JAVAEE多线程

本是古典何须时尚 2022-02-24 16:20 647阅读 0赞

### **线程:** ###

### **原理:多线程执行时候,在栈内存中,其实每一个执行线程都有一片所属的栈内存的空间,进行方法的** ###

### **压栈,和弹栈.** ###

### **原理图;** ###

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### **Thread类:** ###

### **构造方法:** ###

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     <li> <h3 style="margin-left:0px;"><code>public Thread()</code>:分配一个新的线程对象。</h3> </li> 
     <li> <h3 style="margin-left:0px;"><code>public Thread(String name)</code>:分配一个指定名字的新的线程对象。</h3> </li> 
     <li> <h3 style="margin-left:0px;"><code>public Thread(Runnable target)</code>:分配一个带有指定目标新的线程对象。</h3> </li> 
     <li> <h3 style="margin-left:0px;"><code>public Thread(Runnable target,String name)</code>:分配一个带有指定目标新的线程对象并指定名字。</h3> </li> 
    </ul><h3 style="margin-left:0px;"><span style="color:#333333;"><strong>常用方法：</strong></span></h3> <h3><span style="color:#333333;"><code>public&nbsp;String&nbsp;getName()</code>:获取当前线程名称。</span></h3> <h3><span style="color:#333333;"><code>public&nbsp;static&nbsp;Thread&nbsp;currentThread()</code>:返回对当前正在执行的线程对象的引用。</span></h3> <h3><span style="color:#333333;"><code>public&nbsp;void&nbsp;start()</code>:导致此线程开始执行;&nbsp;Java虚拟机调用此线程的run方法。</span></h3> <h3><span style="color:#333333;"><code>public&nbsp;void&nbsp;run()</code>:此线程要执行的任务在此处定义代码。</span></h3> <h3><span style="color:#333333;"><code>public&nbsp;static&nbsp;void&nbsp;sleep(long&nbsp;millis)</code>:使当前正在执行的线程以指定的毫秒数暂停（暂时停止执行）。</span></h3> <h3><span style="color:#333333;">注意:如果一个类继承Thread,则不适合资源的共享,但是实现了Runable接口的话,则很容易的实现资源共享.</span></h3> </td> 
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### **创建多线程:** ###

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### ***多线程三种创建方法:*** ###

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   <td style="border-color:#d3d3d3;"> <h3><span style="color:#a9b7c6;"><span style="color:#cc7832;">package&nbsp;</span>com.heima.biji<span style="color:#cc7832;">;</span><br><span style="color:#53804d;">//1,通过继承的方式创建线程</span><br><span style="color:#cc7832;">public&nbsp;class&nbsp;</span>Demo01&nbsp;{ <br> &nbsp; &nbsp; <span style="color:#cc7832;">public&nbsp;static&nbsp;void&nbsp;</span><span style="color:#ffc66d;">main</span>(String[]&nbsp;args)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#53804d;">//创建自定义对象</span><br> &nbsp; &nbsp; &nbsp; &nbsp; Mythread01&nbsp;mythread01&nbsp;=&nbsp;<span style="color:#cc7832;">new&nbsp;</span><strong>Mythread01</strong>(<span style="color:#6a8759;">"德玛"</span>)<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#53804d;">//创建线程对象</span><br> &nbsp; &nbsp; &nbsp; &nbsp; Thread&nbsp;thread&nbsp;=&nbsp;<span style="color:#cc7832;">new&nbsp;</span><strong>Thread</strong>(mythread01)<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#53804d;">//开启线程</span><br> &nbsp; &nbsp; &nbsp; &nbsp; thread.<strong>start</strong>()<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#53804d;">//在主方法体中执行for循环</span><br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#cc7832;">for&nbsp;</span>(<span style="color:#cc7832;">int&nbsp;</span>j&nbsp;=&nbsp;<span style="color:#6897bb;">0</span><span style="color:#cc7832;">;&nbsp;</span>j&nbsp;&lt;&nbsp;<span style="color:#6897bb;">50</span><span style="color:#cc7832;">;&nbsp;</span>j++)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.<span style="color:#9876aa;"><em>out</em></span>.<strong>println</strong>(<span style="color:#6a8759;">"main线程:"</span>+j)<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; }<br> &nbsp; &nbsp; }<br> }</span></h3> </td> 
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   <td style="border-color:#d3d3d3;"> <h3><span style="color:#a9b7c6;"><span style="color:#cc7832;">package&nbsp;</span>com.heima.biji<span style="color:#cc7832;">;</span><br><span style="color:#cc7832;">public&nbsp;class&nbsp;</span>Mythread01&nbsp;<span style="color:#cc7832;">extends&nbsp;</span>Thread&nbsp;{ <br> &nbsp; &nbsp; <span style="color:#53804d;">//定义指定的线程名称的构造方法</span><br> &nbsp; &nbsp; <span style="color:#cc7832;">public&nbsp;</span><span style="color:#ffc66d;">Mythread01</span>(String&nbsp;name){ <br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#53804d;">//调用父类的String参数的构造方法,指定线程的名称</span><br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#cc7832;">super</span>(name)<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; }<br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#53804d;">//重写run方法,完成该线程的执行的逻辑</span><br> &nbsp; &nbsp; <span style="color:#bbb529;">@Override</span><br> &nbsp; &nbsp; <span style="color:#cc7832;">public&nbsp;void&nbsp;</span><span style="color:#ffc66d;">run</span>()&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#cc7832;">for&nbsp;</span>(<span style="color:#cc7832;">int&nbsp;</span>i&nbsp;=&nbsp;<span style="color:#6897bb;">0</span><span style="color:#cc7832;">;&nbsp;</span>i&nbsp;&lt;&nbsp;<span style="color:#6897bb;">50</span><span style="color:#cc7832;">;&nbsp;</span>i++)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.<span style="color:#9876aa;"><em>out</em></span>.<strong>println</strong>(<strong>getName</strong>()+<span style="color:#6a8759;">":正在执行"</span>+i)<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; }<br> &nbsp; &nbsp; }<br> }</span></h3> </td> 
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   <td style="border-color:#d3d3d3;"> <h3><span style="color:#a9b7c6;"><span style="color:#cc7832;">package&nbsp;</span>com.heima.biji<span style="color:#cc7832;">;</span><br><span style="color:#53804d;">//3.匿名内部内方法创建线程</span><br><span style="color:#cc7832;">public&nbsp;class&nbsp;</span>Demo03&nbsp;{ <br> &nbsp; &nbsp; <span style="color:#cc7832;">public&nbsp;static&nbsp;void&nbsp;</span><span style="color:#ffc66d;">main</span>(String[]&nbsp;args)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; Runnable&nbsp;runnable&nbsp;=&nbsp;<span style="color:#cc7832;">new&nbsp;</span>Runnable()&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#bbb529;">@Override</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#cc7832;">public&nbsp;void&nbsp;</span><span style="color:#ffc66d;">run</span>()&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#cc7832;">for&nbsp;</span>(<span style="color:#cc7832;">int&nbsp;</span>i&nbsp;=&nbsp;<span style="color:#6897bb;">0</span><span style="color:#cc7832;">;&nbsp;</span>i&nbsp;&lt;&nbsp;<span style="color:#6897bb;">50</span><span style="color:#cc7832;">;&nbsp;</span>i++)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.<span style="color:#9876aa;"><em>out</em></span>.<strong>println</strong>(<span style="color:#6a8759;">"子类中的:"</span>+i+<span style="color:#6a8759;">"循环"</span>)<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }<br> &nbsp; &nbsp; &nbsp; &nbsp; }<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#53804d;">//创建线程的对象并调用runnable.</span><br> &nbsp; &nbsp; &nbsp; &nbsp; Thread&nbsp;thread&nbsp;=&nbsp;<span style="color:#cc7832;">new&nbsp;</span><strong>Thread</strong>(runnable)<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#53804d;">//启动线程</span><br> &nbsp; &nbsp; &nbsp; &nbsp; thread.<strong>start</strong>()<span style="color:#cc7832;">;</span><br><span style="color:#cc7832;">&nbsp; &nbsp; &nbsp; &nbsp; for&nbsp;</span>(<span style="color:#cc7832;">int&nbsp;</span>j&nbsp;=&nbsp;<span style="color:#6897bb;">0</span><span style="color:#cc7832;">;&nbsp;</span>j&nbsp;&lt;&nbsp;<span style="color:#6897bb;">50</span><span style="color:#cc7832;">;&nbsp;</span>j++)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.<span style="color:#9876aa;"><em>out</em></span>.<strong>println</strong>(<span style="color:#6a8759;">"父类中的:"</span>+j+<span style="color:#6a8759;">"循环"</span>)<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; }<br> &nbsp; &nbsp; }<br> }</span></h3> </td> 
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### **三种方式各自好处:** ###

### **继承** ###

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### **接口** ###

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### **匿名内部内** ###

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   <td style="border-color:#d3d3d3;"> <h3><span style="color:#333333;">使用线程的内匿名内部类方式，可以方便的实现每个线程执行不同的线程任务操作。</span></h3> </td> 
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### **实现Runnable接口比继承Threed类所具有的优势** ###

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   <td style="border-color:#d3d3d3;"> <h3>1.适应多个相同的程序代码的线程去共享一个资源.</h3> <h3>2.可以避免java中的单继承的局限性.</h3> <h3>3.增加程序的健壮性,实现解耦操作,任务可以被多个线程共享,任务和线程独立.</h3> <h3>4.线程池只能放入实现Runnable或Callable类线程,不能直接放入继承Thread的类</h3> <h3><strong>耦合性:类和类之间的相互影响的程度.</strong></h3> <h3>扩充:在java中,每次程序运行至少启动2个线程,一个是main线程,一个是垃圾收集线程,</h3> <h3>因为每当使用Java命令执行一个类的时候,一个是垃圾收集线程,因为每当使用Java执行一个类</h3> <h3>实际东辉启动一个jvm,每个JVM其实都是在操作系统启动一个进程.</h3> </td> 
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### **线程安全:** ###

### **定义:** ###

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   <td style="border-color:#d3d3d3;"> <h3><span style="color:#333333;">如果有多个线程在同时运行，而这些线程可能会同时运行这段代码。程序每次运行结果和单线程运行的结果是一样的，而且其他的变量的值也和预期的是一样的，就是线程安全的。</span></h3> </td> 
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### **实例题目:** ###

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### **线程同步:** ###

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   <td style="border-color:#d3d3d3;"> <h3>当我们使用多个线程访问同一资源的时候,且多个线程中对资源有写的操作,就容易出现线程安全问题</h3> <h3><strong>解决:</strong></h3> <h3>解决上诉问题多线程访问一个资源安全性问题,也就是解决重复的问题,java中提供了(<strong>synchronized</strong>)来解决</h3> <h3><strong>线程访问使用三种方式完成同步操作</strong></h3> <h3><strong>1.<span style="color:#e30000;">同步代码快</span>(synchronized)关键字可以用于方法的某个区块中表示区块资源的互斥访问.</strong></h3> <h3><strong>格式:</strong></h3> <h3>&nbsp;</h3> <h3><span style="color:#333333;">synchronized(同步锁){ </span></h3> <h3><span style="color:#333333;">需要同步操作的代码</span></h3> <h3><span style="color:#333333;">}</span></h3> <h3><strong>同步锁:</strong></h3> <h3><strong>对象的同步锁只是一个概念,可以想象为在对象上标志记了一个锁</strong></h3> <h3><strong>.锁对象(可以是任意数据对象)</strong></h3> <h3><strong>.多个线程对象,要使用同一把锁.</strong></h3> <h3>注意:在任何时候,最多仍许一个线程拥有同步锁,谁拿到锁就进入代码块,其他的线程只能在外等着(BLDCKED).</h3> <h3><strong>2.同步方法</strong></h3> <h3><strong>3.锁机制</strong></h3> </td> 
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### **同步方法:** ###

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   <td style="border-color:#d3d3d3;"> <h3><span style="color:#e30000;"><strong>同步方法<strong>:使用synchronized修饰的方法,就叫做同步方法,保证A线程执行该方法的时候,其他线程只能在方法外等着。</strong></strong></span></h3> <h3>&nbsp;</h3> <h3><span style="color:#e30000;"><strong>public synchronized void method(){ </strong></span></h3> <h3><span style="color:#e30000;"><strong>可能会产生线程安全问题的代码</strong></span></h3> <h3><span style="color:#e30000;"><strong>}</strong></span></h3> <h3><span style="color:#e30000;"><strong>同步锁是谁:</strong></span></h3> <h3><span style="color:#e30000;"><strong>对于非static方法,同步锁就是this.</strong></span></h3> <h3><span style="color:#e30000;"><strong>对于static方法,我们使用当前方法所有类的字节代码对象(类名.class)</strong></span></h3> </td> 
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### **package com.heima.biji;** ###

### **//同步方法** ###

### **public class Mythread04 implements Runnable\{**  ###

### **        private int ticket = 100;//定义电影票的个数** ###

### **        //重写run方法** ###

### **        @Override** ###

### **        public void run() \{**  ###

### **            //每个窗口买票的过程** ###

### **            //窗口永远在开启** ###

### **            while (true)\{**  ###

### **                sellTicket();** ###

### **            \}** ###

### **        \}** ###

### **        public synchronized void sellTicket()\{**  ###

### **            if(ticket>0)\{**  ###

### **                try \{**  ###

### **                    Thread.sleep(100);** ###

### **                \} catch (InterruptedException e) \{**  ###

### **                    e.printStackTrace();** ###

### **                \}** ###

### **                //获取当前线程对象的名字** ###

### **                String name = Thread.currentThread().getName();** ###

### **                System.out.println(name + "正在买:" + ticket-- + "张");** ###

### **            \}** ###

### **        \}** ###

### **    \}** ###

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### **Lock锁:** ###

### **java.util.concurrent.loks.Lock机制提供了比synchronized代码块,和synchronized方法** ###

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   <td style="border-color:#d3d3d3;"> <h3 style="margin-left:0px;"><span style="color:#333333;">Lock锁也称同步锁，加锁与释放锁方法化了，如下：</span></h3> <h3><span style="color:#333333;"><code>public&nbsp;void&nbsp;lock()</code>:加同步锁。</span></h3> <h3><span style="color:#333333;">&nbsp;lock他是一个接口,他只能new 实现类ReentrantLock</span></h3> <h3><span style="color:#333333;"><code>public&nbsp;void&nbsp;unlock()</code>:释放同步锁。</span></h3> </td> 
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### **代码快:** ###

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### **package com.heima.biji;** ###

### **import java.lang.invoke.VarHandle;** ###

### **import java.util.concurrent.locks.Lock;** ###

### **import java.util.concurrent.locks.ReentrantLock;** ###

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### **//Lock锁** ###

### **public class Mythread05 implements Runnable \{**  ###

### **    //设置票数** ###

### **    private int ticket = 100;** ###

### **    Lock lock = new ReentrantLock();** ###

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### **    //执行买票操作** ###

### **    @Override** ###

### **    public void run() \{**  ###

### **        while (true) \{**  ###

### **            lock.lock();//加同步锁** ###

### **            if (ticket > 0) \{//有票可以买** ###

### **                //每个窗口买票的操作** ###

### **                //窗口 永远开启** ###

### **                try \{**  ###

### **                    Thread.sleep(100);** ###

### **                \} catch (InterruptedException e) \{**  ###

### **                    e.printStackTrace();** ###

### **                \}** ###

### **                //获取当前线程对象的名字** ###

### **                String name = Thread.currentThread().getName();** ###

### **                System.out.println(name + "正在买:" + ticket-- + "票");** ###

### **            \}** ###

### **            lock.unlock();//释放同步锁** ###

### **        \}** ###

### **    \}** ###

### **\}**     ###

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### **线程的状态:** ###

### 当线程被创建并启动后,他既不是一启就进入执行状态,也不是一直处于执行状态: ###

### 在线程生命周期中有**6种状态**. ###

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   <td style="border-color:#d3d3d3;"> <h3><strong>线程状态</strong></h3> </td> 
   <td style="border-color:#d3d3d3;"> <h3><strong>导致方式条件</strong></h3> </td> 
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   <td style="border-color:#d3d3d3;"> <h3>NEW(新建)</h3> </td> 
   <td style="border-color:#d3d3d3;"> <h3><span style="color:#333333;">线程刚被创建，但是并未启动。还没调用start方法。</span></h3> </td> 
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   <td style="border-color:#d3d3d3;"> <h3>Runnable(可运行)</h3> </td> 
   <td style="border-color:#d3d3d3;"> <h3><span style="color:#333333;">线程可以在java虚拟机中运行的状态，可能正在运行自己代码，也可能没有，这取决于操作系统处理器。</span></h3> </td> 
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   <td style="border-color:#d3d3d3;"> <h3>Blocked(锁阻塞)</h3> </td> 
   <td style="border-color:#d3d3d3;"> <h3><span style="color:#333333;">当一个线程试图获取一个对象锁，而该对象锁被其他的线程持有，则该线程进入Blocked状态；当该线程持有锁时，该线程将变成Runnable状态。</span></h3> </td> 
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   <td style="border-color:#d3d3d3;"> <h3>Waiting(无限等待)</h3> </td> 
   <td style="border-color:#d3d3d3;"> <h3><span style="color:#333333;">一个线程在等待另一个线程执行一个（唤醒）动作时，该线程进入Waiting状态。通过wait()方法进入这个状态后是不能自动唤醒的，必须等待另一个线程调用notify或者notifyAll方法才能够唤醒。</span></h3> </td> 
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   <td style="border-color:#d3d3d3;"> <h3>TimedWaiting(计时等待)</h3> </td> 
   <td style="border-color:#d3d3d3;"> <h3><span style="color:#333333;">同waiting状态，有几个方法有超时参数，调用他们将进入Timed&nbsp;Waiting状态。这一状态将一直保持到超时期满或者接收到唤醒通知。带有超时参数的常用方法有Thread.sleep&nbsp;、Object.wait。</span></h3> </td> 
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###    Teminated(被终止)       :        因为run方法正常退出而死亡，或者因为没有捕获的异常终止了run方法而死亡。 ###

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### **Timed Waiting(计时等待):** ###

*  ### **Timed Waiting在API中的描述为：一个正在限时等待另一个线程执行一个（唤醒）动作的线程处于这一状态。单独的去理解这句话，真是玄之又玄，其实我们在之前的操作中已经接触过这个状态了，在哪里呢？** ###

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### **代码:题目** ###

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   <td style="border-color:#d3d3d3;"> <h3>**<strong>实现一个计数器，计数到100，在每个数字之间暂停1秒，每隔10个数字输出一个字符串</strong>**</h3> </td> 
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   <td style="border-color:#d3d3d3;"> <h3><span style="color:#a9b7c6;"><span style="color:#cc7832;">package&nbsp;</span>com.heima.biji<span style="color:#cc7832;">;</span><br><span style="color:#53804d;">//实现一个计数器，计数到100，在每个数字之间暂停1秒，每隔10个数字输出一个字符串</span><br><span style="color:#cc7832;">public&nbsp;class&nbsp;</span>Demo05&nbsp;<span style="color:#cc7832;">extends&nbsp;</span>Thread&nbsp;{ <br> &nbsp; &nbsp; <span style="color:#53804d;">//重写run</span><br> &nbsp; &nbsp; <span style="color:#bbb529;">@Override</span><br> &nbsp; &nbsp; <span style="color:#cc7832;">public&nbsp;void&nbsp;</span><span style="color:#ffc66d;">run</span>()&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#cc7832;">int&nbsp;</span>[]&nbsp;num=<span style="color:#cc7832;">new&nbsp;int</span>[<span style="color:#6897bb;">100</span>]<span style="color:#cc7832;">;</span><br><span style="color:#cc7832;">&nbsp; &nbsp; &nbsp; &nbsp; for&nbsp;</span>(<span style="color:#cc7832;">int&nbsp;</span>i&nbsp;=&nbsp;<span style="color:#6897bb;">1</span><span style="color:#cc7832;">;&nbsp;</span>i&nbsp;&lt;=num.<span style="color:#9876aa;">length</span><span style="color:#cc7832;">;&nbsp;</span>i++)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#cc7832;">if</span>((i)%<span style="color:#6897bb;">10</span>==<span style="color:#6897bb;">0</span>)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.<span style="color:#9876aa;"><em>out</em></span>.<strong>println</strong>(i)<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.<span style="color:#9876aa;"><em>out</em></span>.<strong>println</strong>(<span style="color:#6a8759;">"--------------"</span>)<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.<span style="color:#9876aa;"><em>out</em></span>.<strong>print</strong>(i+<span style="color:#6a8759;">"&nbsp;"</span>)<span style="color:#cc7832;">;</span><br><span style="color:#cc7832;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; try&nbsp;</span>{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Thread.<em>sleep</em>(<span style="color:#6897bb;">100</span>)<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp;<span style="color:#cc7832;">catch&nbsp;</span>(InterruptedException&nbsp;e)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; e.<strong>printStackTrace</strong>()<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }<br> &nbsp; &nbsp; &nbsp; &nbsp; }<br><br> &nbsp; &nbsp; }<br><br> &nbsp; &nbsp; <span style="color:#cc7832;">public&nbsp;static&nbsp;void&nbsp;</span><span style="color:#ffc66d;">main</span>(String[]&nbsp;args)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; Demo05&nbsp;demo05&nbsp;=&nbsp;<span style="color:#cc7832;">new&nbsp;</span><strong>Demo05</strong>()<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; demo05.<strong>start</strong>()<span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; }<br> }</span></h3> </td> 
  </tr> 
 </tbody> 
</table>

### **通过以上代码发现:** ###

## ##

### \- 进入 TIMED\_WAITING 状态的一种常见情形是调用的 sleep 方法，单独的线程也可以调用，不一定非要有协作关系。 ###

### \- 为了让其他线程有机会执行，可以将Thread.sleep()的调用放线程run()之内。这样才能保证该线程执行过程中会睡眠 ###

### \- sleep与锁无关，线程睡眠到期自动苏醒，并返回到Runnable（可运行）状态。 ###

### **提示:** ###

### **sleep()中指定的时间线程不会运行的最短时间,因此,sleep()方法不能保证线程到期后立即执行.** ###

### ***Blocked线程图:*** ###

## ##

## ##

--------------------

## ##

### **Waiting(无限等待):** ###

### **模拟无限等待:** ###

### **1.使用锁对象调用wait()方法,则该线程就会进入无限等待状态** ###

### **2.其他线程使用锁对象调用notify()或者notifyAll()方法,才可以唤醒无限等待** ###

### **notift()唤醒单个无限等待的线程** ###

### **notifyAll()唤醒多个无限等待的线程** ###

### **3.调用wait()和notify()以及notifyAll()方法的锁对象要一致.** ###

### **4.无限等待,可以切换到可运行或者锁阻塞状态.** ###

<table style="margin-left:0px;"> 
 <tbody> 
  <tr> 
   <td style="border-color:#d3d3d3;"> <h3>&nbsp;</h3> <h3><span style="color:#a9b7c6;"><span style="color:#cc7832;">package&nbsp;</span>com.heima.biji<span style="color:#cc7832;">;</span><br><span style="color:#53804d;">//Wating状态在API中介绍为：一个正在无限期等待另一个线程执行一个特别的（唤醒）动作的线程处于这一状态。</span><br><span style="color:#cc7832;">public&nbsp;class&nbsp;</span>Demo06&nbsp;{ <br> &nbsp; &nbsp; <span style="color:#cc7832;">public&nbsp;static&nbsp;</span>Object&nbsp;<span style="color:#9876aa;"><em>obj&nbsp;</em></span>=&nbsp;<span style="color:#cc7832;">new&nbsp;</span><strong>Object</strong>()<span style="color:#cc7832;">;//锁对象</span></span></h3> <h3>&nbsp; &nbsp; public&nbsp;static&nbsp;void&nbsp;main(String[]&nbsp;args)&nbsp;{ </h3> <h3>&nbsp; &nbsp; &nbsp; &nbsp; //&nbsp;演示waiting匿名内部类</h3> <h3>&nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#a74500;">new&nbsp;<strong>Thread</strong>(new&nbsp;Runnable()&nbsp;{ </span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#bbb529;">@Override</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#cc7832;">public&nbsp;void&nbsp;</span><span style="color:#ffc66d;">run</span><span style="color:#a9b7c6;">()&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</span> <span style="color:#cc7832;">while&nbsp;</span><span style="color:#a9b7c6;">(</span><span style="color:#cc7832;">true</span><span style="color:#a9b7c6;">){ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</span> <span style="color:#cc7832;">synchronized&nbsp;</span><span style="color:#a9b7c6;">(</span><span style="color:#9876aa;"><em>obj</em></span><span style="color:#a9b7c6;">){ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</span> <span style="color:#cc7832;">try&nbsp;</span><span style="color:#a9b7c6;">{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.</span><span style="color:#9876aa;"><em>out</em></span><span style="color:#a9b7c6;">.<strong>println</strong>(&nbsp;Thread.<em>currentThread</em>().<strong>getName</strong>()&nbsp;+</span><span style="color:#6a8759;">"===&nbsp;获取到锁对象，调用wait方法，进入waiting状态，释放锁对象"</span><span style="color:#a9b7c6;">)</span><span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#9876aa;"><em>obj</em></span><span style="color:#a9b7c6;">.<strong>wait</strong>()</span><span style="color:#cc7832;">;&nbsp;</span> <span style="color:#53804d;">//无限等待</span><br><span style="color:#53804d;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //obj.wait(5000);&nbsp;//计时等待,&nbsp;5秒&nbsp;时间到，自动醒来</span><br><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#a9b7c6;">}&nbsp;</span><span style="color:#cc7832;">catch&nbsp;</span><span style="color:#a9b7c6;">(InterruptedException&nbsp;e)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; e.<strong>printStackTrace</strong>()</span><span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#a9b7c6;">}<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.</span><span style="color:#9876aa;"><em>out</em></span><span style="color:#a9b7c6;">.<strong>println</strong>(&nbsp;Thread.<em>currentThread</em>().<strong>getName</strong>()&nbsp;+&nbsp;</span><span style="color:#6a8759;">"===&nbsp;从waiting状态醒来，获取到锁对象，继续执行了"</span><span style="color:#a9b7c6;">)</span><span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#a9b7c6;">}<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }<br> &nbsp; &nbsp; &nbsp; &nbsp; }</span><span style="color:#cc7832;">,</span><span style="color:#6a8759;">"等待线程"</span><span style="color:#a9b7c6;">).<strong>start</strong>()</span><span style="color:#cc7832;">;</span><br><br><span style="color:#cc7832;">&nbsp; &nbsp; &nbsp; &nbsp; new&nbsp;</span><span style="color:#a9b7c6;"><strong>Thread</strong>(</span><span style="color:#cc7832;">new&nbsp;</span><span style="color:#a9b7c6;">Runnable()&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</span> <span style="color:#bbb529;">@Override</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#cc7832;">public&nbsp;void&nbsp;</span><span style="color:#ffc66d;">run</span><span style="color:#a9b7c6;">()&nbsp;{ </span><br><span style="color:#53804d;">//&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; while&nbsp;(true){&nbsp; &nbsp;//每隔3秒&nbsp;唤醒一次</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#cc7832;">try&nbsp;</span><span style="color:#a9b7c6;">{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.</span><span style="color:#9876aa;"><em>out</em></span><span style="color:#a9b7c6;">.<strong>println</strong>(&nbsp;Thread.<em>currentThread</em>().<strong>getName</strong>()&nbsp;+</span><span style="color:#6a8759;">"-----&nbsp;等待3秒钟"</span><span style="color:#a9b7c6;">)</span><span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#a9b7c6;">Thread.<em>sleep</em>(</span><span style="color:#6897bb;">3000</span><span style="color:#a9b7c6;">)</span><span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#a9b7c6;">}&nbsp;</span><span style="color:#cc7832;">catch&nbsp;</span><span style="color:#a9b7c6;">(InterruptedException&nbsp;e)&nbsp;{ <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; e.<strong>printStackTrace</strong>()</span><span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#a9b7c6;">}<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</span> <span style="color:#cc7832;">synchronized&nbsp;</span><span style="color:#a9b7c6;">(</span><span style="color:#9876aa;"><em>obj</em></span><span style="color:#a9b7c6;">){ <span style="color:#a74500;">//同步代码块</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.</span><span style="color:#9876aa;"><em>out</em></span><span style="color:#a9b7c6;">.<strong>println</strong>(&nbsp;Thread.<em>currentThread</em>().<strong>getName</strong>()&nbsp;+</span><span style="color:#6a8759;">"-----&nbsp;获取到锁对象,调用notify方法，释放锁对象"</span><span style="color:#a9b7c6;">)</span><span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#9876aa;"><em>obj</em></span><span style="color:#a9b7c6;">.<strong>notify</strong>()</span><span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#a9b7c6;">}<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }</span><br><span style="color:#53804d;">//&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }</span><br> &nbsp; &nbsp; &nbsp; &nbsp; <span style="color:#a9b7c6;">}</span><span style="color:#cc7832;">,</span><span style="color:#6a8759;">"唤醒线程"</span><span style="color:#a9b7c6;">).<strong>start</strong>()</span><span style="color:#cc7832;">;</span><br> &nbsp; &nbsp; <span style="color:#a9b7c6;">}<br> }</span></h3> <h3>&nbsp;</h3> </td> 
  </tr> 
 </tbody> 
</table>

### **线程的有线通信:** ###

## ##

### **补充知识点:** ###

## ##

--------------------

### **1.多线程的开启:** ###

### 题目:描述Thread类中的start()方法与run()方法的区别 ###

## ##

<table style="margin-left:0px;"> 
 <tbody> 
  <tr> 
   <td style="border-color:#d3d3d3;"> <h3><strong>答:线程对象调用的run()方法不开启线程,仅是对象的调用方法,线程对象调用start()方法启用线程,并jvm调用run()方法在开启的线程中执行.</strong></h3> </td> 
  </tr> 
 </tbody> 
</table>

### 2. ###

### **经典题目:** ###