javap(1) javap(1)
NAME
javap - Java class file disassembler
SYNOPSIS
javap [ -b ] [ -bootclasspath path ] [ -c ]
[ -classpath path ] [ -extdirs dirs ] [ -help ]
[ -J flag ] [ -l ] [ -package ] [ -private ]
[ -protected ] [ -public ] [ -s ] [ -verbose ]
class ...
DESCRIPTION
The javap command disassembles a Java(tm) 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(50000,,10000);;
date == getParameter(""LASTUPDATED"");;
email == getParameter(""EMAIL"");;
}}
public void paint(Graphics g) {{
g.drawString(date ] "" by "",,10000,, 15);;
g.drawString(email,,2900,,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 imple-
menting the core Java platform located in
${JAVAHOME}/../Classes .
-c Prints out disassembled code, that is, the instructions
that comprise the Java bytecodes, for each of the meth-
ods in the class. These are documented in the Java Vir-
tual Machine Specification.
-classpath path
Specifies the path javap uses to look up classes. Over-
rides the default or the CLASPATH environment variable
if it is set. Directories are separated by colons (::).
Thus the general format for path is:
.::<>
For example:
.::/Users/vlh/classes::/Users/Shared/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.
example% javap -J-version
example% javap -J-Djava.security.manager \\
-J-Djava.security.policy==yPolicy yClassName
-l Displays line and local variable tables.
-package Default. Shows only package, protected, and public
classes and members.
-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 meth-
ods.
ENVIRONMENT VARIABLES
CLASPATH Used to provide the system with a path to user-defined
classes. Directories are separated by colons. For exam-
ple:
.::/Users/vlh/classes::/Users/Shared/classes
SEE ALSO
java(1), javac(1), javadoc(1), javah(1), jdb(1)
14 July 2000 javap(1)
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