LetsCoding.cn

1. try {
2.     // Block of code with multiple exit points
3. }
4. finally {
5.     // Block of code that is always executed when the try block is exited,
6.     // no matter how the try block is exited
7. }

1. try {
2.     // Block of code with multiple exit points
3. }
4. catch (Cold e) {
5.     System.out.println("Caught cold!");
6. }
7. catch (APopFly e) {
8.     System.out.println("Caught a pop fly!");
9. }
10. catch (SomeonesEye e) {
11.     System.out.println("Caught someone's eye!");
12. }
13. finally {
14.     // Block of code that is always executed when the try block is exited,
15.     // no matter how the try block is exited.
16.     System.out.println("Is that something to cheer about?");
17. }

1. Caught cold!
2. Is that something to cheer about?

1. static boolean surpriseTheProgrammer(boolean bVal) {
2.     while (bVal) {
3.         try {
4.             return true;
5.         }
6.         finally {
7.             break;
8.         }
9.     }
10.     return false;
11. }

1. static int giveMeThatOldFashionedBoolean(boolean bVal) {
2.     try {
3.         if (bVal) {
4.             return 1;
5.         }
6.         return 0;
7.     }
8.     finally {
9.         System.out.println("Got old fashioned.");
10.     }
11. }

1. // The bytecode sequence for the try block:
2. 0 iload_0               // Push local variable 0 (arg passed as divisor)
3. 1 ifeq 11               // Push local variable 1 (arg passed as dividend)
4. 4 iconst_1              // Push int 1
5. 5 istore_3              // Pop an int (the 1), store into local variable 3
6. 6 jsr 24                // Jump to the mini-subroutine for the finally clause
7. 9 iload_3               // Push local variable 3 (the 1)
8. 10 ireturn               // Return int on top of the stack (the 1)
9. 11 iconst_0              // Push int 0
10. 12 istore_3              // Pop an int (the 0), store into local variable 3
11. 13 jsr 24                // Jump to the mini-subroutine for the finally clause
12. 16 iload_3               // Push local variable 3 (the 0)
13. 17 ireturn               // Return int on top of the stack (the 0)
14. // The bytecode sequence for a catch clause that catches any kind of exception
15. // thrown from within the try block.
16. 18 astore_1              // Pop the reference to the thrown exception, store
17.                          // into local variable 1
18. 19 jsr 24                // Jump to the mini-subroutine for the finally clause
19. 22 aload_1               // Push the reference (to the thrown exception) from
20.                            // local variable 1
21. 23 athrow                // Rethrow the same exception
22. // The miniature subroutine that implements the finally block.
23. 24 astore_2              // Pop the return address, store it in local variable 2
24. 25 getstatic #8          // Get a reference to java.lang.System.out
25. 28 ldc #1                // Push < string "Got old fashioned." > from the constant pool
26. 30 invokevirtual #7      // Invoke System.out.println()
27. 33 ret 2                 // Return to return address stored in local variable 2

本文出自：碼農(nóng)合作社 》JVM中finally子句介紹，轉(zhuǎn)載請(qǐng)注明。