Two ways for a sub-thread to interrupt the work of the main thread

1. thread. Join

The Code is as follows:

1. Package demo;
3. Import java. util. Random;
5. Public class waitallsubthread {
7. // Int livethreadnum; // record the number of running sub-threads
9. Int N; // Number of worker threads
11. Public waitallsubthread (int n ){
12. This. n = N;
13. }
15. Class worker implements runnable {
17. String name;
18. Int sleep;
20. Public worker (string name, int sleep ){
21. This. Name = Name;
22. This. Sleep = sleep;
23. }
25. Public void run (){
27. // Uplive (); // calculate that this thread has been working.
29. System. Out. println (name + ", start to work .");
30. Try {
31. Thread. Sleep (sleep); // virtual operation. 10 s random time
32. } Catch (interruptedexception e ){
33. System. Out. println (name + "interrupted .");
34. }
35. System. Out. println (name + ", end to work [" + sleep + "] Sleep .");
37. // Downlive (); // This thread is finished
38. }
39. }
41. //// Synchronous method for recording the number of threads.
42. // Private synchronized void downlive (){
43. // Livethreadnum --;
44. //}
45. //
46. // Private synchronized void uplive (){
47. // Livethreadnum ++;
48. //}
49. //
50. // Private synchronized Boolean islive (){
51. // Return livethreadnum> 0;
52. //}
54. Public void run (){
56. System. Out. println ("------------- main run start -------------");
57. Int sleepsaid = 10*1000; // virtual maximum time of each worker thread
58. Random Rm = new random ();
60. Thread [] ths = new thread [N];
61. For (INT I = 0; I <ths. length; I ++ ){
62. Ths [I] = new thread (new worker ("worker-" + I, Rm. nextint (sleepsaid) + 1 ));
63. Ths [I]. Start ();
64. }
66. For (thread TH: ths ){
67. Try {
68. Th. Join (); // join method
69. } Catch (interruptedexception e ){
70. E. printstacktrace ();
71. }
72. }
73. //// Wait for all worker threads to finish.
74. // While (islive ()){
75. // Try {
76. // Thread. Sleep (1000); // check whether all threads are completed every 1 s.
77. //} Catch (interruptedexception e ){
78. // System. Out. println ("main thread sleep interrupted .");
79. //}
80. //}
81. System. Out. println ("--------------- main run end --------------");
82. }
84. Public static void main (string [] ARGs ){
85. Waitallsubthread wast = new waitallsubthread (10 );
86. Wast. Run ();
87. }
88. }

2. countdownlatch

The Code is as follows:

1. Package demo;
3. Import java. util. Random;
4. Import java. util. Concurrent. countdownlatch;
6. Public class countdownlatchuse {
8. Final countdownlatch downlatch;
9. Int N; // Number of worker threads
11. Public countdownlatchuse (int n ){
12. This. downlatch = new countdownlatch (N );
13. This. n = N;
14. }
16. Class worker implements runnable {
18. String name;
19. Int sleep;
21. Public worker (string name, int sleep ){
22. This. Name = Name;
23. This. Sleep = sleep;
24. }
26. Public void run (){
27. System. Out. println (name + ", start to work .");
28. Try {
29. Thread. Sleep (sleep); // virtual operation. 10 s random time
30. } Catch (interruptedexception e ){
31. System. Out. println (name + "interrupted .");
32. }
33. System. Out. println (name + ", end to work [" + sleep + "] Sleep .");
34. Medone (); // completed by a worker thread
35. }
36. }
38. Private void medone (){
39. Downlatch. Countdown ();
40. }
42. Public void run (){
44. System. Out. println ("------------- main run start -------------");
45. Int sleepsaid = 10*1000; // virtual maximum time of each worker thread
46. Random Rm = new random ();
47. For (INT I = 0; I <n; I ++ ){
48. New thread (new worker ("worker-" + I, Rm. nextint (sleepsaid) + 1). Start ();
49. }
51. Try {
52. Downlatch. Await (); // wait for all worker threads to finish.
53. } Catch (interruptedexception e ){
54. System. Out. println ("Main interrupted .");
55. }
56. System. Out. println ("--------------- main run end --------------");
57. }
59. Public static void main (string [] ARGs ){
61. Countdownlatchuse MTU = new countdownlatchuse (10 );
62. MTU. Run ();
63. }
64. }