使用IDEA Maven搭建mybatis環境

　創建一個空的Maven項目

 

 

在p 1 <dependencies>

<!-- mybatis核心包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.3.0</version>
        </dependency>
        <!-- mysql驅動包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.29</version>
        </dependency>
        <!-- junit測試包 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>  
 </dependencies>

在java創建包edu.wang.pojo創建一個User.java

創建User實體

package edu.wang.pojo;

public class User {
    private int uid;
    private String uname;
    private int uage;

    public int getUid() {
        return uid;
    }

    public void setUid(int uid) {
        this.uid = uid;
    }

    public String getUname() {
        return uname;
    }

    public void setUname(String uname) {
        this.uname = uname;
    }

    public int getUage() {
        return uage;
    }

    public void setUage(int uage) {
        this.uage = uage;
    }
}

user mybatis
create table users
(
    uid int primary key auto_increment,
    uname varchar(20) not null,
    uage int not null
)
insert into users(uid,uname,uage) values(null,'張三',20),(null,'李四',18)
select * from users

創建數據庫和相應的表后，在resources文件夾中創建（mybatis-config.xml）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>
    <!-- 環境配置 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <!-- 數據庫連接相關配置 ,這里動態獲取config.properties文件中的內容-->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis" />
                <property name="username" value="root" />
                <property name="password" value="root" />
            </dataSource>
        </environment>
    </environments>
    <!-- mapping文件路徑配置 -->
    <mappers>
        <mapper resource="mapper/UserMapper.xml"/>
    </mappers>

</configuration>

在resources創建一個mpaaer文件夾，存放需要映射的xml文件

在mapper創建UserMapper.xml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為映射的根節點，namespace指定Dao接口的完整類名
 mybatis會依據這個接口動態創建一個實現類去實現這個接口，
 而這個實現類是一個Mapper對象-->

-->
 <mapper namespace="edu.wang.pojo.User"> 
　　<!--id ="接口中的方法名"  

　　parameterType="傳入的參數類型"

　　resultType = "返回實體類對象，使用包.類名"-->

 <select id="findById" parameterType="int" resultType="edu.wang.pojo.User"> select * from users where uid = #{id} 

</select> </mapper>

創建完UserMapper.xml文件后需要配置到mybatis-config.xml文件中

 

編寫單元測試類

package Test;

import edu.wang.pojo.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.Reader;

public class UserTest {
    @Test
    public void userFindByIdTest(){
        //定義讀取文件名
        String resources = "mybatis-config.xml";
        //創建流
        Reader reader=null;
        try {
            //讀取mybatis-config.xml文件到reader對象中
            reader= Resources.getResourceAsReader(resources);
        } catch (IOException e) {
            e.printStackTrace();
        }
        //初始化mybatis,創建SqlSessionFactory類的實例
        SqlSessionFactory sqlMapper=new SqlSessionFactoryBuilder().build(reader);
        //創建session實例
        SqlSession session=sqlMapper.openSession();
        //傳入參數查詢，返回結果
        User user=session.selectOne("findById",1);
        //輸出結果
        System.out.println(user.getUname());
        //關閉session
        session.close();

    }
}

執行程序查看結果