java的多线程学习，第一记

import com.sun.org.apache.xpath.internal.SourceTree;

public class test{

    //继承Thread类并重写run方法
    public static class MyThread extends Thread{
        @Override
        public void run(){
            System.out.println("I am a child thread");
        }
    }

    public static void main(String[] args) {
        //创建线程
        MyThread thread = new MyThread();
        //启动线程
        thread.start();
    }


}

public class test1{

    public static class RunableTask implements Runnable{

        @Override
        public void run(){
            System.out.println("I am a child thread");
        }
    }

    public static void main(String[] args) {
        RunableTask task = new RunableTask();
        new Thread(task).start();
        new Thread(task).start();
    }
}

import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;

public class test2{
    

    public static class CallerTask implements Callable<String>{

        @Override
        public String call()throws Exception{
            return "hello";
        }
    }

    public static void main(String[] args) {
        //create asynchronous task
        FutureTask<String> futureTask = new FutureTask<>(new CallerTask());
        //start thread
        new Thread(futureTask).start();
        try {
            //wait task excute 
            String result = futureTask.get();
            System.out.println(result);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}