javap(1) javap(1)
NAME
javap - Java class file disassembler
SYNOPSIS
javap [ options ] class ...
DESCRIPTION
The javap command disassembles a Java class file. The options determine the output. If no options
are used, javap prints out the package, protected, and public fields and methods of the classes
passed to it. The javap command displays its output to stdout. 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 yields:
Compiled from DocFooter.java
public class DocFooter extends java.applet.Applet {
java.lang.String date;
java.lang.String email;
public void init();
public void paint(java.awt.Graphics);
public DocFooter();
}
OPTIONS
The following options are supported:
-b Ensures backward compatibility with javap in JDK 1.1.
-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 jre/lib/charsets.jar.
-c Prints out disassembled code, that is, the instructions that comprise the Java byte-codes, bytecodes,
codes, for each of the methods in the class. These are documented in the Java Virtual
Machine Specification.
-classpath path
Specifies the path javap uses to look up classes. Overrides the default or the CLASS-PATH CLASSPATH
PATH environment variable if it is set. Directories are separated by colons (:).
Thus the general format for path is:
.:<your_path>
For example:
.:/home/avh/classes:/usr/local/java/classes
-extdirs dirs Overrides location at which installed extensions are searched. The default location
for extensions is jre/lib/ext.
-help Prints out help message for javap.
-Jflag Passes flag directly to runtime system.
javap -J-version
javap -JJ-Djava.security.manager
-Djava.security.policy=MyPolicy MyClassName
-l Displays line and local variable tables.
-package Shows only package, protected, and public classes and members. This is the default.
-private Shows all classes and members.
-protected Shows only protected and public classes and members.
-public Shows only public classes and members.
-s Displays internal type signatures.
-verbose Prints stack size, number of locals, and args for methods.
ENVIRONMENT VARIABLES
CLASSPATH Used to provide the system with a path to user-defined classes. Directories are sepa-rated separated
rated by colons. For example:
.:/home/avh/classes:/usr/local/java/classes
SEE ALSO
java(1), javac(1), javadoc(1), javah(1), jdb(1)
13 June 2000 javap(1)
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