电商生鲜网站开发（四）——后台开发：商品模块-图片上传/多条件拼接sql

增加商品

上传图片

更新商品

删除商品

批量上下架

图片上传功能

文件名UUID

通用唯一识别码（Universally Unique Identifier）

防止重名、防止发图

生成规则：日期和时间、MAC地址、HashCode、随机数

配置application.properties

# 上传文件的路径，根据部署情况自行修改 该值注入到Constan类中
file.upload.dir=/Users/cat/Documents/project/java/online_mall/mall-prepare-static

Constant常量类

package com.learn2333.mall.common;import com.google.common.collect.Sets;
import com.learn2333.mall.exception.MallException;
import com.learn2333.mall.exception.MallExceptionEnum;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;import java.util.Set;/*** 描述：    常量值*/
@Component
public class Constant {public static final String MALL_USER = "mall_user";public static final String SALT = "learn2333";public static String FILE_UPLOAD_DIR;//因为是static无法直接注入，使用set方法为静态变量注入赋值@Value("${file.upload.dir}")public void setFileUploadDir(String fileUploadDir) {FILE_UPLOAD_DIR = fileUploadDir;}

controller

    @PostMapping("/admin/upload/file")public ApiRestResponse upload(HttpServletRequest httpServletRequest,@RequestParam("file") MultipartFile file) {String fileName = file.getOriginalFilename();String suffixName = fileName.substring(fileName.lastIndexOf("."));  //后缀//生成文件名称UUIDUUID uuid = UUID.randomUUID();String newFileName = uuid.toString() + suffixName;//创建文件File fileDirectory = new File(Constant.FILE_UPLOAD_DIR);File destFile = new File(Constant.FILE_UPLOAD_DIR + newFileName);//如果文件夹不存在if (!fileDirectory.exists()) {if (!fileDirectory.mkdir()) {//创建文件夹throw new MallException(MallExceptionEnum.MKDIR_FAILED);}}//文件写入try {file.transferTo(destFile);} catch (IOException e) {e.printStackTrace();}//返回文件地址try {return ApiRestResponse.success(getHost(new URI(httpServletRequest.getRequestURL() + "")) + "/images/"+ newFileName);} catch (URISyntaxException e) {return ApiRestResponse.error(MallExceptionEnum.UPLOAD_FAILED);}}/*** 获取ip和端口号* @param uri* @return*/private URI getHost(URI uri) {URI effectiveURI;try {effectiveURI = new URI(uri.getScheme(), uri.getUserInfo(), uri.getHost(), uri.getPort(),null, null, null);} catch (URISyntaxException e) {effectiveURI = null;}return effectiveURI;}

自定义静态资源映射目录

上传图片后回显

配置SpringBootWebMvcConfig

静态资源到本地目录到映射

package com.learn2333.mall.config;import com.learn2333.mall.common.Constant;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;/*** 描述：     配置Swagger地址映射*/
@Configuration
public class MallWebMvcConfig implements WebMvcConfigurer {@Overridepublic void addResourceHandlers(ResourceHandlerRegistry registry) {//图片目录映射registry.addResourceHandler("/images/**").addResourceLocations("file:" + Constant.FILE_UPLOAD_DIR);registry.addResourceHandler("swagger-ui.html").addResourceLocations("classpath:/META-INF/resources/");registry.addResourceHandler("/webjars/**").addResourceLocations("classpath:/META-INF/resources/webjars/");}
}

商品批量上下架

MyBatis遍历List

where语句拼接

    <update id="batchUpdateSellStatus">update mall_productset status = #{sellStatus}where id in<foreach collection="ids" open="(" close=")" item="id" separator=",">#{id}</foreach></update>

后台管理员商品列表接口

调用分页PageHelper，跟商品分类模块类似

前台用户商品列表接口

商品列表：搜索功能

使用入参判空、加%通配符、like关键字sql拼接

传入ProductListReq实体

package com.learn2333.mall.model.request;import java.util.Date;public class ProductListReq {private String keyword;  //关键字private Integer categoryId;        //分类idprivate String orderBy;       //排序方式//分页private Integer pageNum = 1;private Integer pageSize = 10;get;set;
}

ProjectController

    @ApiOperation("商品列表")@GetMapping("product/list")public ApiRestResponse list(ProductListReq productListReq){PageInfo list = productService.list(productListReq);return ApiRestResponse.success(list);}

对与这种条件比较多的，拼接麻烦的查询，可以建一个query，也方便后续的修改

ProductListQuery

package com.learn2333.mall.model.query;import java.util.List;/*** 描述：       查询商品列表的Query*/
public class ProductListQuery {private String keyword;//查询一个目录下的商品，不一定是只有当前目录下，还包含子目录，子子目录下的商品；因此之前传入一个目录的id现在还要获取它子目录的所有idprivate List<Integer> categoryIds;get;set;
}

productServiceImpl

    @Overridepublic PageInfo list(ProductListReq productListReq) {//构建Query对象ProductListQuery productListQuery = new ProductListQuery();//搜索处理if (!StringUtils.isEmpty(productListReq.getKeyword())) {String keyword = new StringBuilder().append("%").append(productListReq.getKeyword()).append("%").toString();productListQuery.setKeyword(keyword);}//目录处理：如果查某个目录下的商品，不仅是需要查出该目录下的，还要把所有子目录的所有商品都查出来，所以要拿到一个目录id的Listif (productListReq.getCategoryId() != null) {//复用之前写过的传入目录id查询子目录方法listCategoryForCustomerList<CategoryVO> categoryVOList = categoryService.listCategoryForCustomer(productListReq.getCategoryId());//将得到的树形目录结构categoryVOList展开ArrayList<Integer> categoryIds = new ArrayList<>();categoryIds.add(productListReq.getCategoryId());//用下面定义的方法来处理子目录的遍历，//通过下面的函数处理就可以将categoryVOList中子目录所有id放入categoryIds，因为传入的是List<CategoryVO>引用类型getCategoryIds(categoryVOList, categoryIds);productListQuery.setCategoryIds(categoryIds);}//排序处理String orderBy = productListReq.getOrderBy(); //为了系统安全，不能传入什么就直接按照什么排序，而是要拿到前台传入的排序规则if (Constant.ProductListOrderBy.PRICE_ASC_DESC.contains(orderBy)) {    //contains判断是否包含PageHelper.startPage(productListReq.getPageNum(), productListReq.getPageSize(), orderBy);} else {PageHelper.startPage(productListReq.getPageNum(), productListReq.getPageSize());}List<Product> productList = productMapper.selectList(productListQuery);PageInfo pageInfo = new PageInfo(productList);return pageInfo;}//递归遍历子目录private void getCategoryIds(List<CategoryVO> categoryVOList, ArrayList<Integer> categoryIds) {for (int i = 0; i < categoryVOList.size(); i++) {CategoryVO categoryVO = categoryVOList.get(i);if (categoryVO != null) {categoryIds.add(categoryVO.getId());getCategoryIds(categoryVO.getChildCategory(), categoryIds);}}}

常量(排序方式接口)

package com.learn2333.mall.common;import com.google.common.collect.Sets;
import com.learn2333.mall.exception.MallException;
import com.learn2333.mall.exception.MallExceptionEnum;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;import java.util.Set;/*** 描述：    常量值*/
@Component
public class Constant {public static final String MALL_USER = "mall_user";public static final String SALT = "learn2333";public static String FILE_UPLOAD_DIR;@Value("${file.upload.dir}")public void setFileUploadDir(String fileUploadDir) {FILE_UPLOAD_DIR = fileUploadDir;}public interface ProductListOrderBy {Set<String> PRICE_ASC_DESC = Sets.newHashSet("price desc", "price asc");}

ProductMapper接口

    List<Product> selectList(@Param("query") ProductListQuery query);

ProductMapper

    <select id="selectList" resultMap="BaseResultMap"parameterType="com.learn2333.mall.model.query.ProductListQuery">select<include refid="Base_Column_List"/>from mall_product<where><if test="query.keyword != null">and name like #{query.keyword}</if><if test="query.categoryIds != null">and category_id in<foreach collection="query.categoryIds" close=")" item="item" open="(" separator=",">#{item}</foreach></if><!--上架商品-->and status = 1</where>order by update_time desc</select>

排序功能、MyBatis PageHelper、枚举：order by

总结

商品的搜索、排序、目录查询

常见问题：更新和新增不要用一个接口，虽然方便，但是从长期维护角度每一个接口要明确分工；排序的时候要用常量枚举判断，不要直接传入，否则可能被黑客利用，攻击数据库。