Master Spring Boot 3.2.5: Maven Property Expansion & Advanced Config

1. Maven automatic property expansion

Using resource filtering you can expand Maven project properties with @...@ placeholders. Example pack.yml:

pack:
  app:
    java-version: "java.version@"
    springboot-version: "@project.parent.version@"
    sourceEncoding: "@project.build.sourceEncoding@"

Inject values:

@Value("${pack.app.java-version}")
private String javaVersion;
@Value("${pack.app.springboot-version}")
private String springBootVersion;
@Value("${pack.app.sourceEncoding}")
private String sourceEncoding;

Result:

java-version: 17.0.9, springboot-version: 3.2.5, sourceEncoding: UTF-8

Maven parent definition:

2. SpringApplication externalized configuration

Set properties under spring.main.* to externalize configuration, e.g.:

spring:
  main:
    web-application-type: servlet
    banner-mode: off

Other properties can be set programmatically:

SpringApplication app = new SpringApplication(Application.class);
app.setWebApplicationType(WebApplicationType.SERVLET);
app.setBannerMode(Mode.CONSOLE);
app.run(args);

File‑based configuration overrides code settings.

3. Changing configuration file location and name

Use system properties or environment variables: spring.config.name (or SPRING_CONFIG_NAME) – default

application

spring.config.location

(or SPRING_CONFIG_LOCATION) – path or URL of the file

Example startup commands:

java -Dspring.config.name=app -jar MyApp.jar
java -Dspring.config.location=d:\xxxooo\app.yml -jar MyApp.jar

4. Activating profiles

Specify active profiles in application.yml:

spring:
  profiles:
    active:
    - dev

If no profile is set, the default profile is used; you can change it with:

spring:
  profiles:
    default: dev

Profile activation image:

5. Setting parent and child containers

SpringApplicationBuilder builder = new SpringApplicationBuilder(Application.class);
builder.child(ChildConfig.class);
builder.parent(ParentConfig.class);
builder.build().run(args);

6. Customizing DispatcherServlet path

spring:
  mvc:
    servlet:
      path: /api

Programmatic registration:

@Bean(name = DEFAULT_DISPATCHER_SERVLET_REGISTRATION_BEAN_NAME)
public DispatcherServletRegistrationBean dispatcherServletRegistration() {
  DispatcherServlet dispatcherServlet = new DispatcherServlet();
  DispatcherServletRegistrationBean registration = new DispatcherServletRegistrationBean(dispatcherServlet, "/api");
  registration.setName("dispatcherServlet");
  registration.setLoadOnStartup(0);
  return registration;
}

7. Configuring access logs

server:
  tomcat:
    basedir: "pack-tomcat"
    accesslog:
      enabled: true
      pattern: "%t %a %r %s (%D microseconds)"

Logs are written under the Tomcat base directory; you can change the directory with the basedir setting.

8. Enabling Tomcat MBean registry

server:
  tomcat:
    mbeanregistry:
      enabled: true

After enabling, MBean metrics are visible via JConsole.

9. Generating build information

Add the Spring Boot Maven plugin with the build-info goal:

<plugin>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-maven-plugin</artifactId>
  <version>3.2.5</version>
  <executions>
    <execution>
      <goals>
        <goal>build-info</goal>
      </goals>
    </execution>
  </executions>
</plugin>

10. Generating Git information

Include the Git commit ID plugin:

<plugin>
  <groupId>io.github.git-commit-id</groupId>
  <artifactId>git-commit-id-maven-plugin</artifactId>
</plugin>

After building, a git.properties file is packaged in the JAR and can be inspected for repository state.