MyBatis(iBatis 3)入门示例 及 整合Mybatis与Spring3
以前的iBatis 项目在2010 年5 月，将代码库迁致Google Code，并更名为MyBatis。本示例用的是ibatis-3-core-3.0.0.208.zip，首先加如mybatis和mysql数据库的jar包。
table.sql
create database mybatis;
use mybatis;
create table user(
id int primary key auto_increment,
name varchar(50)
);
insert into user values(null,'张三');
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>
<typeAliases>
<typeAlias alias="User" type="com.nantian.mybatis.model.User"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://127.0.0.1:3306/mybatis"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/nantian/mybatis/model/UserMapper.xml"/>
</mappers>
</configuration>
DBUtil
package com.nantian.mybatis.data;
import java.io.IOException;
import java.io.Reader;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
public class DBUtil {
private static final DBUtil dbUtil = new DBUtil();
private SqlSessionFactory sqlSessionFactory = null;
private DBUtil() {
try {
String resource = "com/nantian/mybatis/data/configuration.xml";
Reader reader = Resources.getResourceAsReader(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public static DBUtil getInstance() {
return dbUtil;
}
public SqlSessionFactory getSqlSessionFactory() {
return sqlSessionFactory;
}
}
User
package com.nantian.mybatis.model;
public class User {
private int id;
private String name;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
UserMapper
package com.nantian.mybatis.model;
public interface UserMapper {
public User selectUser(int id);
}
UserMapper.xml
<?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.nantian.mybatis.model.UserMapper">
<select id="selectUser" parameterType="int" resultType="User">
select id,name from user where id = #{id}
</select>
</mapper>
Test
package com.nantian.mybatis.test;
import junit.framework.TestCase;
import org.apache.ibatis.session.SqlSession;
import com.nantian.mybatis.data.DBUtil;
import com.nantian.mybatis.model.User;
import com.nantian.mybatis.model.UserMapper;
public class Test extends TestCase {
public void selectUser() {
SqlSession sqlSession = DBUtil.getInstance().getSqlSessionFactory()
.openSession();
try {
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
User user = userMapper.selectUser(1);
System.out.println(user.getName());
} finally {
sqlSession.close();
}
}
}
Mybatis3可以使用注解了。注解是非常简单明了的，但是JAVA 注解既有局限性，在语句比较复杂的情况下又比较容易混乱。所以，如果你的语句比较复杂，最好还是使用XML 来映射语句。这主要取决于你和你的项目团队，决定哪个更适合于你，主要还是以稳健为主。也就是说，你不需要制约于哪一种方式，你可以很容易的把注解转为XML，也可以把XML 转化为注解。
整合Mybatis与Spring3
http://www.iyunv.com/topic/1018134
1.实体bean
Java代码
[*]package org.hyn.bean;
[*]
[*]public class User {
[*] private int id;
[*] private String name;
[*] private int age;
[*]...//长长的set get 方法
2.Mapper及配置文件
Java代码
[*]package org.hyn.maper;
[*]
[*]import org.hyn.bean.User;
[*]
[*]public interface UserMapper {
[*] public void insertUser(User user);
[*]
[*] public User getUser(String name);
[*]}
Java代码
[*]<?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="org.hyn.maper.UserMapper">
[*] <insert id="insertUser" parameterType="org.hyn.bean.User">
[*] insert into user(name,age) values(#{name},#{age})
[*] </insert>
[*] <select id="getUser" resultType="org.hyn.bean.User"
[*] parameterType="java.lang.String">
[*] select * from user where name=#{name}
[*] </select>
[*]
[*] <!-- 当使用该Mybatis与Spring整合的时候，该文件必须和相应的Mapper接口文件同名，并在同一路径下 -->
[*]</mapper>
3.spring配置文件
Java代码
[*]<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
[*] <property name="dataSource" ref="myDataSource" />
[*]
[*] <!-- <property name="configLocation" value=""/> -->
[*] <!--
[*]
该属性用来指定MyBatis的XML配置文件路径,跟Spring整合时，编写MyBatis映射文件的目的无非是配置一下typeAlias、setting之类的元素。不用在其中指定数据源，或者事务处理方式。就算配置了也会被忽略。因为这些都是使用Spring中的配置
[*] 。当然如果你不打算添加typeAlias 之类的设置的话，你连MyBatis的配置文件都不用写，更不用配置这个属性了
[*] -->
[*]
[*] <!--<property name="mapperLocations" value="src/UserMapper.xml"/>-->
[*] <!-- 该配置文件用来指定Mapper映射文件的位置 ，如果映射文件与相应的接口同名，且在同一路径下，那么可以不配置该选项-->
[*]</bean>
[*]
[*]
<!-- 注册Mapper方式一
[*]
<bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
[*]
<property name="mapperInterface" value="org.hyn.maper.UserMapper"/>
[*]
<property name="sqlSessionFactory" ref="sqlSessionFactory"/>
[*]</bean>
[*]-->
[*]
[*]<!-- 注册Mapper方式二：也可不指定特定mapper，而使用自动扫描包的方式来注册各种Mapper ，配置如下：-->
[*]<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
[*] <property name="basePackage" value="org.hyn.maper" />
[*]</bean>
4.测试类
Java代码
[*]@Test
[*]public void testGetUser() {
[*] ApplicationContext aContext = new FileSystemXmlApplicationContext("WebRoot/WEB-INF/applicationContext.xml");
[*] UserMapper userMapper = aContext.getBean(UserMapper.class);
[*] User user = userMapper.getUser("张三");
[*] System.out.println(user.toString());
[*]}
[*]
[*]@Test
[*]public void testAddUser(){
[*] ApplicationContext aContext = new FileSystemXmlApplicationContext("WebRoot/WEB-INF/applicationContext.xml");
[*] UserMapper userMapper = aContext.getBean(UserMapper.class);
[*] User user = new User();
[*] user.setName("张三");
[*] user.setAge(18);
[*] userMapper.insertUser(user);
[*] System.out.println("添加成功");
[*]}
下面付上源代码
mybatis mapper pojo的两种方式
1.如果数据库和pojo的属性名都一样的话可以用如下方式：
<select id="getUser" resultType="org.guarx.domain.User" parameterType="java.lang.String">
<!]>
</select>
<select id="getUsers" resultType="org.guarx.domain.User">
<!]>
</select>
2.如果数据库columns name和pojo的属性名称不一样（大多数情况下）
（1）第一种方式：
<select id="getUsers" resultType="org.guarx.domain.User">
<!]>
</select>
（2）第二种方式：
<resultMap type="org.guarx.domain.User" id="userMapper">
<result column="t_id" property="id"/>
<result column="t_username" property="username"/>
<result column="t_desc" property="description"/>
</resultMap>
<select id="getAll" resultMap="userMapper">
<!]>
</select>
[*]
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