线程池中的运行方法

Question

I little bit out of understanding java.util.concurent package, all those services and executors.

I need a quite simple thing - let say I have

    for( int i=0;i<1000;i++){  
        doSomething(i); //all tasks are run 10ms and does not lock each other
    }       

What is the easiest way to convert this code to run by group of 10 threads.

If possible can I re-use proposed solution for another group of tasks(not wrapping each time in run())?

Answer 1

Here is what you need :

ExecutorService executor = Executors.newFixedThreadPool(10);
for (int i = 0; i < 1000; i++) {
Runnable worker = new doSomething(i);
executor.execute(worker);
}
executor.shutdown();

and your doSomething class will be like this :

class doSomething implements Runnable {
int i=0;
doSomething(int i) {
    this.i = i;
}
@Override
public void run() {
    try {
        // Do what you want here
        Thread.sleep(10000);
    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}
}

Edited : ExecutorService#shutdown() initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted. Invocation has no additional effect if already shut down. This method does not wait for previously submitted tasks to complete execution. Use awaitTermination to do that.