Our solution is to install the Java JDK and JRE pacakges. install-java-openjdk-6-jdk-and-jre
On Ubuntu, the default Java JDK is called
To install OpenJDK on Ubuntu, there are three major packages:
apt-get install openjdk-6-jdk apt-get install openjdk-6-jre-headless apt-get install openjdk-6-jre-lib
find -type f -name tools.jar
This error can happen when you install a package such as ant which depends on the Java JRE, but not the Java JDK.
Some developers believe that the ant package should also require the Java JDK, which would solve this error.
When you try to build something using ant, the build fails because your system is missing openjdk-6-jdk.