命令线程按照创建/启动的顺序运行

Question

我如何按实例化的顺序订购线程。例如，如何使以下程序按顺序打印数字1 … 10。

public class ThreadOrdering {
    public static void main(String[] args) {

        class MyRunnable implements Runnable{
            private final int threadnumber;

            MyRunnable(int threadnumber){
                this.threadnumber = threadnumber;
            }

            public void run() {
                System.out.println(threadnumber);
            }
        }

        for(int i=1; i<=10; i++){
            new Thread(new MyRunnable(i)).start();
        }
    }
}

Answer 1

听起来像您想要的那样[ExecutorService.invokeAll](http://download.oracle.com/javase/6/docs/api/java/util/concurrent/ExecutorService.html#invokeAll%28java.util.Collection%29)，它将以固定顺序返回工作线程的结果，即使它们可以按任意顺序进行调度：

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

public class ThreadOrdering {

    static int NUM_THREADS = 10;

    public static void main(String[] args) {
        ExecutorService exec = Executors.newFixedThreadPool(NUM_THREADS);
        class MyCallable implements Callable<Integer> {
            private final int threadnumber;

            MyCallable(int threadnumber){
                this.threadnumber = threadnumber;
            }

            public Integer call() {
                System.out.println("Running thread #" + threadnumber);
                return threadnumber;
            }
        }

        List<Callable<Integer>> callables =
            new ArrayList<Callable<Integer>>();
        for(int i=1; i<=NUM_THREADS; i++) {
            callables.add(new MyCallable(i));
        }
        try {
            List<Future<Integer>> results =
                exec.invokeAll(callables);
            for(Future<Integer> result: results) {
                System.out.println("Got result of thread #" + result.get());
            }
        } catch (InterruptedException ex) {
            ex.printStackTrace();
        } catch (ExecutionException ex) {
            ex.printStackTrace();
        } finally {
            exec.shutdownNow();
        }
    }

}