package com.interview.javabasic.bytecode;
public class ByteCodeSample {
private static volatile Integer i = 1;

public static void main(String[] args) {
    int j=5;
    i++;
    ++j;
    System.out.println(i);
    System.out.println(j);
}

}

如上所示代码编译之后字节码文件如下：

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//

package com.interview.javabasic.bytecode;

public class ByteCodeSample {
private static volatile Integer i = 1;

public ByteCodeSample() {
}

public static void main(String[] var0) {
    byte var1 = 5;
    Integer var2 = i;
    i = i + 1;
    int var4 = var1 + 1;
    System.out.println(i);
    System.out.println(var4);
}

}