mybatis解析--转载

转载http://www.cnblogs.com/wushiqi54719880/archive/2011/07/26/2117601.html

本文主要介绍了如何使用mybatis进行简单的数据库操作。本人使用的是mybatis3.05。

Mybatics 是apache 开源项目的一个数据持久层框架，其包括sql maper（sql 映射）以及 Data access object的内容。我们将通过以下示例来讲解mybatics 的相关内容。

1.创建数据库表（User表）

CREATE TABLE `NewTable` (`userId`  bigint(20) NOT NULL AUTO_INCREMENT ,`userName`  varchar(30) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL ,`password`  varchar(80) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL ,`comment`  varchar(250) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,PRIMARY KEY (`userId`),UNIQUE INDEX `UQ_User_userName` (`userName`) USING BTREE)

2.2. 创建实体类

package com.mybatis.config;public class User {    private int userId;    private String userName;    private String password;    private String comment;

    // get  set 方法    public int getUserId() {        return userId;    }    public void setUserId(int userId) {        this.userId = userId;    }    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;    }    public String getComment() {        return comment;    }    public void setComment(String comment) {        this.comment = comment;    }}

3. 定义数据访问接口

package com.mybatis.config;import java.util.List;public interface UserDao {

    // 对数据的访问主要为 增删改查        public int insert(User user);        public int update(User user);        public int delete(String userName);        public List<User> selectAll();        public int countAll();        public User findByUserName(String userName);}

4.创建MyBatis映射文件（UserDaoMapper.xml）--数据访问接口映射文件，在xml文件中实现

<?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"> <mapper namespace="com.mybatis.config.UserDao">    <select id="countAll" resultType="int">        select count(*) c from user;    </select>        <select id="selectAll" resultType="com.mybatis.config.User">        select * from user order by userName asc    </select>        <insert id="insert" parameterType="com.mybatis.config.User">        insert into user(userName,password,comment) values(#{userName},#{password},#{comment})    </insert>        <update id="update" parameterType="com.mybatis.config.User">        update user set userName=#{userName},password=#{password},comment=#{comment} where userName=#{userName}    </update>        <delete id="delete" parameterType="int">        delete from user where userName=#{userName}    </delete>        <select id="findByUserName" parameterType="String" resultType="com.mybatis.config.User">        select * from user where userName=#{userName}    </select></mapper>

5. 创建mybatis配置文件--- 配置文件1，写入数据访问映射文件的路径 ，userMapperDao.xml 文件

MyBatis-Configuration.xml

<?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">
<configuration>
    <mappers>
        <mapper resource="com/mybatis/UserDaoMapper.xml"/>
    </mappers>
</configuration>

6  编写服务层接口（UserService.java）

package com.mybatis;

public interface UserService {
    public int countAll();

    public List<User> listAll();
}

7 编写服务层实现代码（UserServiceImpl.java）

package com.mybatis;
public class UserServiceImpl implements UserService {
    private UserDao userDao;

    public UserDao getUserDao() {
        return userDao;
    }
    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
    
    public int countAll() {
        return this.userDao.countAll();
    }

   public list<User> listAll()

   {

        return this.userDao.selectAll();

   }
}

8 编写spring配置文件（applicationContext.xml）

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
        <property name="url" value="jdbc:mysql://localhost:3306/hlp?useUnicode=true&amp;characterEncoding=UTF-8&amp;zeroDateTimeBehavior=convertToNull"></property>
        <property name="username" value="root"></property>
        <property name="password" value="1234"></property>
        <property name="maxActive" value="100"></property>
        <property name="maxIdle" value="30"></property>
        <property name="maxWait" value="500"></property>
        <property name="defaultAutoCommit" value="true"></property>
    </bean>

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="configLocation" value="classpath:MyBatis-Configuration.xml"></property>
        <property name="dataSource" ref="dataSource" />
    </bean>

    <bean id="userDao" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <property name="mapperInterface" value="com.mybatis.UserDao"></property>
        <property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
    </bean>

    <bean id="userService" class="com.mybatis.UserServiceImpl">
        <property name="userDao" ref="userDao"></property>
    </bean>

</beans>

9. 编写测试代码

package com.mybatis;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;


public class UserServiceTest {
    
    @Test
    public void userServiceTest(){
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserService userService = (UserService)context.getBean("userService");
        System.out.println(userService.countAll());
    }
}