第二章分类，推荐，搜索，评价，购物车开发 - 3.4 商品评价 - 编写 service - 《Java 架构直通车》

在 foodie-dev-pojo 模块中的 com.imooc.pojo.vo 包内新建 ItemCommentVO 类

package com.imooc.pojo.vo;
import java.util.Date;
/**
 * 用于展示商品评价的 VO
 * Created by 92578 on 2020/8/22 21:28
 **/
public class ItemCommentVO {
    private Integer commentLevel;
    private String content;
    private String sepcName;
    private Date createdTime;
    private String userFace;
    private String nickname;
    public Integer getCommentLevel() {
        return commentLevel;
    }
    public void setCommentLevel(Integer commentLevel) {
        this.commentLevel = commentLevel;
    }
    public String getContent() {
        return content;
    }
    public void setContent(String content) {
        this.content = content;
    }
    public String getSepcName() {
        return sepcName;
    }
    public void setSepcName(String sepcName) {
        this.sepcName = sepcName;
    }
    public Date getCreatedTime() {
        return createdTime;
    }
    public void setCreatedTime(Date createdTime) {
        this.createdTime = createdTime;
    }
    public String getUserFace() {
        return userFace;
    }
    public void setUserFace(String userFace) {
        this.userFace = userFace;
    }
    public String getNickname() {
        return nickname;
    }
    public void setNickname(String nickname) {
        this.nickname = nickname;
    }
}

在 foodie-dev-mapper 模块中的 com.imooc.mapper 包下面创建 ItemsMapperCustom 接口

package com.imooc.mapper;
import com.imooc.pojo.vo.ItemCommentVO;
import org.apache.ibatis.annotations.Param;
import java.util.List;
import java.util.Map;
public interface ItemsMapperCustom {
    public List<ItemCommentVO> queryItemComments(@Param("paramsMap") Map<String, Object> map);
}

在 foodie-dev-service 模块中的 ItemService 接口内添加 queryPagedComments 方法

package com.imooc.service;
import com.imooc.pojo.Items;
import com.imooc.pojo.ItemsImg;
import com.imooc.pojo.ItemsParam;
import com.imooc.pojo.ItemsSpec;
import com.imooc.pojo.vo.CommentLevelCountsVO;
import com.imooc.pojo.vo.ItemCommentVO;
import java.util.List;
/**
 * Created by 92578 on 2020/8/22 16:17
 **/
public interface ItemService {
    /**
     * 根据商品 id 查询详情
     *
     * @param itemId
     * @return
     */
    public Items queryItemById(String itemId);
    /**
     * 根据商品 id 查询商品图片列表
     *
     * @param itemId
     * @return
     */
    public List<ItemsImg> queryItemImgList(String itemId);
    /**
     * 根据商品 id 查询商品规格
     *
     * @param itemId
     * @return
     */
    public List<ItemsSpec> queryItemSpecList(String itemId);
    /**
     * 根据商品 id 查询商品参数
     *
     * @param itemId
     * @return
     */
    public ItemsParam queryItemsParam(String itemId);
    /**
     * 根据商品 id 查询商品的评价等级数量
     *
     * @param itemId
     */
    public CommentLevelCountsVO queryCommentCounts(String itemId);
    /**
     * 根据商品 id 查询商品的评价（分页）
     *
     * @param itemId
     * @param level
     * @return
     */
    public List<ItemCommentVO> queryPagedComments(String itemId, Integer level);
}

在 foodie-dev-service 模块中完善 ItemServiceImpl 类，实现 queryPagedComments 接口

package com.imooc.service.impl;
import com.imooc.enums.CommentLevel;
import com.imooc.mapper.*;
import com.imooc.pojo.*;
import com.imooc.pojo.vo.CommentLevelCountsVO;
import com.imooc.pojo.vo.ItemCommentVO;
import com.imooc.service.ItemService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import tk.mybatis.mapper.entity.Example;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
 * Created by 92578 on 2020/8/22 16:18
 **/
@Service
public class ItemServiceImpl implements ItemService {
    @Autowired
    private ItemsMapper itemsMapper;
    @Autowired
    private ItemsImgMapper itemsImgMapper;
    @Autowired
    private ItemsSpecMapper itemsSpecMapper;
    @Autowired
    private ItemsParamMapper itemsParamMapper;
    @Autowired
    private ItemsCommentsMapper itemsCommentsMapper;
    @Autowired
    private ItemsMapperCustom itemsMapperCustom;
    /**
     * 根据商品 id 查询详情
     *
     * @param itemId
     * @return
     */
    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public Items queryItemById(String itemId) {
        return itemsMapper.selectByPrimaryKey(itemId);
    }
    /**
     * 根据商品 id 查询商品图片列表
     *
     * @param itemId
     * @return
     */
    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public List<ItemsImg> queryItemImgList(String itemId) {
        Example itemsImgExp = new Example(ItemsImg.class);
        Example.Criteria criteria = itemsImgExp.createCriteria();
        criteria.andEqualTo("itemId", itemId);
        return itemsImgMapper.selectByExample(itemsImgExp);
    }
    /**
     * 根据商品 id 查询商品规格
     *
     * @param itemId
     * @return
     */
    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public List<ItemsSpec> queryItemSpecList(String itemId) {
        Example itemsSpecExp = new Example(ItemsSpec.class);
        Example.Criteria criteria = itemsSpecExp.createCriteria();
        criteria.andEqualTo("itemId", itemId);
        return itemsSpecMapper.selectByExample(itemsSpecExp);
    }
    /**
     * 根据商品 id 查询商品参数
     *
     * @param itemId
     * @return
     */
    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public ItemsParam queryItemsParam(String itemId) {
        Example itemsParamExp = new Example(ItemsParam.class);
        Example.Criteria criteria = itemsParamExp.createCriteria();
        criteria.andEqualTo("itemId", itemId);
        return itemsParamMapper.selectOneByExample(itemsParamExp);
    }
    /**
     * 根据商品 id 查询商品的评价等级数量
     *
     * @param itemId
     */
    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public CommentLevelCountsVO queryCommentCounts(String itemId) {
        Integer goodCounts = getCommentCounts(itemId, CommentLevel.GOOD.type);
        Integer normalCounts = getCommentCounts(itemId, CommentLevel.NORMAL.type);
        Integer badCounts = getCommentCounts(itemId, CommentLevel.BAD.type);
        Integer totalCounts = goodCounts + normalCounts + badCounts;
        CommentLevelCountsVO countsVO = new CommentLevelCountsVO();
        countsVO.setTotalCounts(totalCounts);
        countsVO.setGoodCounts(goodCounts);
        countsVO.setNormalCounts(normalCounts);
        countsVO.setBadCounts(badCounts);
        return countsVO;
    }
    /**
     * 根据商品 id 查询商品的评价（分页）
     *
     * @param itemId
     * @param level
     * @return
     */
    @Transactional(propagation = Propagation.SUPPORTS)
    @Override
    public List<ItemCommentVO> queryPagedComments(String itemId, Integer level) {
        Map<String, Object> map = new HashMap<>();
        map.put("itemId", itemId);
        map.put("level", level);
        List<ItemCommentVO> list = itemsMapperCustom.queryItemComments(map);
        return list;
    }
    @Transactional(propagation = Propagation.SUPPORTS)
    Integer getCommentCounts(String itemId, Integer level) {
        ItemsComments condition = new ItemsComments();
        condition.setItemId(itemId);
        if (level != null) {
            condition.setCommentLevel(level);
        }
        return itemsCommentsMapper.selectCount(condition);
    }
}

在 foodie-dev-mapper 模块中的 resource\mapper 文件夹里创建 ItemsMapperCustom.xml

<?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.imooc.mapper.ItemsMapperCustom">
    <select id="queryItemComments" parameterType="Map" resultType="com.imooc.pojo.vo.ItemCommentVO">
        select ic.comment_level as commentLevel,
               ic.content       as content,
               ic.sepc_name     as sepcName,
               ic.created_time  as createdTime,
               u.face           as userFace,
               u.nickname       as nickname
        from items_comments as ic
                 left join users as u on ic.user_id = u.id
        where ic.item_id = #{paramsMap.itemId}
            <if test=" paramsMap.level != null and paramsMap.level != '' ">
                and ic.comment_level = #{paramsMap.level}
            </if>
    </select>
</mapper>