How to De-Compile An Exsisting Jar

PLEASE NOTE:
THIS IS FOR EDUCATIONAL PURPOSES ONLY I AM NOT IN ANYWAY RESPONSIBLE FOR HOW OTHERS MAY USE THIS KNOWLEDGE

So Why am I going to tell you guys?
I have run into the problem of needing to go back to an earlier version of a plugin to grab a piece of code. So what is a way to get back older versions? De-compile.

Personally, I use JD-GUI To Download Use This

Now, just place it somewhere on your desktop. Get A Jar File, and drag and drop it ontop of the .exe.

This will open the program and have your source at your finger tips!

Remember, i am not responsible for how others use the knowledge.

As This Person stated Below:

Keep this in mind and Please be respectful of others.

Hope This Helped!

 

Kodfod
I use JD-GUI as well, it is useful.

You should add screenshots that are cropped showing how to use it.

 

Wow this this is GREAT im new to making plugins so having this lets me learn alot quicker (no I wont use it to still peoples plugins) but thanks for posting this

 

McLuke500 No offense to the developers who will use JD-GUI (I use it also), if they can't figure out how to use it, then they shouldn't be developing. Its as simple as File > Open.

 

Yeah I suppose but most resource threads have like code quotes and pictures to make them look nice and this is just text.

 

True, but its such a deliciously simple program. Including images would be like spoon-feeding a 23-year old man.

 

Thanks man, makes it so much easyer to learn plugin developing!

 

@BMX_ATCMAN14 I have AVG and Avast, never got that...

 

It's fun to decompile your own plugins.

 

chaseoes Yes, its fun to see that Eclipse swaps String adding with StringBuilder.append(). Glad to see its making minor optimizations for me.

 

I never got that, Here is the virus total

2 out of 41 (4.8787%) Say it's a virus

Here is Vipre:

 

Its not eclipse which does this Every compiler does this

 

Actually, that's the Sun compiler, not Eclipse. See http://docs.oracle.com/javase/specs/jls/se5.0/html/expressions.html#15.18.1.2

 

Well played.

 

Cool tool

 

I just use Jad in command line, however I really dont like it when this sort of useful information is so easily usable for people that wish to use it maliciously.

 

its in french!!!!

 

lol wut?

 

-> http://java.decompiler.free.fr/?q=jdgui
Then scroll down and download the windows version
then go to the download page: http://dl.free.fr/getfile.pl?file=/bTgGKgfL

FRENCH!!!!!?!!

Oh ya btw:
how do you edit the source from decompiling?

 

File > Save All Sources

Then import the archive file into your JRE and Blam have fun =)

 

Hey, I have netbeens :B
Where is the jre?

 

zecheesy
Google is your friend

And i made a type-o i ment JDK

Which is Java Development Kit

 

Especially stuff done in a non-secure way such as opening a url which puts data into a database based on $_GET, if someone got that url (Easily with jd-gui) then it's SQL injection heaven... Fortunately most people who realize that can be exploited know they send data in a more secure way.

 

Is all about security for me, if it takes an extra 300ms to handle, it's worth it.