浅谈多线程中的锁的几种用法总结(必看)

package com.ietree.basicskill.mutilthread.lock;import java.util.concurrent.locks.Lock;import java.util.concurrent.locks.ReentrantLock;/** * Created by Administrator on 2017/5/17. */public class UseReentrantLock {  private Lock lock = new ReentrantLock();  public void method1(){    try {      lock.lock();      System.out.println("当前线程:" + Thread.currentThread().getName() + "进入method1..");      Thread.sleep(1000);      System.out.println("当前线程:" + Thread.currentThread().getName() + "退出method1..");      Thread.sleep(1000);    } catch (InterruptedException e) {      e.printStackTrace();    } finally {      lock.unlock();    }  }  public void method2(){    try {      lock.lock();      System.out.println("当前线程:" + Thread.currentThread().getName() + "进入method2..");      Thread.sleep(2000);      System.out.println("当前线程:" + Thread.currentThread().getName() + "退出method2..");      Thread.sleep(1000);    } catch (InterruptedException e) {      e.printStackTrace();    } finally {      lock.unlock();    }  }  public static void main(String[] args) {    final UseReentrantLock ur = new UseReentrantLock();    Thread t1 = new Thread(new Runnable() {      @Override      public void run() {        ur.method1();        ur.method2();      }    }, "t1");    t1.start();    try {      Thread.sleep(10);    } catch (InterruptedException e) {      e.printStackTrace();    }    //System.out.println(ur.lock.getQueueLength());  }}

package com.ietree.basicskill.mutilthread.lock;import java.util.concurrent.locks.ReentrantReadWriteLock;/** * Created by Administrator on 2017/5/17. */public class UseReentrantReadWriteLock {  private ReentrantReadWriteLock rwLock = new ReentrantReadWriteLock();  private ReentrantReadWriteLock.ReadLock readLock = rwLock.readLock();  private ReentrantReadWriteLock.WriteLock writeLock = rwLock.writeLock();  public void read(){    try {      readLock.lock();      System.out.println("当前线程:" + Thread.currentThread().getName() + "进入...");      Thread.sleep(3000);      System.out.println("当前线程:" + Thread.currentThread().getName() + "退出...");    } catch (Exception e) {      e.printStackTrace();    } finally {      readLock.unlock();    }  }  public void write(){    try {      writeLock.lock();      System.out.println("当前线程:" + Thread.currentThread().getName() + "进入...");      Thread.sleep(3000);      System.out.println("当前线程:" + Thread.currentThread().getName() + "退出...");    } catch (Exception e) {      e.printStackTrace();    } finally {      writeLock.unlock();    }  }  public static void main(String[] args) {    final UseReentrantReadWriteLock urrw = new UseReentrantReadWriteLock();    Thread t1 = new Thread(new Runnable() {      @Override      public void run() {        urrw.read();      }    }, "t1");    Thread t2 = new Thread(new Runnable() {      @Override      public void run() {        urrw.read();      }    }, "t2");    Thread t3 = new Thread(new Runnable() {      @Override      public void run() {        urrw.write();      }    }, "t3");    Thread t4 = new Thread(new Runnable() {      @Override      public void run() {        urrw.write();      }    }, "t4");//    t1.start();//    t2.start();//    t1.start(); // R//    t3.start(); // W    t3.start();    t4.start();  }}

package com.ietree.basicskill.mutilthread.lock;import java.util.concurrent.locks.Condition;import java.util.concurrent.locks.Lock;import java.util.concurrent.locks.ReentrantLock;/** * Created by Administrator on 2017/5/17. */public class UseCondition {  private Lock lock = new ReentrantLock();  private Condition condition = lock.newCondition();  public void method1(){    try {      lock.lock();      System.out.println("当前线程：" + Thread.currentThread().getName() + "进入等待状态..");      Thread.sleep(3000);      System.out.println("当前线程：" + Thread.currentThread().getName() + "释放锁..");      condition.await();  // Object wait      System.out.println("当前线程：" + Thread.currentThread().getName() +"继续执行...");    } catch (Exception e) {      e.printStackTrace();    } finally {      lock.unlock();    }  }  public void method2(){    try {      lock.lock();      System.out.println("当前线程：" + Thread.currentThread().getName() + "进入..");      Thread.sleep(3000);      System.out.println("当前线程：" + Thread.currentThread().getName() + "发出唤醒..");      condition.signal();    //Object notify    } catch (Exception e) {      e.printStackTrace();    } finally {      lock.unlock();    }  }  public static void main(String[] args) {    final UseCondition uc = new UseCondition();    Thread t1 = new Thread(new Runnable() {      @Override      public void run() {        uc.method1();      }    }, "t1");    Thread t2 = new Thread(new Runnable() {      @Override      public void run() {        uc.method2();      }    }, "t2");    t1.start();    t2.start();  }}

package com.ietree.basicskill.mutilthread.lock;import java.util.concurrent.locks.Condition;import java.util.concurrent.locks.ReentrantLock;/** * Created by Administrator on 2017/5/17. */public class UseManyCondition {  private ReentrantLock lock = new ReentrantLock();  private Condition c1 = lock.newCondition();  private Condition c2 = lock.newCondition();  public void m1(){    try {      lock.lock();      System.out.println("当前线程：" +Thread.currentThread().getName() + "进入方法m1等待..");      c1.await();      System.out.println("当前线程：" +Thread.currentThread().getName() + "方法m1继续..");    } catch (Exception e) {      e.printStackTrace();    } finally {      lock.unlock();    }  }  public void m2(){    try {      lock.lock();      System.out.println("当前线程：" +Thread.currentThread().getName() + "进入方法m2等待..");      c1.await();      System.out.println("当前线程：" +Thread.currentThread().getName() + "方法m2继续..");    } catch (Exception e) {      e.printStackTrace();    } finally {      lock.unlock();    }  }  public void m3(){    try {      lock.lock();      System.out.println("当前线程：" +Thread.currentThread().getName() + "进入方法m3等待..");      c2.await();      System.out.println("当前线程：" +Thread.currentThread().getName() + "方法m3继续..");    } catch (Exception e) {      e.printStackTrace();    } finally {      lock.unlock();    }  }  public void m4(){    try {      lock.lock();      System.out.println("当前线程：" +Thread.currentThread().getName() + "唤醒..");      c1.signalAll();    } catch (Exception e) {      e.printStackTrace();    } finally {      lock.unlock();    }  }  public void m5(){    try {      lock.lock();      System.out.println("当前线程：" +Thread.currentThread().getName() + "唤醒..");      c2.signal();    } catch (Exception e) {      e.printStackTrace();    } finally {      lock.unlock();    }  }  public static void main(String[] args) {    final UseManyCondition umc = new UseManyCondition();    Thread t1 = new Thread(new Runnable() {      @Override      public void run() {        umc.m1();      }    },"t1");    Thread t2 = new Thread(new Runnable() {      @Override      public void run() {        umc.m2();      }    },"t2");    Thread t3 = new Thread(new Runnable() {      @Override      public void run() {        umc.m3();      }    },"t3");    Thread t4 = new Thread(new Runnable() {      @Override      public void run() {        umc.m4();      }    },"t4");    Thread t5 = new Thread(new Runnable() {      @Override      public void run() {        umc.m5();      }    },"t5");    t1.start();  // c1    t2.start();  // c1    t3.start();  // c2    try {      Thread.sleep(2000);    } catch (InterruptedException e) {      e.printStackTrace();    }    t4.start();  // c1    try {      Thread.sleep(2000);    } catch (InterruptedException e) {      e.printStackTrace();    }    t5.start();  // c2  }}