Hibernate二级缓存

使用Java工程实现一个Hibernate二级缓存，使用Ehcache方法，工程目录如图





首先新建一个pojo

package com.hibernate.pojo;

import java.io.Serializable;

import java.util.Date;

public class User implements Serializable{

/**

*

*/

private static final long serialVersionUID = 1L;

private String id;

private String name;

private String password;

private Date createTime;

private Date expireTime;

public String getId() {

return id;

}

public void setId(String id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getPassword() {

return password;

}

public void setPassword(String password) {

this.password = password;

}

public Date getCreateTime() {

return createTime;

}

public void setCreateTime(Date createTime) {

this.createTime = createTime;

}

public Date getExpireTime() {

return expireTime;

}

public void setExpireTime(Date expireTime) {

this.expireTime = expireTime;

}

}

然后建立对应的User.hbm.xml

<?xml version="1.0"?>

<!DOCTYPE hibernate-mapping PUBLIC

"-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="com.hibernate.pojo"> <!-- 所在的包 -->

<class name="User" table="user">

<id name="id">

<generator class="native"/> <!-- 自增 -->

</id>

<property name="name"/>

<property name="password"/>

<property name="createTime"/>

<property name="expireTime"/>

</class>

</hibernate-mapping>

新建dao借口，并且实现

package com.hibernate.dao;

import java.util.List;

import com.hibernate.pojo.User;

import com.page.ben.Pager;

public interface UserDao {

public void saveUser(User user);

public User findUserByName(String name);

public User findUserById(String name);

public void updateUser(User user);

public void remove(User user);

public long geCount();

public List<User> findByPage(Pager page);

}

package com.hibernate.dao;

import java.util.List;

import org.hibernate.HibernateException;

import org.hibernate.Query;

import org.hibernate.Session;

import org.hibernate.Transaction;

import com.hibernate.pojo.User;

import com.hibernate.utils.HibernateUtil;

import com.page.ben.Pager;

public class UserDaoImpl implements UserDao{

private Session s = null;

private Transaction tx = null;

@Override

public void saveUser(User user) {

try{

s = HibernateUtil.getSession();

tx = s.beginTransaction();

s.save(user);

tx.commit();

}catch(HibernateException e){

tx.rollback();

}finally{

if(s!=null){

s.close();

}

}

}

@Override

public User findUserByName(String name) {

User user = null;

String sql="from User where name=?";

try{

s = HibernateUtil.getSession();

tx = s.beginTransaction();

Query query = s.createQuery(sql);

query.setString(0, name);

query.setCacheable(true);

user = (User)query.uniqueResult();

query = null;

tx.commit ();

}catch(HibernateException e){

tx.rollback();

}finally{

if(s!=null){

s.close();

}

}

return user;

}

@Override

public User findUserById(String name) {

User user = null;

String sql="from User where name=?";

try{

s = HibernateUtil.getSession();

tx = s.beginTransaction();

Query query = s.createQuery(sql);

query.setString(0, name);

query.setCacheable(true);

user = (User)query.uniqueResult();

tx.commit ();

}catch(HibernateException e){

tx.rollback();

}finally{

if(s!=null){

s.close();

}

}

return user;

}

@Override

public void updateUser(User user) {

String sql="update User set password=? where name=?";

try{

s = HibernateUtil.getSession();

tx = s.beginTransaction();

Query query = s.createQuery(sql);

query.setString(0, user.getPassword());

query.setString(1, user.getName());

query.executeUpdate();

tx.commit ();

}catch(HibernateException e){

tx.rollback();

}finally{

if(s!=null){

s.close();

}

}

}

@Override

public void remove(User user) {

String sql="delete from User where name=?";

try{

s = HibernateUtil.getSession();

tx = s.beginTransaction();

Query query = s.createQuery(sql);

query.setString(0, user.getName());

query.executeUpdate();

tx.commit ();

}catch(HibernateException e){

tx.rollback();

}finally{

if(s!=null){

s.close();

}

}

}

@Override

public long geCount(){

long count=0;

String sql="select count(*) from User";

try{

s = HibernateUtil.getSession();

tx = s.beginTransaction();

Query query = s.createQuery(sql);

count= (long) query.uniqueResult();

tx.commit ();

}catch(HibernateException e){

tx.rollback();

}finally{

if(s!=null){

s.close();

}

}

return count;

}

@Override

public List<User> findByPage(Pager page) {

List<User> list=null;

StringBuffer buf = new StringBuffer("from User order by id desc");

String sql=buf.toString();

System.out.println(sql);

try{

System.out.println("---------");

s = HibernateUtil.getSession();

tx = s.beginTransaction();

Query query = s.createQuery(sql);

query.setFirstResult((page.getPageNo()-1)*page.getPageSize());

query.setMaxResults(page.getPageSize());

query.setCacheable(true);

list= query.list();

query=null;

tx.commit ();

}catch(HibernateException e){

tx.rollback();

}finally{

if(s!=null){

s.close();

}

}

System.out.println("---------"+list.size());

return list;

}

}

然后写一个通用类用来读Hibernate的文件类

package com.hibernate.utils;

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.cfg.Configuration;

public class HibernateUtil {

private static SessionFactory sessionFactory;

/**

* 主要为了获得session

* @return

*/

public static SessionFactory getSessionFactory() {

return sessionFactory;

}

/*getsession方法*/

public static Session getSession(){

return sessionFactory.openSession();

}

private HibernateUtil(){

}

static{

/*加载配置文件*/

Configuration configuration=new Configuration();

configuration.configure();

sessionFactory =configuration.buildSessionFactory();

}

}

在src先放入配置文件hibernate.cfg.xml

<?xml version='1.0' encoding='UTF-8'?>

<!DOCTYPE hibernate-configuration PUBLIC

"-//Hibernate/Hibernate Configuration DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools. -->

<hibernate-configuration>

<session-factory>

<property name="dialect">

org.hibernate.dialect.MySQLDialect

</property>

<property name="connection.url">

jdbc:mysql://127.0.0.1:3306/hibernate

</property>

<property name="connection.username">root</property>

<property name="connection.password">root</property>

<property name="connection.driver_class">

com.mysql.jdbc.Driver

</property>

<property name="myeclipse.connection.profile">Test</property>

<property name="hbm2ddl.auto">update</property>

<property name="hibernate.connection.autocommit">true</property>

<property name="show_sql">true</property>

<property name="defaultAutoCommit">true</property>

<property name="maxActive">10000</property>

<property name="maxIdle">50</property>

<property name="maxWait">3000</property>

<property name="initialSize">10</property>

<property name="minIdle">20</property>

<property name="dialect">

org.hibernate.dialect.MySQLDialect

</property>

<!-- 配置二级缓存提供商，注意此处并不是缓存的jar包 -->

<!-- <property name="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory</property> -->

<property name="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</property>

<property name="hibernate.cache.use_second_level_cache">true</property>

<property name="hibernate.cache.use_query_cache">true</property>

<!-- 把user.hbm.xml这个映射文件引入进来。 -->

<mapping resource="com/hibernate/pojo/User.hbm.xml" />

</session-factory>

</hibernate-configuration>

同时还有缓存配置文件

<?xml version="1.0" encoding="UTF-8"?>

<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../config/ehcache.xsd">

<!-- 如果缓存内存溢出，则存储到硬盘空间 -->

<diskStore path="java.io.path"/>

<!-- 内存支持的最大对象的数量 -->

<!-- 对象是否永久生效，建议为false，这样下面的两个参数才会有效 -->

<!-- 对象的间隔周期，默认单位为秒。即60秒后如果还没人用这个对象，会提前销毁 -->

<!-- 对象的生命周期，默认单位为秒 -->

<!-- 是否支持溢出到硬盘，建议为true -->

<!-- 硬盘上支持的最大对象的数量 -->

<!-- 对象的替换策略 -->

<defaultCache

maxElementsInMemory="10000"

eternal="false"

timeToIdleSeconds="2"

timeToLiveSeconds="3"

overflowToDisk="true"

maxElementsOnDisk="10000000"

memoryStoreEvictionPolicy="LRU"

/>

</ehcache>

写一个测试类

package com.hibernate.test;

import java.util.Date;

import java.util.List;

import com.hibernate.dao.UserDao;

import com.hibernate.dao.UserDaoImpl;

import com.hibernate.pojo.User;

import com.page.ben.Pager;

import com.page.service.PageService;

import com.page.service.impl.PageServiceImpl;

public class Test {

private static String pagerMethod;

private static Pager page;

private static int currentPage = 1;

public static String getPagerMethod() {

return pagerMethod;

}

public static void setPagerMethod(String pagerMethod) {

Test.pagerMethod = pagerMethod;

}

public static Pager getPage() {

return page;

}

public static void setPage(Pager page) {

Test.page = page;

}

public static int getCurrentPage() {

return currentPage;

}

public static void setCurrentPage(int currentPage) {

Test.currentPage = currentPage;

}

private static UserDao dao = new UserDaoImpl();

public static void main(String[] args) {

for(int i=0;i<50;i++){

User user = new User();

user.setName("admin"+i);

user.setPassword("123");

user.setCreateTime(new Date());

user.setExpireTime(new Date());

// dao.saveUser(user);

}

User user3 = new User();

user3.setName("用户名");

user3.setPassword("456");

// dao.updateUser(user3);

// dao.remove(user3);

// System.out.println(dao.geCount());

// 分页测试

String inpage="1";

String inmeth=null;

// String inmeth="first";//首页

// String inmeth="forward";//下一页

// String inmeth="backward";//上一页

// String inmeth="last";//末页

PageServiceImpl pageServiceImpl=new PageServiceImpl();

if(inpage==null){

currentPage=1;

}else {

currentPage=Integer.valueOf(inpage);

}

pagerMethod = inmeth;

int rows = 0;

rows = (int)dao.geCount();

page = new Pager(5, rows);

// System.out.println("首页"+page.getFirstPageNo());

// System.out.println("末页"+page.getLastPageNo());

// System.out.println("下一页"+page.getNextPageNo());

// System.out.println("页数"+page.getPageCount());

// System.out.println("当前页"+page.getPageNo());

// System.out.println("每页显示数"+page.getPageSize());

// System.out.println("上一页"+page.getPrePageNo());

// System.out.println("行数"+page.getRowCount());

//

page = pageServiceImpl.getPagerByMethodName(page,pagerMethod, currentPage, rows);

System.out.println("---------------------");

System.out.println("首页"+page.getFirstPageNo());

System.out.println("末页"+page.getLastPageNo());

System.out.println("下一页"+page.getNextPageNo());

System.out.println("页数"+page.getPageCount());

System.out.println("当前页"+page.getPageNo());

System.out.println("每页显示数"+page.getPageSize());

System.out.println("上一页"+page.getPrePageNo());

System.out.println("行数"+page.getRowCount());

List<User> list = dao.findByPage(page);

System.out.println("======================");

for (User user : list) {

System.out.println(user.getId()+" "+user.getName());

}

System.out.println("总记录数"+rows);

System.out.println("总页数"+page.getPageCount());

System.out.println("每页行数"+page.getPageSize());

System.out.println("当前页"+currentPage);

List<User> lists = dao.findByPage(page);

for (User user : list) {

System.out.println(user.getId()+" "+user.getName());

}

//缓存测试

User user2=dao.findUserByName("admin0");

System.out.println(user2.getPassword()+" "+user2.getCreateTime());

User user4=dao.findUserById("admin0");

System.out.println(user4.getPassword()+" "+user4.getCreateTime());

try {

Thread.sleep(2001);

} catch (InterruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

long a=System.currentTimeMillis();

User user5=dao.findUserById("admin0");

System.out.println(System.currentTimeMillis()-a);

System.out.println(user5.getPassword()+" "+user5.getCreateTime());

long b=System.currentTimeMillis();

User user6=dao.findUserById("admin0");

System.out.println(System.currentTimeMillis()-b);

System.out.println(user6.getPassword()+" "+user6.getCreateTime());

}

}

其中工程中用到了分页的一个自己封装jar包，实现可以看另一篇博客
http://blog.csdn.net/wang_shuyu/article/details/53675928