《Java多線程編程核心技術》讀后感（十五）

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線程的狀態

線程對象在不同的運行時期有不同的狀態，狀態信息就存在與State枚舉類中。

驗證New,Runnable，Terminated

new:線程實例化后還從未執行start()方法時的狀態

runnable：線程進入運行的狀態

terminated：線程被銷毀時的狀態

package Seven;public class MyThread extends Thread {public MyThread() {System.out.println("構造方法中的狀態：" + Thread.currentThread().getState());}@Overridepublic void run() {System.out.println("run方法中的狀態：" + 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方法中的狀態1：" + t.getState());Thread.sleep(1000);t.start();Thread.sleep(1000);System.out.println("main方法中的狀態2：" + t.getState());} catch (InterruptedException e) {// TODO Auto-generated catch block
            e.printStackTrace();}}}

注意：構造方法中的日志時main主線程的

驗證Time_waiting

Time_waiting：線程執行了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方法中的狀態：" + t.getState());} catch (InterruptedException e) {// TODO Auto-generated catch block
            e.printStackTrace();}}
}

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?驗證Blocked

blocked:出現在某一個線程等待鎖的時候

package Seven;public class MyService {synchronized static public void serviceMethod() {try {System.out.println(Thread.currentThread().getName() + "進入了業務方法！");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狀態：" + t2.getState());}
}

驗證waiting

waiting：是線程執行了object.wait()方法后所處的狀態

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狀態：" + t.getState());} catch (InterruptedException e) {// TODO Auto-generated catch block
            e.printStackTrace();}}
}

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