1）Thread:
public class ThreadTest extends Thread {
public void run(){
System.out.println(Thread.currentThread()+"say : hello");
}
public static void main(String[] args){
new ThreadTest().start();
new ThreadTest().start();
new ThreadTest().start();
new ThreadTest().start();
new ThreadTest().start();
}
}执行结果：
Thread[Thread-2,5,main]say : hello
Thread[Thread-4,5,main]say : hello
Thread[Thread-3,5,main]say : hello
Thread[Thread-0,5,main]say : hello
Thread[Thread-1,5,main]say : hello
2）Runnable：
public class RunnableTest implements Runnable{
public void run() {
System.out.println(Thread.currentThread()+"say: hello");
}
public static void main(String[] args){
RunnableTest rt = new RunnableTest();
new Thread(rt,"111").start();
new Thread(rt,"222").start();
new Thread(rt,"333").start();
new Thread(rt).start();
new Thread(rt).start();
}
}
执行结果：
Thread[111,5,main]say: hello
Thread[333,5,main]say: hello
Thread[Thread-0,5,main]say: hello
Thread[222,5,main]say: hello
Thread[Thread-1,5,main]say: hello
3）Callable：
public class CallableTest implements Callable{//Callable是泛型，不一定为String类型
public String call() throws Exception {
System.out.println(Thread.currentThread()+" say : hello");
return "返回字符串："+Thread.currentThread().toString();
}
public static void main(String[] args){
//Callable和Future一个产生结果，一个拿到结果。
//Callable接口类似于Runnable，但是Runnable不会返回结果，
//而Callable可以返回结果，这个返回值可以被Future拿到，
//也就是说，Future可以拿到异步执行任务的返回值。
CallableTest ct = new CallableTest();//相当于Callable执行call()内容
CallableTest ct2 = new CallableTest();
FutureTask ft = new FutureTask<>(ct);//相当于Futrue计算Callable返回的结果
FutureTask ft2 = new FutureTask<>(ct2);
new Thread(ft,"有返回值得线程").start();
new Thread(ft2).start();
try {
//callable的返回值
System.out.println(ft.get());
System.out.println(ft2.get());
} catch (Exception e) {
e.printStackTrace();
}
}
} 执行结果：
Thread[Thread-0,5,main] say : hello
Thread[有返回值得线程,5,main] say : hello
返回字符串：Thread[有返回值得线程,5,main]
返回字符串：Thread[Thread-0,5,main]