Java四种线程创建方式示例代码

class MyThread extends Thread {
    @Override
    public void run() {
        System.out.println("线程在执行：" + Thread.currentThread().getName());
    }
}
 
public class Test {
    public static void main(String[] args) {
        MyThread t = new MyThread();
        t.start(); // ❗必须是 start()
    }
}

t.run(); // 这不是多线程，只是普通方法调用

t.start(); // JVM 创建新线程

class A extends Thread extends B // ❌ 不可能

class MyRunnable implements Runnable {
    @Override
    public void run() {
        System.out.println("线程执行：" + Thread.currentThread().getName());
    }
}
 
public class Test {
    public static void main(String[] args) {
        Runnable task = new MyRunnable();
        Thread t = new Thread(task);
        t.start();
    }
}

class TicketTask implements Runnable {
    private int ticket = 100;
 
    public void run() {
        while (ticket > 0) {
            System.out.println(Thread.currentThread().getName()
                + " 卖出第 " + ticket-- + " 张票");
        }
    }
}
 
public static void main(String[] args) {
    TicketTask task = new TicketTask();
    new Thread(task, "窗口1").start();
    new Thread(task, "窗口2").start();
}

import java.util.concurrent.*;
 
class MyCallable implements Callable<Integer> {
    @Override
    public Integer call() throws Exception {
        Thread.sleep(1000);
        return 100;
    }
}
 
public class Test {
    public static void main(String[] args) throws Exception {
        Callable<Integer> task = new MyCallable();
 
        FutureTask<Integer> futureTask = new FutureTask<>(task);
 
        Thread t = new Thread(futureTask);
        t.start();
 
        Integer result = futureTask.get(); // 阻塞等待结果
        System.out.println("结果：" + result);
    }
}

ExecutorService pool = Executors.newFixedThreadPool(3);
 
pool.execute(() -> {
    System.out.println(Thread.currentThread().getName());
});
 
pool.shutdown();

// Runnable
pool.execute(() -> System.out.println("无返回值"));
 
// Callable
Future<Integer> f = pool.submit(() -> 1 + 2);
System.out.println(f.get());