Running Multiple JDK Versions with the Maven Toolchains Plugin
When working with Java projects, you may end up working across multiple JDKs. It may be that you use different vendors, such as Oracle or the OpenJDK, or whether you're working with different Java versions.
It can be annoying to constantly change your JAVA_HOME, and doesn't work when you may need multiple JDKs in a single project.
Fortunately, the Maven Toolchain Plugin has us covered.
In our top-level pom.xml we need to add the plugin, and define which JDKs:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-toolchains-plugin</artifactId>
<version>1.1</version>
<executions>
<execution>
<goals>
<goal>toolchain</goal>
</goals>
</execution>
</executions>
<configuration>
<toolchains>
<jdk>
<version>1.11</version>
<vendor>openjdk</vendor>
</jdk>
</toolchains>
</configuration>
</plugin>
Then, in our global ~/.m2/toolchains.xml we provide paths to the toolchains our machine supports. For instance, on Arch Linux, I have the following setup:
<?xml version="1.0" encoding="UTF8"?>
<toolchains>
<!-- JDK toolchains -->
<toolchain>
<type>jdk</type>
<provides>
<version>1.7</version>
<vendor>openjdk</vendor>
</provides>
<configuration>
<jdkHome>/usr/lib/jvm/java-7-openjdk</jdkHome>
</configuration>
</toolchain>
<toolchain>
<type>jdk</type>
<provides>
<version>1.8</version>
<vendor>openjdk</vendor>
</provides>
<configuration>
<jdkHome>/usr/lib/jvm/java-8-openjdk</jdkHome>
</configuration>
</toolchain>
<toolchain>
<type>jdk</type>
<provides>
<version>1.11</version>
<vendor>openjdk</vendor>
</provides>
<configuration>
<jdkHome>/usr/lib/jvm/java-11-openjdk</jdkHome>
</configuration>
</toolchain>
</toolchains>
