When learning about the JVM recently, I came across the need to view the.class file. Here are two recommended methods:

Method 1: Use the javap command provided by the JDK

For example, a simple helloworld.java program:

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("hello world!"); }}Copy the code

Javac-parameters -d HelloWorld.



How do I read the binary bytecode file once I have it?

The first way is to use the JDK’s built-in decompiler: javap-verbose xxx.class:

Method 2: use notepad++ to view (HexEditor plug-in required)

Installation process:

  • Download the HexEditor plug-inHexEditor(64-bit, 32-bit), extraction code:imoc
  • After downloading, place the package in the plugins directory under the notepad++ installation directory and copy the 64-bit HexEditor folder into the plugins directory:



Then make sure to close all notepad++ processes and reopen notepad++ :



Click in the red circleHIcon to view binary encoding:



Done!