Annotation Interface TestBean
@TestBean
is an annotation that can be applied to a field in a test
class to override a bean in the test's
ApplicationContext
using a static factory method.
By default, the bean to override is inferred from the type of the annotated
field. If multiple candidates exist, a @Qualifier
annotation can be
used to help disambiguate. In the absence of a @Qualifier
annotation,
the name of the annotated field will be used as a fallback qualifier.
Alternatively, you can explicitly specify a bean name to replace by setting the
value
or name
attribute.
A new bean definition will be created if a corresponding bean definition does
not exist. However, if you would like for the test to fail when a corresponding
bean definition does not exist, you can set the enforceOverride
attribute to true
.
The instance is created from a zero-argument static factory method in the
test class whose return type is compatible with the annotated field. In the
case of a nested test class, the enclosing class hierarchy is also searched.
Similarly, if the test class extends from a base class or implements any
interfaces, the entire type hierarchy is searched. Alternatively, a factory
method in an external class can be referenced via its fully-qualified method
name following the syntax <fully-qualified class name>#<method name>
— for example, "org.example.TestUtils#createCustomerRepository"
.
The factory method is deduced as follows.
- If the
methodName()
is specified, look for a static method with that name. - If a method name is not specified, look for exactly one static method named with either the name of the annotated field or the name of the bean (if specified).
Consider the following example.
class CustomerServiceTests {
@TestBean
private CustomerRepository repository;
// @Test methods ...
private static CustomerRepository repository() {
return new TestCustomerRepository();
}
}
In the example above, the repository
bean is replaced by the
instance generated by the repository()
method. Not only is the
overridden instance injected into the repository
field, but it is
also replaced in the BeanFactory
so that other injection points for
that bean use the overridden bean instance.
To make things more explicit, the bean and method names can be set, as shown in the following example.
class CustomerServiceTests {
@TestBean(name = "customerRepository", methodName = "createTestCustomerRepository")
CustomerRepository repository;
// @Test methods ...
static CustomerRepository createTestCustomerRepository() {
return new TestCustomerRepository();
}
}
NOTE: Only singleton beans can be overridden. Any attempt to override a non-singleton bean will result in an exception.
- Since:
- 6.2
- Author:
- Simon Baslé, Stephane Nicoll, Sam Brannen
- See Also:
-
Optional Element Summary
Modifier and TypeOptional ElementDescriptionboolean
Whether to require the existence of a bean definition for the bean being overridden.Name of the static factory method that will be used to instantiate the bean to override.Name of the bean to override.Alias forname()
.
-
Element Details
-
value
Alias forname()
.Intended to be used when no other attributes are needed — for example,
@TestBean("customBeanName")
.- See Also:
- Default:
- ""
-
name
Name of the bean to override.If left unspecified, the bean to override is selected according to the annotated field's type, taking qualifiers into account if necessary. See the class-level documentation for details.
- See Also:
- Default:
- ""
-
methodName
String methodNameName of the static factory method that will be used to instantiate the bean to override.A search will be performed to find the factory method in the test class, in one of its superclasses, or in any implemented interfaces. In the case of a nested test class, the enclosing class hierarchy will also be searched.
Alternatively, a factory method in an external class can be referenced via its fully-qualified method name following the syntax
<fully-qualified class name>#<method name>
— for example,"org.example.TestUtils#createCustomerRepository"
.If left unspecified, the name of the factory method will be detected based either on the name of the annotated field or the name of the bean.
- Default:
- ""
-
enforceOverride
boolean enforceOverrideWhether to require the existence of a bean definition for the bean being overridden.Defaults to
false
which means that a new bean definition will be created if a corresponding bean definition does not exist.Set to
true
to cause an exception to be thrown if a corresponding bean definition does not exist.- Default:
- false
-