I have a jar package, the code is a confusion, in the package there are many class in the root directory of the, I now want to recompile this bag inside a class in the directory, but need to recompile the class to refer to the bags under the root directory of a lot of class, after decompiling, I saw under the root directory of the class didn't set package, so, according to the requirement of Java compilation, the rest of the directory to reference the class it was impossible, because there is no package name, I now is to use javac command line compiler compiler is not in the past, no matter what I do? Recompile sure can in theory, but just don't know what to use special way to give advice or comments please predecessors!