《Java多线程编程核心技术》读后感（十五）

 

 

线程的状态

线程对象在不同的运行时期有不同的状态，状态信息就存在与State枚举类中。

验证New,Runnable，Terminated

new:线程实例化后还从未执行start()方法时的状态

runnable：线程进入运行的状态

terminated：线程被销毁时的状态

package Seven;public class MyThread extends Thread {public MyThread() {System.out.println("构造方法中的状态：" + Thread.currentThread().getState());}@Overridepublic void run() {System.out.println("run方法中的状态：" + Thread.currentThread().getState());}
}

package Seven;public class Run {// NEW,// RUNNABLE,// TERMINATED,// BLOCKED,// WAITING,// TIMED_WAITING,public static void main(String[] args) {try {MyThread t = new MyThread();System.out.println("main方法中的状态1：" + t.getState());Thread.sleep(1000);t.start();Thread.sleep(1000);System.out.println("main方法中的状态2：" + t.getState());} catch (InterruptedException e) {// TODO Auto-generated catch block
            e.printStackTrace();}}}

注意：构造方法中的日志时main主线程的

验证Time_waiting

Time_waiting：线程执行了Thread.sleep（）

package Seven;public class MyThread extends Thread {@Overridepublic void run() {try {System.out.println("begin sleep");Thread.sleep(10000);System.out.println("  end sleep");} catch (InterruptedException e) {e.printStackTrace();}}
}

package Seven;public class Run {// NEW,// RUNNABLE,// TERMINATED,// BLOCKED,// WAITING,// TIMED_WAITING,public static void main(String[] args) {try {MyThread t = new MyThread();t.start();Thread.sleep(1000);System.out.println("main方法中的状态：" + t.getState());} catch (InterruptedException e) {// TODO Auto-generated catch block
            e.printStackTrace();}}
}

 

 验证Blocked

blocked:出现在某一个线程等待锁的时候

package Seven;public class MyService {synchronized static public void serviceMethod() {try {System.out.println(Thread.currentThread().getName() + "进入了业务方法！");Thread.sleep(10000);} catch (InterruptedException e) {e.printStackTrace();}}}

package Seven;public class MyThread1 extends Thread {@Overridepublic void run() {MyService.serviceMethod();}}

package Seven;public class MyThread2 extends Thread {@Overridepublic void run() {MyService.serviceMethod();}}

package Seven;public class Run {// NEW,// RUNNABLE,// TERMINATED,// BLOCKED,// WAITING,// TIMED_WAITING,public static void main(String[] args) throws InterruptedException {MyThread1 t1 = new MyThread1();t1.setName("a");t1.start();MyThread2 t2 = new MyThread2();t2.setName("b");t2.start();//Thread.sleep(1000);System.out.println("main方法中的t2状态：" + t2.getState());}
}

验证waiting

waiting：是线程执行了object.wait()方法后所处的状态

package Seven;public class Lock {public static final Byte lock = new Byte("0");}

package Seven;public class MyThread extends Thread {@Overridepublic void run() {try {synchronized (Lock.lock) {Lock.lock.wait();}} catch (InterruptedException e) {e.printStackTrace();}}
}

package Seven;public class Run {// NEW,// RUNNABLE,// TERMINATED,// BLOCKED,// WAITING,// TIMED_WAITING,public static void main(String[] args) {try {MyThread t = new MyThread();t.start();Thread.sleep(1000);System.out.println("main方法中的t状态：" + t.getState());} catch (InterruptedException e) {// TODO Auto-generated catch block
            e.printStackTrace();}}
}