if (classes == null || classes.size() == 0 ) { throw new BuildException("classdir attribute must be set!",
if ( projectFile != null && !(new File(projectFile).exists()) ) { throw new BuildException("file not found in projectFile attribute!", getLocation()); } if ( projectFile == null && (classes == null || classes.size() == 0 )  ) { throw new BuildException("classdir attribute must be set when not using projectFile attribute!",
    protected void checkParameters() throws BuildException {        if (classes == null || classes.size() == 0 ) {            throw new BuildException("classdir attribute must be set!",                                     getLocation());        }		if (homeDir == null)			throw new BuildException("home attribute must be set!", getLocation());    }