Java 字节码

1
2
3
4
5
6
7
8

public class Bytecode {

    public static void main(String[] args) {
        int a = 1;
        int b = 2;
        System.out.println(a + b);
    }
}

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21

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

  public static void main(java.lang.String[]);
    Code:
       0: iconst_1
       1: istore_1
       2: iconst_2
       3: istore_2
       4: getstatic     #7                  // Field java/lang/System.out:Ljava/io/PrintStream;
       7: iload_1
       8: iload_2
       9: iadd
      10: invokevirtual #13                 // Method java/io/PrintStream.println:(I)V
      13: return
}

1
2
3
4
5

<dependency>
    <groupId>org.ow2.asm</groupId>
    <artifactId>asm</artifactId>
    <version>${asm.version}</version>
</dependency>

1
2
3
4
5

<dependency>
    <groupId>org.javassist</groupId>
    <artifactId>javassist</artifactId>
    <version>${javassist.version}</version>
</dependency>

1
2
3
4
5

<dependency>
  <groupId>net.bytebuddy</groupId>
  <artifactId>byte-buddy</artifactId>
  <version>${byte-buddy.version}</version>
</dependency>

1

javap -v YourClass.class | grep 'major version'