线程超时

//    SearchThread.java
class SearchThread extends Thread {
       private List result = new ArrayList();
       private boolean success_flag = false;
       ...........

       public SearchThread(xxxx,xxxxx) {
            .......
       }

       public void run() {
             this.result = API.getSearchResult(xxxx,xxxx,xxxx);
             this.success_flag = true;
       }

       public List getResults() {
             return this.result;
       }

       public boolean isSuccess() {
             return this.success_flag;
       }
}

//  XXXAction.java
...........
SearchThread thread = new SearchThread(xxxxxx,  xxxxxxx);
thread.start();
try {
     thread.join(MAX_WAIT_TIME);
     if (thread.isSuccess()) {
          result_lst = thread.getResults();
     } else {
          throw new DataBaseTimeoutException();
     }
} catch (Exception e) {
     thread.interrupt();
     ........
}
MAX_WAIT_TIME就是最大等待时间20秒，如果join()到达最长等待时间，但 是SearchThread里面的success_flag还没有被设置成true的时候，就是说明已经超时，检索没有完成，这个时候会抛出自定义的 DataBaseTimeoutException，中断线程。