}
The following classes demonstrate the use of named hierarchy levels in order to
merge the configuration for specific levels in a context hierarchy. BaseTests
defines two levels in the hierarchy, parent
and child
. ExtendedTests
extends
BaseTests
and instructs the Spring TestContext Framework to merge the context
configuration for the child
hierarchy level, simply by ensuring that the names
declared via ContextConfiguration
's name
attribute are both "child"
. The result is
that three application contexts will be loaded: one for "/app-config.xml"
, one for
"/user-config.xml"
, and one for {"/user-config.xml", "/order-config.xml"}
. As with
the previous example, the application context loaded from "/app-config.xml"
will be
set as the parent context for the contexts loaded from "/user-config.xml"
and
{"/user-config.xml", "/order-config.xml"}
.
@RunWith(SpringJUnit4ClassRunner.class) @ContextHierarchy({ @ContextConfiguration(name = "parent", locations = "/app-config.xml"), @ContextConfiguration(name = "child", locations = "/user-config.xml") }) public class BaseTests {} @ContextHierarchy( @ContextConfiguration(name = "child", locations = "/order-config.xml") ) public class ExtendedTests extends BaseTests {}
In contrast to the previous example, this example demonstrates how to override the
configuration for a given named level in a context hierarchy by setting
ContextConfiguration
's inheritLocations
flag to false
. Consequently, the
application context for ExtendedTests
will be loaded only from
"/test-user-config.xml"
and will have its parent set to the context loaded from
"/app-config.xml"
.
@RunWith(SpringJUnit4ClassRunner.class) @ContextHierarchy({ @ContextConfiguration(name = "parent", locations = "/app-config.xml"), @ContextConfiguration(name = "child", locations = "/user-config.xml") }) public class BaseTests {} @ContextHierarchy( @ContextConfiguration( name = "child", locations = "/test-user-config.xml", inheritLocations = false )) public class ExtendedTests extends BaseTests {}
Dirtying a context within a context hierarchy | |
---|---|
If |
When you use the DependencyInjectionTestExecutionListener
— which is configured by
default — the dependencies of your test instances are injected from beans in the
application context that you configured with @ContextConfiguration
. You may use setter
injection, field injection, or both, depending on which annotations you choose and
whether you place them on setter methods or fields. For consistency with the annotation
support introduced in Spring 2.5 and 3.0, you can use Spring’s @Autowired
annotation
or the @Inject
annotation from JSR 300.
Tip | |
---|---|
The TestContext framework does not instrument the manner in which a test instance is
instantiated. Thus the use of |
Because @Autowired
is used to perform autowiring by type, if you have multiple bean definitions of the same type, you cannot rely on this
approach for those particular beans. In that case, you can use @Autowired
in
conjunction with @Qualifier
. As of Spring 3.0 you may also choose to use @Inject
in
conjunction with @Named
. Alternatively, if your test class has access to its
ApplicationContext
, you can perform an explicit lookup by using (for example) a call
to applicationContext.getBean("titleRepository")
.
If you do not want dependency injection applied to your test instances, simply do not
annotate fields or setter methods with @Autowired
or @Inject
. Alternatively, you can
disable dependency injection altogether by explicitly configuring your class with
@TestExecutionListeners
and omitting DependencyInjectionTestExecutionListener.class
from the list of listeners.
Consider the scenario of testing a HibernateTitleRepository
class, as outlined in the
Goals section. The next two code listings demonstrate the
use of @Autowired
on fields and setter methods. The application context configuration
is presented after all sample code listings.
Note | |
---|---|
The dependency injection behavior in the following code listings is not specific to JUnit. The same DI techniques can be used in conjunction with any testing framework. The following examples make calls to static assertion methods such as |
The first code listing shows a JUnit-based implementation of the test class that uses
@Autowired
for field injection.
@RunWith(SpringJUnit4ClassRunner.class) // specifies the Spring configuration to load for this test fixture @ContextConfiguration("repository-config.xml") public class HibernateTitleRepositoryTests { // this instance will be dependency injected by type @Autowired private HibernateTitleRepository titleRepository; @Test public void findById() { Title title = titleRepository.findById(new Long(10)); assertNotNull(title); } }
Alternatively, you can configure the class to use @Autowired
for setter injection as
seen below.
@RunWith(SpringJUnit4ClassRunner.class) // specifies the Spring configuration to load for this test fixture @ContextConfiguration("repository-config.xml") public class HibernateTitleRepositoryTests { // this instance will be dependency injected by type private HibernateTitleRepository titleRepository; @Autowired public void setTitleRepository(HibernateTitleRepository titleRepository) { this.titleRepository = titleRepository; } @Test public void findById() { Title title = titleRepository.findById(new Long(10)); assertNotNull(title); } }
The preceding code listings use the same XML context file referenced by the
@ContextConfiguration
annotation (that is, repository-config.xml
), which looks like
this:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <!-- this bean will be injected into the HibernateTitleRepositoryTests class --> <bean id="titleRepository" class="com.foo.repository.hibernate.HibernateTitleRepository"> <property name="sessionFactory" ref="sessionFactory"/> </bean> <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean"> <!-- configuration elided for brevity --> </bean> </beans>
Note | |
---|---|
If you are extending from a Spring-provided test base class that happens to use
// ... @Autowired @Override public void setDataSource(@Qualifier("myDataSource") DataSource dataSource) { super.setDataSource(dataSource); } // ... The specified qualifier value indicates the specific |
Request and session scoped beans have been supported by Spring for several years now, but it’s always been a bit non-trivial to test them. As of Spring 3.2 it’s a breeze to test your request-scoped and session-scoped beans by following these steps.
WebApplicationContext
is loaded for your test by annotating your test
class with @WebAppConfiguration
.
WebApplicationContext
(i.e., via dependency injection).
The following code snippet displays the XML configuration for a login use case. Note
that the userService
bean has a dependency on a request-scoped loginAction
bean.
Also, the LoginAction
is instantiated using SpEL expressions that
retrieve the username and password from the current HTTP request. In our test, we will
want to configure these request parameters via the mock managed by the TestContext
framework.
Request-scoped bean configuration.
<beans> <bean id="userService" class="com.example.SimpleUserService" c:loginAction-ref="loginAction" /> <bean id="loginAction" class="com.example.LoginAction" c:username="{request.getParameter(user)}" c:password="{request.getParameter(pswd)}" scope="request"> <aop:scoped-proxy /> </bean> </beans>
In RequestScopedBeanTests
we inject both the UserService
(i.e., the subject under
test) and the MockHttpServletRequest
into our test instance. Within our
requestScope()
test method we set up our test fixture by setting request parameters in
the provided MockHttpServletRequest
. When the loginUser()
method is invoked on our
userService
we are assured that the user service has access to the request-scoped
loginAction
for the current MockHttpServletRequest
(i.e., the one we just set
parameters in). We can then perform assertions against the results based on the known
inputs for the username and password.
Request-scoped bean test.
@RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration @WebAppConfiguration public class RequestScopedBeanTests { @Autowired UserService userService; @Autowired MockHttpServletRequest request; @Test public void requestScope() { request.setParameter("user", "enigma"); request.setParameter("pswd", "$pr!ng"); LoginResults results = userService.loginUser(); // assert results } }
The following code snippet is similar to the one we saw above for a request-scoped bean;
however, this time the userService
bean has a dependency on a session-scoped
userPreferences
bean. Note that the UserPreferences
bean is instantiated using a
SpEL expression that retrieves the theme from the current HTTP session. In our test,
we will need to configure a theme in the mock session managed by the TestContext
framework.
Session-scoped bean configuration.
<beans> <bean id="userService" class="com.example.SimpleUserService" c:userPreferences-ref="userPreferences" /> <bean id="userPreferences" class="com.example.UserPreferences" c:theme="#{session.getAttribute(theme)}" scope="session"> <aop:scoped-proxy /> </bean> </beans>
In SessionScopedBeanTests
we inject the UserService
and the MockHttpSession
into
our test instance. Within our sessionScope()
test method we set up our test fixture by
setting the expected "theme" attribute in the provided MockHttpSession
. When the
processUserPreferences()
method is invoked on our userService
we are assured that
the user service has access to the session-scoped userPreferences
for the current
MockHttpSession
, and we can perform assertions against the results based on the
configured theme.
Session-scoped bean test.
@RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration @WebAppConfiguration public class SessionScopedBeanTests { @Autowired UserService userService; @Autowired MockHttpSession session; @Test public void sessionScope() throws Exception { session.setAttribute("theme", "blue"); Results results = userService.processUserPreferences(); // assert results } }
In the TestContext framework, transactions are managed by the
TransactionalTestExecutionListener
. Note that TransactionalTestExecutionListener
is
configured by default, even if you do not explicitly declare @TestExecutionListeners
on your test class. To enable support for transactions, however, you must provide a
PlatformTransactionManager
bean in the application context loaded by
@ContextConfiguration
semantics. In addition, you must declare @Transactional
either
at the class or method level for your tests.
For class-level transaction configuration (i.e., setting an explicit bean name for the
transaction manager and the default rollback flag), see the @TransactionConfiguration
entry in the annotation support section.
If transactions are not enabled for the entire test class, you can annotate methods
explicitly with @Transactional
. To control whether a transaction should commit for a
particular test method, you can use the @Rollback
annotation to override the
class-level default rollback setting.
AbstractTransactionalJUnit4SpringContextTests
and
AbstractTransactionalTestNGSpringContextTests
are preconfigured for transactional support at the class level.
Occasionally you need to execute certain code before or after a transactional test
method but outside the transactional context, for example, to verify the initial
database state prior to execution of your test or to verify expected transactional
commit behavior after test execution (if the test was configured not to roll back the
transaction). TransactionalTestExecutionListener
supports the @BeforeTransaction
and
@AfterTransaction
annotations exactly for such scenarios. Simply annotate any public
void
method in your test class with one of these annotations, and the
TransactionalTestExecutionListener
ensures that your before transaction method or
after transaction method is executed at the appropriate time.
Tip | |
---|---|
Any before methods (such as methods annotated with JUnit’s |
The following JUnit-based example displays a fictitious integration testing scenario highlighting several transaction-related annotations. Consult the annotation support section for further information and configuration examples.
@RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration @TransactionConfiguration(transactionManager="txMgr", defaultRollback=false) @Transactional public class FictitiousTransactionalTest { @BeforeTransaction public void verifyInitialDatabaseState() { // logic to verify the initial state before a transaction is started } @Before public void setUpTestDataWithinTransaction() { // set up test data within the transaction } @Test // overrides the class-level defaultRollback setting @Rollback(true) public void modifyDatabaseWithinTransaction() { // logic which uses the test data and modifies database state } @After public void tearDownWithinTransaction() { // execute "tear down" logic within the transaction } @AfterTransaction public void verifyFinalDatabaseState() { // logic to verify the final state after transaction has rolled back } }
Avoid false positives when testing ORM code | |
---|---|
When you test application code that manipulates the state of the Hibernate session, make sure to flush the underlying session within test methods that execute that code. Failing to flush the underlying session can produce false positives: your test may pass, but the same code throws an exception in a live, production environment. In the following Hibernate-based example test case, one method demonstrates a false positive, and the other method correctly exposes the results of flushing the session. Note that this applies to JPA and any other ORM frameworks that maintain an in-memory unit of work. // ... @Autowired private SessionFactory sessionFactory; @Test // no expected exception! public void falsePositive() { updateEntityInHibernateSession(); // False positive: an exception will be thrown once the session is // finally flushed (i.e., in production code) } @Test(expected = GenericJDBCException.class) public void updateWithSessionFlush() { updateEntityInHibernateSession(); // Manual flush is required to avoid false positive in test sessionFactory.getCurrentSession().flush(); } // ... |
The org.springframework.test.context.junit4
package provides support classes for JUnit
4.5+ based test cases.
AbstractJUnit4SpringContextTests
: Abstract base test class that integrates the
Spring TestContext Framework with explicit ApplicationContext
testing support in
a JUnit 4.5+ environment.
When you extend AbstractJUnit4SpringContextTests
, you can access the following
protected
instance variable:
applicationContext
: Use this variable to perform explicit bean lookups or to test
the state of the context as a whole.
AbstractTransactionalJUnit4SpringContextTests
: Abstract transactional extension
of AbstractJUnit4SpringContextTests
that also adds some convenience functionality
for JDBC access. Expects a javax.sql.DataSource
bean and a
PlatformTransactionManager
bean to be defined in the ApplicationContext
.
When you extend AbstractTransactionalJUnit4SpringContextTests
you can access the
following protected
instance variables:
applicationContext
: Inherited from the AbstractJUnit4SpringContextTests
superclass. Use this variable to perform explicit bean lookups or to test the state of
the context as a whole.
jdbcTemplate
: Use this variable to execute SQL statements to query the database.
Such queries can be used to confirm database state both prior to and after
execution of database-related application code, and Spring ensures that such queries run
in the scope of the same transaction as the application code. When used in conjunction
with an ORM tool, be sure to avoid false positives.
Tip | |
---|---|
These classes are a convenience for extension. If you do not want your test classes to
be tied to a Spring-specific class hierarchy — for example, if you want to directly
extend the class you are testing — you can configure your own custom test classes by
using |
The Spring TestContext Framework offers full integration with JUnit 4.5+ through a
custom runner (tested on JUnit 4.5 — 4.11). By annotating test classes with
@RunWith(SpringJUnit4ClassRunner.class)
, developers can implement standard JUnit-based
unit and integration tests and simultaneously reap the benefits of the TestContext
framework such as support for loading application contexts, dependency injection of test
instances, transactional test method execution, and so on. The following code listing
displays the minimal requirements for configuring a test class to run with the custom
Spring Runner. @TestExecutionListeners
is configured with an empty list in order to
disable the default listeners, which otherwise would require an ApplicationContext to be
configured through @ContextConfiguration
.
@RunWith(SpringJUnit4ClassRunner.class) @TestExecutionListeners({}) public class SimpleTest { @Test public void testMethod() { // execute test logic... } }
The org.springframework.test.context.testng
package provides support classes for
TestNG based test cases.
AbstractTestNGSpringContextTests
: Abstract base test class that integrates the
Spring TestContext Framework with explicit ApplicationContext
testing support in
a TestNG environment.
When you extend AbstractTestNGSpringContextTests
, you can access the following
protected
instance variable:
applicationContext
: Use this variable to perform explicit bean lookups or to test
the state of the context as a whole.
AbstractTransactionalTestNGSpringContextTests
: Abstract transactional extension
of AbstractTestNGSpringContextTests
that adds some convenience functionality for JDBC
access. Expects a javax.sql.DataSource
bean and a PlatformTransactionManager
bean to
be defined in the ApplicationContext
.
When you extend AbstractTransactionalTestNGSpringContextTests
, you can access the following
protected
instance variables:
applicationContext
: Inherited from the AbstractTestNGSpringContextTests
superclass. Use this variable to perform explicit bean lookups or to test the state of
the context as a whole.
jdbcTemplate
: Use this variable to execute SQL statements to query the database.
Such queries can be used to confirm database state both prior to and after
execution of database-related application code, and Spring ensures that such queries run
in the scope of the same transaction as the application code. When used in conjunction
with an ORM tool, be sure to avoid false positives.
Tip | |
---|---|
These classes are a convenience for extension. If you do not want your test classes to
be tied to a Spring-specific class hierarchy — for example, if you want to directly
extend the class you are testing — you can configure your own custom test classes by
using |
The Spring MVC Test framework provides first class JUnit support for testing client
and server-side Spring MVC code through a fluent API. Typically it loads the actual
Spring configuration through the TestContext framework and always uses the
DispatcherServlet
to process requests thus approximating full integration tests
without requiring a running Servlet container.
Client-side tests are RestTemplate
-based and allow tests for code that relies on the
RestTemplate
without requiring a running server to respond to the requests.
Before Spring Framework 3.2, the most likely way to test a Spring MVC controller was to
write a unit test that instantiates the controller, injects it with mock or stub
dependencies, and then calls its methods directly, using a MockHttpServletRequest
and
MockHttpServletResponse
where necessary.
Although this is pretty easy to do, controllers have many annotations, and much remains
untested. Request mappings, data binding, type conversion, and validation are just a few
examples of what isn’t tested. Furthermore, there are other types of annotated methods
such as @InitBinder
, @ModelAttribute
, and @ExceptionHandler
that get invoked as
part of request processing.
The idea behind Spring MVC Test is to be able to re-write those controller tests by
performing actual requests and generating responses, as they would be at runtime, along
the way invoking controllers through the Spring MVC DispatcherServlet
. Controllers can
still be injected with mock dependencies, so tests can remain focused on the web layer.
Spring MVC Test builds on the familiar "mock" implementations of the Servlet API
available in the spring-test
module. This allows performing requests and generating
responses without the need for running in a Servlet container. For the most part
everything should work as it does at runtime with the exception of JSP rendering, which
is not available outside a Servlet container. Furthermore, if you are familiar with how
the MockHttpServletResponse
works, you’ll know that forwards and redirects are not
actually executed. Instead "forwarded" and "redirected" URLs are saved and can be
asserted in tests. This means if you are using JSPs, you can verify the JSP page to
which the request was forwarded.
All other means of rendering including @ResponseBody
methods and View
types (besides
JSPs) such as Freemarker, Velocity, Thymeleaf, and others for rendering HTML, JSON, XML,
and so on should work as expected, and the response will contain the generated content.
Below is an example of a test requesting account information in JSON format:
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*; import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*; @RunWith(SpringJUnit4ClassRunner.class) @WebAppConfiguration @ContextConfiguration("test-servlet-context.xml") public class ExampleTests { @Autowired private WebApplicationContext wac; private MockMvc mockMvc; @Before public void setup() { this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build(); } @Test public void getAccount() throws Exception { this.mockMvc.perform(get("/accounts/1").accept(MediaType.parseMediaType("application/json;charset=UTF-8"))) .andExpect(status().isOk()) .andExpect(content().contentType("application/json")) .andExpect(jsonPath("$.name").value("Lee")); } }
The test relies on the WebApplicationContext
support of the TestContext framework.
It loads Spring configuration from an XML configuration file located in the same package
as the test class (also supports JavaConfig) and injects the created
WebApplicationContext
into the test so a MockMvc
instance can be created with it.
The MockMvc
is then used to perform a request to "/accounts/1"
and verify the
resulting response status is 200, the response content type is "application/json"
, and
response content has a JSON property called "name" with the value "Lee". JSON content is
inspected with the help of Jayway’s JsonPath
project. There are lots of other options for verifying the result of the performed
request and those will be discussed later.
The fluent API in the example above requires a few static imports such as
MockMvcRequestBuilders.*
, MockMvcResultMatchers.*
, and MockMvcBuilders.*
. An easy
way to find these classes is to search for types matching "MockMvc*". If using
Eclipse, be sure to add them as "favorite static members" in the Eclipse preferences
underJava → Editor → Content Assist → Favorites. That will allow use of content
assist after typing the first character of the static method name. Other IDEs (e.g.
IntelliJ) may not require any additional configuration. Just check the support for code
completion on static members.
The goal of server-side test setup is to create an instance of MockMvc
that can be
used to perform requests. There are two main options.
The first option is to point to Spring MVC configuration through the TestContext
framework, which loads the Spring configuration and injects a WebApplicationContext
into the test to use to create a MockMvc
:
@RunWith(SpringJUnit4ClassRunner.class) @WebAppConfiguration @ContextConfiguration("my-servlet-context.xml") public class MyWebTests { @Autowired private WebApplicationContext wac; private MockMvc mockMvc; @Before public void setup() { this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build(); } // ... }
The second option is to simply register a controller instance without loading any Spring configuration. Instead basic Spring MVC configuration suitable for testing annotated controllers is automatically created. The created configuration is comparable to that of the MVC JavaConfig (and the MVC namespace) and can be customized to a degree through builder-style methods:
public class MyWebTests { private MockMvc mockMvc; @Before public void setup() { this.mockMvc = MockMvcBuilders.standaloneSetup(new AccountController()).build(); } // ... }
Which option should you use?
The "webAppContextSetup" loads the actual Spring MVC configuration resulting in a more complete integration test. Since the TestContext framework caches the loaded Spring configuration, it helps to keep tests running fast even as more tests get added. Furthermore, you can inject mock services into controllers through Spring configuration, in order to remain focused on testing the web layer. Here is an example of declaring a mock service with Mockito:
<bean id="accountService" class="org.mockito.Mockito" factory-method="mock"> <constructor-arg value="org.example.AccountService"/> </bean>
Then you can inject the mock service into the test in order set up and verify expectations:
@RunWith(SpringJUnit4ClassRunner.class) @WebAppConfiguration @ContextConfiguration("test-servlet-context.xml") public class AccountTests { @Autowired private WebApplicationContext wac; private MockMvc mockMvc; @Autowired private AccountService accountService; // ... }
The "standaloneSetup" on the other hand is a little closer to a unit test. It tests one controller at a time, the controller can be injected with mock dependencies manually, and it doesn’t involve loading Spring configuration. Such tests are more focused in style and make it easier to see which controller is being tested, whether any specific Spring MVC configuration is required to work, and so on. The "standaloneSetup" is also a very convenient way to write ad-hoc tests to verify some behavior or to debug an issue.
Just like with integration vs unit testing, there is no right or wrong answer. Using the "standaloneSetup" does imply the need for some additional "webAppContextSetup" tests to verify the Spring MVC configuration. Alternatively, you can decide write all tests with "webAppContextSetup" and always test against actual Spring MVC configuration.
To perform requests, use the appropriate HTTP method and additional builder-style
methods corresponding to properties of MockHttpServletRequest
. For example:
mockMvc.perform(post("/hotels/{id}", 42).accept(MediaType.APPLICATION_JSON));
In addition to all the HTTP methods, you can also perform file upload requests, which
internally creates an instance of MockMultipartHttpServletRequest
:
mockMvc.perform(fileUpload("/doc").file("a1", "ABC".getBytes("UTF-8")));
Query string parameters can be specified in the URI template:
mockMvc.perform(get("/hotels?foo={foo}", "bar"));
Or by adding Servlet request parameters:
mockMvc.perform(get("/hotels").param("foo", "bar"));
If application code relies on Servlet request parameters, and doesn’t check the query
string, as is most often the case, then it doesn’t matter how parameters are added. Keep
in mind though that parameters provided in the URI template will be decoded while
parameters provided through the param(...)
method are expected to be decoded.
In most cases it’s preferable to leave out the context path and the Servlet path from
the request URI. If you must test with the full request URI, be sure to set the
contextPath
and servletPath
accordingly so that request mappings will work:
mockMvc.perform(get("/app/main/hotels/{id}").contextPath("/app").servletPath("/main"))
Looking at the above example, it would be cumbersome to set the contextPath and
servletPath with every performed request. That’s why you can define default request
properties when building the MockMvc
:
public class MyWebTests { private MockMvc mockMvc; @Before public void setup() { mockMvc = standaloneSetup(new AccountController()) .defaultRequest(get("/") .contextPath("/app").servletPath("/main") .accept(MediaType.APPLICATION_JSON).build(); }
The above properties will apply to every request performed through the MockMvc
. If the
same property is also specified on a given request, it will override the default value.
That is why, the HTTP method and URI don’t matter, when setting default request
properties, since they must be specified on every request.
Expectations can be defined by appending one or more .andExpect(..)
after call to
perform the request:
mockMvc.perform(get("/accounts/1")).andExpect(status().isOk());
MockMvcResultMatchers.*
defines a number of static members, some of which return types
with additional methods, for asserting the result of the performed request. The
assertions fall in two general categories.
The first category of assertions verify properties of the response, i.e the response status, headers, and content. Those are the most important things to test for.
The second category of assertions go beyond the response, and allow inspecting Spring MVC specific constructs such as which controller method processed the request, whether an exception was raised and handled, what the content of the model is, what view was selected, what flash attributes were added, and so on. It is also possible to verify Servlet specific constructs such as request and session attributes. The following test asserts that binding/validation failed:
mockMvc.perform(post("/persons")) .andExpect(status().isOk()) .andExpect(model().attributeHasErrors("person"));
Many times when writing tests, it’s useful to dump the result of the performed request.
This can be done as follows, where print()
is a static import from
MockMvcResultHandlers
:
mockMvc.perform(post("/persons")) .andDo(print()) .andExpect(status().isOk()) .andExpect(model().attributeHasErrors("person"));
As long as request processing causes an unhandled exception, the print()
method will
print all the available result data to System.out
.
In some cases, you may want to get direct access to the result and verify something that
cannot be verified otherwise. This can be done by appending .andReturn()
at the end
after all expectations:
MvcResult mvcResult = mockMvc.perform(post("/persons")).andExpect(status().isOk()).andReturn(); // ...
When all tests repeat the same expectations, you can define the common expectations once
when building the MockMvc
:
standaloneSetup(new SimpleController()) .alwaysExpect(status().isOk()) .alwaysExpect(content().contentType("application/json;charset=UTF-8")) .build()
Note that the expectation is always applied and cannot be overridden without
creating a separate MockMvc
instance.
When JSON response content contains hypermedia links created with Spring HATEOAS, the resulting links can be verified:
mockMvc.perform(get("/people").accept(MediaType.APPLICATION_JSON)) .andExpect(jsonPath("$.links[?(@.rel == self)].href").value("http://localhost:8080/people"));
When XML response content contains hypermedia links created with Spring HATEOAS, the resulting links can be verified:
Map<String, String> ns = Collections.singletonMap("ns", "http://www.w3.org/2005/Atom"); mockMvc.perform(get("/handle").accept(MediaType.APPLICATION_XML)) .andExpect(xpath("/person/ns:link[@rel=self]/@href", ns).string("http://localhost:8080/people"));
When setting up a MockMvc
, you can register one or more Filter
instances:
mockMvc = standaloneSetup(new PersonController()).addFilters(new CharacterEncodingFilter()).build();
Registered filters will be invoked through MockFilterChain
from spring-test
and the
last filter will delegates to the DispatcherServlet
.
The framework’s own tests include many sample tests intended to demonstrate how to use Spring MVC Test. Browse these examples for further ideas. Also the spring-mvc-showcase has full test coverage based on Spring MVC Test.
Client-side tests are for code using the RestTemplate
. The goal is to define expected
requests and provide "stub" responses:
RestTemplate restTemplate = new RestTemplate(); MockRestServiceServer mockServer = MockRestServiceServer.createServer(restTemplate); mockServer.expect(requestTo("/greeting")).andRespond(withSuccess("Hello world", MediaType.TEXT_PLAIN)); // use RestTemplate ... mockServer.verify();
In the above example, MockRestServiceServer
— the central class for client-side REST
tests — configures the RestTemplate
with a custom ClientHttpRequestFactory
that
asserts actual requests against expectations and returns "stub" responses. In this case
we expect a single request to "/greeting" and want to return a 200 response with
"text/plain" content. We could define as many additional requests and stub responses as
necessary.
Once expected requests and stub responses have been defined, the RestTemplate
can be
used in client-side code as usual. At the end of the tests mockServer.verify()
can be
used to verify that all expected requests were performed.
Just like with server-side tests, the fluent API for client-side tests requires a few
static imports. Those are easy to find by searching "MockRest*". Eclipse users
should add "MockRestRequestMatchers.*"
and "MockRestResponseCreators.*"
as "favorite
static members" in the Eclipse preferences under Java → Editor → Content Assist →
Favorites. That allows using content assist after typing the first character of the
static method name. Other IDEs (e.g. IntelliJ) may not require any additional
configuration. Just check the support for code completion on static members.
Spring MVC Test’s own tests include example tests of client-side REST tests.
The PetClinic application, available on
Github, illustrates several features
of the Spring TestContext Framework in a JUnit 4.5+ environment. Most test
functionality is included in the AbstractClinicTests
, for which a partial listing
is shown below:
import static org.junit.Assert.assertEquals; // import ... @ContextConfiguration public abstract class AbstractClinicTests extends AbstractTransactionalJUnit4SpringContextTests { @Autowired protected Clinic clinic; @Test public void getVets() { Collection<Vet> vets = this.clinic.getVets(); assertEquals("JDBC query must show the same number of vets", super.countRowsInTable("VETS"), vets.size()); Vet v1 = EntityUtils.getById(vets, Vet.class, 2); assertEquals("Leary", v1.getLastName()); assertEquals(1, v1.getNrOfSpecialties()); assertEquals("radiology", (v1.getSpecialties().get(0)).getName()); // ... } // ... }
Notes:
AbstractTransactionalJUnit4SpringContextTests
class, from
which it inherits configuration for Dependency Injection (through the
DependencyInjectionTestExecutionListener
) and transactional behavior (through the
TransactionalTestExecutionListener
).
clinic
instance variable — the application object being tested — is set by
Dependency Injection through @Autowired
semantics.
getVets()
method illustrates how you can use the inherited
countRowsInTable()
method to easily verify the number of rows in a given table, thus
verifying correct behavior of the application code being tested. This allows for
stronger tests and lessens dependency on the exact test data. For example, you can add
additional rows in the database without breaking tests.
AbstractClinicTests
depend on a minimum amount of data already in the database
before the test cases run. Alternatively, you might choose to populate the database
within the test fixture set up of your test cases — again, within the same
transaction as the tests.
The PetClinic application supports three data access technologies: JDBC, Hibernate, and
JPA. By declaring @ContextConfiguration
without any specific resource locations, the
AbstractClinicTests
class will have its application context loaded from the default
location, AbstractClinicTests-context.xml
, which declares a common DataSource
.
Subclasses specify additional context locations that must declare a
PlatformTransactionManager
and a concrete implementation of Clinic
.
For example, the Hibernate implementation of the PetClinic tests contains the following
implementation. For this example, HibernateClinicTests
does not contain a single line
of code: we only need to declare @ContextConfiguration
, and the tests are inherited
from AbstractClinicTests
. Because @ContextConfiguration
is declared without any
specific resource locations, the Spring TestContext Framework loads an application
context from all the beans defined in AbstractClinicTests-context.xml
(i.e., the
inherited locations) and HibernateClinicTests-context.xml
, with
HibernateClinicTests-context.xml
possibly overriding beans defined in
AbstractClinicTests-context.xml
.
@ContextConfiguration public class HibernateClinicTests extends AbstractClinicTests { }
In a large-scale application, the Spring configuration is often split across multiple
files. Consequently, configuration locations are typically specified in a common base
class for all application-specific integration tests. Such a base class may also add
useful instance variables — populated by Dependency Injection, naturally — such as a
SessionFactory
in the case of an application using Hibernate.
As far as possible, you should have exactly the same Spring configuration files in your
integration tests as in the deployed environment. One likely point of difference
concerns database connection pooling and transaction infrastructure. If you are
deploying to a full-blown application server, you will probably use its connection pool
(available through JNDI) and JTA implementation. Thus in production you will use a
JndiObjectFactoryBean
or <jee:jndi-lookup>
for the DataSource
and
JtaTransactionManager
. JNDI and JTA will not be available in out-of-container
integration tests, so you should use a combination like the Commons DBCP
BasicDataSource
and DataSourceTransactionManager
or HibernateTransactionManager
for them. You can factor out this variant behavior into a single XML file, having the
choice between application server and a local configuration separated from all other
configuration, which will not vary between the test and production environments. In
addition, it is advisable to use properties files for connection settings. See the
PetClinic application for an example.
Consult the following resources for more information about testing: