创建线程的三种方式

第一种 implements Runnable

public class TestJoin implements Runnable{
    @Override
    public void run() {
        try {
            Thread.sleep(1);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
        for (int i = 0; i < 200; i++) {
            System.out.println(i);
        }
    }

    public static void main(String[] args) throws InterruptedException {
        TestJoin testJoin = new TestJoin();
        Thread thread = new Thread(testJoin);
        thread.start();
        for (int i = 0; i < 1000; i++) {
            if(i==200){
                thread.join();
            }
            System.out.println("main"+i);
        }
    }
}

第二种 extends Thread

public class TestThread extends Thread{
    @Override
    public void run() {
        for (int i = 0; i < 200; i++) {
            System.out.println("新线程:"+i);
        }
    }

    public static void main(String[] args) {
        TestThread testThread = new TestThread();
        testThread.start();
        for (int i = 0; i < 200; i++) {
            System.out.println("旧:"+i);
        }
    }
}

第三种 implements Callable<？>

import java.util.concurrent.*;

public class TestCallable implements Callable<String> {
    @Override
    public String call() throws Exception {
        for (int i = 0; i < 100; i++) {
            System.out.println(Thread.currentThread().getName()+i);
        }
        return Thread.currentThread().getName();
    }

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        TestCallable testCallable = new TestCallable();
        ExecutorService executorService = Executors.newFixedThreadPool(3);
        Future<String> submit1 = executorService.submit(testCallable);
        Future<String> submit2 = executorService.submit(testCallable);
        Future<String> submit3 = executorService.submit(testCallable);
        System.out.println(submit1.get());
        System.out.println(submit2.get());
        System.out.println(submit3.get());
        executorService.shutdown();
    }
}