JavaWeb完整案例详细步骤( 五 ) _生活百科

<?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.wfy.mapper.BrandMapper">? <resultMap id="brandResultMap" type="brand"> <result property="brandName" column="brand_name"/> <result property="companyName" column="company_name"/> </resultMap>?? <delete id="DeleteByIds"> delete from brand where id in <foreach collection="ids" item="id" open="(" separator="," close=")"> #{id} </foreach> </delete> <select id="SelectByPageAndCondition" resultMap="brandResultMap"> select * from brand <where> <if test="brand.brandName !=null and brand.brandName!=''"> and brand_name like #{brand.brandName} </if> <if test="brand.companyName !=null and brand.companyName!=''"> and company_name like #{brand.companyName} </if> <if test="brand.status !=null"> and status=#{brand.status} </if> </where>? limit #{begin} ,#{size}? </select> <select id="SelectTotalCountByCondition" resultType="java.lang.Integer"> select count(*) from brand <where> <if test="brandName !=null and brandName!=''"> and brand_name like #{brandName} </if> <if test="companyName !=null and companyName!=''"> and company_name like #{companyName} </if> <if test="status !=null"> and status=#{status} </if> </where>??</select>??</mapper>

注意这里的映射文件需要在resource目录下创建分层目录，通过‘\’进行分割
及文件的目录名为：“ com\wfy\mapper”

Service层(业务逻辑层)

因为我们需要不断的调用SqlSession的方法，通过mapper映像的方式，为了降低程序的耦合度，同时为了简化代码，通过接口的方式来实现对方法的调用

创建BrandService接口

package com.wfy.service;?import com.wfy.pojo.Brand;import com.wfy.pojo.PageBean;?import java.util.List;?public interface BrandService {? //查询所有数据 public List<Brand> SelectAll(); //新增数据 void AddBrand(Brand brand); //更改数据信息 //获取查询到的数据进行表格显现 Brand SelectById(int id); void UpdateBrand(Brand brand);? //删除指定数据 void DeleteById(int id);? //删除多条数据 void DeleteByIds(int[] ids);? //分页查询 currentPage--当前页码 pageSize--每页展示条数 PageBean<Brand> SelectByPage(int currentPage,int pageSize);? //分页条件查询 PageBean<Brand> SelectByPageAndCondition(int currentPage,int pageSize,Brand brand);?}