Java Decompilers

[Nepomuk]

Hi everyone!
I was wondering, how many of you have used a Java Decompiler so far and what experiences did you make?

I've used the DJ Java Decompiler 3.9 (which uses JAD) a bit lately and found it very useful. However it costs 20$ and I wasn't planning to spend any money on it (especially as I'm not planning to send any money internationally ).

I haven't tried JAD by it's self yet, can anyone share their experiences?

The same goes for Mocha. Anyone know it?

I've found a list of decompilers on http://www.program-transformation.or...avaDecompilers and a test on http://www.javaworld.com/javaworld/j...compilers.html, but I'd like to hear your opinions on the various Decompilers.

Also, does anyone know, if (or in which circumstances) decompiling a Library, which you found online (e.g. from apache) is legal? (Of course without stealing the code, just for learning.)

Greetings,
Nepomuk

[r035198x]

Hi everyone!
I was wondering, how many of you have used a Java Decompiler so far and what experiences did you make?

I've used the DJ Java Decompiler 3.9 (which uses JAD) a bit lately and found it very useful. However it costs 20$ and I wasn't planning to spend any money on it (especially as I'm not planning to send any money internationally ).

I haven't tried JAD by it's self yet, can anyone share their experiences?

The same goes for Mocha. Anyone know it?

I've found a list of decompilers on http://www.program-transformation.or...avaDecompilers and a test on http://www.javaworld.com/javaworld/j...compilers.html, but I'd like to hear your opinions on the various Decompilers.

Also, does anyone know, if (or in which circumstances) decompiling a Library, which you found online (e.g. from apache) is legal? (Of course without stealing the code, just for learning.)

Greetings,
Nepomuk

I've only used cavaj a long time ago when I was trying to see how people decompile other people's code.
I don't use any decompilers any more. I'd say if someone wanted you to see the source code, they'd give you the source code itself along with the jars or classes so I don't decompile other people's code.

[Nepomuk]

I've only used cavaj a long time ago when I was trying to see how people decompile other people's code.
I don't use any decompilers any more. I'd say if someone wanted you to see the source code, they'd give you the source code itself along with the jars or classes so I don't decompile other people's code.

Hm, cavaj seems to use JAD too. But this one is freeware, which is certainly a plus.

By the way, I don't use them often, as I think too, that you shouldn't access other peoples code without their permission if not really necessary. But sometimes, when I'm doing something completely new and just can't think of a solution AND know where I can find one that works, I can have a look at it, understand it and hopefully write something that will work afterwards.

To that extent, this has happened twice since I've started programming in Java (about 4 years ago). So I guess, that can be considered OK.

Anyone else with experience in decompiling?

Greetings,
Nepomuk

[ivmai]

Java decompilers

IMHO, the best java decompiler is Jad (v1.5.8g) at this moment. Unfortunately, it's no longer maintained by the author. To improve the quality of decompiled code (or decompile Java 1.5+ classes), there's a helper tool - JadRetro. (The classes to be decompiled, first processed with JadRetro, and, then, decompiled by Jad.)

Also, there's a good JD-GUI decompiler, which is still being developed (but at present, it can't replace Jad in most cases).