mybatis源码学习之基础工程准备

mybatis源码学习及分析——基础工程准备

转行做Java一年了，基本的框架等会用，但总停留在表面，未能够深入学习。今年需要多多学习主流框架的源码，提高自己的编码水平。

1.Maven依赖

<dependency>    <groupId>mysql</groupId>    <artifactId>mysql-connector-java</artifactId>    <version>5.1.39</version></dependency><dependency>    <groupId>org.mybatis</groupId>    <artifactId>mybatis</artifactId>    <version>3.4.1</version></dependency>

可选项：slf4j、junit、fastjson、guava等根据自己需要添加。

2.工程结构

3.Entity

package com.cumt.mybatisstudy.entity;import java.util.Date;/** * Created by caicf on 2017/1/3. */public class User {    private int id;    private String name;    private int age;    private Date createDate;    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 int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public Date getCreateDate() {        return createDate;    }    public void setCreateDate(Date createDate) {        this.createDate = createDate;    }}

4.mybatis-config.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.cumt.mybatisstudy.entity.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://localhost:3306/mybatis_study"/>                <property name="username" value="root"/>                <property name="password" value="123456"/>            </dataSource>        </environment>    </environments>    <mappers>        <mapper resource="UserMapper.xml"/>    </mappers></configuration>

5.Mapper接口及映射文件

public interface UserMapper {    User findById(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.cumt.mybatisstudy.mapper.UserMapper">    <resultMap id="baseRs" type="com.cumt.mybatisstudy.entity.User">        <id column="id" property="id" javaType="java.lang.Integer"/>        <id column="name" property="name" javaType="java.lang.String"/>        <id column="age" property="age" javaType="java.lang.Integer"/>        <id column="create_date" property="createDate" javaType="java.util.Date"/>    </resultMap>    <select id="findById" parameterType="int" resultMap="baseRs">        select * from `user` where id = #{id}    </select></mapper>

6.创建数据库及数据表

SET FOREIGN_KEY_CHECKS=0;-- ------------------------------ Table structure for user-- ----------------------------DROP TABLE IF EXISTS `user`;CREATE TABLE `user` (  `id` int(11) NOT NULL,  `name` varchar(255) DEFAULT NULL,  `age` int(11) DEFAULT NULL,  `create_date` datetime DEFAULT NULL,  PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;-- ------------------------------ Records of user-- ----------------------------INSERT INTO `user` VALUES ('1', 'as', '12', '2017-01-03 16:30:43');

7.新建测试类用来Debug源码

public class MybatisStart {    private static final Logger log = LoggerFactory.getLogger(MybatisStart.class);    @Test    public void queryTest() throws IOException {        Reader reader = Resources.getResourceAsReader("mybatis-config.xml");        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);        SqlSession session = sqlSessionFactory.openSession();        UserMapper userMapper = session.getMapper(UserMapper.class);        User user = userMapper.findById(1);        log.info("name= {} ; age= {}", user.getName(), user.getAge());    }}

执行queryTest可以看到日志：

至此，基本的配置完成，接下来通过断点跟踪源码的执行过程。

附：工程文件地址 http://git.oschina.net/cai_cf/MybatisStudy