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启动线程

• 继承类Thread
• 实现Runnable接口
• 实现Callable接口（包装成FutureTask）

public class NewThread extends Thread{
   	/*扩展自Thread类*/	@Override	public void run() {
   		System.out.println("I am extends Thread");	}		/*实现Runnable接口*/	private static class UseRun implements Runnable{
   		@Override		public void run() {
   			System.out.println("I am implements Runnable");		}			}		/*实现Callable接口，允许有返回值*/	private static class UseCall implements Callable
   
    {
   		@Override		public String call() throws Exception {
   			System.out.println("I am implements Callable");			return "CallResult";		}			}			public static void main(String[] args) 			throws InterruptedException, ExecutionException {
   		new NewThread().start();		UseRun useRun = new UseRun();		new Thread(useRun).start();		Thread t = new Thread(useRun);		t.interrupt();				UseCall useCall = new UseCall();		FutureTask
    
      futureTask = new FutureTask<>(useCall);		new Thread(futureTask).start();		System.out.println(futureTask.get());	}}
    
   

执行结果：

I am extends ThreadI am implements RunnableI am implements CallableCallResult

停止线程

interrupt（）中断一个线程，并不是强行关闭这个线程，把中断标志位置为true

isInterrupted（）判断当前线程是否处于中断状态，判断中断标志位是否为true interrupted（）（static方法）判断当前线程是否处于中断状态，中断标志位改为false

public class EndRunnable {
   		private static class UseRunnable implements Runnable{
   				@Override		public void run() {
   			String threadName = Thread.currentThread().getName();						System.out.println(threadName+" interrput flag is "					+Thread.currentThread().isInterrupted());								while(!Thread.currentThread().isInterrupted()) {
   				System.out.println(threadName+" is run!");			}			System.out.println(threadName+" interrput flag is "					+Thread.currentThread().isInterrupted());		}				}	public static void main(String[] args) throws InterruptedException {
   		UseRunnable useRunnable = new UseRunnable();		Thread endThread = new Thread(useRunnable,"endThread");		endThread.start();		Thread.sleep(1);		endThread.interrupt();	}}

执行结果：

endThread interrput flag is falseendThread is run!endThread is run!endThread is run!endThread is run!endThread interrput flag is true

若方法抛出InterruptedException，线程的中断标志位会被复位成false，需要我们自己在catch里再次中断（调用interrupt方法）

Java里所有阻塞方法都会抛出InterruptedException异常

public class HasInterrputException {
   		private static SimpleDateFormat formater = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss_SSS");		private static class UseThread extends Thread{
   				public UseThread(String name) {
   			super(name);		}				@Override		public void run() {
   			String threadName = Thread.currentThread().getName();						System.out.println(threadName+" interrput flag is "+isInterrupted());			while(!isInterrupted()) {
   				try {
   					System.out.println("UseThread:"+formater.format(new Date()));					Thread.sleep(3000);				} catch (InterruptedException e) {
   					System.out.println(threadName+" catch interrput flag is "							+isInterrupted()+ " at "							+(formater.format(new Date())));												interrupt();										System.out.println(threadName+" interrput flag is " +isInterrupted());					e.printStackTrace();				}				System.out.println(threadName);							}			System.out.println(threadName+" interrput flag is "+isInterrupted());		}	}	public static void main(String[] args) throws InterruptedException {
   		Thread endThread = new UseThread("HasInterrputEx");		endThread.start();		System.out.println("Main:"+formater.format(new Date()));		Thread.sleep(800);		System.out.println("Main begin interrupt thread:"+formater.format(new Date()));		endThread.interrupt();	}}

执行结果：

HasInterrputEx interrput flag is falseUseThread:2019-06-22 23:04:59_236Main:2019-06-22 23:04:59_236Main begin interrupt thread:2019-06-22 23:05:00_038HasInterrputEx catch interrput flag is false at 2019-06-22 23:05:00_038HasInterrputEx interrput flag is truejava.lang.InterruptedException: sleep interrupted	at java.lang.Thread.sleep(Native Method)	at javaStudy.ch1.HasInterrputException$UseThread.run(HasInterrputException.java:31)HasInterrputExHasInterrputEx interrput flag is true

若使用标志位的方式（volatile）控制线程运行和停止，需要注意在线程运行时如果调用了阻塞方法，那么就判断不了标志位进行停止了，要和interrupted（）一起进行线程状态判断

线程生命周期

yield（）：将线程从运行转到就绪状态，这时可能cpu又选到此线程继续执行 join（）：线程A执行了B的join方法，线程A必须等待B执行完成了以后，线程A才能继续自己的工作

守护线程：和主线程共死，finally不能保证一定执行，所以线程执行完需要进行关闭释放资源等操作时，一定不能使用守护线程

yield，sleep方法持有的锁不会释放

wait（）方法调用前，必须持有锁，调用了wait方法后，锁就会被释放，当wait方法返回（其他线程调用notifyAll唤醒），线程会重新持有锁 notify（）方法调用前，必须持有锁，调用notify方法本身不会释放锁，synchronized方法执行完才会释放锁，因此一般将notify放到synchronized方法最后一行

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