MyBatis3入门一（简单查询、插入）

1. 环境

mybatis-3.2版本，jdk1.6版本，Oracle数据库

2. 功能

实现基本的数据单条插入、单条查询功能。

3. 准备工作

3.1 下载mybatis-3.2，需要引用其中的若干包

mybatis-3.2.0.jar
lib/asm-3.3.1.jar
lib/cglib-2.2.2.jar
lib/commons-logging-1.1.1.jar
lib/javassist-3.17.1-GA.jar
lib/log4j-1.2.17.jar
lib/slf4j-api-1.7.2.jar
lib/slf4j-log4j12-1.7.2.jar

3.2 项目的目录结构

src\com\clzhang\sample\struts2\mapper
　　MemberUserMapper.java 　　　　　　　　　　　　　　mybatis的mapper处理类
src\com\clzhang\sample\struts2\mapper\entity
　　MemberUserBean.java　　　　　　　　　　　　　　　　mybatis的entity类
src\com\clzhang\sample\struts2\test
　　MyBatisTest.java　　　　　　　　　　　　　　　　　　测试类，最终应该是在service的package中调用mapper中的方法。

resources\config
　　mybatis-config.xml        mybatis的配置文件
resources\com\clzhang\sample\struts2\mapper
　　MemberUserMapper.xml      mybatis的mapper配置文件

3.3 假定数据库已经创建，表结构也已经创建，并且有测试数据

这里数据库为Oracle，表名：MEMBER_USER，数据结构如下（假设已经存在测试数据）：

CREATE TABLE MEMBER_USER (
ID NUMBER NOT NULL PRIMARY KEY,
NAME VARCHAR2(30),
PERSONMOBILE VARCHAR2(20),
ADDRESS VARCHAR2(255),
AGE NUMBER);

4. 具体步骤

4.1 创建entity类

package com.clzhang.sample.struts2.mapper.entity;

public class MemberUserBean {
private int id;
private String name;
private String personMobile;
private String address;

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;
}

public String getPersonMobile() {
return personMobile;
}

public void setPersonMobile(String personMobile) {
this.personMobile = personMobile;
}

public String getAddress() {
return address;
}

public void setAddress(String address) {
this.address = address;
}

}

4.2 创建mapper类

package com.clzhang.sample.struts2.mapper;

import com.clzhang.sample.struts2.mapper.entity.MemberUserBean;

public interface MemberUserMapper {
public void insertUser(MemberUserBean user);
public MemberUserBean getUser(int id);
}

4.3 创建mybatis-config.xml的配置文件，位置于resources/config目录

<?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>
<settings>
<setting name="cacheEnabled" value="false" />
<setting name="useGeneratedKeys" value="true" />
<setting name="defaultExecutorType" value="REUSE" />
</settings>
<typeAliases>
<typeAlias alias="MemberUser" type="com.clzhang.sample.struts2.mapper.entity.MemberUserBean"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="oracle.jdbc.driver.OracleDriver"/>
<property name="url" value="jdbc:oracle:thin:@192.168.2.136:1521:jingdu"/>
<property name="username" value="jingdu"/>
<property name="password" value="jingdu"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/clzhang/sample/struts2/mapper/MemberUserMapper.xml" />
</mappers>
</configuration>

4.4 创建MemberUserMapper.xml配置文件，位置于：resources\com\clzhang\sample\struts2\mapper\

<?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.clzhang.sample.struts2.mapper.MemberUserMapper">

<cache />

<select id="getUser" resultType="MemberUser" parameterType="int">
select
ID,
NAME,
PERSONMOBILE,
PERSONREMARK,
ADDRESS
FROM MEMBER_USER
WHERE ID = #{id}
</select>

<insert id="insertUser" parameterType="MemberUser">
INSERT INTO MEMBER_USER (ID, NAME, PERSONMOBILE, ADDRESS)
VALUES(#{id}, #{name}, #{personMobile}, #{address})
</insert>

</mapper>

4.5 创建测试类

package com.clzhang.sample.struts2.test;

import java.io.IOException;
import java.io.Reader;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import org.junit.Test;

import com.clzhang.sample.struts2.mapper.MemberUserMapper;
import com.clzhang.sample.struts2.mapper.entity.MemberUserBean;

/**
* mybatis的测试类，真正的应用，应该在service包中调用。
* @author Administrator
*
*/
public class MyBatisTest {
private static final String MYBATIS_CONFIG_FILENAME = "config/mybatis-config.xml";
private static SqlSessionFactory sqlSessionFactory;

static {
Reader reader = null;
try {
reader = Resources.getResourceAsReader(MYBATIS_CONFIG_FILENAME);
} catch (IOException e) {
System.out.println(e.getMessage());
}
// 一旦你创建了 SqlSessionFactory 后,SqlSessionFactoryBuilder这个类就不需要存在了。
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
}

/**
* SqlSessionFactory 应该在你的应用执行期间都存在。没有理由来处理或重新创建它。
* @return
*/
public static SqlSessionFactory getSqlSessionFactory() {
return sqlSessionFactory;
}

//    @Test
public void testAdd() {
// SqlSession 的实例不能被共享,也是线程不安全的。因此最佳的范围是请求或方法范围。
SqlSession sqlSession = getSqlSessionFactory().openSession();
try {
// 从技术上来说,当被请求时,任意映射器实例的最宽范围和 SqlSession 是相同的。最佳范围是方法范围。
MemberUserMapper mapper = sqlSession
.getMapper(MemberUserMapper.class);

MemberUserBean memberUser = new MemberUserBean();
memberUser.setId(1003);
memberUser.setName("张三");
memberUser.setPersonMobile("18387887878");
memberUser.setAddress("北京丰台某公司");

mapper.insertUser(memberUser);
sqlSession.commit();
} finally {
sqlSession.close();
}
}

@Test
public void getUser() {
SqlSession sqlSession = getSqlSessionFactory().openSession();
try {
MemberUserMapper mapper = sqlSession
.getMapper(MemberUserMapper.class);
MemberUserBean memberUser = mapper.getUser(725);

System.out.println("name:" + memberUser.getName() + "\tmobile:"
+ memberUser.getPersonMobile() + "\taddress:" + memberUser.getAddress());
} finally {
sqlSession.close();
}
}

}

测试输出：

name:吴经理 mobile:13695769533 address:浙江省乐清市北白象金炉工业区