linux view the hex file checks to see class

1. Source:

package com.example.demo.threadmanage;

/**
 * Created by Administrator on 2020/2/7.
 */
public class test {
    public static void main(String[] args) {
        System.out.println(Integer.MAX_VALUE);
    }
}

2.linux hex checks to see: xxd, hexdump -C, vi:!% Xxd can

xxd filename

 

 Or hexdump -C filename as a result, vi command mode:%! Enter xxd it is the same

3. Review disassembly

 

 

java -c filename 

Compiled from "test.java"
public class com.example.demo.threadmanage.test {
  public com.example.demo.threadmanage.test();
    Code:
       0: aload_0
       1: invokespecial #1                  // Method java/lang/Object."<init>":()V
       4: return

  public static void main(java.lang.String[]);
    Code:
       0: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
       3: ldc           #4                  // int 2147483647
       5: invokevirtual #5                  // Method java/io/PrintStream.println:(I)V
       8: return
}

 

javap -verbose filename

Last modified 2020-2-8; size 599 bytes
  MD5 checksum cf41171923a25303c43a624b6e9f63b1
  Compiled from "test.java"
public class com.example.demo.threadmanage.test
  minor version: 0
  major version: 52
  flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
   #1 = Methodref          #7.#22         // java/lang/Object."<init>":()V
   #2 = Fieldref           #23.#24        // java/lang/System.out:Ljava/io/PrintStream;
   #3 = Class              #25            // java/lang/Integer
   #4 = Integer            2147483647
   #5 = Methodref          #26.#27        // java/io/PrintStream.println:(I)V
   #6 = Class              #28            // com/example/demo/threadmanage/test
   #7 = Class              #29            // java/lang/Object
   #8 = Utf8               <init>
   #9 = Utf8               ()V
  #10 = Utf8               Code
  #11 = Utf8               LineNumberTable
  #12 = Utf8               LocalVariableTable
  #13 = Utf8               this
  #14 = Utf8               Lcom/example/demo/threadmanage/test;
  #15 = Utf8               main
  #16 = Utf8               ([Ljava/lang/String;)V
  #17 = Utf8               args
  #18 = Utf8               [Ljava/lang/String;
  #19 = Utf8               MethodParameters
  #20 = Utf8               SourceFile
  #21 = Utf8               test.java
  #22 = NameAndType        #8:#9          // "<init>":()V
  #23 = Class              #30            // java/lang/System
  #24 = NameAndType        #31:#32        // out:Ljava/io/PrintStream;
  #25 = Utf8               java/lang/Integer
  #26 = Class              #33            // java/io/PrintStream
  #27 = NameAndType        #34:#35        // println:(I)V
  #28 = Utf8               com/example/demo/threadmanage/test
  #29 = Utf8               java/lang/Object
  #30 = Utf8               java/lang/System
  #31 = Utf8               out
  #32 = Utf8               Ljava/io/PrintStream;
  #33 = Utf8               java/io/PrintStream
  #34 = Utf8               println
  #35 = Utf8               (I)V
{
  public com.example.demo.threadmanage.test();
    descriptor: ()V
    flags: ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
         0: aload_0
         1: invokespecial #1                  // Method java/lang/Object."<init>":()V
         4: return
      LineNumberTable:
        line 6: 0
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0       5     0  this   Lcom/example/demo/threadmanage/test;

  public static void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=1
         0: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
         3: ldc           #4                  // int 2147483647
         5: invokevirtual #5                  // Method java/io/PrintStream.println:(I)V
         8: return
      LineNumberTable:
        line 8: 0
        line 9: 8
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0       9     0  args   [Ljava/lang/String;
    MethodParameters:
      Name                           Flags
      args
}
SourceFile: "test.java"