Mybatis入门

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项目依赖
创建domain类、dao接口、daoImpl类、mapper接口
从XML中读取SqlSessionFactory
测试类

项目依赖：

如果使用Maven来构建项目，那么在pom.xml文件中添加以下依赖：

<dependency>    <groupId>mysql</groupId>    <artifactId>mysql-connector-java</artifactId>    <version>5.1.27</version></dependency><dependency>    <groupId>org.mybatis</groupId>    <artifactId>mybatis</artifactId>    <version>3.3.0</version></dependency>

<dependency>    <groupId>log4j</groupId>    <artifactId>log4j</artifactId>    <version>1.2.17</version></dependency>
<dependency>    <groupId>junit</groupId>    <artifactId>junit</artifactId>    <version>4.12</version></dependency>

创建domain类、dao类、mapper类

创建domain类 -- Admin.java

package com.mob.domain;/** * Created by jianwl on 2015/11/17. */public class Admin {    private Long id;    private String userName;    private String password;    private String nickName;    public Long getId() {        return id;    }    public void setId(Long 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;    }    public String getNickName() {        return nickName;    }    public void setNickName(String nickName) {        this.nickName = nickName;    }}

创建dao接口 -- AdminDao.java

package com.mob.dao;import com.mob.domain.Admin;import org.apache.ibatis.session.SqlSession;/** * Created by jianwl on 2015/11/17. */public interface AdminDao {    Admin getAdminById(SqlSession sqlSession,Long id);}

创建daoImpl类 -- AdminDaoImpl.java

package com.mob.dao;import com.mob.domain.Admin;import com.mob.mapper.AdminMapper;import org.apache.ibatis.session.SqlSession;/** * Created by jianwl on 2015/11/17. */public class AdminDaoImpl implements AdminDao {    @Override    public Admin getAdminById(SqlSession sqlSession, Long id) {        AdminMapper mapper = sqlSession.getMapper(AdminMapper.class);        return mapper.getAdminById(id);    }}

创建mapper接口 -- AdminMapper.java

package com.mob.mapper;import com.mob.domain.Admin;import org.apache.ibatis.session.SqlSession;/** * Created by jianwl on 2015/11/17. */public interface AdminMapper {    Admin getAdminById(Long id);}

从XML中读取SqlSessionFactory

每个基于 MyBatis 的应用都是以一个 SqlSessionFactory 的实例为中心的；SqlSessionFactory 的实例可以通过 SqlSessionFactoryBuilder 获得，然后通过SqlSessionFactory实例得到SqlSession；创建一个工具类MybatisUtil.java 获取SqlSessionFactory实例

public class MybatisUtil {    private static final Logger logger = Logger.getLogger(MybatisUtil.class);    private static SqlSessionFactory sqlSessionFactory_mybatis_W = null;    private static final String CONF_MYBATIS_W = "db_mybatis_conf/mybatis-conf.xml";     static {        logger.info(">>>>>>>>>>>>>>>>>>>>>INIT MybatisUtil BEGIN<<<<<<<<<<<<<<<<<<<<<<");        Reader rdr;        try {            rdr = Resources.getResourceAsReader(CONF_MYBATIS_W);            sqlSessionFactory_mybatis_W = new SqlSessionFactoryBuilder().build(rdr);            rdr.close();        } catch (IOException e){            e.printStackTrace();        }        logger.info(">>>>>>>>>>>>>>>>>>>INIT MybatisUtil FINSH<<<<<<<<<<<<<<<<<<<<<<<<<<<");    }    public static SqlSessionFactory getSqlSessionFactory_mybatis_W(){        return sqlSessionFactory_mybatis_W;    }}

mybatis-conf.xml 配置文件

</pre><p><pre name="code" class="html"><?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>    <properties resource="mysql/config.properties"></properties>    <typeAliases>        <typeAlias type="com.mob.domain.Admin" alias="Admin"/>    </typeAliases>    <environments default="${environment}">        <environment id="local">            <transactionManager type="${transactionManager_type}"/>            <dataSource type="${datasource_type}">                <property name="driver" value="${driver}" />                <property name="url" value="${hermes-url}" />                <property name="username" value="${hermes-username}" />                <property name="password" value="${hermes-password}" />                <property name="poolMaximumIdleConnections" value="${jdbc.minPoolSize}" />                <property name="poolMaximumActiveConnections" value="${jdbc.maxPoolSize}" />                <property name="poolTimeToWait" value="${jdbc.maxIdleTime}" />                <property name="poolPingQuery" value="SELECT NOW()" />                <property name="poolPingEnabled" value="true" />            </dataSource>        </environment>        <environment id="development">            <transactionManager type="${transactionManager_type}"/>            <dataSource type="${datasource_type}">                <property name="driver" value="${driver}" />                <property name="url" value="${interact-url}" />                <property name="username" value="${hermes-username}" />                <property name="password" value="${hermes-password}" />                <property name="poolMaximumIdleConnections" value="${jdbc.minPoolSize}" />                <property name="poolMaximumActiveConnections" value="${jdbc.maxPoolSize}" />                <property name="poolTimeToWait" value="${jdbc.maxIdleTime}" />                <property name="poolPingQuery" value="SELECT NOW()" />                <property name="poolPingEnabled" value="true" />            </dataSource>        </environment>        <environment id="production">            <transactionManager type="${transactionManager_type}"/>            <dataSource type="${datasource_type}">                <property name="driver" value="${driver}" />                <property name="url" value="${hermes-url}" />                <property name="username" value="${hermes-username}" />                <property name="password" value="${hermes-password}" />                <property name="poolMaximumIdleConnections" value="${jdbc.minPoolSize}" />                <property name="poolMaximumActiveConnections" value="${jdbc.maxPoolSize}" />                <property name="poolTimeToWait" value="${jdbc.maxIdleTime}" />                <property name="poolPingQuery" value="SELECT NOW()" />                <property name="poolPingEnabled" value="true" />            </dataSource>        </environment>    </environments>    <mappers>        <mapper resource="com/mob/mapper/AdminMapper.xml"/>    </mappers></configuration>

config.properties 配置文件

</pre><pre name="code" class="html"><pre name="code" class="html">environment=locallogImpl=LOG4JtransactionManager_type=JDBCdatasource_type=POOLEDdriver=com.mysql.jdbc.Driverjdbc.initialPoolSize=1jdbc.minPoolSize=1jdbc.maxPoolSize=5jdbc.acquireIncrement=1jdbc.maxIdleTime=200jdbc.checkoutTimeout=3000# hermeshermes-url=jdbc:mysql://localhost/test?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNullhermes-username=roothermes-password=123456

AdminMapper.xml 配置文件（** 注意： namespace为AdminMapper接口的完全限定名，select中的id与接口中的方法名需一致）

<?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.mob.mapper.AdminMapper">    <resultMap type="Admin" id="admin">        <id property="id" column="id" />        <result property="userName" column="user_name"/>        <result property="password" column="password"/>        <result property="nickName" column="nick_name"/>    </resultMap>    <select id="getAdminById" parameterType="long" resultMap="admin">        SELECT *        FROM admin        WHERE id = #{value}    </select></mapper>

测试类AdminTest

package com.mob.admin;import com.mob.dao.AdminDaoImpl;import com.mob.domain.Admin;import com.mob.utils.MybatisUtil;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.log4j.Logger;import org.junit.Test;/** * Created by jianwl on 2015/11/17. */public class AdminTest {    private static final Logger logger = Logger.getLogger(AdminTest.class);    @Test    public void getAdminById() {        SqlSessionFactory sqlSessionFactory_mybatis_w = MybatisUtil.getSqlSessionFactory_mybatis_W();        SqlSession sqlSession = sqlSessionFactory_mybatis_w.openSession();        AdminDaoImpl adminDao = new AdminDaoImpl();        Long id = 1L;        try {            Admin admin = adminDao.getAdminById(sqlSession, id);            logger.info("id = " + admin.getId() + " username = " + admin.getUserName()                            + " password = " + admin.getPassword() + " nickname = " + admin.getNickName()            );        } finally {            sqlSession.close();        }    }}

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