java多線程併發處理

<pre name="code" class="java">public class ThreadRelatedService {

    // key point: records list must be ordered
    public void exec() {
        // System.out.println("Start ThreadRelatedService.exec:");
        List<String> list = new ArrayList<String>();
        // if there are 91000 records in the table
        for (int i = 0; i < 900000; i++) {
            list.add(String.valueOf(i));
        }
        for (int i = 0; i < 9; i++) {
            // get part records from table by page
            List<String> sublist = list.subList(100000 * i, 100000 * (i + 1));
            subExec(sublist);
        }
        // System.out.println("End ThreadRelatedService.exec:");

    }

    private void subExec(List<String> list) {
        // System.out.println("Start ThreadRelatedService.subExec:");
        Thread[] threadPool = new Thread[10];
        for (int i = 0; i <= 9; i++) {
            // divide one page data to parts for different thread to process
            // subList(fromIndex,toIndex),data of toIndex will not be selected
            List<String> sublist = list.subList(10000 * i, 10000 * (i + 1));
            threadPool[i] = new Thread(new ThreadImpl(sublist), "Thread" + i);
            threadPool[i].start();

        }

        for (Thread thread : threadPool) {
            try {
                thread.join();
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        // System.out.println("End ThreadRelatedService.subExec:");
    }

    private class ThreadImpl implements Runnable {
        private List<String> list;

        public ThreadImpl(List<String> list) {
            this.list = list;
        }

        @Override
        public void run() {
            // System.out.println("Thread" + Thread.currentThread().getId());
            // System.out.println("Start ThreadRelatedService.run:");
            String result = "";
            for (String str : list) {
                result += str + "_";
            }
            System.out.println(result);
            // System.out.println("End ThreadRelatedService.run:");
        }
    }
}