mybatis框架-01

mybatis

• 在idea中新建一个maven空项目名为Mybatis
• 在这个空项目下新建一个module名为mybatis-01,以及新建以下的文件
  

在Mybatis的pom.xml中导入依赖文件以便所有的module都可以使用

<?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.hu</groupId>
    <artifactId>Mybatis</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>mbatis-01</module>
    </modules>

    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.49</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.5</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
        </dependency>

    </dependencies>


    <build>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>

</project>

• 新建一个User类

package com.hu.pojo;


import lombok.*;

@AllArgsConstructor
@NoArgsConstructor
@Setter
@Getter
@ToString
public class User {
    private Integer id;
    private String username;
    private String password;

}

• 新建一个UserMapper接口(用于操作数据库)

package com.hu.mapper;

import com.hu.pojo.User;

import java.util.List;

public interface UserMapper {
     List<User> getUserList();
}

• 在该类的同包下新建一个UserMapper.xml用于对User类进行CRUD的配置

<?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.hu.mapper.UserMapper">
    <select id="getUserList" resultType="com.hu.pojo.User">
        select  * from mybatis.user
    </select>
</mapper>

• 新建一个MybatisUtils类作为工具类获取SqlSession对象

package com.hu.utils;
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 java.io.IOException;
import java.io.InputStream;

public class MybatisUtils {

    private static InputStream resourceAsStream = null;
    private static SqlSessionFactory build = null;

    static {
        try {
            resourceAsStream = Resources.getResourceAsStream("mybatis-config.xml");
            build = new SqlSessionFactoryBuilder().build(resourceAsStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static SqlSession getSqlSession() {
        return build.openSession();
    }

}

• 在test包下新建一个test类进行测试

package com.hu.mapper;
import com.hu.pojo.User;
import com.hu.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.List;

public class UserMapperTest {

    @Test
    public void test1(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> list = mapper.getUserList();
        for (User user : list) {
            System.out.println(user);
        }
    }

}