switch-to-java

#!/bin/bash

# Calling this script will make the build run on the entered Java version - it
# is called with either 8 or 9 as parameter.
#
# The assumption is that the system JDK is version 8 and that JDK 9 is
# installed somewhere as well. The script edits the ~/.mavenrc file to define
# the JAVA_HOME variable for Maven and makes sure that project-specific
# .mvn/jvm.config files are either present or not, depending on the version.

java_version=$1
# define the path to your Java 9 install here
java_9_path="/opt/jdk-9"

if [ $java_version -eq 8 ]; then
	if [ -f ~/.mavenrc ]; then
    	sed -i -e 's/^JAVA_HOME/#JAVA_HOME/' ~/.mavenrc
    fi
    if [ -f $PWD/.mvn/jvm.config ]; then
        mv -f $PWD/.mvn/jvm.config $PWD/.mvn/jvm9.config
    fi
elif [ $java_version -eq 9 ]; then
	if [ -f ~/.mavenrc ]; then
    	sed -i -e 's/^JAVA_HOME/#JAVA_HOME/' ~/.mavenrc
    else
    	echo "JAVA_HOME=\"$java_9_path\"" >> ~/.mavenrc
    fi
    sed -i -e 's/#*JAVA_HOME/JAVA_HOME/' ~/.mavenrc
    if [ -f $PWD/.mvn/jvm9.config ]; then
        mv -f $PWD/.mvn/jvm9.config $PWD/.mvn/jvm.config
    fi
else
    echo "Unknown version $java_version - doing nothing"
fi