java 8的多线程示例

Question

我需要一个Java 8的多线程示例.

我需要能够手动选择线程数.

在下面的示例中,我遇到Thread.currentThread().getName()的问题,我需要使用lambda表达式.

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Thread {

    public static void main(String args[]) {
       ExecutorService service = Executors.newFixedThreadPool(10);
       for (int i =0; i<100; i++){
           service.submit(new Task(i));
       }
    }

final class Task implements Runnable{
    private int taskId;

    public Task(int id){
        this.taskId = id;
    }

    @Override
    public void run() {
        System.out.println("Task ID : " + this.taskId +" performed by "
            + Thread.currentThread().getName());
    }
}

Answer 1

使用IntStream可以轻松完成Lambda.

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.stream.IntStream;

public class ThreadLauncher
{

  public static void main(String args[])
  {
    ExecutorService service = Executors.newFixedThreadPool(10);
    IntStream.range(0, 100).forEach(i -> service.submit(new Task(i)));
  }
}

final class Task
    implements Runnable
{
  private int taskId;

  public Task(int id)
  {
    this.taskId = id;
  }

  @Override
  public void run()
  {
    System.out.println("Task ID : " + this.taskId + " performed by "
        + Thread.currentThread().getName());
  }
}

Answer 2

对于lambda，我建议：

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Main {
    public static void main(String args[]) {
        ExecutorService service = Executors.newFixedThreadPool(10);
        for (int i =0; i < 100; i++) {
            final int fi = i;
            service.submit(() -> System.out.println("Task ID : " + fi + " performed by "
                                                      + Thread.currentThread().getName()));
        }
    }
}

或者如果您想全力以赴lambdas

public class Main {
    public static void main(String args[]) {
        ExecutorService service = Executors.newFixedThreadPool(10);
        IntStream.range(0, 100)
                 .forEach(i -> service.submit(() 
                            -> System.out.println("Task ID : " + i + " performed by " + Thread.currentThread().getName())));
    }
}