kb1ns / jrip

Java bytecode parser

重复造个字节码解析小轮子以深入学习Java Bytecode技术。
Inspired by @zxh0/classpy

TODO

1. 未解析异常信息表
2. 未解析常量池引用
3. 未解析本地变量表

源代码:

import java.util.ResourceBundle;

public class Hello{
    private final int h = 2;

    public static void main(String[] args){
        System.out.println("Hello, world.\n");
        ResourceBundle rb = ResourceBundle.getBundle("test");
        rb.getString("key");
    }
}

解析Demo:

public class #10(ConstantClass)->null {
    private final #13(ConstantUtf8)->I #12(ConstantUtf8)->h
    public #16(ConstantUtf8)-><init> #17(ConstantUtf8)->()V {
    [Code:
        aload_0 
        invokespecial 00 01 
        aload_0 
        iconst_2 
        putfield 00 02 
        _return 
    ]
    }
    public static #20(ConstantUtf8)->main #21(ConstantUtf8)->([Ljava/lang/String;)V {
    [Code:
        getstatic 00 03 
        ldc 04 
        invokevirtual 00 05 
        ldc 06 
        invokestatic 00 07 
        astore_1 
        aload_1 
        ldc 08 
        invokevirtual 00 09 
        pop 
        _return 
    ]
    }
}

javap解析:

pixyonly::~/Workspace/idea-2016/class-ripper->$ javap -v ~/Engineering/Hello.class
Classfile /Users/pixyonly/Engineering/Hello.class
  Last modified Apr 9, 2016; size 686 bytes
  MD5 checksum 77352977e4d91bbfd9ef2ccc0989e87a
  Compiled from "Hello.java"
public class Hello
  minor version: 0
  major version: 52
  flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
   #1 = Methodref          #11.#24        // java/lang/Object."<init>":()V
   #2 = Fieldref           #10.#25        // Hello.h:I
   #3 = Fieldref           #26.#27        // java/lang/System.out:Ljava/io/PrintStream;
   #4 = String             #28            // Hello, world.\n
   #5 = Methodref          #29.#30        // java/io/PrintStream.println:(Ljava/lang/String;)V
   #6 = String             #31            // test
   #7 = Methodref          #32.#33        // java/util/ResourceBundle.getBundle:(Ljava/lang/String;)Ljava/util/ResourceBundle;
   #8 = String             #34            // key
   #9 = Methodref          #32.#35        // java/util/ResourceBundle.getString:(Ljava/lang/String;)Ljava/lang/String;
  #10 = Class              #36            // Hello
  #11 = Class              #37            // java/lang/Object
  #12 = Utf8               h
  #13 = Utf8               I
  #14 = Utf8               ConstantValue
  #15 = Integer            2
  #16 = Utf8               <init>
  #17 = Utf8               ()V
  #18 = Utf8               Code
  #19 = Utf8               LineNumberTable
  #20 = Utf8               main
  #21 = Utf8               ([Ljava/lang/String;)V
  #22 = Utf8               SourceFile
  #23 = Utf8               Hello.java
  #24 = NameAndType        #16:#17        // "<init>":()V
  #25 = NameAndType        #12:#13        // h:I
  #26 = Class              #38            // java/lang/System
  #27 = NameAndType        #39:#40        // out:Ljava/io/PrintStream;
  #28 = Utf8               Hello, world.\n
  #29 = Class              #41            // java/io/PrintStream
  #30 = NameAndType        #42:#43        // println:(Ljava/lang/String;)V
  #31 = Utf8               test
  #32 = Class              #44            // java/util/ResourceBundle
  #33 = NameAndType        #45:#46        // getBundle:(Ljava/lang/String;)Ljava/util/ResourceBundle;
  #34 = Utf8               key
  #35 = NameAndType        #47:#48        // getString:(Ljava/lang/String;)Ljava/lang/String;
  #36 = Utf8               Hello
  #37 = Utf8               java/lang/Object
  #38 = Utf8               java/lang/System
  #39 = Utf8               out
  #40 = Utf8               Ljava/io/PrintStream;
  #41 = Utf8               java/io/PrintStream
  #42 = Utf8               println
  #43 = Utf8               (Ljava/lang/String;)V
  #44 = Utf8               java/util/ResourceBundle
  #45 = Utf8               getBundle
  #46 = Utf8               (Ljava/lang/String;)Ljava/util/ResourceBundle;
  #47 = Utf8               getString
  #48 = Utf8               (Ljava/lang/String;)Ljava/lang/String;
{
  public Hello();
    descriptor: ()V
    flags: ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
         0: aload_0
         1: invokespecial #1                  // Method java/lang/Object."<init>":()V
         4: aload_0
         5: iconst_2
         6: putfield      #2                  // Field h:I
         9: return
      LineNumberTable:
        line 3: 0
        line 4: 4

  public static void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=2, args_size=1
         0: getstatic     #3                  // Field java/lang/System.out:Ljava/io/PrintStream;
         3: ldc           #4                  // String Hello, world.\n
         5: invokevirtual #5                  // Method java/io/PrintStream.println:(Ljava/lang/String;)V
         8: ldc           #6                  // String test
        10: invokestatic  #7                  // Method java/util/ResourceBundle.getBundle:(Ljava/lang/String;)Ljava/util/ResourceBundle;
        13: astore_1
        14: aload_1
        15: ldc           #8                  // String key
        17: invokevirtual #9                  // Method java/util/ResourceBundle.getString:(Ljava/lang/String;)Ljava/lang/String;
        20: pop
        21: return
      LineNumberTable:
        line 7: 0
        line 8: 8
        line 9: 14
        line 10: 21
}
SourceFile: "Hello.java"