package com.home;
public class SynchronizedTest implements Runnable {
  public synchronized void method1() {
    System.out.println("method1获得锁，正常运行!");
    method2();
  }
  public synchronized void method2() {
    System.out.println("method2获得锁，也正常运行!");
  }
  @Override
  public void run() {
    method1();
  }
  public static void main(String[] args) {
    SynchronizedTest st = new SynchronizedTest();
    new Thread(st).start();
    new Thread(st).start();
  }
}

package com.home;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class LockTest implements Runnable {
  Lock lock = new ReentrantLock();
  public void method1() {
    lock.lock();
    System.out.println("method1获得锁，正常运行!");
    method2();
    lock.unlock();
  }
  public void method2() {
    lock.lock();
    System.out.println("method2获得锁，也正常运行!");
    lock.unlock();
  }
  @Override
  public void run() {
    method1();
  }
  public static void main(String[] args) {
    LockTest lt = new LockTest();
    new Thread(lt).start();
    new Thread(lt).start();
  }
}

method1获得锁，正常运行!
method2获得锁，也正常运行!
method1获得锁，正常运行!
method2获得锁，也正常运行!

package com.home;
import java.util.Random;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
class ReadWrte {
  // 共享数据，可以多个线程读数据，只能有一个线程写数据
  private int data;
  // 创建读写锁
  ReadWriteLock rwLock = new ReentrantReadWriteLock();
  /**
   * 读数据，上读锁
   */
  public void get() {
    // 读锁
    rwLock.readLock().lock();
    try {
      System.out.println(Thread.currentThread().getName() + ",Read!");
      Thread.sleep((long) Math.random() * 1000);
      System.out.println(Thread.currentThread().getName() + " 读出的数据为：" +
        this.getData());
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      rwLock.readLock().unlock();
    }
  }
  /**
   * 写数据，上写锁
   *
   * @param data
   */
  public void put(int data) {
    // 写锁
    rwLock.writeLock().lock();
    try {
      System.out.println(Thread.currentThread().getName() + ",Write!");
      Thread.sleep((long) Math.random() * 1000);
      this.setData(data);
      System.out.println(Thread.currentThread().getName() + " 写入的数据为：" +
        this.getData());
    } catch (InterruptedException e) {
      e.printStackTrace();
    } finally {
      rwLock.writeLock().unlock();
    }
  }
  public int getData() {
    return data;
  }
  public void setData(int data) {
    this.data = data;
  }
}
/**
 * 测试类
 *
 * @author itmyhome
 *
 */
public class ReadWriteLockTest {
  /**
   * @param args
   */
  public static void main(String[] args) {
    // 创建ReadWrte对象
    final ReadWrte rw = new ReadWrte();
    for (int i = 0; i < 10; i++) {
      // 创建并启动10个读线程
      new Thread(new Runnable() {
          @Override
          public void run() {
            rw.get();
          }
        }).start();
      // 创建并启动10个写线程
      new Thread(new Runnable() {
          @Override
          public void run() {
            // 写入一个随机数
            rw.put(new Random().nextInt(8));
          }
        }).start();
    }
  }
}

Thread-0,Read!
Thread-4,Read!
Thread-8,Read!
Thread-12,Read!
Thread-0 读出的数据为：0
Thread-4 读出的数据为：0
Thread-8 读出的数据为：0
Thread-12 读出的数据为：0
Thread-19,Write!
Thread-19 写入的数据为：5
Thread-7,Write!
Thread-7 写入的数据为：7
Thread-3,Write!
Thread-3 写入的数据为：4
Thread-16,Read!
Thread-16 读出的数据为：4
Thread-11,Write!
Thread-11 写入的数据为：0
Thread-15,Write!
Thread-15 写入的数据为：5
Thread-2,Read!
Thread-2 读出的数据为：5
Thread-17,Write!
Thread-17 写入的数据为：2
Thread-6,Read!
Thread-6 读出的数据为：2
Thread-1,Write!
Thread-1 写入的数据为：5
Thread-13,Write!
Thread-13 写入的数据为：4
Thread-9,Write!
Thread-9 写入的数据为：7
Thread-5,Write!
Thread-5 写入的数据为：2
Thread-10,Read!
Thread-10 读出的数据为：2
Thread-18,Read!
Thread-14,Read!
Thread-18 读出的数据为：2
Thread-14 读出的数据为：2