2021-09-29

2024-04-12 12:24:44

CGB2105-Day15

闪耀太阳 2021-08-09 11:25:04

2730

收藏 11 分类专栏： 2105 版权

2105 专栏收录该内容 17 篇文章 26 订阅订阅专栏

1. 全局异常处理/事务控制关系

2 商品分类业务实现

2.1 商品分类查询优化

2.1.1 现有代码存在的问题

问题说明: 如果经过2次for循环, 链接数据库的次数将会很多, 直接影响查询的效率.
优化: 尽可能的降低查询的次数,同时满足用户需求

2.1.2 优化策略

数据结构: Map<K,V> map
Key=“父级ID” Value=List<当前父级的子级>
用法: 如果想要获取任意父级的子级 map.get(父级的ID)
用法说明: Value 只有父级的子级信息,没有嵌套结构
Map<父级ID,List<ItemCat{id=xx,name=xx,children=null}>>

2.1.3 封装Map集合

原理图:

2.1.3 封装Map实现

  /**
     * 1.封装Map集合   Map<Key=父级ID,value=List<ItemCat对象>>
     * 2.说明:  将所有的数据库的父子关系,进行封装.(没有嵌套!!!!)
     * 3.优势:  只查询一次数据库,就可以完成父子关系的封装.
        策略:
     *      1. key不存在, 准备一个新List集合,将自己当作第一个元素追加
     *      2. key存在,  获取原有list集合,将自己追加.
     *
     */
    public Map<Integer,List<ItemCat>> initMap(){
        //Map中包含了所有的父子级关系.
        Map<Integer,List<ItemCat>> map = new HashMap<>();
        //1.查询item_cat表中的所有的记录(1/2/3级菜单)
        List<ItemCat> itemCatList = itemCatMapper.selectList(null);
        //2.实现数据的封装
        for(ItemCat itemCat : itemCatList){
            int key = itemCat.getParentId();
            if(map.containsKey(key)){ //存在
                List<ItemCat> list = map.get(key);
                //将自己追加到其中
                list.add(itemCat);
            }else{  //不存在: 准备List集合,将自己作为第一个元素封装
                List<ItemCat> list = new ArrayList<>();
                list.add(itemCat);
                map.put(key,list);
            }
        }
        //将封装的数据进行返回.
        return map;
    }

2.1.4 后台代码完整实现

 /**
     * 1.封装Map集合   Map<Key=父级ID,value=List<ItemCat对象>>
     * 2.说明:  将所有的数据库的父子关系,进行封装.(没有嵌套!!!!)
     * 3.优势:  只查询一次数据库,就可以完成父子关系的封装.
        策略:
     *      1. key不存在, 准备一个新List集合,将自己当作第一个元素追加
     *      2. key存在,  获取原有list集合,将自己追加.
     *
     */
    public Map<Integer,List<ItemCat>> initMap(){
        //Map中包含了所有的父子级关系.
        Map<Integer,List<ItemCat>> map = new HashMap<>();
        //1.查询item_cat表中的所有的记录(1/2/3级菜单)
        List<ItemCat> itemCatList = itemCatMapper.selectList(null);
        //2.实现数据的封装
        for(ItemCat itemCat : itemCatList){
            int key = itemCat.getParentId();
            if(map.containsKey(key)){ //存在
                List<ItemCat> list = map.get(key);
                //将自己追加到其中
                list.add(itemCat);
            }else{  //不存在: 准备List集合,将自己作为第一个元素封装
                List<ItemCat> list = new ArrayList<>();
                list.add(itemCat);
                map.put(key,list);
            }
        }
        //将封装的数据进行返回.
        return map;
    }
<span class="token comment">/**
 * level 1 只查询一级商品分类
 *       2 查询一级/二级  嵌套封装
 *       3 查询一级/二级/三级   嵌套封装
 * @param level
 * @return
 */</span>
<span class="token annotation punctuation">@Override</span>
<span class="token keyword">public</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span></span> <span class="token function">findItemCatList</span><span class="token punctuation">(</span><span class="token class-name">Integer</span> level<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token keyword">long</span> startTime <span class="token operator">=</span> <span class="token class-name">System</span><span class="token punctuation">.</span><span class="token function">currentTimeMillis</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token comment">//Map集合里边封装的是所有的父子级关系.</span>
    <span class="token class-name">Map</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Integer</span><span class="token punctuation">,</span><span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> map <span class="token operator">=</span> <span class="token function">initMap</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">if</span><span class="token punctuation">(</span>level <span class="token operator">==</span> <span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span> <span class="token comment">//只获取1级菜单. parent_id = 0</span>
        <span class="token keyword">return</span> map<span class="token punctuation">.</span><span class="token function">get</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
    <span class="token comment">//用户查询1/2级商品分类信息</span>
    <span class="token keyword">if</span><span class="token punctuation">(</span>level <span class="token operator">==</span> <span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
        <span class="token keyword">return</span> <span class="token function">getLevel2List</span><span class="token punctuation">(</span>map<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>

    <span class="token comment">//如果程序执行到这里,则说明用户查询的是1-2-3级菜单</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span></span> list <span class="token operator">=</span> <span class="token function">getLevel3List</span><span class="token punctuation">(</span>map<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">long</span> endTime <span class="token operator">=</span> <span class="token class-name">System</span><span class="token punctuation">.</span><span class="token function">currentTimeMillis</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"耗时:"</span><span class="token operator">+</span><span class="token punctuation">(</span>endTime<span class="token operator">-</span>startTime<span class="token punctuation">)</span><span class="token operator">+</span><span class="token string">"毫秒"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">return</span> list<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span></span> <span class="token function">getLevel3List</span><span class="token punctuation">(</span><span class="token class-name">Map</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Integer</span><span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> map<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token comment">//1.先查询1-2级</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span></span> oneList <span class="token operator">=</span> <span class="token function">getLevel2List</span><span class="token punctuation">(</span>map<span class="token punctuation">)</span><span class="token punctuation">;</span>

    <span class="token comment">//2.遍历集合</span>
    <span class="token keyword">for</span><span class="token punctuation">(</span><span class="token class-name">ItemCat</span> oneItemCat <span class="token operator">:</span> oneList<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
        <span class="token comment">//获取二级集合信息</span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span></span> twoList <span class="token operator">=</span> oneItemCat<span class="token punctuation">.</span><span class="token function">getChildren</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token keyword">if</span><span class="token punctuation">(</span>twoList <span class="token operator">==</span> <span class="token keyword">null</span> <span class="token operator">||</span> twoList<span class="token punctuation">.</span><span class="token function">size</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">==</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
            <span class="token comment">//当前一级菜单没有二级元素.结束本次循环,开始下一次!!!</span>
            <span class="token keyword">continue</span><span class="token punctuation">;</span>
        <span class="token punctuation">}</span>
        <span class="token comment">//该元素有二级,应该查询三级.</span>
        <span class="token keyword">for</span><span class="token punctuation">(</span><span class="token class-name">ItemCat</span> twoItemCat <span class="token operator">:</span> twoList<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
            <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span></span> threeList <span class="token operator">=</span> map<span class="token punctuation">.</span><span class="token function">get</span><span class="token punctuation">(</span>twoItemCat<span class="token punctuation">.</span><span class="token function">getId</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            twoItemCat<span class="token punctuation">.</span><span class="token function">setChildren</span><span class="token punctuation">(</span>threeList<span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token punctuation">}</span>
    <span class="token punctuation">}</span>
    <span class="token keyword">return</span> oneList<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token comment">//查询一级和二级信息</span>
<span class="token keyword">public</span> <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span></span> <span class="token function">getLevel2List</span><span class="token punctuation">(</span><span class="token class-name">Map</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Integer</span><span class="token punctuation">,</span> <span class="token class-name">List</span><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> map<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token comment">//思路: 先查询一级,之后循环遍历,再次封装2级</span>
    <span class="token comment">//1.获取一级</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span></span> oneList <span class="token operator">=</span> map<span class="token punctuation">.</span><span class="token function">get</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">for</span><span class="token punctuation">(</span><span class="token class-name">ItemCat</span> oneItemCat <span class="token operator">:</span> oneList<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
        <span class="token comment">//2.如何根据一级查询二级? 通过Map集合获取</span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span></span> twoList <span class="token operator">=</span> map<span class="token punctuation">.</span><span class="token function">get</span><span class="token punctuation">(</span>oneItemCat<span class="token punctuation">.</span><span class="token function">getId</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token comment">//3.实现了一级二级的封装</span>
        oneItemCat<span class="token punctuation">.</span><span class="token function">setChildren</span><span class="token punctuation">(</span>twoList<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
    <span class="token keyword">return</span> oneList<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

2.2 商品分类状态修改

2.2.1 页面JS分析

2.2.2 业务接口文档说明

请求路径: /itemCat/status/{id}/{status}
请求类型: put
请求参数:

参数名称	参数说明	备注
id	用户ID值	不能为null
status	用户的状态信息	不能为null

返回值: SysResult对象

参数名称	参数说明	备注
status	状态信息	200表示服务器请求成功 201表示服务器异常
msg	服务器返回的提示信息	可以为null
data	服务器返回的业务数据	可以为null

2.2.3 编辑ItemCatController

 /**
     * 业务需求: 实现状态的修改
     * 1.URL: /itemCat/status/{id}/{status}
     * 2.请求类型: put
     * 3.返回值: SysResult对象
     */
    @PutMapping("/status/{id}/{status}")
    public SysResult updateStatus(ItemCat itemCat){
    itemCatService<span class="token punctuation">.</span><span class="token function">updateStatus</span><span class="token punctuation">(</span>itemCat<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">return</span> <span class="token class-name">SysResult</span><span class="token punctuation">.</span><span class="token function">success</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

2.2.4 编辑ItemCatService

 @Override
    public void updateStatus(ItemCat itemCat) {//id/status
    itemCatMapper<span class="token punctuation">.</span><span class="token function">updateById</span><span class="token punctuation">(</span>itemCat<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

2.3 商品分类新增操作

2.3.1 业务说明

如果是一级菜单,则不需要勾选父级.
如果有父级,只能勾选1-2级.

2.3.2 页面JS说明

商品分类菜单信息 2级展现JS

async findParentItemCatList() {
        //动态获取商品分类信息  type=2表示获取2级商品分类信息
        const {
          data: result
        } = await this.$http.get("/itemCat/findItemCatList/2")
        if (result.status !== 200) return this.$message.error("获取商品分类列表失败!!")
        this.parentItemCatList = result.data
      },
<span class="token comment">//2.发起Ajax请求,实现新增操作</span>
 async <span class="token function">addItemCatForm</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token comment">//先将整个表单进行校验</span>
    <span class="token keyword">this</span><span class="token punctuation">.</span>$refs<span class="token punctuation">.</span>itemCatFormRef<span class="token punctuation">.</span><span class="token function">validate</span><span class="token punctuation">(</span>async validate <span class="token operator">=</span><span class="token operator">&gt;</span> <span class="token punctuation">{<!-- --></span>
      <span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token operator">!</span>validate<span class="token punctuation">)</span> <span class="token keyword">return</span>
      <span class="token keyword">const</span> <span class="token punctuation">{<!-- --></span>
        data<span class="token operator">:</span> result
      <span class="token punctuation">}</span> <span class="token operator">=</span> await <span class="token keyword">this</span><span class="token punctuation">.</span>$http<span class="token punctuation">.</span><span class="token function">post</span><span class="token punctuation">(</span><span class="token string">"/itemCat/saveItemCat"</span><span class="token punctuation">,</span> <span class="token keyword">this</span><span class="token punctuation">.</span>itemCatForm<span class="token punctuation">)</span>
      <span class="token keyword">if</span> <span class="token punctuation">(</span>result<span class="token punctuation">.</span>status <span class="token operator">!=</span><span class="token operator">=</span> <span class="token number">200</span><span class="token punctuation">)</span> <span class="token keyword">return</span> <span class="token keyword">this</span><span class="token punctuation">.</span>$message<span class="token punctuation">.</span><span class="token function">error</span><span class="token punctuation">(</span><span class="token string">"新增商品分类失败"</span><span class="token punctuation">)</span>
      <span class="token keyword">this</span><span class="token punctuation">.</span>$message<span class="token punctuation">.</span><span class="token function">success</span><span class="token punctuation">(</span><span class="token string">"新增商品分类成功!!!"</span><span class="token punctuation">)</span>
      <span class="token comment">//新增成功,则刷新分类列表信息</span>
      <span class="token keyword">this</span><span class="token punctuation">.</span><span class="token function">findItemCatList</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
      <span class="token keyword">this</span><span class="token punctuation">.</span>addItemCatDialogVisible <span class="token operator">=</span> <span class="token boolean">false</span>
    <span class="token punctuation">}</span><span class="token punctuation">)</span>
  <span class="token punctuation">}</span><span class="token punctuation">,</span>

2.3.3 业务接口文档说明

请求路径: /itemCat/saveItemCat
请求类型: post
请求参数: 表单数据

参数名称	参数说明	备注
name	商品分类名称	不能为null
parentId	用户父级ID	不能为null
level	分类级别	1 2 3 商品分类级别

返回值: SysResult对象

参数名称	参数说明	备注
status	状态信息	200表示服务器请求成功 201表示服务器异常
msg	服务器返回的提示信息	可以为null
data	服务器返回的业务数据	可以为null

2.3.4 编辑ItemCatController

 /**
     * 需求: 实现商品分类入库
     * URL: /itemCat/saveItemCat
     * 类型: post类型
     * 参数: itemCat对象~~~JSON
     * 返回值: SysResult
     */
    @PostMapping("/saveItemCat")
    public SysResult saveItemCat(@RequestBody ItemCat itemCat){
    itemCatService<span class="token punctuation">.</span><span class="token function">saveItemCat</span><span class="token punctuation">(</span>itemCat<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">return</span> <span class="token class-name">SysResult</span><span class="token punctuation">.</span><span class="token function">success</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

2.3.5 编辑ItemCatServiceImpl

	@Override
    @Transactional
    public void saveItemCat(ItemCat itemCat) {
    itemCat<span class="token punctuation">.</span><span class="token function">setStatus</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    itemCatMapper<span class="token punctuation">.</span><span class="token function">insert</span><span class="token punctuation">(</span>itemCat<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

2.4 商品分类删除操作

2.4.1 业务说明

1.如果被删除的标签是3级标签,则可以直接删除.
2.如果被删除的标签是2级标签,则需要先删除3级,再删除2级.
3.如果被删除的标签是1级标签,则需要先删除3级,在删除2级.最后删除1级.

2.4.2 页面JS分析

2.4.3 业务接口文档说明

请求路径: /itemCat/deleteItemCat
请求类型: delete
业务描述: 当删除节点为父级时,应该删除自身和所有的子节点
请求参数:

参数名称	参数说明	备注
id	用户id号	不能为null
level	商品分类级别一级,二级,三级

返回值结果 SysResult对象

参数名称	参数说明	备注
status	状态信息	200表示服务器请求成功 201表示服务器异常
msg	服务器返回的提示信息	可以为null
data	服务器返回的业务数据	可以为null

2.4.4 编辑ItemCatController

 /**
     * 商品分类删除操作
     * URL:  /itemCat/deleteItemCat?id=1&level=3
     * 类型:  delete
     * 参数:  id/level
     * 返回值: SysResult对象
     */
    @DeleteMapping("/deleteItemCat")
    public SysResult deleteItemCat(Integer id,Integer level){
    itemCatService<span class="token punctuation">.</span><span class="token function">deleteItemCat</span><span class="token punctuation">(</span>id<span class="token punctuation">,</span>level<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">return</span> <span class="token class-name">SysResult</span><span class="token punctuation">.</span><span class="token function">success</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

2.4.5 编辑ItemCatServiceImpl

/**
     * 1.易用性,性能高
     *
     * @param id
     * @param level
     */
    @Override
    @Transactional  //添加事务的控制
    public void deleteItemCat(Integer id, Integer level) {
        if(level == 3){
            itemCatMapper.deleteById(id);
        }
    <span class="token keyword">if</span><span class="token punctuation">(</span>level <span class="token operator">==</span> <span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
        <span class="token comment">//1.先删除3级菜单</span>
        <span class="token class-name">QueryWrapper</span> queryWrapper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">QueryWrapper</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        queryWrapper<span class="token punctuation">.</span><span class="token function">eq</span><span class="token punctuation">(</span><span class="token string">"parent_id"</span><span class="token punctuation">,</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span>
        itemCatMapper<span class="token punctuation">.</span><span class="token function">delete</span><span class="token punctuation">(</span>queryWrapper<span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token comment">//2.再删除2级菜单</span>
        itemCatMapper<span class="token punctuation">.</span><span class="token function">deleteById</span><span class="token punctuation">(</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>

    <span class="token comment">//如果程序执行到这一行 则需要先删除3级/再删除2级/最后删除1级</span>
    <span class="token keyword">if</span><span class="token punctuation">(</span>level <span class="token operator">==</span> <span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Integer</span><span class="token punctuation">&gt;</span></span> ids <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ArrayList</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token punctuation">&gt;</span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token comment">//1.查询所有的二级菜单</span>
        <span class="token class-name">QueryWrapper</span> queryWrapper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">QueryWrapper</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        queryWrapper<span class="token punctuation">.</span><span class="token function">eq</span><span class="token punctuation">(</span><span class="token string">"parent_id"</span><span class="token punctuation">,</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">ItemCat</span><span class="token punctuation">&gt;</span></span> twoList <span class="token operator">=</span> itemCatMapper<span class="token punctuation">.</span><span class="token function">selectList</span><span class="token punctuation">(</span>queryWrapper<span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token class-name">ItemCat</span> twoItemCat <span class="token operator">:</span> twoList<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span>
            <span class="token comment">//删除3级菜单</span>
            queryWrapper<span class="token punctuation">.</span><span class="token function">clear</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            queryWrapper<span class="token punctuation">.</span><span class="token function">eq</span><span class="token punctuation">(</span><span class="token string">"parent_id"</span><span class="token punctuation">,</span>twoItemCat<span class="token punctuation">.</span><span class="token function">getId</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token comment">//delete from item_cat where parent_id = "二级ID"</span>
            itemCatMapper<span class="token punctuation">.</span><span class="token function">delete</span><span class="token punctuation">(</span>queryWrapper<span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token comment">//获取需要删除的ID信息</span>
            ids<span class="token punctuation">.</span><span class="token function">add</span><span class="token punctuation">(</span>twoItemCat<span class="token punctuation">.</span><span class="token function">getId</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token punctuation">}</span>
        <span class="token comment">//将所有的二级/一级ID封装到List集合中</span>
        ids<span class="token punctuation">.</span><span class="token function">add</span><span class="token punctuation">(</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span>
        itemCatMapper<span class="token punctuation">.</span><span class="token function">deleteBatchIds</span><span class="token punctuation">(</span>ids<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
<span class="token punctuation">}</span>

3. 商品管理实现

3.1 表设计

1.item表设计商品表(商品的基本信息)

2.item_desc 表设计商品详情表 item_desc 专门保存大字段(html/url/图片网址…)

设计要求: item表与itemDesc表应该一对一. item.id = itemDesc.id

3.2.Item POJO对象设计

/**
 * @author 刘昱江
 * 时间 2021/4/7
 */
@TableName("item")
@Data
@Accessors(chain = true)
public class Item extends BasePojo{
    @TableId(type = IdType.AUTO)
    private Integer id;         //商品Id号
    private String title;       //商品标题信息
    private String sellPoint;   //卖点信息
    private Integer price;      //商品价格 精度问题!!! 将小数扩大100倍 页面中将数据缩小100倍
    private Integer num;        //商品数量
    private String images;       //商品图片 1.jpg,2.jpg,3.jpg
    private Integer itemCatId;  //商品分类ID号
    private Boolean status;     //状态信息    0 下架 1 上架

}

3.3 商品列表展现

3.3.1 需求说明

要求: 当用户打开商品列表页面时,应该采用分页的方式展现商品信息.

3.3.2 页面JS分析

3.3.3 业务接口文档实现

请求路径: /item/getItemList?query=&pageNum=1&pageSize=10
请求类型: get
请求参数: 使用pageResult对象接收

参数名称	参数说明	备注信息
query	用户查询的数据	可以为null
pageNum	分页查询的页数	必须赋值不能为null
pageSize	分页查询的条数	必须赋值不能为null

返回值结果:

参数名称	参数说明	备注
status	状态信息	200表示服务器请求成功 201表示服务器异常
msg	服务器返回的提示信息	可以为null
data	服务器返回的业务数据	商品分页对象

3.3.4 编辑ItemController

@RestController
@CrossOrigin
@RequestMapping("/item")
public class ItemController {
<span class="token annotation punctuation">@Autowired</span>
<span class="token keyword">private</span> <span class="token class-name">ItemService</span> itemService<span class="token punctuation">;</span>

<span class="token comment">/**
 * 业务逻辑: 查询商品分页
 * URL: /item/getItemList?query=&amp;pageNum=1&amp;pageSize=10
 * 类型: GET
 * 接收参数: PageResult对象
 * 返回值: SysResult
 */</span>
<span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/getItemList"</span><span class="token punctuation">)</span>
<span class="token keyword">public</span> <span class="token class-name">SysResult</span> <span class="token function">getItemList</span><span class="token punctuation">(</span><span class="token class-name">PageResult</span> pageResult<span class="token punctuation">)</span><span class="token punctuation">{<!-- --></span><span class="token comment">//3个参数</span>

    <span class="token comment">//返回5个参数,total/rows分页记录</span>
    pageResult <span class="token operator">=</span> itemService<span class="token punctuation">.</span><span class="token function">getItemList</span><span class="token punctuation">(</span>pageResult<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">return</span> <span class="token class-name">SysResult</span><span class="token punctuation">.</span><span class="token function">success</span><span class="token punctuation">(</span>pageResult<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

3.3.5 编辑ItemServiceImpl

@Service
public class ItemServiceImpl implements ItemService{
<span class="token annotation punctuation">@Autowired</span>
<span class="token keyword">private</span> <span class="token class-name">ItemMapper</span> itemMapper<span class="token punctuation">;</span>

<span class="token comment">/**
 * 实现商品的分页操作
 * @param pageResult
 * @return
 */</span>
<span class="token annotation punctuation">@Override</span>
<span class="token keyword">public</span> <span class="token class-name">PageResult</span> <span class="token function">getItemList</span><span class="token punctuation">(</span><span class="token class-name">PageResult</span> pageResult<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span>
    <span class="token comment">//参数1:页数  参数2: 条数</span>
    <span class="token class-name">Page</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Item</span><span class="token punctuation">&gt;</span></span> page <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Page</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token punctuation">&gt;</span></span><span class="token punctuation">(</span>pageResult<span class="token punctuation">.</span><span class="token function">getPageNum</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span>pageResult<span class="token punctuation">.</span><span class="token function">getPageSize</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token class-name">QueryWrapper</span> queryWrapper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">QueryWrapper</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token comment">//如果参数有值true 如果query参数没有值 false</span>
    <span class="token keyword">boolean</span> flag <span class="token operator">=</span> <span class="token class-name">StringUtils</span><span class="token punctuation">.</span><span class="token function">hasLength</span><span class="token punctuation">(</span>pageResult<span class="token punctuation">.</span><span class="token function">getQuery</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    queryWrapper<span class="token punctuation">.</span><span class="token function">like</span><span class="token punctuation">(</span>flag<span class="token punctuation">,</span><span class="token string">"title"</span><span class="token punctuation">,</span>pageResult<span class="token punctuation">.</span><span class="token function">getQuery</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token comment">//利用MP的分页API 实现查询</span>
    page <span class="token operator">=</span> itemMapper<span class="token punctuation">.</span><span class="token function">selectPage</span><span class="token punctuation">(</span>page<span class="token punctuation">,</span>queryWrapper<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">long</span> total <span class="token operator">=</span> page<span class="token punctuation">.</span><span class="token function">getTotal</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Item</span><span class="token punctuation">&gt;</span></span> list <span class="token operator">=</span> page<span class="token punctuation">.</span><span class="token function">getRecords</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token comment">//封装成功之后原来3个参数   封装之后变为5个 之后返回</span>
    <span class="token keyword">return</span> pageResult<span class="token punctuation">.</span><span class="token function">setTotal</span><span class="token punctuation">(</span>total<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">setRows</span><span class="token punctuation">(</span>list<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

码农公寓

2021-09-29

CGB2105-Day15

1. 全局异常处理/事务控制关系

2 商品分类业务实现

2.1 商品分类查询优化

2.1.1 现有代码存在的问题

2.1.2 优化策略

2.1.3 封装Map集合

2.1.3 封装Map实现

2.1.4 后台代码完整实现

2.2 商品分类状态修改

2.2.1 页面JS分析

2.2.2 业务接口文档说明

2.2.3 编辑ItemCatController

2.2.4 编辑ItemCatService

2.3 商品分类新增操作

2.3.1 业务说明

2.3.2 页面JS说明

2.3.3 业务接口文档说明

2.3.4 编辑ItemCatController

2.3.5 编辑ItemCatServiceImpl

2.4 商品分类删除操作

2.4.1 业务说明

2.4.2 页面JS分析

2.4.3 业务接口文档说明

2.4.4 编辑ItemCatController

2.4.5 编辑ItemCatServiceImpl

3. 商品管理实现

3.1 表设计

3.2.Item POJO对象设计

3.3 商品列表展现

3.3.1 需求说明

3.3.2 页面JS分析

3.3.3 业务接口文档实现

3.3.4 编辑ItemController

3.3.5 编辑ItemServiceImpl

3.3.6 页面效果展现

码农公寓

CGB2105-Day15

1. 全局异常处理/事务控制关系

2 商品分类业务实现

2.1 商品分类查询优化

2.1.1 现有代码存在的问题

2.1.2 优化策略

2.1.3 封装Map集合

2.1.3 封装Map实现

2.1.4 后台代码完整实现

2.2 商品分类状态修改

2.2.1 页面JS分析

2.2.2 业务接口文档说明

2.2.3 编辑ItemCatController

2.2.4 编辑ItemCatService

2.3 商品分类新增操作

2.3.1 业务说明

2.3.2 页面JS说明

2.3.3 业务接口文档说明

2.3.4 编辑ItemCatController

2.3.5 编辑ItemCatServiceImpl

2.4 商品分类删除操作

2.4.1 业务说明

2.4.2 页面JS分析

2.4.3 业务接口文档说明

2.4.4 编辑ItemCatController

2.4.5 编辑ItemCatServiceImpl

3. 商品管理实现

3.1 表设计

3.2.Item POJO对象设计

3.3 商品列表展现

3.3.1 需求说明

3.3.2 页面JS分析

3.3.3 业务接口文档实现

3.3.4 编辑ItemController

3.3.5 编辑ItemServiceImpl

3.3.6 页面效果展现

相关文章