javap

[Dillinger4]

Is there anyway i can run the disassembler and get a human readable version of the whole .class file. If the disassembler is run a human readable verson of the API defined by the specified class is produced. If javap is run with the -c switch the API is produced along with the byte code. The API is readable but the byte code is somewhat hard to interpret.

[CornedBee]

Bytecode? Isn't it bytecode assembly?

Assembly is hard to interpret, that's a fact. There are some java decompilers on the web, try searching for them on google.

[CornedBee]

jad is the best I know, unfortunatly its location is a tripod member page that is unavailable most of the time.

[Dillinger4]

It dosen't look like Assembly. Try disassembling a .class file using javap. Tell me what you think.

C:\jdk1.3\bin> javap -c -classpath C:\Dirs; Class

[JCScoobyRS]

DJDecompiler is great. It takes a class file and turns it into the original .java file. If you're interested, let me know. Later, Jeremy

[CornedBee]

Method void init()
   0 getstatic #3 <Field java.io.PrintStream out>
   3 ldc #4 <String "Initializing">
   5 invokevirtual #5 <Method void println(java.lang.String)>
   8 aload_0
   9 invokevirtual #6 <Method java.awt.Rectangle getBounds()>
  12 getfield #7 <Field int width>
  15 istore_1
  16 aload_0
  17 invokevirtual #6 <Method java.awt.Rectangle getBounds()>
  20 getfield #8 <Field int height>
  23 istore_2
  24 aload_0
  25 iload_2
  26 iload_1
  27 multianewarray #9 dim #2 <Class [[B>
  31 putfield #2 <Field byte arHeight[][]>
  34 aload_0
  35 aload_0
  36 invokevirtual #10 <Method java.net.URL getCodeBase()>
  39 ldc #11 <String "asg.png">
  41 invokevirtual #12
    <Method java.awt.Image getImage(java.net.URL, java.lang.String)>

Well, if that doesn't look like assembly I don't know what does.
Always the same scheme:
ByteOffset OpCodeName [Parameters]

[Dillinger4]

Honestly i dont know what Assembler looks like. It all looks like scribble to me.

[ccoder]

Originally posted by CornedBee
Well, if that doesn't look like assembly I don't know what does.
Always the same scheme:
ByteOffset OpCodeName [Parameters]

It's bytecode.

Take a look at http://www.mozilla.org/projects/ef/t.../examples.html to see an example of java source code and the corresponding bytecode and x86 assembler code.

[CornedBee]

No, it's assembly. Bytecode would be just that, bytecode. It would look the same as machine code. This is bytecode assembly, and it looks very much like other assembly, especially MMX or SSE assembly (the normal x86 instruction have only 2, 3 or 4 letters).

[ccoder]

Bytecode is the machine language of the VM, not the platform on which it is running. If it were true machine code you wouldn't need the JVM to convert your .class files.

[CornedBee]

Yeah, so?

[Dillinger4]

Yeah CornedBee is right in the respect that it is Assembly. I just didn't recognize it at first since im not use to looking at Assmbler code.