Convert a .class to .java file (decompiler)

 

JD - Java decompiler
The Java Decompiler project aims to develop tools in order to decompile and analyze Java 5 byte code and the later versions.
JD is Open Source and free to use.
Also available is JD-GUI, a standalone graphical utility that displays Java source codes of .class files, and JD-Eclipse, a plug-in for the Eclipse platform.

Jad
Jad, the fast JAva Decompiler, is a program that reads one or more Java class files and converts them into Java source files which can be compiled again.
Jad is a 100% pure C++ program and it generally works several times faster than decompilers written in Java. Jad doesn't use the Java runtime for its functioning, therefore no special setup is required (like changes to the CLASSPATH variable).
Jad is not open source but it is free to use.
Make sure to download the GUI interface, FrontEnd Plus .
On Windows, a file association with the .class extension is made so if you click on a class file then the decompiled is shown in FrontEnd Plus right away.
http://www.kpdus.com/jad.html
JAD is good but out-dated, the new class format introduced with JDK1.5 is not well supported.

JadClipse - .class 파일을 보기 위한 plugin
JadClipse is a plug-in that seamlessly integrates Jad (the fast Java decompiler) with Eclipse.
Normally, when opening a class file the Class File Viewer will show a brief API outline of the class. If you install this plug-in, however, the Class File Viewer will be replaced with the JadClipse Class File Viewer that shows the decompiled source of the class.

JarPlug - .jar 파일을 보기 위한 plugin
By default, the support for viewing and editing JAR file in Eclipse is very limited.
With JarPlug, it is possible delete or update items stored in a JAR.

1.    Jad/JadClipse - .class의 소스를 보기 위한 plugin
아래에서 다운받아 eclipse의 plugin폴더에 넣은 후 이클립스 재시작 합니다.
http://cid-b8b46a1f85e98311.office.live.com/embedicon.aspx/dev^_tools/net.sf.jadclipse^_3.3.0.jar

https://skydrive.live.com/embed?cid=B8B46A1F85E98311&resid=B8B46A1F85E98311%211008&authkey=AI3LoboZjnX3xQ4

https://skydrive.live.com/embed?cid=B8B46A1F85E98311&resid=B8B46A1F85E98311%211009&authkey=AG9vJkmVsin3H7s

Eclipse가 설치된 폴더에 넣고 후 경로를 window-preference-java-JadClipse 항목에 기입하면 됩니다.
http://cid-b8b46a1f85e98311.office.live.com/embedicon.aspx/dev^_tools/jad158g.win.zip

설치가 완료되었다면 window-preference-general-editors-file association을 선택하여 .class 파일의 associated editors를 JadClipse Class File View로 default 세팅합니다.

2.    JarPlug - .jar의 소스를 보기 위한 plugin
Install New Software에서 아래 주소를 입력하여 모두 설치한다.
http://www.simontuffs.com/jar-plug