pom configuration to force usage of jvm 7 with scala maven plugin - scala

Question

Because of an incompatibility between a scala 2.9.2 project and the java 8 version, i need to manually specify jvm usage in my maven project.
The pom.xml i make, using documentation here :
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.netlogo.extension</groupId>
<packaging>jar</packaging>
<artifactId>rungekuta</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>${lib.org.scala-lang.scala.version}</version>
</dependency>
<dependency>
<groupId>org.nlogo</groupId>
<artifactId>netlogo</artifactId>
<version>5.2</version>
<scope>provided</scope>
</dependency>
</dependencies>
<properties>
<lib.org.scala-lang.scala.version>2.9.3</lib.org.scala-lang.scala.version>
<maven.scala.version>${lib.org.scala-lang.scala.version}</maven.scala.version>
</properties>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.2.1</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.5.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
</pluginManagement>
<plugins>
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.2.1</version>
<executions>
<execution>
<id>scala-compile-first</id>
<phase>process-resources</phase>
<goals>
<goal>add-source</goal>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.2</version>
<configuration>
<archive>
<manifestEntries>
<Extension-Name>rungekuta</Extension-Name>
<Class-Manager>org.netlogo.extension.rungeKuta.RungeKutaExtension</Class-Manager>
<NetLogo-Extension-API-Version>5.0</NetLogo-Extension-API-Version>
</manifestEntries>
</archive>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<verbose>true</verbose>
<fork>true</fork>
<executable>/home/reyman/Logiciels/jdk1.7.0_80/bin/javac</executable>
<compilerVersion>1.3</compilerVersion>
</configuration>
</plugin>
</plugins>
</build>
<name>${project.artifactId} ${project.version}</name>
<repositories>
<repository>
<id>snapshots.scala-tools.org</id>
<name>Scala snapshots repository</name>
<url>http://scala-tools.org/repo-snapshots/</url>
</repository>
<repository>
<id>scala-tools.org</id>
<name>Scala repository</name>
<url>http://scala-tools.org/repo-releases/</url>
</repository>
</repositories>
</project>
I try this without success, maven continue to use my current jvm 8 and not the jvm given in maven-compiler-plugin : <executable>/home/reyman/Logiciels/jdk1.7.0_80/bin/javac</executable>
How can i force usage of the jvm 7 during mvn compile of my mixed scala/java sources project ?

Answer 1

This worked for me:
<plugin>
<inherited>true</inherited>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>

Answer 2

Use Something like this:
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.2.1</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
</configuration>
</plugin>
modify it per your need.
Here is my complete Build , I don't know if it will help you.
I'm pasting it here because it's too long for comment:
<build>
<finalName>KAIBICHI</finalName>
<pluginManagement>
<plugins>
<plugin>
<artifactId>maven-eclipse-plugin</artifactId>
<version>2.9</version>
<configuration>
<additionalProjectnatures>
<projectnature>org.springframework.ide.eclipse.core.springnature</projectnature>
</additionalProjectnatures>
<additionalBuildcommands>
<buildcommand>org.springframework.ide.eclipse.core.springbuilder</buildcommand>
</additionalBuildcommands>
<downloadSources>true</downloadSources>
<downloadJavadocs>true</downloadJavadocs>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.5.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
<compilerArgument>-Xlint:all</compilerArgument>
<showWarnings>true</showWarnings>
<showDeprecation>true</showDeprecation>
</configuration>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.2.1</version>
<configuration>
<mainClass>org.test.int1.Main</mainClass>
</configuration>
</plugin>
</plugins>
</build>

Answer 3

I had the same problem trying to use minify-maven-plugin 1.7 with java6. It needs Java7.
The problem is that Maven needs to run with the proper JVM to use the plugins, so the only solution I found was to export JAVA_HOME before running maven:
ORIGINAL_JAVA_HOME=$JAVA_HOME
export JAVA_HOME=/usr/lib/jvm/jdk1.7.0_79
mvn jetty:run
export JAVA_HOME=$ORIGINAL_JAVA_HOME
if you need to do this frequently maybe you can add to your bashrc an alias like
alias mvn7='ORIGINAL_JAVA_HOME=$JAVA_HOME; export JAVA_HOME=/usr/lib/jvm/jdk1.7.0_79; mvn jetty:run; export JAVA_HOME=$ORIGINAL_JAVA_HOME'

Answer 4

This worked for me, but I had to allow Eclipse (Mars) to adjust plugin configuration. I tested my pom.xml with an empty project and it seems to build without incident.
I am using jenv to manage my Java environment outside of Eclipse which is much easier when you have many Java versions installed.
Here is the pom.xml I am using:
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.netlogo.extension</groupId>
<packaging>jar</packaging>
<artifactId>rungekuta</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>${lib.org.scala-lang.scala.version}</version>
</dependency>
<!--
<dependency>
<groupId>org.nlogo</groupId>
<artifactId>netlogo</artifactId>
<version>5.2</version>
<scope>provided</scope>
</dependency>
-->
</dependencies>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<lib.org.scala-lang.scala.version>2.9.3</lib.org.scala-lang.scala.version>
<maven.scala.version>${lib.org.scala-lang.scala.version}</maven.scala.version>
</properties>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.2.1</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.5.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<!--This plugin's configuration is used to store Eclipse m2e settings only. It has no influence on the Maven build itself.-->
<plugin>
<groupId>org.eclipse.m2e</groupId>
<artifactId>lifecycle-mapping</artifactId>
<version>1.0.0</version>
<configuration>
<lifecycleMappingMetadata>
<pluginExecutions>
<pluginExecution>
<pluginExecutionFilter>
<groupId>
net.alchim31.maven
</groupId>
<artifactId>
scala-maven-plugin
</artifactId>
<versionRange>
[3.2.1,)
</versionRange>
<goals>
<goal>testCompile</goal>
</goals>
</pluginExecutionFilter>
<action>
<ignore></ignore>
</action>
</pluginExecution>
</pluginExecutions>
</lifecycleMappingMetadata>
</configuration>
</plugin>
</plugins>
</pluginManagement>
<plugins>
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.2.1</version>
<executions>
<execution>
<id>scala-compile-first</id>
<phase>process-resources</phase>
<goals>
<goal>add-source</goal>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.2</version>
<configuration>
<archive>
<manifestEntries>
<Extension-Name>rungekuta</Extension-Name>
<Class-Manager>org.netlogo.extension.rungeKuta.RungeKutaExtension</Class-Manager>
<NetLogo-Extension-API-Version>5.0</NetLogo-Extension-API-Version>
</manifestEntries>
</archive>
</configuration>
</plugin>
</plugins>
</build>
<name>${project.artifactId} ${project.version}</name>
<repositories>
<repository>
<id>snapshots.scala-tools.org</id>
<name>Scala snapshots repository</name>
<url>http://scala-tools.org/repo-snapshots/</url>
</repository>
<repository>
<id>scala-tools.org</id>
<name>Scala repository</name>
<url>http://scala-tools.org/repo-releases/</url>
</repository>
</repositories>
</project>