Entry

Java: Disassemble: How to disassemble on the command line? [javap.exe]

Apr 22nd, 2006 09:56
Knud van Eeden,

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--- Knud van Eeden --- 22 April 2021 - 04:45 pm ----------------------
Java: Disassemble: How to disassemble on the command line? [javap.exe]
===
To disassemble, run e.g. the program
  javap.exe
===
Steps: Overview:
 1. -Possibly download and install the Sun Java JDK
     (because this installs also the program javap.exe)
 2. -Open an MSDOS box and type the following command
     (the filename without the .class or .java file extension)
      javap.exe <myJavaClassFilename>
       e.g.
        javap.exe HelloWorld
 3. -That will show a screen output similar to the following:
--- cut here: begin --------------------------------------------------
 javad HelloWorldApplet
 Compiled from "HelloWorldApplet.java"
 public class HelloWorldApplet extends java.applet.Applet{
    public HelloWorldApplet();
    public void paint(java.awt.Graphics);
 }
--- cut here: end ----------------------------------------------------
 4. -To compare this output, this was the original Java
     program
--- cut here: begin --------------------------------------------------
 import java.applet.Applet;
 import java.awt.Graphics;
 public class HelloWorldApplet extends Applet {
  public void paint( Graphics g ) {
   g. drawString( "Hello world!", 50, 25 );
  }
 }
--- cut here: end ----------------------------------------------------
 5. -For a list of command line parameters, type
      javap.exe -help
     1. -That will show a screen output similar to the following:
--- cut here: begin --------------------------------------------------
 javap.exe -help
 Usage: javap <options> <classes>...
 where options include:
    -c                        Disassemble the code
    -classpath <pathlist>     Specify where to find user class files
    -extdirs <dirs>           Override location of installed extensions
    -help                     Print this usage message
    -J<flag>                  Pass <flag> directly to the runtime
                              system
    -l                        Print line number and local variable
                              tables
    -public                   Show only public classes and members
    -protected                Show protected/public classes and members
    -package                  Show package/protected/public classes
                              and members (default)
    -private                  Show all classes and members
    -s                        Print internal type signatures
    -bootclasspath <pathlist> Override location of class files loaded
                              by the bootstrap class loader
    -verbose                  Print stack size, number of locals and
                              args for methods If verifying, print
                              reasons for failure
--- cut here: end ----------------------------------------------------
===
Internet: see also:
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