from small one page howto to huge articles all in one place
 

search text in:





Poll
Which kernel version do you use?





poll results

Last additions:
using iotop to find disk usage hogs

using iotop to find disk usage hogs

words:

887

views:

106372

userrating:

average rating: 1.7 (85 votes) (1=very good 6=terrible)


May 25th. 2007:
Words

486

Views

220627

why adblockers are bad


Workaround and fixes for the current Core Dump Handling vulnerability affected kernels

Workaround and fixes for the current Core Dump Handling vulnerability affected kernels

words:

161

views:

101021

userrating:

average rating: 1.3 (28 votes) (1=very good 6=terrible)


April, 26th. 2006:

Druckversion
You are here: manpages





javap

Section: Basic Tools (1)
Updated: 8 August 2014
Index Return to Main Contents
 

NAME

javap - Disassembles one or more class files.  

SYNOPSIS

javap [options] classfile...

options

The command-line options. See Options.

classfile

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

DESCRIPTION

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

OPTIONS

-help
--help
-?

Prints a help message for the javap command.

-version

Prints release information.

-l

Prints line and local variable tables.

-public

Shows only public classes and members.

-protected

Shows only protected and public classes and members.

-private
-p

Shows all classes and members.

-Joption

Passes the specified option to the JVM. For example:

javap -J-version
javap -J-Djava.security.manager -J-Djava.security.policy=MyPolicy MyClassName
 
For more information about JVM options, see the command documentation.

-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 disassembled code, for example, the instructions that comprise the Java bytecodes, for each of the methods in the class.

-verbose

Prints stack size, number of locals and arguments for methods.

-classpath path

Specifies the path the javap command uses to look up classes. Overrides the default or the CLASSPATH environment variable when it is set.

-bootclasspath path

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

-extdir dirs

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

EXAMPLE

Compile the following DocFooter class:

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 the javap DocFooter.class command yields the following:

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 command yields the following:

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        
}
 
 

SEE ALSO

* java(1)

* javac(1)

* javadoc(1)

* javah(1)

* jdb(1)

* jdeps(1)


 

Index

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLE
SEE ALSO


Please read "Why adblockers are bad".



Other free services
toURL.org
Shorten long
URLs to short
links like
http://tourl.org/2
tourl.org
.
Reverse DNS lookup
Find out which hostname(s)
resolve to a
given IP or other hostnames for the server
www.reversednslookup.org
rdf newsfeed | rss newsfeed | Atom newsfeed
- Powered by LeopardCMS - Running on Gentoo -
Copyright 2004-2017 Sascha Nitsch Unternehmensberatung UG(haftungsbeschränkt)
Valid XHTML1.1 : Valid CSS : buttonmaker
- Level Triple-A Conformance to Web Content Accessibility Guidelines 1.0 -
- Copyright and legal notices -
Time to create this page: 2.7 ms