源代码

    public static void main(String[] args) throws Exception {
        String init = "init";
        try{
            String ok = "process";
        }catch (RuntimeException e){
            String ok = "RuntimeException";
            return;
        }catch (Exception e){
            String ok = "Exception";
            return;
        }catch (Error e){
            String ok = "Error";
            return;
        }finally {
            String ok = "finally";
        }

        return;
    }

字节码

关键点解释 (前面的魔数之类的就不说了)

Classfile /Users/fang/Documents/test2/src/main/java/cc/SumTask.class
  Last modified 2018-4-6; size 812 bytes
  MD5 checksum 60f31a4a4feedbb971918879e2a977f2
  Compiled from "SumTask.java"
public class SumTask
  minor version: 0
  major version: 52
  flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
   #1 = Methodref          #12.#32        // java/lang/Object."<init>":()V
   #2 = String             #33            // init
   #3 = String             #34            // process
   #4 = String             #35            // finally
   #5 = Class              #36            // java/lang/RuntimeException
   #6 = String             #37            // RuntimeException
   #7 = Class              #38            // java/lang/Exception
   #8 = String             #39            // Exception
   #9 = Class              #40            // java/lang/Error
  #10 = String             #41            // Error
  #11 = Class              #42            // SumTask
  #12 = Class              #43            // java/lang/Object
  #13 = Class              #44            // SumTask$E
  #14 = Utf8               E
  #15 = Utf8               InnerClasses
  #16 = Utf8               <init>
  #17 = Utf8               ()V
  #18 = Utf8               Code
  #19 = Utf8               LineNumberTable
  #20 = Utf8               main
  #21 = Utf8               ([Ljava/lang/String;)V
  #22 = Utf8               StackMapTable
  #23 = Class              #45            // "[Ljava/lang/String;"
  #24 = Class              #46            // java/lang/String
  #25 = Class              #36            // java/lang/RuntimeException
  #26 = Class              #38            // java/lang/Exception
  #27 = Class              #40            // java/lang/Error
  #28 = Class              #47            // java/lang/Throwable
  #29 = Utf8               Exceptions
  #30 = Utf8               SourceFile
  #31 = Utf8               SumTask.java
  #32 = NameAndType        #16:#17        // "<init>":()V
  #33 = Utf8               init
  #34 = Utf8               process
  #35 = Utf8               finally
  #36 = Utf8               java/lang/RuntimeException
  #37 = Utf8               RuntimeException
  #38 = Utf8               java/lang/Exception
  #39 = Utf8               Exception
  #40 = Utf8               java/lang/Error
  #41 = Utf8               Error
  #42 = Utf8               SumTask
  #43 = Utf8               java/lang/Object
  #44 = Utf8               SumTask$E
  #45 = Utf8               [Ljava/lang/String;
  #46 = Utf8               java/lang/String
  #47 = Utf8               java/lang/Throwable
{
  public SumTask();
    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 4: 0

  public static void main(java.lang.String[]) throws java.lang.Exception;
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC, ACC_STATIC
    Code:
      stack=1, locals=7, args_size=1
         0: ldc           #2                  // String init
         2: astore_1
         3: ldc           #3                  // String process
         5: astore_2
         6: ldc           #4                  // String finally
         8: astore_2
         9: goto          48
        12: astore_2
        13: ldc           #6                  // String RuntimeException
        15: astore_3
        16: ldc           #4                  // String finally
        18: astore        4
        20: return
        21: astore_2
        22: ldc           #8                  // String Exception
        24: astore_3
        25: ldc           #4                  // String finally
        27: astore        4
        29: return
        30: astore_2
        31: ldc           #10                 // String Error
        33: astore_3
        34: ldc           #4                  // String finally
        36: astore        4
        38: return
        39: astore        5
        41: ldc           #4                  // String finally
        43: astore        6
        45: aload         5
        47: athrow
        48: return
      Exception table:
         from    to  target type
             3     6    12   Class java/lang/RuntimeException
             3     6    21   Class java/lang/Exception
             3     6    30   Class java/lang/Error
             3     6    39   any
            12    16    39   any
            21    25    39   any
            30    34    39   any
            39    41    39   any
      LineNumberTable:
        line 11: 0
        line 13: 3
        line 24: 6
        line 25: 9
        line 14: 12
        line 15: 13
        line 24: 16
        line 16: 20
        line 17: 21
        line 18: 22
        line 24: 25
        line 19: 29
        line 20: 30
        line 21: 31
        line 24: 34
        line 22: 38
        line 24: 39
        line 25: 45
        line 27: 48
      StackMapTable: number_of_entries = 5
        frame_type = 255 /* full_frame */
          offset_delta = 12
          locals = [ class "[Ljava/lang/String;", class java/lang/String ]
          stack = [ class java/lang/RuntimeException ]
        frame_type = 72 /* same_locals_1_stack_item */
          stack = [ class java/lang/Exception ]
        frame_type = 72 /* same_locals_1_stack_item */
          stack = [ class java/lang/Error ]
        frame_type = 72 /* same_locals_1_stack_item */
          stack = [ class java/lang/Throwable ]
        frame_type = 8 /* same */
    Exceptions:
      throws java.lang.Exception
}
SourceFile: "SumTask.java"
InnerClasses:
     static #14= #13 of #11; //E=class SumTask$E of class SumTask