简介

MyBatis 是支持普通 SQL 查询，存储过程和高级映射的优秀持久层框架，其几乎消除了所有的 JDBC 代码和参数的手工设置以及结果集的检索。MyBatis 使用简单的 XML 或注解用于配置和原始映射，将接口和 Java 的 POJOs（Plain Old Java Objects，普通的 Java对象）映射成数据库中的记录。MyBatis 应用程序大都使用 SqlSessionFactory 实例，SqlSessionFactory 实例可以通过 SqlSessionFactoryBuilder 获得，而　SqlSessionFactoryBuilder 则可以从一个 XML 配置文件或者一个预定义的配置类的实例获得。

依赖

mybatis-3.2.2.jar 核心jar

mysql-connector-java-5.1.10-bin.jar 数据库访问

1.Configuration配置

在resources下，新建Configuration.xml

2.Entity实体类

示例：

package com.zyzpp.model;public class User {    private int id;    private String userName;    private int userAge;    private String userAddress;    private List
    
      cards;    ....}

3.Dao层接口

示例：

package com.zyzpp.inter;public interface IUserOperation {    public User selectUserByID(int id);    public List
    
      selectUsers(String userName);    public void addUser(User user);    public void updateUser(User user);    public void deleteUser(int id);    public List
     
       getUserArticles(@Param("userid") int userid);      //多个参数要加注释区分    public User getUserCards(int id);    public int getCount(User user);    public List
      
        getLimit(Map map);}

4.Mapper配置

说白了，就是实现上步接口方法


        
        
        
         
         
         
             
              
              
              
          
         
         
         
         
     
              insert into user(userName,userAge,userAddress)        values(#{userName},#{userAge},#{userAddress})    
         
         
     
              update user set userName =        #{userName},userAge=#{userAge},userAddress=#{userAddress} where        id=#{id}    
         
         
     
              delete from user where id=#{id}

5.开始使用

import java.io.Reader;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;public class Test {    private static SqlSessionFactory sqlSessionFactory;    private static Reader reader;    private static String resource = "Configuration.xml";    //mybatis的配置文件    static{        try{            /*使用MyBatis提供的Resources类加载mybatis的配置文件（它也加载关联的映射文件）*/            reader=Resources.getResourceAsReader(resource);             sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);//构建sqlSession的工厂        }catch (Exception e) {            e.printStackTrace();        }    }    public static void main(String[] args) {        Test test =new Test();        User user=new User();        test.getLimit();//      test.getCount(user);//  test.getUserCards(1);//  test.getUserArticles(1);//      test.getUserList("%");//      test.addUser();//      test.updateUser(1, "这是更新后的地址");//      test.deleteUser(3);    }    /*     * 以ID查找单个数据     */    public void getUserByID(int id){        SqlSession session=sqlSessionFactory.openSession();        try{        IUserOperation userOperation=session.getMapper(IUserOperation.class);        User user=userOperation.selectUserByID(id);        System.out.println("查询ID："+id+"结果如下\n"+"名字："+user.getUserName()+" 年龄："+user.getUserAge()+" 地址："+user.getUserAddress());        }finally {            session.close();        }    }    /*     * 以name查找符合的List列表     */    public void getUserList(String userName){        SqlSession session=sqlSessionFactory.openSession();        try{            IUserOperation userOperation=session.getMapper(IUserOperation.class);            List
    
      users = userOperation.selectUsers(userName);            System.out.println("查询结果如下：");            for(User user: users){                System.out.println(user.toString());            }        }finally {            session.close();        }    }    /*     * 增加一个用户     */    public void addUser(){        User user = new User();        user.setUserAddress("人民广场");        user.setUserAge(18);        user.setUserName("飞鸟");        SqlSession session = sqlSessionFactory.openSession();        try{        IUserOperation userOperation =session .getMapper(IUserOperation.class);        userOperation.addUser(user);        session.commit();        System.out.println("当前增加的用户ID："+user.getId());        }finally {            session.close();        }    }    /*     * 更新数据     */    public void updateUser(int id,String content){        //先得到用户，然后修改提交        SqlSession session = sqlSessionFactory.openSession();        try{            IUserOperation userOperation = session.getMapper(IUserOperation.class);            User user = userOperation.selectUserByID(id);            user.setUserAddress(content);            userOperation.updateUser(user);            session.commit();            System.out.println("更新ID："+id+"成功！");        }finally {            session.close();        }    }    /*     * 删除数据     */    public void deleteUser(int id){        SqlSession session = sqlSessionFactory.openSession();        try{            IUserOperation userOperation = session.getMapper(IUserOperation.class);            userOperation.deleteUser(id);            session.commit();            System.out.println("删除ID："+id+"成功！");        }finally {            session.close();        }    }    /*     * 多对一     */    public void getUserArticles(int userid){        SqlSession session = sqlSessionFactory.openSession();        try {        IUserOperation userOperation=session.getMapper(IUserOperation.class);        List
     
       articles = userOperation.getUserArticles(userid);        for(Article article:articles){        System.out.println("标题："+article.getTitle()+"：内容："+article.getContent()+        "：作者是："+article.getUser().getUserName()+"：地址："+        article.getUser().getUserAddress());        }        } finally {        session.close();        }        }    /*     * 一对多     */    private void getUserCards(int userid) {        SqlSession session = sqlSessionFactory.openSession();        try {            IUserOperation userOperation = session.getMapper(IUserOperation.class);            User user = userOperation.getUserCards(userid);            System.out.println(user.toString());            for (Card card : user.getCards()) {                System.out.println(card.toString());            }        } finally {            session.close();        }    }    /*     * 按条件查询总条数     */    private int getCount(User user){        SqlSession session = sqlSessionFactory.openSession();        try {            IUserOperation userOperation = session.getMapper(IUserOperation.class);            int i = userOperation.getCount(user);            System.out.println("总条数："+i);            return i;        } finally {            session.close();        }    }    /**     * 按条件查询List记录     */    private void getLimit(){        SqlSession session = sqlSessionFactory.openSession();        try {            IUserOperation userOperation = session.getMapper(IUserOperation.class);            Map
      
        map=new HashMap
       
        ();            Page page=new Page();            page.setDbIndex(0);            page.setDbNumber(1);            User user=new User();            user.setId(1);            map.put("page", page);            map.put("user", user);            List
        
          users = userOperation.getLimit(map);            System.out.println("查询结果如下：");            for(User use: users){                System.out.println(use.toString());            }        } finally {            session.close();        }    }}