Mybatis框架搭建

思路：

1. 搭建环境

   
   



2. 导入Mybatis

   
   



3. 编写代码

   
   



4. 测试

   
   

一.搭建环境

• 创建数据库

  /*
  Navicat Premium Data Transfer
  ​
  Source Server         : Mybatis
  Source Server Type   : MySQL
  Source Server Version : 50528
  Source Host           : localhost:3306
  Source Schema         : mybatis
  ​
  Target Server Type   : MySQL
  Target Server Version : 50528
  File Encoding         : 65001
  ​
  Date: 03/03/2022 13:11:06
  */
  ​
  SET NAMES utf8mb4;
  SET FOREIGN_KEY_CHECKS = 0;
  ​
  -- ----------------------------
  -- Table structure for employee
  -- ----------------------------
  DROP TABLE IF EXISTS `employee`;
  CREATE TABLE `employee`  (
   `id` int(10) NOT NULL AUTO_INCREMENT,
   `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
   `age` int(10) NOT NULL,
   `position` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
   PRIMARY KEY (`id`) USING BTREE
  ) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact;
  ​
  -- ----------------------------
  -- Records of employee
  -- ----------------------------
  INSERT INTO `employee` VALUES (1, '张三', 20, '员工');
  INSERT INTO `employee` VALUES (2, '李四', 18, '员工');
  INSERT INTO `employee` VALUES (3, '王五', 35, '经理');
  ​
  SET FOREIGN_KEY_CHECKS = 1;
  ​
  

• 创建数据库连接信息配置文件db.properties

  db.driver = com.mysql.jdbc.Driver
  db.url = jdbc:mysql://localhost:3306/learn-test?useUnicode=true&characterEncoding=utf8
  db.username = root
  db.password = root

   

  
  



• 新建项目,并且在pom.xml中添加项目依赖

  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>4.0.0modelVersion>
  
     <groupId>com.wfygroupId>
     <artifactId>WorkerartifactId>
     <packaging>pompackaging>
     <version>1.0-SNAPSHOTversion>
     <modules>
         <module>worker-01module>
     modules>
     
     <dependencies>
         
         <dependency>
             <groupId>org.mybatisgroupId>
             <artifactId>mybatisartifactId>
             <version>3.5.2version>
         dependency>
         
         <dependency>
             <groupId>mysqlgroupId>
             <artifactId>mysql-connector-javaartifactId>
             <version>8.0.11version>
         dependency>
         
         <dependency>
             <groupId>junitgroupId>
             <artifactId>junitartifactId>
             <version>4.12version>
             <scope>testscope>
         dependency>
     dependencies>
     <build>
         <resources>
             <resource>
                 <directory>src/main/javadirectory>
                 <includes>
                     <include>**/*.xmlinclude>
                     <include>**/*.propertiesinclude>
                 includes>
             resource>
  ​
             <resource>
                 <directory>src/main/resourcesdirectory>
                 <includes>
                     <include>**/*.xmlinclude>
                     <include>**/*.propertiesinclude>
                 includes>
             resource>
         resources>
     build>
  project>
  ​

   

  
  

  二、创建模块

  
  
  
  

  • 创建Mybatis的核心配置文件mybatis-config.xml

    version="1.0" encoding="UTF-8" ?>
     PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
     "http://mybatis.org/dtd/mybatis-3-config.dtd">
    <configuration>
     <environments default="development">
       <environment id="development">
         <transactionManager type="JDBC"/>
         <dataSource type="POOLED">
           <property name="driver" value="${driver}"/>
           <property name="url" value="${url}"/>
           <property name="username" value="${username}"/>
           <property name="password" value="${password}"/>
         dataSource>
       environment>
     environments>
     <mappers>
       <mapper resource="mapper/UserMapper"/>
     mappers>
    configuration>

     

    
    
  
  
  
  

• 编写Mybatis工具类

  package 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;
  ​
  //SqlSessionFactory --->SqlSession
  public class MybatisUtil {
  ​
     private static SqlSessionFactory sqlSessionFactory;
  ​
     static {
         try {
             //使用Mybatis的第一步---->获取SqlSessionFactory对象
             String resource = "mybatis-config.xml";
             InputStream inputStream = Resources.getResourceAsStream(resource);
              sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
             e.printStackTrace();
        }
    }
     //既然有了 SqlSessionFactory，顾名思义，我们可以从中获得 SqlSession 的实例。
     // SqlSession 提供了在数据库执行 SQL 命令所需的所有方法。你可以通过 SqlSession 实例来直接执行已映射的 SQL 语句
     public static SqlSession getSqlSession()
    {
         return  sqlSessionFactory.openSession();
  ​
    }
  ​
  }
  ​

   

  
  

三.编写代码

• 实体类User 创建Pojo实体

  package pojo;
  ​
  //实体类
  public class User {
     private int id ;
     private  String name;
     private  int age;
     private  String position;
  ​
     public User() {
    }
  ​
     public User(int id, String name, int age, String position) {
         this.id = id;
         this.name = name;
         this.age = age;
         this.position = position;
    }
  ​
     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 String getPosition() {
         return position;
    }
  ​
     public void setPosition(String position) {
         this.position = position;
    }
  ​
     @Override
     public String toString() {
         return "User{" +
                 "id=" + id +
                 ", name='" + name + '\'' +
                 ", age=" + age +
                 ", position='" + position + '\'' +
                 '}';
    }
  }
  ​

   

  
  

• Dao接口

  version="1.0" encoding="UTF-8" ?>
  
         PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
  <mapper namespace="dao.UserDao">
     
   <select id="getUserList" resultType="pojo.User">
      select * from mybatis.employee;
   select>
  mapper>

   

  
  

• 接口实现类

  package dao;
  ​
  import pojo.User;
  ​
  import java.util.List;
  ​
  //Dao接口
  public interface UserDao {
  ​
     List<User> getUserList();
  ​
  }
  ​

   

  
  

• 编写测试类

  package dao;
  ​
  import org.apache.ibatis.session.SqlSession;
  import org.junit.Test;
  import pojo.User;
  import utils.MybatisUtil;
  ​
  import java.util.List;
  ​
  public class UserDaoTest {
     @Test
     public void test ()
    {
         //第一步:获得SqlSession对象
        SqlSession sqlSession= MybatisUtil.getSqlSession();
        //第二步:执行SQL
         UserDao mapper=sqlSession.getMapper(UserDao.class);
        List<User> userList= mapper.getUserList();
         for (User user : userList) {
             System.out.println(user);
        }
  ​
         //关闭sqlSession
         sqlSession.close();
    }
  }
  ​
  




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原文链接：https://www.cnblogs.com/wfy-studying/p/15961974.html