mybatis环境搭建步骤（含配置文件代码）

浅浅的花香味﹌ 2022-12-28 12:37 49阅读 0赞

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1.创建web项目

2.将所需要的jar包放在项目内，并且build-path

3.创建资源文件夹resources

4.在资源文件夹中创建xml文件mybatis-config.xml,文件代码如下：

<?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>
      
      <typeAliases>
        <typeAlias alias="Dept" type="org.entity.Dept"/>
      </typeAliases>
    
      <environments default="development">
        <environment id="development">
          <transactionManager type="JDBC"/>
          <dataSource type="POOLED">
            <property name="driver" value="com.mysql.jdbc.Driver"/>
            <property name="url" value="jdbc:mysql://localhost:3306/schooldb"/>
            <property name="username" value="root"/>
            <property name="password" value="root"/>
          </dataSource>
        </environment>
      </environments>
      <mappers>
      
        <mapper resource="org/dao/IDeptDao.xml"/>
      </mappers>
    </configuration>

5.创建entity包，根据数据库表创建实体类，一个表对应一个实体类，表中的字段对应实体类中的属性

6.创建dao包，在dao包中创建接口（在接口写方法，增删改查）

public int addDept(Dept dept);
    public List<Dept> findDeptAll();

7.在dao层中编写mapper.xml文件，一般mapper文件和接口文件名相同

8.IDeptDao.xml中的内容如下：

<?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="org.dao.IDeptDao">
      
      <select id="findCountDept"  resultType="int">
        select count(*) from dept
      </select>
      
      <insert id="addDept" parameterType="org.entity.Dept">
          insert into dept(did,dname) values(#{did},#{dname}); 
      </insert>
      
      <update id="updateDept" parameterType="org.entity.Dept">
        update dept set dname = #{dname} where did = #{did}
      </update>
      
      <delete id="delDept" parameterType="org.entity.Dept" >
       delete from dept where did = #{did}
      </delete>
      
      <select id="findDeptAll" resultType="org.entity.Dept">
        select * from dept;
      </select>
      
      <select id="findDeptById" resultType="org.entity.Dept"
                   parameterType="int">
        select * from dept where did = #{did}
      </select>
    </mapper>

9.编写测试类，代码如下：

package org.test;
    
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.List;
    import java.util.Scanner;
    
    import org.apache.ibatis.io.Resources;
    import org.apache.ibatis.session.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactoryBuilder;
    import org.dao.IDeptDao;
    import org.entity.Dept;
    import org.junit.After;
    import org.junit.Before;
    import org.junit.Test;
    
    
    public class TestMain {
      
      //单元测试
      String path = "mybatis-config.xml";
      SqlSession session = null;
      InputStream in =null;
      
      @Before
      public void before(){
        try {
          in = Resources.getResourceAsStream(path);
          session = new SqlSessionFactoryBuilder().build(in).openSession();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      
      //查询部门数量
      @Test
      public void testCount() {
        // 加载xml文件
        int count = session.selectOne("org.dao.IDeptDao.findCountDept");
        System.out.println("一共有：" + count + "个部门");
      }
    
      //添加信息
      @Test
      public void addDept(){
          Dept dept = new Dept();
          dept.setDid(6);
          dept.setDname("运维部");
          int rel = session.insert("org.dao.IDeptDao.addDept",dept);
          //提交（增删改）
          session.commit();
          if(rel>0){
            System.out.println("添加成功");
          }else{
            System.out.println("添加失败");
          }
        
      }
    
      //查询全部
      @Test
      public void findAllDept(){
          List<Dept> dList = session.getMapper(IDeptDao.class).findDeptAll();
          for (Dept dept : dList) {
            System.out.println("编号："+dept.getDid()+",名称："+dept.getDname());
          }
      }
    
      //根据编号查询
      public Dept findDeptById(int did){
        Dept dept = session.getMapper(IDeptDao.class).findDeptById(did);
        return dept;
      }
      
      //修改
      @Test
      public void updateDel(){
        findAllDept();
        System.out.println("请输入用户编号:");
        Scanner sc = new Scanner(System.in);
        int did = sc.nextInt();
        //根据编号查询
        Dept dept = findDeptById(did);
        System.out.println("需要修改的部门信息：");
        System.out.println("编号："+dept.getDid()+",名称："+dept.getDname());
        System.out.println("请输入新的部门名称：");
        dept.setDname(sc.next());
        //调用修改的方法
        int rel = session.getMapper(IDeptDao.class).updateDept(dept);
        //提交
        session.commit();
        if(rel>0){
          System.out.println("修改成共");
        }else{
          System.out.println("修改失败");
        }
      }
      
      
      //删除
      @Test
      public void delDept(){
        findAllDept();
        System.out.println("请输入需要删除的编号：");
        Scanner sc = new Scanner(System.in);
        Dept dept = session
              .getMapper(IDeptDao.class)
              .findDeptById(sc.nextInt());
        //调用删除
        int rel = session.getMapper(IDeptDao.class).delDept(dept);
        session.commit();
        if(rel>0){
          System.out.println("删除成功");
          findAllDept();
        }
        
      }
      
      //最后执行
      @After
      public void after(){
        if(session!=null){
          session.close();
        }
      }
    }

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