Duplicate a method

[gkorland]

Hi,

I'm trying to duplicate a method, what is the a best practice?
e.g.

public void foo(){
some code...
}

add another duplicate method:

public void foo(int i){
some code...
}

[cat4hire]

You are not trying to duplicate, rather to overload the method. I usually do this:
1) create a StringBuffer where I place the java source code for the new method;
2) use CtNewMethod.make() to obtain a new CtMethod for the source code;
3) add the method to the CtClass.

[gkorland]

The thing is that I want the new method to look the same as the original code, for that I want to copy the original code.

The problem is that when I use the:
newMethod.setBody(method, null); to copy the original body I need to add the following code to fix the MaxLocals:
CodeAttribute code = newMethod.getMethodInfo().getCodeAttribute();
code.setMaxLocals(code.getMaxLocals() + 1);

Isn't there a better way?

Guy

[chiba]

Your way is dangerous. Suppose the following method:

int foo(int i) {
int j = 3;
return j + i;
}

At the bytecode level, the variable i would be register 1 and j would be register 2.

If you add a parameter k, you must change the bytecode
of the method body so that the variable j will be register
3 because k will be register 2.

Current Javassist does not provide direct support for
adding a new parameter. :-<

[gkorland]

Yes, thanks I found it myself few days ago, do you think there's a way to make it happen anyway?