02Mybatis快速入门

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Mybaitis快速入门

一、开发步骤

1. 添加Mybatis坐标
2. 创建user数据表
3. 编写User实体类
4. 编写映射文件UserMapper.xml
5. 编写核心文件sqlMapperConfig.xml
6. 编写测试类

二、添加坐标

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.yuwendeng</groupId>
    <artifactId>Spring_mybatis_quick</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.32</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.6</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>
    
</project>

三、编写映射文件

<?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="userMapper">
    <select id="findAll" resultType="com.yuwendeng.domain.User">
        SELECT * from user
    </select>
</mapper>

四、编写核心文件

<?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>
    <!--数据源环境-->
    <environments default="developement">
        <environment id="developement">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/test"/>
                <property name="username" value="root"/>
                <property name="password" value="742200yu"/>
            </dataSource>
        </environment>
    </environments>
    <!--加载映射文件-->
    <mappers>
        <mapper resource="com/yuwendeng/mapper/UserMapper.xml"></mapper>
    </mappers>
</configuration>

五、编写测试类

package com.yuwendeng.test;

import com.yuwendeng.domain.User;
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 java.io.IOException;
import java.io.InputStream;
import java.util.List;


public class MybatisTest {
    @Test
    public void test1() throws IOException {
//        获得核心配置文件
        InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapperConfig.xml");
//        获得session工厂对象
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
//        获得session会话对象
        SqlSession sqlSession = sqlSessionFactory.openSession();
//        执行操作  参数：namespace+id
        List<User> userList = sqlSession.selectList("userMapper.findAll");
//        打印数据
        System.out.println(userList);
//        释放资源
        sqlSession.close();
    }
}