项目搭建系列之二：SpringMVC框架下配置MyBatis

<!-- mybatis begin -->
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.2.3</version>
</dependency>
<!-- mybatis end -->    

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.31</version>
</dependency>

CREATE DATABASE mybatis_test;
USE mybatis_test;
CREATE TABLE user (
  name varchar(50) CHARACTER SET utf8 DEFAULT NULL,
  age int(11) DEFAULT NULL,
  UNIQUE KEY name (name)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

package cn.jxufe.web.mybatis;

public class User {
    private String name;
    private Integer age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public User(String name, Integer age) {
        super();
        this.name = name;
        this.age = age;
    }

    public User() {
        super();
    }
}

<?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">
<!-- 为这个mapper指定一个唯一的namespace，namespace的值习惯上设置成包名+sql映射文件名，这样就能够保证namespace的值是唯一的 -->
<mapper namespace="cn.jxufe.web.mybatis.UserMapper">
    <!-- 这里namespace必须是UserMapper接口的路径，不然要运行的时候要报错 “is not known to the MapperRegistry” -->
    <insert id="insertUser" parameterType="User">
        insert into user(name,age) values(#{name},#{age})
        <!-- 这里sql结尾不能加分号，否则报“ORA-00911”的错误 -->
    </insert>
　　<!-- 在select标签中编写查询的SQL语句， 设置select标签的id属性为getUser，id属性值必须是唯一的，
　　　　不能够重复使用parameterType属性指明查询时使用的参数类型，resultType属性指明查询返回的结果集类型 -->
    <!-- 这里的id必须和UserMapper接口中的接口方法名相同，不然运行的时候也要报错 -->
    <select id="getUser" resultType="User" parameterType="java.lang.String">
        select * from user where name=#{name}
    </select>
</mapper>  

package cn.jxufe.web.mybatis;

public interface UserMapper {
    public void insertUser(User user);

    public User getUser(String name);
}

<?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>   
        <!-- changes from the defaults for testing -->   
        <setting name="cacheEnabled" value="false" />   
        <setting name="useGeneratedKeys" value="true" />   
        <setting name="defaultExecutorType" value="REUSE" />   
    </settings>   
    <typeAliases>   
       <typeAlias alias="User" type="cn.jxufe.web.mybatis.User"/>   
    </typeAliases>   
    <environments default="development">   
       <environment id="development">   
           <transactionManager type="jdbc"/>   
　　　　　　 <!-- 配置数据库连接信息 -->
           <dataSource type="POOLED">   
              <property name="driver" value="com.mysql.jdbc.Driver"/>   
              <property name="url" value="jdbc:mysql://127.0.0.1:3306/mybatis_test"/>   
              <property name="username" value="root"/>   
              <property name="password" value="123456"/>   
           </dataSource>   
       </environment>   
    </environments>   
    <mappers>
        <!-- 注册UserMapper.xml文件--> 
        <mapper resource="mappers/UserMapper.xml" />   
    </mappers>   
</configuration>  

package cn.jxufe.web.mybatis;

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 MyBatisUtil {
    private final static SqlSessionFactory sqlSessionFactory;
    static {
        String resource = "mybatis-config.xml";
        Reader reader = null;
        try {
            reader = Resources.getResourceAsReader(resource);
        } catch (IOException e) {
            System.out.println(e.getMessage());

        }
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
    }

    public static SqlSessionFactory getSqlSessionFactory() {
        return sqlSessionFactory;
    }
}

package cn.jxufe.web.mybatis;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

public class TestMyBatis {
    static SqlSessionFactory sqlSessionFactory = null;
    static {
        sqlSessionFactory = MyBatisUtil.getSqlSessionFactory();
    }

//    public static void main(String[] args) {
//        testAdd();
//        getUser();
//    }

    public static void testAdd() {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        try {
            UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
            User user = new User("lisi", new Integer(25));
            userMapper.insertUser(user);
            sqlSession.commit();// 这里一定要提交，不然数据进不去数据库中
        } finally {
            sqlSession.close();
        }
    }

    public static void getUser() {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        try {
            UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
            User user = userMapper.getUser("lisi");
            System.out.println("name: " + user.getName() + "|age: "
                    + user.getAge());
        } finally {
            sqlSession.close();
        }
    }
}