Runs a shell command of your choice to install the tool. Ubuntu example, assuming the Jenkins user is in `/etc/sudoers`:

    sudo apt-get --yes install openjdk-6-jdk

(In this case specify e.g. `/usr/lib/jvm/java-6-openjdk-i386` as the home directory.)

As another example, to install an older version of Sun JDK 6 for (x86) Linux, you can use the obsolete DLJ:

    bin=jdk-6u13-dlj-linux-i586.bin
    if [ \! -f $bin ]
    then
        wget --no-verbose http://download.java.net/dlj/binaries/$bin
        sh $bin --unpack --accept-license
    fi

(In this case specify `jdk1.6.0_13` as the home directory.)