eclipse 整合mybatis的过程

一、下载mybatis和数据库驱动的jar，我这里用到的数据库是pgAdmin III ，所以我下载的jar包分别为mybatis-3.0.2 jar和po's'tgresql-42.2.1.jar,如图所示

二、创建一个java项目，导入下载的jar包，构建的结构如下图所示：

三、分析

1.现在数据库中创建一个名为mybatis的数据库：创建的列有id(自动生长的)、name、sex、age,具体的创建过程自己创建。

2.先创建一个User.java类，如下图：

package com.mybatis.model.impl;

public class User {
    private Integer id;
    private String name;
    private String sex;
    private Integer age;
    public User()
    {
    }
    public User(final String name,final String sex,final Integer age)
    {
        this.name=name;
        this.sex=sex;
        this.age=age;
    }
    public Integer getId()
    {
        return this.id;
    }
    public void setId(final Integer id)
    {
        this.id=id;
    }

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

    public String getSex()
    {
        return this.sex;
    }
    public void setSex(final String sex)
    {
        this.sex=sex;
    }

    public Integer getAge()
    {
        return this.age;
    }
    public void setAge(final Integer age)
    {
        this.age=age;
    }
    @Override
    public String toString()
    {
        return "User [id="+id+",name="+name+",sex="+sex+",age"+age+"]";
    }
}

3.创建一个UserMapper.java接口，这里只是负责提供数据CRUD的接口，具体的实现在下面的UserMapper.xml文件中。

package com.mybatis.mapper;

import java.util.List;

import com.mybatis.model.impl.User;

public interface UserMapper {

    public void insertUser(User user) throws Exception;

    public User selectOneUser(int id) throws Exception;

    public List<User> selectAllUser() throws Exception;

    public void deleteUser() throws Exception;

}

4.创建一个xml文件，名为UserMapper.xml,映射到上面的UserMapper接口。

<?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.mybatis.mapper.UserMapper"><!-- 这个是映射到上面的UserMapper接口的 -->
    <insert id="insertUser" parameterType="com.mybatis.model.impl.User" useGeneratedKeys="true"
    keyProperty="id" >
        insert into tb_user(name,sex,age)
        values(#{name},#{sex},#{age})
    </insert>

    <select id="selectAllUser" resultType="com.mybatis.model.impl.User">
        select * from tb_user
    </select>
    <delete id="deleteUser">
        delete from tb_user

    </delete>
    <select id="selectOneUser" parameterType="java.lang.Integer"
    resultType="com.mybatis.model.impl.User">
        select * from tb_user where id=#{id}
    </select>
</mapper>

5.创建一个mybatis.xml文件来连接数据库。

<?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">

<!-- XML配置文件包含对MyBatis系统的核心设置 -->
<configuration>
      <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
              <!-- <property name="driver" value="com.mysql.jdbc.Driver" /> -->
                <property name="driver" value="org.postgresql.Driver" />
                <property name="url" value="jdbc:postgresql://localhost:5432/mybatis"/>
                <property name="username" value="postgres" />
                <property name="password" value="p" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="UserMapper.xml"/>
    </mappers>
</configuration>

6.创建一个MybatisTest.java类类运行测试。

package com.mybatis.test;
import java.io.Reader;
import java.util.List;

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 com.mybatis.mapper.UserMapper;
import com.mybatis.model.impl.User;;

public class MyBatisTest {

    public static void main(final String[] args) throws Exception{
        // TODO Auto-generated method stub
          //读取MyBatis配置文件
        final Reader reader=Resources.getResourceAsReader("mybatis.xml");;
        //初始化mybatis，创建SqlSessionFactory类的实例。
        final SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(reader);
        //创建Session实例
        final SqlSession session=sqlSessionFactory.openSession();
        //创建User对象
        final UserMapper userMapper=session.getMapper(UserMapper.class);
        //插入数据
        User user=new User("Carson","男",23);
        userMapper.insertUser(user);
        user=new User("THL","女",23);
        userMapper.insertUser(user);
        session.commit();

        //查询数据
        final List<User> list=userMapper.selectAllUser();
        System.out.println(list);

        //删除数据
//        userMapper.deleteUser();
        session.commit();
        session.close();

    }

}

6.运行的结果如图，这是在没有运行删除语句时产生的结果。

以上是个人代码，如果有要转发的，请点赞，thx~.