spring+Mybatis+ memcached简单示例

spring、Mybatis、memcached是什么，干什么的我这里就不介绍了。

我这边用的是spring是3.2.4的，Mybatis是3.2.2的，数据库用的是postgreSQL

一、首先我们先来准备环境吧：

1、memcached的准备

1、下载及安装服务器端软件：

windows版本：http://yunpan.cn/QIU88cTyMbY6w

下载后将其解压，随便放在一个目录下，比如我放的是F:\mysoft\memcached\soft\server下，

在cmd中输入：

C:\Documents and Settings\admin>f:F:\>cd F:\mysoft\memcached\soft\server\memcached-1.2.6-win3F:\mysoft\memcached\soft\server\memcached-1.2.6-win32-bin>memcached.exe -dinstall（安装）F:\mysoft\memcached\soft\server\memcached-1.2.6-win32-bin>memcached.exe -d start（启动）

默认的缓存大小为64M，如果不够用，请打开注册表，找到：

HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/memcached  Server . 

将其修改为：

“F:\mysoft\memcached\soft\server\memcached-1.2.6-win32-bin/memcached.exe” -d runservice -m 512  

2、下载客户端包

http://yunpan.cn/QIUWjULt4ujd8

至此memcached准备好了。

2、jar包

如下：

3、我的项目结构图

二、接下来就是编写代码了（具体不讲了，语文没学好，不会面熟，直接上代码吧）

1、数据库表

CREATE TABLE users(  id integer NOT NULL,  username character(20),  password character(20),  CONSTRAINT user_pkey PRIMARY KEY (id))WITH (  OIDS=FALSE);ALTER TABLE users  OWNER TOpostgres;

再插入点数据吧：

INSERT INTO users(id, username, password) VALUES (3, 'guozi3', '123456');

2、User.java

package org.mybatisSpring.example.entity;import java.io.Serializable;/* * 注意，一定要实现Serializable，这个memcached要求的 */public class User implements Serializable{/** *  */private static final long serialVersionUID = -6805933163488630157L;private int id;private String userName;private String passWord;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getUserName() {return userName;}public void setUserName(String userName) {this.userName = userName;}public String getPassWord() {return passWord;}public void setPassWord(String passWord) {this.passWord = passWord;}}

3、UserDao.java（注意这里一定要是接口，具体的实现不需要写，值需要在UserMapper.xml配置即可，也可以向如下注释的用注解，这里不讲注解方式）

package org.mybatisSpring.example.dao;import org.mybatisSpring.example.entity.User;public interface UserDao {//@Select("select * from users where id=#{id}")public User getUserById(Integer id);//@Delete("DELETE FROM users WHERE id=#{id}")public int deleteById(int id);//@Select("select count(*) from users")public int countUser();//@Insert("INSERT INTO users(id, username, password) VALUES (#{id}, #{userName}, #{passWord})")public int saveUser(User user);//@Update("UPDATE users SET username=#{userName}, password=#{passWord} WHERE id=#{id}")public int updateUser(User user);}

4、UserMapper.xml（mybatis的映射文件当然你也可以用注解，那就不需要这个了）

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE mapper  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"  "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><!-- 命名空间 是必须的 --><mapper namespace="org.mybatisSpring.example.dao.UserDao"><select id="getUserById" parameterType="int" resultType="User">select * from users where id=#{id} </select></mapper>

5、web.xml

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5"><display-name>MybatisSpringDemo</display-name><!-- 这个是后面加上的，没加之前启动服务器会报java.lang.IllegalStateException: BeanFactory not initialized or already closed - call 'refresh' before accessing beans via the ApplicationContext这个错 --><context-param><param-name>contextConfigLocation</param-name><param-value>        classpath*:/applicationContext.xml</param-value></context-param><!-- 添加spring支持 --><listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener>  <welcome-file-list><welcome-file>index.jsp</welcome-file></welcome-file-list></web-app>

6、config.properties（数据的配置信息及memcached的配置都放在这里）

dataSource.driver=org.postgresql.DriverdataSource.url = jdbc:postgresql://127.0.0.1:5432/testdataSource.username = postgresdataSource.password = postgres#memcached settingmemcache.server=127.0.0.1:11211memcache.initConn=20memcache.minConn=10memcache.maxConn=50memcache.maintSleep=3000memcache.nagle=falsememcache.socketTO=3000

7、mybatis-config.xml（mybatis的配置文件）

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"><!-- XML 配置文件包含对 MyBatis 系统的核心设置,包含获取数据库连接实例的数据源和 决定事务范围和控制的事务管理器。 --><configuration><typeAliases><typeAlias alias="User" type="org.mybatisSpring.example.entity.User" /></typeAliases><mappers><mapper resource="org/mybatisSpring/example/entity/UserMapper.xml" /></mappers></configuration>

8、UserService.java

package org.mybatisSpring.example.service;import org.mybatisSpring.example.entity.User;public interface UserService {public User getUserById(Integer id);}

9、UserServiceImpl.java（这里用到了memcached,但是用之前还要在spring的配置文件中配置，稍后会附上spring的配置文件代码）

package org.mybatisSpring.example.service.Impl;import org.mybatisSpring.example.dao.UserDao;import org.mybatisSpring.example.entity.User;import org.mybatisSpring.example.service.UserService;import com.danga.MemCached.MemCachedClient;public class UserServiceImpl implements UserService {private UserDao userDao;private MemCachedClient memCachedClient;public void setUserDao(UserDao userDao) {this.userDao = userDao;}public void setMemCachedClient(MemCachedClient memCachedClient) {this.memCachedClient = memCachedClient;}public MemCachedClient getMemCachedClient() {return memCachedClient;}@Overridepublic User getUserById(Integer id) {User user;if(this.memCachedClient.get("user") != null){System.out.println("缓存中的user");System.out.println(this.memCachedClient.get("user"));user = (User) this.memCachedClient.get("user");}else{System.out.println("数据库中查询出来的user");user = userDao.getUserById(id);this.memCachedClient.add("user", user);}return user;}}

10、applicationContext.xml（这个很重要，并且这里的default-lazy-init="true"会报ERROR com.schooner.MemCached.SchoonerSockIOPool - attempting to get SockIO from uninitialized pool错误）

<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:tx="http://www.springframework.org/schema/tx"xmlns:jpa="http://www.springframework.org/schema/data/jpa"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsdhttp://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsdhttp://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.2.xsd"default-lazy-init="false"><context:property-placeholder location="classpath:/config.properties" /><!-- 数据源的定义 --><bean id="dataSource"class="org.springframework.jdbc.datasource.DriverManagerDataSource"><property name="driverClassName" value="${dataSource.driver}" /><property name="url" value="${dataSource.url}" /><property name="username" value="${dataSource.username}" /><property name="password" value="${dataSource.password}" /></bean><bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><property name="configLocation" value="classpath:mybatis-config.xml"></property><property name="dataSource" ref="dataSource" /></bean><bean id="userDao" class="org.mybatis.spring.mapper.MapperFactoryBean"><property name="mapperInterface" value="org.mybatisSpring.example.dao.UserDao" /><property name="sqlSessionFactory" ref="sqlSessionFactory" /></bean><bean id="userService" class="org.mybatisSpring.example.service.Impl.UserServiceImpl"><property name="userDao" ref="userDao" /><property name="memCachedClient" ref="memCachedClient" /></bean><!-- memcached配置 --><bean id="memcachedPool" class="com.danga.MemCached.SockIOPool"factory-method="getInstance" init-method="initialize"destroy-method="shutDown"> <constructor-arg><value>memCachedPool</value></constructor-arg>         <property name="servers"><list><value>${memcache.server}</value></list></property>        <property name="initConn"><value>${memcache.initConn}</value></property>         <property name="minConn"><value>${memcache.minConn}</value></property> <property name="maxConn"><value>${memcache.maxConn}</value></property> <property name="maintSleep"><value>${memcache.maintSleep}</value></property> <property name="nagle"><value>${memcache.nagle}</value></property> <property name="socketTO"><value>${memcache.socketTO}</value></property></bean> <bean id="memCachedClient" class="com.danga.MemCached.MemCachedClient"><constructor-arg><value>memCachedPool</value></constructor-arg></bean></beans>

11、下面我们来测试下Test.java

package org.mybatisSpring.example.test;import org.mybatisSpring.example.entity.User;import org.mybatisSpring.example.service.UserService;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Test {public static void main(String[] args) {ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");UserService userService = (UserService) context.getBean("userService");User user = userService.getUserById(3);System.out.println(user.getUserName());}}

结果：

第一次运行：

log4j:WARN No appenders could be found for logger (org.springframework.core.env.StandardEnvironment).
log4j:WARN Please initialize the log4j system properly.
数据库中查询出来的user
guozi3  

第二次运行（不是直接插数据库，而是从缓存中取的数据）：

log4j:WARN No appenders could be found for logger (org.springframework.core.env.StandardEnvironment).
log4j:WARN Please initialize the log4j system properly.
缓存中的user
org.mybatisSpring.example.entity.User@12e8b9c
guozi3

好了，到这里就完成了。下班回家了

MybatisSpringDemo.zip