java - javap in a programmable way

Question

Can we use javap in our own java code in a programmable way?

for example, the following code:

public class TestClass {
    public static void main(String[] args) {
        System.out.println("hello world");
    }
}

using javap in command line, we got :

// Header + consts 1..22 snipped
const #22 = String      #23;    //  hello world
const #23 = Asciz       hello world;

public static void main(java.lang.String[]);
  Signature: ([Ljava/lang/String;)V
  Code:
   Stack=2, Locals=1, Args_size=1
   0:   getstatic       #16; //Field java/lang/System.out:Ljava/io/PrintStream;
   3:   ldc     #22; //String hello world
   5:   invokevirtual   #24; //Method java/io/PrintStream.println:(Ljava/lang/String;)V
   8:   return
  // Debug info snipped
}

can I print only the Constant Pool using javap's API?

Answer 1

There is no API for javap internals, but you can look for the source code of javap, which is in the package com.sun.tools.javap. The entry class is com.sun.tools.javap.Main. So another way to run javap is java -cp $JAVA_HOME/lib/tools.jar com.sun.tools.javap.Main YourTestClass