Java线程之锁对象Lock-同步问题更完美的处理方式代码实例

public class LockTest { 
  public static void main(String[] args) { 
    final Outputter1 output = new Outputter1(); 
    new Thread() { 
      public void run() { 
        output.output("zhangsan"); 
      }; 
    }.start();    
    new Thread() { 
      public void run() { 
        output.output("lisi"); 
      }; 
    }.start(); 
  } 
} 
class Outputter1 { 
  private Lock lock = new ReentrantLock();// 锁对象 
  public void output(String name) { 
    // TODO 线程输出方法 
    lock.lock();// 得到锁 
    try { 
      for(int i = 0; i < name.length(); i++) { 
        System.out.print(name.charAt(i)); 
      } 
    } finally { 
      lock.unlock();// 释放锁 
    } 
  } 
} 

public class ReadWriteLockTest { 
  public static void main(String[] args) { 
    final Data data = new Data(); 
    for (int i = 0; i < 3; i++) { 
      new Thread(new Runnable() { 
        public void run() { 
          for (int j = 0; j < 5; j++) { 
            data.set(new Random().nextInt(30)); 
          } 
        } 
      }).start(); 
    }     
    for (int i = 0; i < 3; i++) { 
      new Thread(new Runnable() { 
        public void run() { 
          for (int j = 0; j < 5; j++) { 
            data.get(); 
          } 
        } 
      }).start(); 
    } 
  } 
} 
class Data {   
  private int data;// 共享数据   
  public void set(int data) { 
    System.out.println(Thread.currentThread().getName() + "准备写入数据"); 
    try { 
      Thread.sleep(20); 
    } catch (InterruptedException e) { 
      e.printStackTrace(); 
    } 
    this.data = data; 
    System.out.println(Thread.currentThread().getName() + "写入" + this.data); 
  }   
  public void get() { 
    System.out.println(Thread.currentThread().getName() + "准备读取数据"); 
    try { 
      Thread.sleep(20); 
    } catch (InterruptedException e) { 
      e.printStackTrace(); 
    } 
    System.out.println(Thread.currentThread().getName() + "读取" + this.data); 
  } 
} 

Thread-1准备写入数据 
Thread-3准备读取数据 
Thread-2准备写入数据 
Thread-0准备写入数据 
Thread-4准备读取数据 
Thread-5准备读取数据 
Thread-2写入12 
Thread-4读取12 
Thread-5读取5 
Thread-1写入12 

public synchronized void set(int data) {...}   
public synchronized void get() {...} 

Thread-0准备写入数据 
Thread-0写入9 
Thread-5准备读取数据 
Thread-5读取9 
Thread-5准备读取数据 
Thread-5读取9 
Thread-5准备读取数据 
Thread-5读取9 
Thread-5准备读取数据 
Thread-5读取9 

class Data {   
  private int data;// 共享数据 
  private ReadWriteLock rwl = new ReentrantReadWriteLock();   
  public void set(int data) { 
    rwl.writeLock().lock();// 取到写锁 
    try { 
      System.out.println(Thread.currentThread().getName() + "准备写入数据"); 
      try { 
        Thread.sleep(20); 
      } catch (InterruptedException e) { 
        e.printStackTrace(); 
      } 
      this.data = data; 
      System.out.println(Thread.currentThread().getName() + "写入" + this.data); 
    } finally { 
      rwl.writeLock().unlock();// 释放写锁 
    } 
  }   
  public void get() { 
    rwl.readLock().lock();// 取到读锁 
    try { 
      System.out.println(Thread.currentThread().getName() + "准备读取数据"); 
      try { 
        Thread.sleep(20); 
      } catch (InterruptedException e) { 
        e.printStackTrace(); 
      } 
      System.out.println(Thread.currentThread().getName() + "读取" + this.data); 
    } finally { 
      rwl.readLock().unlock();// 释放读锁 
    } 
  } 
} 

Thread-4准备读取数据 
Thread-3准备读取数据 
Thread-5准备读取数据 
Thread-5读取18 
Thread-4读取18 
Thread-3读取18 
Thread-2准备写入数据 
Thread-2写入6 
Thread-2准备写入数据 
Thread-2写入10 
Thread-1准备写入数据 
Thread-1写入22 
Thread-5准备读取数据