javap(1)		    General Commands Manual		      javap(1)



Name
       javap - The Java Class File Disassembler

       Disassembles class files.

SYNOPSIS
       javap [ options ] classes


DESCRIPTION
       The  javap  command  disassembles  one  or more class files. Its output
       depends on the options used. If no options are used, javap  prints  out
       the  package,  protected,  and public fields and methods of the classes
       passed to it. javap prints its output to stdout.

	  options
	     Command-line options.

	  classes
	     List of one or more classes (separated by spaces) to be processed
	     for  annotations  (such  as  DocFooter.class).  You may specify a
	     class that can be found in the class path, by its file name  (for
	     example, /home/user/myproject/src/DocFooter.class), or with a URL
	     (for example, file:///home/user/myproject/src/DocFooter.class).


       For example, compile the following class declaration:

       import java.awt.*;
       import java.applet.*;

       public class DocFooter extends Applet {
	       String date;
	       String email;

	       public void init() {
		       resize(500,100);
		       date = getParameter("LAST_UPDATED");
		       email = getParameter("EMAIL");
	       }

	       public void paint(Graphics g) {
		       g.drawString(date + " by ",100, 15);
		       g.drawString(email,290,15);
	       }
       }


       The output from javap DocFooter.class yields:

       Compiled from "DocFooter.java"
       public class DocFooter extends java.applet.Applet {
	 java.lang.String date;
	 java.lang.String email;
	 public DocFooter();
	 public void init();
	 public void paint(java.awt.Graphics);
       }


       The output from javap -c DocFooter.class yields:

       Compiled from "DocFooter.java"
       public class DocFooter extends java.applet.Applet {
	 java.lang.String date;

	 java.lang.String email;

	 public DocFooter();
	   Code:
	      0: aload_0
	      1: invokespecial #1		   // Method java/applet/Applet."<init>":()V
	      4: return

	 public void init();
	   Code:
	      0: aload_0
	      1: sipush	       500
	      4: bipush	       100
	      6: invokevirtual #2		   // Method resize:(II)V
	      9: aload_0
	     10: aload_0
	     11: ldc	       #3		   // String LAST_UPDATED
	     13: invokevirtual #4		   // Method getParameter:(Ljava/lang/String;)Ljava/lang/String;
	     16: putfield      #5		   // Field date:Ljava/lang/String;
	     19: aload_0
	     20: aload_0
	     21: ldc	       #6		   // String EMAIL
	     23: invokevirtual #4		   // Method getParameter:(Ljava/lang/String;)Ljava/lang/String;
	     26: putfield      #7		   // Field email:Ljava/lang/String;
	     29: return

	 public void paint(java.awt.Graphics);
	   Code:
	      0: aload_1
	      1: new	       #8		   // class java/lang/StringBuilder
	      4: dup
	      5: invokespecial #9		   // Method java/lang/StringBuilder."<init>":()V
	      8: aload_0
	      9: getfield      #5		   // Field date:Ljava/lang/String;
	     12: invokevirtual #10		   // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
	     15: ldc	       #11		   // String  by
	     17: invokevirtual #10		   // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
	     20: invokevirtual #12		   // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
	     23: bipush	       100
	     25: bipush	       15
	     27: invokevirtual #13		   // Method java/awt/Graphics.drawString:(Ljava/lang/String;II)V
	     30: aload_1
	     31: aload_0
	     32: getfield      #7		   // Field email:Ljava/lang/String;
	     35: sipush	       290
	     38: bipush	       15
	     40: invokevirtual #13		   // Method java/awt/Graphics.drawString:(Ljava/lang/String;II)V
	     43: return
       }


OPTIONS
	  -help --help -?
	     Prints out help message for javap.

	  -version
	     Prints out version information.

	  -l Prints out line and local variable tables.

	  -public
	     Shows only public classes and members.

	  -protected
	     Shows only protected and public classes and members.

	  -package
	     Shows only package, protected, and public	classes	 and  members.
	     This is the default.

	  -private -p
	     Shows all classes and members.

	  -Jflag
	     Pass flag directly to the runtime system. Some examples:
	     javap -J-version
	     javap -J-Djava.security.manager -J-Djava.security.policy=MyPolicy MyClassName

	  -s Prints internal type signatures.

	  -sysinfo
	     Shows  system  information	 (path,	 size,	date, MD5 hash) of the
	     class being processed.

	  -constants
	     Shows static final constants.

	  -c Prints out disassembled code, i.e., the  instructions  that  com-
	     prise  the	 Java bytecodes, for each of the methods in the class.
	     These are documented in the Java Virtual Machine Specification @
	     http://java.sun.com/docs/books/vmspec/.

	  -verbose
	     Prints stack size, number of locals and args for methods.

	  -classpath path
	     Specifies the path javap uses to look up classes. Overrides the
	     default or the CLASSPATH environment variable if it is set.

	  -bootclasspath path
	     Specifies path from which to load bootstrap classes. By default,
	     the bootstrap classes are the classes implementing the core Java
	     platform located in jre/lib/rt.jar and several other jar files.

	  -extdirs dirs
	     Overrides location at which installed extensions are searched
	     for. The default location for extensions is the value of
	     java.ext.dirs.


SEE ALSO
       javac(1), java(1), jdb(1), javah(1), javadoc(1)

				  16 Mar 2012			      javap(1)