Mybatis基于注解的方式访问数据库

1. 使用方式：在Service层直接调用

 package com.disappearwind.service;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Repository;
 import org.springframework.stereotype.Service;
 
 import com.disappearwind.mapper.UserInfoMapper;
 import com.disappearwind.model.UserInfo;
 
 /**
  * 用户service
  *
  */
 @Service
 @Repository
 public class UserInfoService{
 
     @Autowired
     private UserInfoMapper userInfoMapper;
 
      public UserInfo selectByPrimaryKey(Integer id){
          return userInfoMapper.selectByPrimaryKey(id);
      }
 }

UserInfoService

2. Mapper层申明

 package com.disappearwind.mapper;
 
 import com.disappearwind.model.UserInfo;
 
 public interface UserInfoMapper {
     UserInfo selectByPrimaryKey(Integer id);
 }

UserInfoMapper

3. mpper.xml配置文件

 <?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.disappearwind.mapper.UserInfoMapper" >
 
   <resultMap id="BaseResultMap" type="com.disappearwind.model.UserInfo">
         <id column="UserInfoID" property="userinfoid" jdbcType="INTEGER" />
         <result column="Name" property="username" jdbcType="VARCHAR" />
         <result column="Phone" property="phone" jdbcType="CHAR" />
         <result column="Pwd" property="pwd" jdbcType="CHAR" />
     </resultMap>
 
      <sql id="Base_Column_List">
         UserInfoID, Name, Type, TypeRemark, HeadUrl,BigImgUrl,GreatImgUrl,
         NickName, Sex, Status,Labels, StoryCount,
         FriendCount, FollowerCount, FavouriteCount, HotNum,
         CreateDate,Description
     </sql>
 
   <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
     select
     <include refid="Base_Column_List" />
     from userinfo
     where UserInfoID = #{userinfoid,jdbcType=INTEGER}
   </select>
 
 </mapper>

UserInfoMapper.xml

4. 实体model层

 package com.disappearwind.model;
 
 public class UserInfo {
     private Integer userinfoid;
 
     private String username;
 
     private String phone;
 
     private String pwd;
 
     public Integer getUserinfoid() {
         return userinfoid;
     }
 
     public void setUserinfoid(Integer userinfoid) {
         this.userinfoid = userinfoid;
     }
 
     public String getUsername() {
         return username;
     }
 
     public void setUsername(String username) {
         this.username = username;
     }
 
     public String getPhone() {
         return phone;
     }
 
     public void setPhone(String phone) {
         this.phone = phone;
     }
 
     public String getPwd() {
         return pwd;
     }
 
     public void setPwd(String pwd) {
         this.pwd = pwd;
     }
 
     public UserInfo() {
     }
 }

UserInfo

5. SpringMVC配置

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
     xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"
     xmlns:aop="http://www.springframework.org/schema/aop"
     xsi:schemaLocation="
         http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-4.0.xsd
         http://www.springframework.org/schema/aop
         http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
         http://www.springframework.org/schema/tx
         http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
         ">
     <context:component-scan base-package="com.disappearwind.*" />
 </beans>

context.xml

注意：context.xml的位置在web.xml中的如下配置节配置

<context-param>
　　<param-name>contextConfigLocation</param-name>
　　<param-value>classpath:context.xml</param-value>
</context-param>

用此方案的好处：省得写DAO层，只要Mapper层的方法申明和mapper.xml的方法申明保持一致，并且文件名也保持一致（UserInfoMapper.java和UserInfoMapper.xml）就能顺利的访问