（1）新建好maven基本项目，引入mabatis的依赖

　　说明：在以前的dao层我们通常是直接用一个dao方法来操作数据库的，这里我们要将dao的类改成一个接口类，在impl文件用另一个类来实现它的所有的抽象方法。

resources目录建一个mybatis-config.xml文件，这个是配置mybatis框架的主要配置，mapper下的UsersMapper.xml是用来配置mysql的映射语句

（2）、新建一个MyBatisUtil工具类：

package edu.nf.mybatis.tools;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;/** * 描述: * mybatis工具类，这个工具类主要 是解析mybatis-config.xml， * 并初始化一个SqlSessionFactory工厂，然后通过这个工厂来创建SqlSession实例。 * 一个SqlSessionr实例其实就是一个变相的Connection对象 * @author lance * @create 2018-09-10 10:38 */public class MyBatisUtil {   /**声明ggwhSqlSessionFactory*/    private static SqlSessionFactory sqlSessionFactory;   /* 在静态代码块中初始化SqlSessionFactory*/    static{        //找到mybatis-config.xml配置文件，并构建一个输入流       //由于配置文件放在resources目录中，编译后会存放在classpath中       try {           //通过Resources类从classpath中找到xml文件并读取，返回一个InputStream的对象           InputStream is =Resources.getResourceAsStream("mybatis-config.xml");           //通过这个输入流来构建一个SqlSessionFactory对象           //通过上面的输入流传递给builder对象进行解析           sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);       } catch (IOException e) {           throw new RuntimeException(e.getMessage());       }   }   /**    * 提供一个获取SqlSession的方法    *    * */   public static SqlSession getSqlSession(){       //openSession方法构建一个sqlSession对象        return sqlSessionFactory.openSession();   }    public static SqlSession getSqlSession(Boolean falg){        //openSession方法构建一个sqlSession对象        return sqlSessionFactory.openSession(falg);    }}

 

（3）新建dao接口类与实现类具体如下：

UserDaoInf接口类：

package edu.nf.mybatis.dao;import edu.nf.mybatis.entity.Users;import java.util.List;import java.util.Map;/** * @Author lance * */public interface UserDaoInf {    /**     * 添加用户     */     void saveUser(Users users);    /**     * 修改用户     */     void updateUser(Users users);    /**     * 删除用户     */    void deleteUser(String uid);    /**     * 根据ID查询某条用户数据     */    Users findUsersById(String uid);    /**     * 查询所有的用户信息，保存在一个集合中     */    List
     
       findAll();    /**     * 统计查询     */    int userCount();    /**     * 模糊查询     */    List
      
        likeUsers(String name);    /**     * 查询所有的用户信息     */    List
       
         findAll2();    /**     * 查询单条的用户信息     */    Map
        
          findUserMap(String uid);    /**     * 查询多条的用户信息     */    List
         
        
       
      
     

　　/** 　　 * 多条记录封装一个map，Map
     
       :键是这条记录的主键，值是封装实体的对象  　　* @return  　　*/ 　　@MapKey("mid") 　　Map
      
        getMateialMap();
      
     

　　}

UserDaoImpl实现类：

package edu.nf.mybatis.dao.impl;import edu.nf.mybatis.dao.UserDaoInf;import edu.nf.mybatis.entity.Users;import edu.nf.mybatis.tools.MyBatisUtil;import javafx.beans.property.adapter.ReadOnlyJavaBeanBooleanProperty;import org.apache.ibatis.session.SqlSession;import java.util.List;import java.util.Map;/** * 描述: * 接口实现类 * @author lance * @create 2018-09-10 14:13 */public class UserDaoImpl implements UserDaoInf {    @Override    public int userCount() {        SqlSession session = MyBatisUtil.getSqlSession();        int count = 0;        try {            UserDaoInf dao = session.getMapper(UserDaoInf.class);            count= dao.userCount();        } catch (Exception e) {            e.printStackTrace();        }finally {            session.close();        }        return count;    }    @Override    public List
     
       likeUsers(String name) {        SqlSession session = MyBatisUtil.getSqlSession();        List
      
        list = null;        try {            UserDaoInf dao = session.getMapper(UserDaoInf.class);            list= dao.likeUsers(name);        } catch (Exception e) {            e.printStackTrace();        }finally {            session.close();        }        return list;    }    @Override    public void saveUser(Users user) {        //获取SqlSession实例        SqlSession session = MyBatisUtil.getSqlSession();        try {            //方式一：            //获取相应的Mapper,getMapper方法需要传递一个接口的对象            //并且返回的这个Mapper对象同样是实现了UserDao接口            //这个Mapper对象最核心的作用就是和mybatis的mapper映射配置文件进行关联            UserDaoInf dao = session.getMapper(UserDaoInf.class);            //调用这个实现类的saveUser方法将数据保存在数据库中            dao.saveUser(user);            //方式二：            //bint row = session.insert("edu.nf.mybatis.entity.saveUser",user);            //手动提交事务            session.commit();        } catch (Exception e) {            e.printStackTrace();            //在异常加回滚事务            session.rollback();        }finally {            session.close();        }    }    @Override    public void updateUser(Users users) {        SqlSession session = MyBatisUtil.getSqlSession();        try{            UserDaoInf dao = session.getMapper(UserDaoInf.class);            dao.updateUser(users);            session.commit();        }catch (Exception e){            e.printStackTrace();            session.rollback();        }finally {            session.close();        }    }    @Override    public void deleteUser(String uid) {        SqlSession session = MyBatisUtil.getSqlSession();        try{            UserDaoInf dao = session.getMapper(UserDaoInf.class);            dao.deleteUser(uid);            session.commit();        }catch (Exception e){            e.printStackTrace();            session.rollback();        }finally {            session.close();        }    }    @Override    public Users findUsersById(String uid) {        SqlSession session = MyBatisUtil.getSqlSession();        Users user=null;        try {            UserDaoInf dao = session.getMapper(UserDaoInf.class);            user = dao.findUsersById(uid);        } catch (Exception e) {            throw new RuntimeException(e.getMessage());        }finally {            session.close();        }        return user;    }    @Override    public List
       
         findAll() {        List
        
          list = null;        SqlSession session = MyBatisUtil.getSqlSession();        try {            UserDaoInf dao = session.getMapper(UserDaoInf.class);            list = dao.findAll();        } catch (Exception e) {            throw new RuntimeException(e.getMessage());        }        return list;    }    @Override    public List
         
           findAll2() {        SqlSession session = MyBatisUtil.getSqlSession();        List
          
            list = null; try{ UserDaoInf dao = session.getMapper(UserDaoInf.class); list = dao.findAll2(); }catch (Exception e){ throw new RuntimeException(e.getMessage()); }finally { session.close(); } return list; } @Override public Map
           
             findUserMap(String uid) { SqlSession session = MyBatisUtil.getSqlSession(); Map
            
              map = null; try { UserDaoInf dao = session.getMapper(UserDaoInf.class); map = dao.findUserMap(uid); } catch (Exception e) { throw new RuntimeException(e.getMessage()); }finally { session.close(); } return map; } @Override public List
             
            
           
          
         
        
       
      
     

（4）配置XML配置

  mybatis-config.xml的配置

UserMapper.xml配置：

     
     
         
          
          
              
               
           
      　　
          
      
               insert into user_info(u_id,u_name) values(#{uid},#{userName})    
          
      
               update user_info set u_name=#{userName} where u_id=#{uid}    
          
      
               delete from user_info where u_id=#{uid}    
          
          
              select u_id as uid, u_name as userName from user_info where u_id=#{uid}        
          
              select u_id as uid ,u_name as userName from user_info        
          
              select u_id as uid,u_name as userName from user_info where u_name like #{userName}"%"        
          
              select count(*) from user_info        
          
              select * from user_info        
          
              select * from user_info where u_id = #{uid}        
          
              select * from user_info    　　
     

　　    　　 select * from Material 　　

（5）测试：

package eud.nf.mybatis.dao.test;import edu.nf.mybatis.dao.UserDaoInf;import edu.nf.mybatis.dao.impl.UserDaoImpl;import edu.nf.mybatis.entity.Users;import edu.nf.mybatis.tools.UUIDUtils;import org.junit.Test;import java.util.List;import java.util.Map;/** * 描述: * * @author lance * @create 2018-09-10 15:15 */public class UserDaoImplTest {    @Test    public void testSaveUsers(){        Users users = new Users();        //users.setUid(UUIDUtils.createUUID());        users.setUid("1007");        users.setUserName("test6");        UserDaoInf dao = new UserDaoImpl();        dao.saveUser(users);    }    @Test    public void testUpdateUsers(){        Users users = new Users();        users.setUid("1006");        users.setUserName("admin");        UserDaoInf dao = new UserDaoImpl();        dao.updateUser(users);    }    @Test    public void testDeleteUsers(){        UserDaoInf dao = new UserDaoImpl();        dao.deleteUser("1010");    }    @Test    public void testFindUsersById(){        UserDaoInf dao = new UserDaoImpl();        Users user = dao.findUsersById("1001");        System.out.println(user.getUid());        System.out.println(user.getUserName());    }    @Test    public  void testFindAll(){        UserDaoInf dao = new UserDaoImpl();        List
     
       list = dao.findAll();        for (Users users : list) {            System.out.println(users);        }    }    @Test    public void testUserCount(){        UserDaoInf dao = new UserDaoImpl();        int count = dao.userCount();        System.out.println(count);    }    @Test    public void testLikeUser(){        UserDaoInf dao = new UserDaoImpl();        List
      
        list = dao.likeUsers("test6");        for (Users users : list) {            System.out.println(users.getUid());            System.out.println(users.getUserName());        }    }    @Test    public void testFindAll2(){        UserDaoInf dao = new UserDaoImpl();        List
       
         list = dao.findAll2();        for (Users users : list) {            System.out.println(users.getUid());            System.out.println(users.getUserName());        }    }    @Test    public void testFindUsersMap(){        UserDaoInf dao = new UserDaoImpl();        Map
        
          map = dao.findUserMap("1001");        for (String s : map.keySet()) {            System.out.println(s +":"+ map.get(s));        }    }    @Test    public void testFindUsersListMap(){        UserDaoInf dao = new UserDaoImpl();        List