## Name

javap - The Java Class File Disassembler

Disassembles class files.

## SYNOPSIS

    f3
    javap [ f3optionsf3 ] classes

## DESCRIPTION

The f3javap command disassembles one or more class files. Its output depends on the options used. If no options are used, f3javap prints out the package, protected, and public fields and methods of the classes passed to it. f3javap 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 f2DocFooter.class). 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), or with a URL (for example, f2file:///home/user/myproject/src/DocFooter.class).

For example, compile the following class declaration:

    f3
    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 f3javap DocFooter.class yields:

    f3
    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 f3javap -c DocFooter.class yields:

    f3
    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 f3javap.

-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 f2flag directly to the runtime system. Some examples:

    f3
    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 comprise the Java bytecodes, for each of the methods in the class. These are documented in the

f2Java Virtual Machine Specification @

http://docs.oracle.com/javase/specs/.

-verbose Prints stack size, number of f2locals and f2args for methods.

-classpath path Specifies the path f3javap 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 f2jre/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 f2java.ext.dirs.

## SEE ALSO

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