Hibernate用ThreadLocal模式(线程局部变量模式)管理Session

public class ThreadLocal {
<span style="white-space:pre"> </span>private Map values = Collections.synchronizedMap(new HashMap());
<span style="white-space:pre"> </span>public Object get() {
<span style="white-space:pre"> </span>Thread curThread = Thread.currentThread();
<span style="white-space:pre"> </span>Object o = values.get(curThread);
<span style="white-space:pre"> </span>if (o == null && !values.containsKey(curThread)) {
<span style="white-space:pre">  </span>o = initialValue();
<span style="white-space:pre">  </span>values.put(curThread, o);
<span style="white-space:pre"> </span>}
<span style="white-space:pre"> </span>values.put(Thread.currentThread(), newValue);
<span style="white-space:pre"> </span>return o;
<span style="white-space:pre"> </span>}
<span style="white-space:pre"> </span>public Object initialValue() {
<span style="white-space:pre"> </span>return null;
<span style="white-space:pre"> </span>}
}

<span style="font-family:System;font-size:14px;">package com.lc.util;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
/**
 * 升级的MySessionFactory 线程局部模式
 * @author xuliugen
 */
public class HibernateUtil {
 private static SessionFactory sessionFactory = null;
 // 使用线程局部模式
 private static ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
 /*
 * 默认的构造函数
 */
 private HibernateUtil() {
 }
 /*
 * 静态的代码块
 */
 static {
 sessionFactory = new Configuration().configure().buildSessionFactory();
 }
 /*
 * 获取全新的的session
 */
 public static Session openSession() {
 return sessionFactory.openSession();
 }
 /*
 * 获取和线程关联的session
 */
 public static Session getCurrentSession() {
 Session session = threadLocal.get();
 // 判断是是是否得到
 if (session == null) {
  session = sessionFactory.openSession();
  // 把session放到 threadLocal，相当于该session已经于线程绑定
  threadLocal.set(session);
 }
 return session;
 }
}</span>

<span style="font-family:System;font-size:14px;">package com.lc.view;
import org.hibernate.Session;
import com.lc.util.HibernateUtil;
public class TestHibernateUtil {
 public static void main(String[] args) {
 Session s1 = HibernateUtil.getCurrentSession(); 
 Session s2 = HibernateUtil.getCurrentSession();
 System.out.println(s1.hashCode()+"  "+s2.hashCode());
 /*
  * 1432950766  1432950766
  * 结果是两个hashCode是一样的，证明是线程相关的
  */
 }
}</span><span style="font-family:System;font-size:14px;">
</span>