Mybatis简单工程

2024-02-11 19:00:46

一：创建Maven

直接用idea本地仓库.创建完成即可
打开main -> 右键 ->找到directory-> 建立target和Resources文件夹(前提：没有target和Resources文件)

二：配置pom.xml （放置Resources文件）

<?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>org.example</groupId>
  <artifactId>mybatis-01</artifactId>
  <version>1.0-SNAPSHOT</version>
  
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.1</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.9</version>
    </dependency>
  </dependencies>
  
</project>

标红 ->右键找到maven->点第一项->等待下载完成

三.配置XML（放置Resources文件）

环境配置.xml（mybatis-cfg.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>
    <!-- 环境配置-->
    <environments default="development">
        <environment id="development">
            <!--配置事务-->
            <transactionManager type="JDBC"/>
            <!--配置数据源-->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8"/>
                <property name="username" value="root"/>
                <property name="password" value=""/>
            </dataSource>
        </environment>
    </environments>
    <!--引入映射配置-->
    <mappers>
        <!--使用相对路径方式引入-->
        <mapper resource="UserDao.xml"/>
    </mappers>
</configuration>

映射配置.xml（UserDao.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.po.dao.UserDao">
    
    <select id="getAllUser" resultType="com.po.pojo.User">
            select * from user
    </select>
    <select id="getUserById" resultType="com.po.pojo.User">
            select * from user where id = #{id}
    </select>
    <insert id="insertUser">
        insert into user value(#{id},#{name},#{password})
    </insert>
    <update id="updateUser">
        update user set name=#{name},password=#{password} where id=#{id}
    </update>
    <delete id="deleteUser">
        delete from user where id=#{id}
    </delete>
    
</mapper>

四：项目

实体类（User.xml）

package com.po.pojo;

public class User {
    private  Integer id;
    private  String name;
    private  String password;

    public User(Integer id, String name ,String password) {
        setId(id);
        setName(name);
        setPassword(password);
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "ID:"+id+"\t"+"NAME:"+name+"\t"+"PASSWORD:"+password;
    }
    
}

创建一个测试.java（selectUser.java）看看自己有没有其他配置出问题

package org.example;

import com.po.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 java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class selectUser {
    public static void main(String[] args) throws IOException {

        InputStream inputStream= Resources.getResourceAsStream("mybatis-cfg.xml");

        SqlSessionFactoryBuilder sqlSessionFactoryBuilder =new SqlSessionFactoryBuilder();

        SqlSessionFactory sqlSessionFactory=sqlSessionFactoryBuilder.build(inputStream);

        SqlSession sqlSession=sqlSessionFactory.openSession();

        List<User> list=sqlSession.selectList("getAllUser");
        for(User user:list){
            System.out.println(user);
        }
        sqlSession.close();
    }

}

结构
创建UserDao接口

package com.po.dao;
import com.po.pojo.User;
import java.util.List;

public interface UserDao {
    List<User> getAllUser();

    User getUserById(Integer id);

    void insertUser(User user);

    void updateUser(User user);

    void deleteUserById(Integer id);
}

测试增删改查（AppTes 放置在你的测试类中t）

 @Test
    public void getAllUser() throws IOException {
        //从xml中获取sqlSessionFactory
        String resource = "mybatis-cfg.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        //获取sqlSession
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //现在的mybatis接口式编程写法
        //相当于接口的实现类
        UserDao userDao = sqlSession.getMapper(UserDao.class);
        List<User> list = userDao.getAllUser();
        for(User user:list){
            System.out.println(user);
        }
        sqlSession.close();
    }

    @Test
    public void getUserById() throws IOException {
        //从xml中获取sqlSessionFactory
        String resource = "mybatis-cfg.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession();
        UserDao userDao = sqlSession.getMapper(UserDao.class);
        User user = userDao.getUserById(1);
        System.out.println(user);
        sqlSession.close();
    }
    @Test
    public void insertUser() throws IOException {
        String resource = "mybatis-cfg.xml";
        InputStream is = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);

        //使用自动提交，如果不使用则需要sqlSession.commit();手动提交
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        //SqlSession sqlSession = sqlSessionFactory.openSession();
        UserDao userDao = sqlSession.getMapper(UserDao.class);
        //需要写有参和无参构造函数
        User user = new User(6,"1","1156");
        userDao.insertUser(user);
        System.out.println(user);

    }
    @Test
    public void updateUser() throws IOException {
        String res = "mybatis-cfg.xml";
        InputStream is = Resources.getResourceAsStream(res);
        SqlSessionFactory  sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        UserDao userDao = sqlSession.getMapper(UserDao.class);
        User user = new User(2,"uzi","1");
        userDao.updateUser(user);

    }
    @Test
    public void deleteUserById() throws IOException {
        String res = "mybatis-cfg.xml";
        InputStream is = Resources.getResourceAsStream(res);
        SqlSessionFactory  sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        UserDao userDao = sqlSession.getMapper(UserDao.class);
        userDao.deleteUserById(5);
    }

（实体类中可以不用创建有参构造，但测试类中自己user.setID（）调用即可）

码农公寓

一：创建Maven

二：配置pom.xml （放置Resources文件）

三.配置XML（放置Resources文件）

四：项目

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