javap.1 revision 5116:d45bc4307996 
1." Copyright (c) 1994, 2011, Oracle and/or its affiliates. All rights reserved.
2." DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3."
4." This code is free software; you can redistribute it and/or modify it
5." under the terms of the GNU General Public License version 2 only, as
6." published by the Free Software Foundation.
7."
8." This code is distributed in the hope that it will be useful, but WITHOUT
9." ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10." FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
11." version 2 for more details (a copy is included in the LICENSE file that
12." accompanied this code).
13."
14." You should have received a copy of the GNU General Public License version
15." 2 along with this work; if not, write to the Free Software Foundation,
16." Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17."
18." Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19." or visit www.oracle.com if you need additional information or have any
20." questions.
21."
22.TH javap 1 "10 May 2011"
23
24.LP
25.SH "Name"
26javap \- The Java Class File Disassembler
27.LP
28.LP
29Disassembles class files.
30.LP
31.SH "SYNOPSIS"
32.LP
33.nf
34\f3
35.fl
36javap [ \fP\f3options\fP\f3 ] classes
37.fl
38\fP
39.fi
40
41.LP
42.SH "DESCRIPTION"
43.LP
44.LP
45The \f3javap\fP command disassembles one or more class files. Its output depends on the options used. If no options are used, \f3javap\fP prints out the package, protected, and public fields and methods of the classes passed to it. \f3javap\fP prints its output to stdout.
46.LP
47.RS 3
48.TP 3
49options
50Command\-line options.
51.TP 3
52classes
53List of one or more classes (separated by spaces) to be processed for annotations (such as \f2DocFooter.class\fP). You may specify a class that can be found in the class path, by its file name (for example, \f2/home/user/myproject/src/DocFooter.class\fP), or with a URL (for example, \f2file:///home/user/myproject/src/DocFooter.class\fP).
54.RE
55
56.LP
57.LP
58For example, compile the following class declaration:
59.LP
60.nf
61\f3
62.fl
63import java.awt.*;
64.fl
65import java.applet.*;
66.fl
67
68.fl
69public class DocFooter extends Applet {
70.fl
71        String date;
72.fl
73        String email;
74.fl
75
76.fl
77        public void init() {
78.fl
79                resize(500,100);
80.fl
81                date = getParameter("LAST_UPDATED");
82.fl
83                email = getParameter("EMAIL");
84.fl
85        }
86.fl
87
88.fl
89        public void paint(Graphics g) {
90.fl
91                g.drawString(date + " by ",100, 15);
92.fl
93                g.drawString(email,290,15);
94.fl
95        }
96.fl
97}
98.fl
99\fP
100.fi
101
102.LP
103.LP
104The output from \f3javap DocFooter.class\fP yields:
105.LP
106.nf
107\f3
108.fl
109Compiled from "DocFooter.java"
110.fl
111public class DocFooter extends java.applet.Applet {
112.fl
113  java.lang.String date;
114.fl
115  java.lang.String email;
116.fl
117  public DocFooter();
118.fl
119  public void init();
120.fl
121  public void paint(java.awt.Graphics);
122.fl
123}
124.fl
125\fP
126.fi
127
128.LP
129.LP
130The output from \f3javap \-c DocFooter.class\fP yields:
131.LP
132.nf
133\f3
134.fl
135Compiled from "DocFooter.java"
136.fl
137public class DocFooter extends java.applet.Applet {
138.fl
139  java.lang.String date;
140.fl
141
142.fl
143  java.lang.String email;
144.fl
145
146.fl
147  public DocFooter();
148.fl
149    Code:
150.fl
151       0: aload_0
152.fl
153       1: invokespecial #1                  // Method java/applet/Applet."<init>":()V
154.fl
155       4: return
156.fl
157
158.fl
159  public void init();
160.fl
161    Code:
162.fl
163       0: aload_0
164.fl
165       1: sipush        500
166.fl
167       4: bipush        100
168.fl
169       6: invokevirtual #2                  // Method resize:(II)V
170.fl
171       9: aload_0
172.fl
173      10: aload_0
174.fl
175      11: ldc           #3                  // String LAST_UPDATED
176.fl
177      13: invokevirtual #4                  // Method getParameter:(Ljava/lang/String;)Ljava/lang/String;
178.fl
179      16: putfield      #5                  // Field date:Ljava/lang/String;
180.fl
181      19: aload_0
182.fl
183      20: aload_0
184.fl
185      21: ldc           #6                  // String EMAIL
186.fl
187      23: invokevirtual #4                  // Method getParameter:(Ljava/lang/String;)Ljava/lang/String;
188.fl
189      26: putfield      #7                  // Field email:Ljava/lang/String;
190.fl
191      29: return
192.fl
193
194.fl
195  public void paint(java.awt.Graphics);
196.fl
197    Code:
198.fl
199       0: aload_1
200.fl
201       1: new           #8                  // class java/lang/StringBuilder
202.fl
203       4: dup
204.fl
205       5: invokespecial #9                  // Method java/lang/StringBuilder."<init>":()V
206.fl
207       8: aload_0
208.fl
209       9: getfield      #5                  // Field date:Ljava/lang/String;
210.fl
211      12: invokevirtual #10                 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
212.fl
213      15: ldc           #11                 // String  by
214.fl
215      17: invokevirtual #10                 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
216.fl
217      20: invokevirtual #12                 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
218.fl
219      23: bipush        100
220.fl
221      25: bipush        15
222.fl
223      27: invokevirtual #13                 // Method java/awt/Graphics.drawString:(Ljava/lang/String;II)V
224.fl
225      30: aload_1
226.fl
227      31: aload_0
228.fl
229      32: getfield      #7                  // Field email:Ljava/lang/String;
230.fl
231      35: sipush        290
232.fl
233      38: bipush        15
234.fl
235      40: invokevirtual #13                 // Method java/awt/Graphics.drawString:(Ljava/lang/String;II)V
236.fl
237      43: return
238.fl
239}
240.fl
241\fP
242.fi
243
244.LP
245.SH "OPTIONS"
246.LP
247.RS 3
248.TP 3
249\-help \-\-help \-?
250Prints out help message for \f3javap\fP.
251.TP 3
252\-version
253Prints out version information.
254.TP 3
255\-l
256Prints out line and local variable tables.
257.TP 3
258\-public
259Shows only public classes and members.
260.TP 3
261\-protected
262Shows only protected and public classes and members.
263.TP 3
264\-package
265Shows only package, protected, and public classes and members. This is the default.
266.TP 3
267\-private \-p
268Shows all classes and members.
269.TP 3
270\-Jflag
271Pass \f2flag\fP directly to the runtime system. Some examples:
272.nf
273\f3
274.fl
275javap \-J\-version
276.fl
277javap \-J\-Djava.security.manager \-J\-Djava.security.policy=MyPolicy MyClassName
278.fl
279\fP
280.fi
281.TP 3
282\-s
283Prints internal type signatures.
284.TP 3
285\-sysinfo
286Shows system information (path, size, date, MD5 hash) of the class being processed.
287.TP 3
288\-constants
289Shows static final constants.
290.TP 3
291\-c
292Prints out disassembled code, i.e., the instructions that comprise the Java bytecodes, for each of the methods in the class. These are documented in the
293.na
294\f2Java Virtual Machine Specification\fP @
295.fi
296http://java.sun.com/docs/books/vmspec/.
297.TP 3
298\-verbose
299Prints stack size, number of \f2locals\fP and \f2args\fP for methods.
300.TP 3
301\-classpath path
302Specifies the path \f3javap\fP uses to look up classes. Overrides the default or the CLASSPATH environment variable if it is set.
303.TP 3
304\-bootclasspath path
305Specifies path from which to load bootstrap classes. By default, the bootstrap classes are the classes implementing the core Java platform located in \f2jre/lib/rt.jar\fP and several other jar files.
306.TP 3
307\-extdirs dirs
308Overrides location at which installed extensions are searched for. The default location for extensions is the value of \f2java.ext.dirs\fP.
309.RE
310
311.LP
312.SH "SEE ALSO"
313.LP
314.LP
315javac(1), java(1), jdb(1), javah(1), javadoc(1)
316.LP
317
318