Getting the source code from java .class file

When we compile .java file using javac, we get .class file. But we can get the source code from class file, but not the full source code. javap, is the utility which gives details of variables and methods declared in the code.


C:\Documents and Settings\chirag.jain\Desktop>javac Test.java

C:\Documents and Settings\chirag.jain\Desktop>javap Test

Compiled from “Test.java”
public class Test extends java.lang.Object{
int number;
public Test();
public void sayHello();
}


To get the byte code details, use javap -c


C:\Documents and Settings\chirag.jain\Desktop>javap -c Test

Compiled from “Test.java”
public class Test extends java.lang.Object{
int number;
public Test();
Code:
0: aload_0
1: invokespecial #1; //Method java/lang/Object.””:()V
4: aload_0
5: iconst_5
6: putfield #2; //Field number:I
9: return
public void sayHello();
Code:
0: getstatic #3; //Field java/lang/System.out:Ljava/io/PrintStream;
3: ldc #4; //String Hello
5: invokevirtual #5; //Method java/io/PrintStream.println:(Ljava/lang/Str
ing;)V
8: return

}