Appendix C. Configuration properties

Although Spring Boot handles a lot of the grunt work when it comes to configuring the components in your application, you may want to fine-tune some of those components. That’s where configuration properties come in handy.

Chapter 3 describes the @ConfigurationProperties annotation and how it can be used to expose properties that you can configure external to application code. Just as you can use @ConfigurationProperties in components that you create, many of Spring Boot’s auto-configured components are also annotated with @ConfigurationProperties, making it possible to configure them via any supported property source.

For example, to specify the port that an embedded Tomcat or Jetty server should listen for requests on, you can set the server.port property. This can be set as a property in application.properties, in application.yml, in an operating system environment variable, or any of the other options listed in section 3.2.

This appendix lists all of the configuration properties offered by Spring Boot components. Note that the applicability of these properties is dependent upon the component being declared as a bean in the Spring application context (most likely by way of auto-configuration). Setting a property for an inactive component will have no effect.