get the source code

[oll3i]

is there a function or a way to get the source code of the program and display it?
i need to display the source code of java program simple hello world would be enough:)

[JosAH]

Like this?

class S{public static void main(String[]a){String s="class S{public static void main(String[]a){String s=;char c=34;System.out.println(s.substring(0,52)+c+s+c+s.substring(52));}}";char c=34;System.out.println(s.substring(0,52)+c+s+c+s.substring(52));}}
 

kind regards,

Jos

[Nepomuk]

Basically, if you have the .java file, just open it with an editor (e.g. notepad). If you don't, you can decode it from a .class file with specific programs. (The legality of this may vary, depending on the licence and country you are in.) And if you have a .jar file, you can unpack that first - a jar file is just a zip file with a different extension and a MANIFEST file.

Greetings,
Nepomuk

[JosAH]

Two nitpicks:

1) a jar file doesn't always need a MANIFEST file;
2) what to do if there's no .java source file around?

kind regards,

Jos

[Nepomuk]

OK, there doesn't have to be a Manifest file. But I answered that "what if there's no .java file" question already. Second sentence... ^^

Greetings,
Nepomuk

[JosAH]

@Nepomuk
Have you ever seen the result of a Java decompiler? They're all crap from what I have seen. It doesn't even compile anymore.

kind regards,

Jos

[Nepomuk]

Actually, I have and for simple programs at least, the output can be quite good. Don't know which decompilers you used of course.

Greetings,
Nepomuk

[oll3i]

no no i just need to write a simple program that displays its source code

[oll3i]

but that would mean i have to write a decompiler

[oll3i]

hmm and how do i strat ? hm hm hm

[oll3i]

so this program will have to read in .class file and then output the source code
i will have to look for patterns?

[Nepomuk]

You don't have to write one yourself, no. I've used DJ Decompiler in the past and was quite pleased with it. However as I said, make sure the licence of whatever you're decompiling actually allows to do so.

Greetings,
Nepomuk

[JosAH]

@oll3i
Programs that display their own source code are called a "quinne"; see my reply #2.

kind regards,

Jos