Switch Java versions from Git Bash

useJava.sh

# Return PATH without directory
#
# @param dir directory to remove
function rmpath() {
    dir="$1"
    result=""

    while read -r dir; do
        if [ "$dir" != "$1" ]; then
            result="$result:$dir"
        fi
    done <<< "$(echo $PATH | tr ":" "\n")";

    echo "$result" | sed 's/^://'
}

# Return PATH with directory appended
#
# @param dir directory to add
function addpath() {
    echo "$PATH:$1"
}

# Add specified Java version to PATH.
# This command will remove any currently registered Java versions.
#
# @param version version to use
function useJava() {
    declare -A JAVA_DIRECTORIES

    ## !!CUSTOMIZE!! this part with your own paths
    JAVA_DIRECTORIES=(
        ["8"]="/c/Program Files/Java/jdk1.8.0_221"
        ["9"]="/c/Program Files/Java/jdk-9.0.4"
        ["12"]="/c/Program Files/OpenJDK/jdk-12.0.2"
    )

    if [ -z "${JAVA_DIRECTORIES[$1]}" ]; then
        echo "Unknown Java version: $1"
        return 1
    fi;

    if where java >/dev/null 2>&1; then
        echo "Removing Java from PATH"

        while read -r javadir; do
            javadir="$(dirname "$javadir")"
            javadir="$(echo $javadir | sed 's/\\/\//g' | sed 's/^\(.*\):/\/\l\1/')"
            echo "Removing $javadir"

            PATH="$(rmpath "$javadir")"
        done <<< "$(where java)";
    fi;

    echo "Adding Java $1 to PATH";
    PATH="$(addpath "${JAVA_DIRECTORIES[$1]}/bin")"
    export JAVA_HOME="${JAVA_DIRECTORIES[$1]}"
}