java 获取线程状态 判断线程是否已启动，java线程,public class

java 获取线程状态 判断线程是否已启动，java线程,public class

public class Test extends Thread {    public void run() {        printMsg();    }    public void printMsg() {        // 获得运行此代码的线程的引用        Thread t = Thread.currentThread();        String name = t.getName();        System.out.println("name = " + name);    }    public static void main(String[] args) {        Test t = new Test();        t.setName("MyThread");        System.out.println("线程状态 = " + t.isAlive());        t.start();        System.out.println("线程已启动...");        System.out.println("线程状态 = " + t.isAlive());    }}