Java创建线程三种方式的优缺点

Z时代
2024-01-10
分类：综合

Java创建线程主要有三种方式：继承Thread类创建线程、实现Runnable接口创建线程和实现Callable和Future创建线程。

继承Thread类


public class Thread1 extends Thread {
  @Override
  public void run() {
    for (int i = 0; i < 10; i++) {
      System.out.println(getName() + ": " + i);
    }
  }
  public static void main(String[] args) {
    for (int i = 0; i < 10; i++) {
      System.out.println(Thread.currentThread().getName() + ": " + i);
      if (i == 2) {
        new Thread1().start();
        new Thread1().start();
      }
    }
  }
}

实现Runnable接口


public class Thread2 implements Runnable {
  @Override
  public void run() {
    for (int i = 0; i < 10; i++) {
      System.out.println(Thread.currentThread().getName() + ": " + i);
    }
  }
  public static void main(String[] args) {
    for (int i = 0; i < 10; i++) {
      System.out.println(Thread.currentThread().getName() + ": " + i);
      if (i == 2) {
        Thread2 thread2 = new Thread2();
        new Thread(thread2).start();
        new Thread(thread2).start();
      }
    }
  }
}

实现Callable接口

FutureTask类包装Callable对象时，封装了Callable对象的call()方法的返回值。


class Thread3 implements Callable {
  @Override
  public Integer call() throws Exception {
    int i = 0;
    for (; i < 10; i++) {
      System.out.println(Thread.currentThread().getName() + ": " + i);
    }
    return i;
  }
  public static void main(String[] args) {
    Thread3 thread3 = new Thread3();
    FutureTask<Integer> futureTask = new FutureTask<Integer>(thread3);
    for (int i = 0; i < 10; i++) {
      System.out.println(Thread.currentThread().getName() + " :" + i);
      if (i == 2) {
        new Thread(futureTask, "有返回值的线程").start();
      }
    }
    try {
      System.out.println("子线程返回值： " + futureTask.get());
    } catch (InterruptedException e) {
      e.printStackTrace();
    } catch (ExecutionException e) {
      e.printStackTrace();
    }
  }
}