ClassFile write creates bad byte code

[johncoleman]

I've followed this example from notes:

BufferedInputStream fin
= new BufferedInputStream(new FileInputStream("Point.class"));
ClassFile cf = new ClassFile(new DataInputStream(fin));


And then used the write method to create the new class. However, tad throws an exception, so it appears the bytecode is invalid.

Here is my code:

InputStream is = getClass().getResourceAsStream(resourceName);
DataInputStream dis = new DataInputStream(is);
ClassFile cf = new ClassFile(dis);
cf.addInterface(interfaceName);
DataOutputStream dos = new DataOutputStream(new FileOutputStream(
rtDirName + File.separator + "new" + ".class"));
cf.write(dos);
dos.flush();
dos.close();
dis.close();

Any ideas what is wrong? If I use the CtClass regular methods to augment the code, it creates valid byte code.

[johncoleman]

opps, I see I should not of changed the classname! d'oh

anyway, this technique allows the class to be modified without loading the original class

[chiba]

You might want to use ClassPool, which does not load a class file as well. ClassPool reads a class file but does not load it.
ClassPool is a utility class for reading a class file from various resources.

[johncoleman]

"chiba" wrote:
You might want to use ClassPool, which does not load a class file as well. ClassPool reads a class file but does not load it.
ClassPool is a utility class for reading a class file from various resources.

Many thanks, yes I have posted code on the other thread how I got my solution.

My debt is to you for this very useful library.

John