65. Build
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65. Build

65.1 Customize dependency versions with Maven

If you use a Maven build that inherits from spring-boot-starter-parent but you want to override a specific third-party dependency you can add appropriate <properties> elements. Browse the spring-dependencies POM for a complete list of properties. For example, to pick a different slf4j version you would add the following:

<properties>
    <slf4j.version>1.7.5<slf4j.version>
</properties>
[Warning]Warning

Each Spring Boot release is designed and tested against a specific set of third-party dependencies. Overriding versions may cause compatibilty issues.

65.2 Remote debug a Spring Boot application started with Maven

To attach a remote debugger to a Spring Boot application started with Maven you can use the mvnDebug command rather than mvn. For example:

$ mvnDebug spring-boot:run

You can now attach a remote debugger to your running application on port 8000.

65.3 Build an executable archive with Ant

To build with Ant you need to grab dependencies, compile and then create a jar or war archive as normal. To make it executable:

  1. Use the appropriate launcher as a Main-Class, e.g. JarLauncher for a jar file, and specify the other properties it needs as manifest entries, principally a Start-Class.
  2. Add the runtime dependencies in a nested "lib" directory (for a jar) and the provided (embedded container) dependencies in a nested lib-provided directory. Remember not to compress the entries in the archive.
  3. Add the spring-boot-loader classes at the root of the archive (so the Main-Class is available).

Example:

<target name="build" depends="compile">
    <copy todir="target/classes/lib">
        <fileset dir="lib/runtime" />
    </copy>
    <jar destfile="target/spring-boot-sample-actuator-${spring-boot.version}.jar" compress="false">
        <fileset dir="target/classes" />
        <fileset dir="src/main/resources" />
        <zipfileset src="lib/loader/spring-boot-loader-jar-${spring-boot.version}.jar" />
        <manifest>
            <attribute name="Main-Class" value="org.springframework.boot.loader.JarLauncher" />
            <attribute name="Start-Class" value="${start-class}" />
        </manifest>
    </jar>
</target>

The Actuator Sample has a build.xml that should work if you run it with

$ ant -lib <path_to>/ivy-2.2.jar

after which you can run the application with

$ java -jar target/*.jar
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