I tried to run an Ant target within Eclipse today and got a fun error: BUILD FAILED java.lang.NoClassDefFoundError: com/sun/javadoc/Type This happened because Ant could not find tools.jar, which contains classes to used to run javac and javadoc. The solution: Open up Window->Preferences->Java->Installed JREs Set your default JRE to a JDK/SDK Open up the one you Read More