一个简单的java类

public class equaltest {

    public static void main(String[] args) {

        Object o1 = new Object();

        Object o2 = new Object();

        if (o1 == o2) {

            System.out.println("o1 == o2");

        } else {

            System.out.println("o1 != o2");

        }

    }

}

Compiled from "equaltest.java"

public class equaltest extends java.lang.Object

  SourceFile: "equaltest.java"

  minor version: 0

  major version: 50

  Constant pool:

const #1 = Method#2.#18;//  java/lang/Object."<init>":()V

const #2 = class#19;//  java/lang/Object

const #3 = Field#20.#21;//  java/lang/System.out:Ljava/io/PrintStream;

const #4 = String#22;//  o1 == o2

const #5 = Method#23.#24;//  java/io/PrintStream.println:(Ljava/lang/String;)V

const #6 = String#25;//  o1 != o2

const #7 = class#26;//  equaltest

const #8 = Asciz<init>;

const #9 = Asciz()V;

const #10 = AscizCode;

const #11 = AscizLineNumberTable;

const #12 = Ascizmain;

const #13 = Asciz([Ljava/lang/String;)V;

const #14 = AscizStackMapTable;

const #15 = class#19;//  java/lang/Object

const #16 = AscizSourceFile;

const #17 = Ascizequaltest.java;

const #18 = NameAndType#8:#9;//  "<init>":()V

const #19 = Ascizjava/lang/Object;

const #20 = class#27;//  java/lang/System

const #21 = NameAndType#28:#29;//  out:Ljava/io/PrintStream;

const #22 = Ascizo1 == o2;

const #23 = class#30;//  java/io/PrintStream

const #24 = NameAndType#31:#32;//  println:(Ljava/lang/String;)V

const #25 = Ascizo1 != o2;

const #26 = Ascizequaltest;

const #27 = Ascizjava/lang/System;

const #28 = Ascizout;

const #29 = AscizLjava/io/PrintStream;;

const #30 = Ascizjava/io/PrintStream;

const #31 = Ascizprintln;

const #32 = Asciz(Ljava/lang/String;)V;

{

public equaltest();

  Signature: ()V

  Code:

   Stack=1, Locals=1, Args_size=1

   0:aload_0

   1:invokespecial#1; //Method java/lang/Object."<init>":()V

   4:return

  LineNumberTable: 

   line 1: 0

public static void main(java.lang.String[]);

  Signature: ([Ljava/lang/String;)V

  Code:

   Stack=2, Locals=3, Args_size=1

   0:new#2; //class java/lang/Object

   3:dup

   4:invokespecial#1; //Method java/lang/Object."<init>":()V

   7:astore_1

   8:new#2; //class java/lang/Object

   11:dup

   12:invokespecial#1; //Method java/lang/Object."<init>":()V

   15:astore_2

   16:aload_1

   17:aload_2

   18:if_acmpne32

   21:getstatic#3; //Field java/lang/System.out:Ljava/io/PrintStream;

   24:ldc#4; //String o1 == o2

   26:invokevirtual#5; //Method java/io/PrintStream.println:(Ljava/lang/String;)V

   29:goto40

   32:getstatic#3; //Field java/lang/System.out:Ljava/io/PrintStream;

   35:ldc#6; //String o1 != o2

   37:invokevirtual#5; //Method java/io/PrintStream.println:(Ljava/lang/String;)V

   40:return

  LineNumberTable: 

   line 4: 0

   line 5: 8

   line 6: 16

   line 7: 21

   line 9: 32

   line 11: 40

  StackMapTable: number_of_entries = 2

   frame_type = 253 /* append */

     offset_delta = 32

     locals = [ class java/lang/Object, class java/lang/Object ]

   frame_type = 7 /* same */

}