Assuming I have Class2.java, it says error: cannot read: Class2.java. I don't what did I miss but I've compiled it by javac -d classes -classpath classes -sourcepath src dtgen.java and I'm pretty sure, there is a dtgen.java in the src folder.

error: cannot read: dtgen.java

Thanks for being patient CB. I think I just have to learn Ant from now on. Again, thanks.