Spring Boot Reference Guide

Authors

Phillip Webb, Dave Syer, Josh Long, Stéphane Nicoll, Rob Winch, Andy Wilkinson, Marcel Overdijk, Christian Dupuis, Sébastien Deleuze, Michael Simons, Vedran Pavić, Jay Bryant, Madhura Bhave

2.1.0.BUILD-SNAPSHOT

Copies of this document may be made for your own use and for distribution to others, provided that you do not charge any fee for such copies and further provided that each copy contains this Copyright Notice, whether distributed in print or electronically.


Table of Contents

I. Spring Boot Documentation
1. About the Documentation
2. Getting Help
3. First Steps
4. Working with Spring Boot
5. Learning about Spring Boot Features
6. Moving to Production
7. Advanced Topics
II. Getting Started
8. Introducing Spring Boot
9. System Requirements
9.1. Servlet Containers
10. Installing Spring Boot
10.1. Installation Instructions for the Java Developer
10.1.1. Maven Installation
10.1.2. Gradle Installation
10.2. Installing the Spring Boot CLI
10.2.1. Manual Installation
10.2.2. Installation with SDKMAN!
10.2.3. OSX Homebrew Installation
10.2.4. MacPorts Installation
10.2.5. Command-line Completion
10.2.6. Windows Scoop Installation
10.2.7. Quick-start Spring CLI Example
10.3. Upgrading from an Earlier Version of Spring Boot
11. Developing Your First Spring Boot Application
11.1. Creating the POM
11.2. Adding Classpath Dependencies
11.3. Writing the Code
11.3.1. The @RestController and @RequestMapping Annotations
11.3.2. The @EnableAutoConfiguration Annotation
11.3.3. The “main” Method
11.4. Running the Example
11.5. Creating an Executable Jar
12. What to Read Next
III. Using Spring Boot
13. Build Systems
13.1. Dependency Management
13.2. Maven
13.2.1. Inheriting the Starter Parent
13.2.2. Using Spring Boot without the Parent POM
13.2.3. Using the Spring Boot Maven Plugin
13.3. Gradle
13.4. Ant
13.5. Starters
14. Structuring Your Code
14.1. Using the “default” Package
14.2. Locating the Main Application Class
15. Configuration Classes
15.1. Importing Additional Configuration Classes
15.2. Importing XML Configuration
16. Auto-configuration
16.1. Gradually Replacing Auto-configuration
16.2. Disabling Specific Auto-configuration Classes
17. Spring Beans and Dependency Injection
18. Using the @SpringBootApplication Annotation
19. Running Your Application
19.1. Running from an IDE
19.2. Running as a Packaged Application
19.3. Using the Maven Plugin
19.4. Using the Gradle Plugin
19.5. Hot Swapping
20. Developer Tools
20.1. Property Defaults
20.2. Automatic Restart
20.2.1. Logging changes in condition evaluation
20.2.2. Excluding Resources
20.2.3. Watching Additional Paths
20.2.4. Disabling Restart
20.2.5. Using a Trigger File
20.2.6. Customizing the Restart Classloader
20.2.7. Known Limitations
20.3. LiveReload
20.4. Global Settings
20.5. Remote Applications
20.5.1. Running the Remote Client Application
20.5.2. Remote Update
21. Packaging Your Application for Production
22. What to Read Next
IV. Spring Boot features
23. SpringApplication
23.1. Startup Failure
23.2. Customizing the Banner
23.3. Customizing SpringApplication
23.4. Fluent Builder API
23.5. Application Events and Listeners
23.6. Web Environment
23.7. Accessing Application Arguments
23.8. Using the ApplicationRunner or CommandLineRunner
23.9. Application Exit
23.10. Admin Features
24. Externalized Configuration
24.1. Configuring Random Values
24.2. Accessing Command Line Properties
24.3. Application Property Files
24.4. Profile-specific Properties
24.5. Placeholders in Properties
24.6. Using YAML Instead of Properties
24.6.1. Loading YAML
24.6.2. Exposing YAML as Properties in the Spring Environment
24.6.3. Multi-profile YAML Documents
24.6.4. YAML Shortcomings
24.7. Type-safe Configuration Properties
24.7.1. Third-party Configuration
24.7.2. Relaxed Binding
24.7.3. Merging Complex Types
24.7.4. Properties Conversion
Converting durations
Converting Data Sizes
24.7.5. @ConfigurationProperties Validation
24.7.6. @ConfigurationProperties vs. @Value
25. Profiles
25.1. Adding Active Profiles
25.2. Programmatically Setting Profiles
25.3. Profile-specific Configuration Files
26. Logging
26.1. Log Format
26.2. Console Output
26.2.1. Color-coded Output
26.3. File Output
26.4. Log Levels
26.5. Log Groups
26.6. Custom Log Configuration
26.7. Logback Extensions
26.7.1. Profile-specific Configuration
26.7.2. Environment Properties
27. Developing Web Applications
27.1. The “Spring Web MVC Framework”
27.1.1. Spring MVC Auto-configuration
27.1.2. HttpMessageConverters
27.1.3. Custom JSON Serializers and Deserializers
27.1.4. MessageCodesResolver
27.1.5. Static Content
27.1.6. Welcome Page
27.1.7. Custom Favicon
27.1.8. Path Matching and Content Negotiation
27.1.9. ConfigurableWebBindingInitializer
27.1.10. Template Engines
27.1.11. Error Handling
Custom Error Pages
Mapping Error Pages outside of Spring MVC
27.1.12. Spring HATEOAS
27.1.13. CORS Support
27.2. The “Spring WebFlux Framework”
27.2.1. Spring WebFlux Auto-configuration
27.2.2. HTTP Codecs with HttpMessageReaders and HttpMessageWriters
27.2.3. Static Content
27.2.4. Template Engines
27.2.5. Error Handling
Custom Error Pages
27.2.6. Web Filters
27.3. JAX-RS and Jersey
27.4. Embedded Servlet Container Support
27.4.1. Servlets, Filters, and listeners
Registering Servlets, Filters, and Listeners as Spring Beans
27.4.2. Servlet Context Initialization
Scanning for Servlets, Filters, and listeners
27.4.3. The ServletWebServerApplicationContext
27.4.4. Customizing Embedded Servlet Containers
Programmatic Customization
Customizing ConfigurableServletWebServerFactory Directly
27.4.5. JSP Limitations
28. Security
28.1. MVC Security
28.2. WebFlux Security
28.3. OAuth2
28.3.1. Client
OpenID Connect Login client registration
OAuth2 Authorization Code client registration
OAuth2 client registration for common providers
28.3.2. Resource Server
28.3.3. Authorization Server
28.4. Actuator Security
28.4.1. Cross Site Request Forgery Protection
29. Working with SQL Databases
29.1. Configure a DataSource
29.1.1. Embedded Database Support
29.1.2. Connection to a Production Database
29.1.3. Connection to a JNDI DataSource
29.2. Using JdbcTemplate
29.3. JPA and Spring Data JPA
29.3.1. Entity Classes
29.3.2. Spring Data JPA Repositories
29.3.3. Creating and Dropping JPA Databases
29.3.4. Open EntityManager in View
29.4. Spring Data JDBC
29.5. Using H2’s Web Console
29.5.1. Changing the H2 Console’s Path
29.6. Using jOOQ
29.6.1. Code Generation
29.6.2. Using DSLContext
29.6.3. jOOQ SQL Dialect
29.6.4. Customizing jOOQ
30. Working with NoSQL Technologies
30.1. Redis
30.1.1. Connecting to Redis
30.2. MongoDB
30.2.1. Connecting to a MongoDB Database
30.2.2. MongoTemplate
30.2.3. Spring Data MongoDB Repositories
30.2.4. Embedded Mongo
30.3. Neo4j
30.3.1. Connecting to a Neo4j Database
30.3.2. Using the Embedded Mode
30.3.3. Neo4jSession
30.3.4. Spring Data Neo4j Repositories
30.4. Gemfire
30.5. Solr
30.5.1. Connecting to Solr
30.5.2. Spring Data Solr Repositories
30.6. Elasticsearch
30.6.1. Connecting to Elasticsearch by REST clients
30.6.2. Connecting to Elasticsearch by Using Jest
30.6.3. Connecting to Elasticsearch by Using Spring Data
30.6.4. Spring Data Elasticsearch Repositories
30.7. Cassandra
30.7.1. Connecting to Cassandra
30.7.2. Spring Data Cassandra Repositories
30.8. Couchbase
30.8.1. Connecting to Couchbase
30.8.2. Spring Data Couchbase Repositories
30.9. LDAP
30.9.1. Connecting to an LDAP Server
30.9.2. Spring Data LDAP Repositories
30.9.3. Embedded In-memory LDAP Server
30.10. InfluxDB
30.10.1. Connecting to InfluxDB
31. Caching
31.1. Supported Cache Providers
31.1.1. Generic
31.1.2. JCache (JSR-107)
31.1.3. EhCache 2.x
31.1.4. Hazelcast
31.1.5. Infinispan
31.1.6. Couchbase
31.1.7. Redis
31.1.8. Caffeine
31.1.9. Simple
31.1.10. None
32. Messaging
32.1. JMS
32.1.1. ActiveMQ Support
32.1.2. Artemis Support
32.1.3. Using a JNDI ConnectionFactory
32.1.4. Sending a Message
32.1.5. Receiving a Message
32.2. AMQP
32.2.1. RabbitMQ support
32.2.2. Sending a Message
32.2.3. Receiving a Message
32.3. Apache Kafka Support
32.3.1. Sending a Message
32.3.2. Receiving a Message
32.3.3. Kafka Streams
32.3.4. Additional Kafka Properties
33. Calling REST Services with RestTemplate
33.1. RestTemplate Customization
34. Calling REST Services with WebClient
34.1. WebClient Runtime
34.2. WebClient Customization
35. Validation
36. Sending Email
37. Distributed Transactions with JTA
37.1. Using an Atomikos Transaction Manager
37.2. Using a Bitronix Transaction Manager
37.3. Using a Java EE Managed Transaction Manager
37.4. Mixing XA and Non-XA JMS Connections
37.5. Supporting an Alternative Embedded Transaction Manager
38. Hazelcast
39. Quartz Scheduler
40. Task Execution and Scheduling
41. Spring Integration
42. Spring Session
43. Monitoring and Management over JMX
44. Testing
44.1. Test Scope Dependencies
44.2. Testing Spring Applications
44.3. Testing Spring Boot Applications
44.3.1. Detecting Web Application Type
44.3.2. Detecting Test Configuration
44.3.3. Excluding Test Configuration
44.3.4. Testing with a mock environment
44.3.5. Testing with a running server
44.3.6. Using JMX
44.3.7. Mocking and Spying Beans
44.3.8. Auto-configured Tests
44.3.9. Auto-configured JSON Tests
44.3.10. Auto-configured Spring MVC Tests
44.3.11. Auto-configured Spring WebFlux Tests
44.3.12. Auto-configured Data JPA Tests
44.3.13. Auto-configured JDBC Tests
44.3.14. Auto-configured Data JDBC Tests
44.3.15. Auto-configured jOOQ Tests
44.3.16. Auto-configured Data MongoDB Tests
44.3.17. Auto-configured Data Neo4j Tests
44.3.18. Auto-configured Data Redis Tests
44.3.19. Auto-configured Data LDAP Tests
44.3.20. Auto-configured REST Clients
44.3.21. Auto-configured Spring REST Docs Tests
Auto-configured Spring REST Docs Tests with Mock MVC
Auto-configured Spring REST Docs Tests with REST Assured
44.3.22. Additional Auto-configuration and Slicing
44.3.23. User Configuration and Slicing
44.3.24. Using Spock to Test Spring Boot Applications
44.4. Test Utilities
44.4.1. ConfigFileApplicationContextInitializer
44.4.2. TestPropertyValues
44.4.3. OutputCapture
44.4.4. TestRestTemplate
45. WebSockets
46. Web Services
47. Calling Web Services with WebServiceTemplate
48. Creating Your Own Auto-configuration
48.1. Understanding Auto-configured Beans
48.2. Locating Auto-configuration Candidates
48.3. Condition Annotations
48.3.1. Class Conditions
48.3.2. Bean Conditions
48.3.3. Property Conditions
48.3.4. Resource Conditions
48.3.5. Web Application Conditions
48.3.6. SpEL Expression Conditions
48.4. Testing your Auto-configuration
48.4.1. Simulating a Web Context
48.4.2. Overriding the Classpath
48.5. Creating Your Own Starter
48.5.1. Naming
48.5.2. autoconfigure Module
48.5.3. Starter Module
49. Kotlin support
49.1. Requirements
49.2. Null-safety
49.3. Kotlin API
49.3.1. runApplication
49.3.2. Extensions
49.4. Dependency management
49.5. @ConfigurationProperties
49.6. Testing
49.7. Resources
49.7.1. Further reading
49.7.2. Examples
50. What to Read Next
V. Spring Boot Actuator: Production-ready features
51. Enabling Production-ready Features
52. Endpoints
52.1. Enabling Endpoints
52.2. Exposing Endpoints
52.3. Securing HTTP Endpoints
52.4. Configuring Endpoints
52.5. Hypermedia for Actuator Web Endpoints
52.6. CORS Support
52.7. Implementing Custom Endpoints
52.7.1. Receiving Input
Input type conversion
52.7.2. Custom Web Endpoints
Web Endpoint Request Predicates
Path
HTTP method
Consumes
Produces
Web Endpoint Response Status
Web Endpoint Range Requests
Web Endpoint Security
52.7.3. Servlet endpoints
52.7.4. Controller endpoints
52.8. Health Information
52.8.1. Auto-configured HealthIndicators
52.8.2. Writing Custom HealthIndicators
52.8.3. Reactive Health Indicators
52.8.4. Auto-configured ReactiveHealthIndicators
52.9. Application Information
52.9.1. Auto-configured InfoContributors
52.9.2. Custom Application Information
52.9.3. Git Commit Information
52.9.4. Build Information
52.9.5. Writing Custom InfoContributors
53. Monitoring and Management over HTTP
53.1. Customizing the Management Endpoint Paths
53.2. Customizing the Management Server Port
53.3. Configuring Management-specific SSL
53.4. Customizing the Management Server Address
53.5. Disabling HTTP Endpoints
54. Monitoring and Management over JMX
54.1. Customizing MBean Names
54.2. Disabling JMX Endpoints
54.3. Using Jolokia for JMX over HTTP
54.3.1. Customizing Jolokia
54.3.2. Disabling Jolokia
55. Loggers
55.1. Configure a Logger
56. Metrics
56.1. Getting started
56.2. Supported monitoring systems
56.2.1. Atlas
56.2.2. Datadog
56.2.3. Datadog
56.2.4. Ganglia
56.2.5. Graphite
56.2.6. Influx
56.2.7. JMX
56.2.8. New Relic
56.2.9. Prometheus
56.2.10. SignalFx
56.2.11. Simple
56.2.12. StatsD
56.2.13. Wavefront
56.3. Supported Metrics
56.3.1. Spring MVC Metrics
56.3.2. Spring WebFlux Metrics
56.3.3. HTTP Client Metrics
56.3.4. Cache Metrics
56.3.5. DataSource Metrics
56.3.6. Hibernate Metrics
56.3.7. RabbitMQ Metrics
56.4. Registering custom metrics
56.5. Customizing individual metrics
56.5.1. Common tags
56.5.2. Per-meter properties
56.6. Metrics endpoint
57. Auditing
58. HTTP Tracing
58.1. Custom HTTP tracing
59. Process Monitoring
59.1. Extending Configuration
59.2. Programmatically
60. Cloud Foundry Support
60.1. Disabling Extended Cloud Foundry Actuator Support
60.2. Cloud Foundry Self-signed Certificates
60.3. Custom context path
61. What to Read Next
VI. Deploying Spring Boot Applications
62. Deploying to the Cloud
62.1. Cloud Foundry
62.1.1. Binding to Services
62.2. Heroku
62.3. OpenShift
62.4. Amazon Web Services (AWS)
62.4.1. AWS Elastic Beanstalk
Using the Tomcat Platform
Using the Java SE Platform
62.4.2. Summary
62.5. Boxfuse and Amazon Web Services
62.6. Google Cloud
63. Installing Spring Boot Applications
63.1. Supported Operating Systems
63.2. Unix/Linux Services
63.2.1. Installation as an init.d Service (System V)
Securing an init.d Service
63.2.2. Installation as a systemd Service
63.2.3. Customizing the Startup Script
Customizing the Start Script when It Is Written
Customizing a Script When It Runs
63.3. Microsoft Windows Services
64. What to Read Next
VII. Spring Boot CLI
65. Installing the CLI
66. Using the CLI
66.1. Running Applications with the CLI
66.1.1. Deduced “grab” Dependencies
66.1.2. Deduced “grab” Coordinates
66.1.3. Default Import Statements
66.1.4. Automatic Main Method
66.1.5. Custom Dependency Management
66.2. Applications with Multiple Source Files
66.3. Packaging Your Application
66.4. Initialize a New Project
66.5. Using the Embedded Shell
66.6. Adding Extensions to the CLI
67. Developing Applications with the Groovy Beans DSL
68. Configuring the CLI with settings.xml
69. What to Read Next
VIII. Build tool plugins
70. Spring Boot Maven Plugin
70.1. Including the Plugin
70.2. Packaging Executable Jar and War Files
71. Spring Boot Gradle Plugin
72. Spring Boot AntLib Module
72.1. Spring Boot Ant Tasks
72.1.1. spring-boot:exejar
72.1.2. Examples
72.2. spring-boot:findmainclass
72.2.1. Examples
73. Supporting Other Build Systems
73.1. Repackaging Archives
73.2. Nested Libraries
73.3. Finding a Main Class
73.4. Example Repackage Implementation
74. What to Read Next
IX. ‘How-to’ guides
75. Spring Boot Application
75.1. Create Your Own FailureAnalyzer
75.2. Troubleshoot Auto-configuration
75.3. Customize the Environment or ApplicationContext Before It Starts
75.4. Build an ApplicationContext Hierarchy (Adding a Parent or Root Context)
75.5. Create a Non-web Application
76. Properties and Configuration
76.1. Automatically Expand Properties at Build Time
76.1.1. Automatic Property Expansion Using Maven
76.1.2. Automatic Property Expansion Using Gradle
76.2. Externalize the Configuration of SpringApplication
76.3. Change the Location of External Properties of an Application
76.4. Use ‘Short’ Command Line Arguments
76.5. Use YAML for External Properties
76.6. Set the Active Spring Profiles
76.7. Change Configuration Depending on the Environment
76.8. Discover Built-in Options for External Properties
77. Embedded Web Servers
77.1. Use Another Web Server
77.2. Disabling the Web Server
77.3. Change the HTTP Port
77.4. Use a Random Unassigned HTTP Port
77.5. Discover the HTTP Port at Runtime
77.6. Enable HTTP Response Compression
77.7. Configure SSL
77.8. Configure HTTP/2
77.8.1. HTTP/2 with Undertow
77.8.2. HTTP/2 with Jetty
77.8.3. HTTP/2 with Tomcat
77.8.4. HTTP/2 with Reactor Netty
77.9. Configure the Web Server
77.10. Add a Servlet, Filter, or Listener to an Application
77.10.1. Add a Servlet, Filter, or Listener by Using a Spring Bean
Disable Registration of a Servlet or Filter
77.10.2. Add Servlets, Filters, and Listeners by Using Classpath Scanning
77.11. Configure Access Logging
77.12. Running Behind a Front-end Proxy Server
77.12.1. Customize Tomcat’s Proxy Configuration
77.13. Enable Multiple Connectors with Tomcat
77.14. Use Tomcat’s LegacyCookieProcessor
77.15. Enable Multiple Listeners with Undertow
77.16. Create WebSocket Endpoints Using @ServerEndpoint
78. Spring MVC
78.1. Write a JSON REST Service
78.2. Write an XML REST Service
78.3. Customize the Jackson ObjectMapper
78.4. Customize the @ResponseBody Rendering
78.5. Handling Multipart File Uploads
78.6. Switch Off the Spring MVC DispatcherServlet
78.7. Switch off the Default MVC Configuration
78.8. Customize ViewResolvers
79. Testing With Spring Security
80. Jersey
80.1. Secure Jersey endpoints with Spring Security
81. HTTP Clients
81.1. Configure RestTemplate to Use a Proxy
82. Logging
82.1. Configure Logback for Logging
82.1.1. Configure Logback for File-only Output
82.2. Configure Log4j for Logging
82.2.1. Use YAML or JSON to Configure Log4j 2
83. Data Access
83.1. Configure a Custom DataSource
83.2. Configure Two DataSources
83.3. Use Spring Data Repositories
83.4. Separate @Entity Definitions from Spring Configuration
83.5. Configure JPA Properties
83.6. Configure Hibernate Naming Strategy
83.7. Use a Custom EntityManagerFactory
83.8. Use Two EntityManagers
83.9. Use a Traditional persistence.xml File
83.10. Use Spring Data JPA and Mongo Repositories
83.11. Expose Spring Data Repositories as REST Endpoint
83.12. Configure a Component that is Used by JPA
83.13. Configure jOOQ with Two DataSources
84. Database Initialization
84.1. Initialize a Database Using JPA
84.2. Initialize a Database Using Hibernate
84.3. Initialize a Database
84.4. Initialize a Spring Batch Database
84.5. Use a Higher-level Database Migration Tool
84.5.1. Execute Flyway Database Migrations on Startup
84.5.2. Execute Liquibase Database Migrations on Startup
85. Messaging
85.1. Disable Transacted JMS Session
86. Batch Applications
86.1. Execute Spring Batch Jobs on Startup
87. Actuator
87.1. Change the HTTP Port or Address of the Actuator Endpoints
87.2. Customize the ‘whitelabel’ Error Page
87.3. Sanitize sensible values
88. Security
88.1. Switch off the Spring Boot Security Configuration
88.2. Change the UserDetailsService and Add User Accounts
88.3. Enable HTTPS When Running behind a Proxy Server
89. Hot Swapping
89.1. Reload Static Content
89.2. Reload Templates without Restarting the Container
89.2.1. Thymeleaf Templates
89.2.2. FreeMarker Templates
89.2.3. Groovy Templates
89.3. Fast Application Restarts
89.4. Reload Java Classes without Restarting the Container
90. Build
90.1. Generate Build Information
90.2. Generate Git Information
90.3. Customize Dependency Versions
90.4. Create an Executable JAR with Maven
90.5. Use a Spring Boot Application as a Dependency
90.6. Extract Specific Libraries When an Executable Jar Runs
90.7. Create a Non-executable JAR with Exclusions
90.8. Remote Debug a Spring Boot Application Started with Maven
90.9. Build an Executable Archive from Ant without Using spring-boot-antlib
91. Traditional Deployment
91.1. Create a Deployable War File
91.2. Convert an Existing Application to Spring Boot
91.3. Deploying a WAR to WebLogic
91.4. Use Jedis Instead of Lettuce
X. Appendices
A. Common application properties
B. Configuration Metadata
B.1. Metadata Format
B.1.1. Group Attributes
B.1.2. Property Attributes
B.1.3. Hint Attributes
B.1.4. Repeated Metadata Items
B.2. Providing Manual Hints
B.2.1. Value Hint
B.2.2. Value Providers
Any
Class Reference
Handle As
Logger Name
Spring Bean Reference
Spring Profile Name
B.3. Generating Your Own Metadata by Using the Annotation Processor
B.3.1. Nested Properties
B.3.2. Adding Additional Metadata
C. Auto-configuration classes
C.1. From the “spring-boot-autoconfigure” module
C.2. From the “spring-boot-actuator-autoconfigure” module
D. Test auto-configuration annotations
E. The Executable Jar Format
E.1. Nested JARs
E.1.1. The Executable Jar File Structure
E.1.2. The Executable War File Structure
E.2. Spring Boot’s “JarFile” Class
E.2.1. Compatibility with the Standard Java “JarFile”
E.3. Launching Executable Jars
E.3.1. Launcher Manifest
E.3.2. Exploded Archives
E.4. PropertiesLauncher Features
E.5. Executable Jar Restrictions
E.6. Alternative Single Jar Solutions
F. Dependency versions