商品分类数据结构改由后端实现，方便多前端使用

ruoyi-mall/src/main/java/com/cyl/pms/controller/ProductCategoryController.java

@@ -45,21 +45,11 @@ public class ProductCategoryController extends BaseController {
     @ApiOperation("查询商品分类列表")
     @PreAuthorize("@ss.hasPermi('pms:productCategory:list')")
     @PostMapping("/list")
-    public ResponseEntity<List<ProductCategory>> list(@RequestBody ProductCategoryQuery query) {
-        List<ProductCategory> list = service.selectList(query, null);
+    public ResponseEntity<List<ProductCategoryVO>> list(@RequestBody ProductCategoryQuery query) {
+        List<ProductCategoryVO> list = service.selectList(query, null);
         return ResponseEntity.ok(list);
     }
 
-    @ApiOperation("导出商品分类列表")
-    @PreAuthorize("@ss.hasPermi('pms:productCategory:export')")
-    @Log(title = "商品分类", businessType = BusinessType.EXPORT)
-    @GetMapping("/export")
-    public ResponseEntity<String> export(ProductCategoryQuery query) {
-        List<ProductCategory> list = service.selectList(query, null);
-        ExcelUtil<ProductCategoryVO> util = new ExcelUtil<>(ProductCategoryVO.class);
-        return ResponseEntity.ok(util.writeExcel(convert.dos2vos(list), "商品分类数据"));
-    }
-
     @ApiOperation("获取商品分类详细信息")
     @PreAuthorize("@ss.hasPermi('pms:productCategory:query')")
     @GetMapping(value = "/{id}")

ruoyi-mall/src/main/java/com/cyl/pms/pojo/vo/ProductCategoryVO.java

@@ -1,9 +1,13 @@
 package com.cyl.pms.pojo.vo;
 
+import com.cyl.pms.domain.ProductCategory;
 import com.ruoyi.common.annotation.Excel;
 import com.fasterxml.jackson.annotation.JsonFormat;
 import com.ruoyi.common.core.domain.BaseAudit;
 import lombok.Data;
+
+import java.util.List;
+
 /**
  * 商品分类 数据视图对象
  * 
@@ -14,21 +18,16 @@ public class ProductCategoryVO extends BaseAudit {
    /** ID */
     private Long id;
    /** 上级分类的编号：0表示一级分类 */
-    @Excel(name = "上级分类的编号：0表示一级分类")
     private Long parentId;
    /** NAME */
-    @Excel(name = "NAME")
     private String name;
    /** 分类级别：0->1级；1->2级 */
-    @Excel(name = "分类级别：0->1级；1->2级")
     private Integer level;
    /** 显示状态：0->不显示；1->显示 */
-    @Excel(name = "显示状态：0->不显示；1->显示")
     private Integer showStatus;
    /** SORT */
-    @Excel(name = "SORT")
     private Integer sort;
    /** 图标 */
-    @Excel(name = "图标")
     private String icon;
+    private List<ProductCategoryVO> children;
 }

ruoyi-mall/src/main/java/com/cyl/pms/service/ProductCategoryService.java

@@ -1,9 +1,16 @@
 package com.cyl.pms.service;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.time.LocalDateTime;
+
+import cn.hutool.core.lang.tree.Tree;
+import cn.hutool.core.lang.tree.TreeNodeConfig;
+import cn.hutool.core.lang.tree.TreeUtil;
 import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
+import com.cyl.pms.convert.ProductCategoryConvert;
+import com.cyl.pms.pojo.vo.ProductCategoryVO;
 import com.github.pagehelper.PageHelper;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.Pageable;
@@ -23,6 +30,8 @@ import com.cyl.pms.pojo.query.ProductCategoryQuery;
 public class ProductCategoryService {
     @Autowired
     private ProductCategoryMapper productCategoryMapper;
+    @Autowired
+    private ProductCategoryConvert convert;
 
     /**
      * 查询商品分类
@@ -41,7 +50,7 @@ public class ProductCategoryService {
      * @param page 分页条件
      * @return 商品分类
      */
-    public List<ProductCategory> selectList(ProductCategoryQuery query, Pageable page) {
+    public List<ProductCategoryVO> selectList(ProductCategoryQuery query, Pageable page) {
         if (page != null) {
             PageHelper.startPage(page.getPageNumber() + 1, page.getPageSize());
         }
@@ -70,9 +79,49 @@ public class ProductCategoryService {
         if (!StringUtils.isEmpty(icon)) {
             qw.eq("icon", icon);
         }
-        return productCategoryMapper.selectList(qw);
+        qw.orderByAsc("sort");
+
+        List<ProductCategory> productCategories = productCategoryMapper.selectList(qw);
+        List<ProductCategoryVO> productCategoryVOS = convert.dos2vos(productCategories);
+        return formatTree(productCategoryVOS);
+
+    }
+
+    private List<ProductCategoryVO> formatTree(List<ProductCategoryVO> nodes) {
+        List<ProductCategoryVO> tree = new ArrayList<>();
+        List<ProductCategoryVO> children = new ArrayList<>();
+        // 1）先获取到所有根节点
+        for (ProductCategoryVO node : nodes) {
+            if (node.getParentId() == null || node.getParentId() == 0 ) {
+                tree.add(node);
+            } else {
+                children.add(node);
+            }
+        }
+        // 2）把所有除根结点外的节点作为子节点，然后遍历每一个根节点
+        for (ProductCategoryVO node : tree) {
+            // 3）递归构建此根的子节点
+            recur(node, children);
+        }
+        return tree;
+    }
+
+    private void recur(ProductCategoryVO rootNode, List<ProductCategoryVO> children) {
+        // 1）遍历剩余子节点，找出当前根的子节点
+        for (ProductCategoryVO node : children) {
+            // 2）如果子节点的父id等于根节点的id，那么就将这个节点加到根节点的children列表中
+            if (rootNode.getId() == node.getParentId()) {
+                if (rootNode.getChildren() == null) {
+                    rootNode.setChildren(new ArrayList<>());
+                }
+                rootNode.getChildren().add(node);
+                // 3）以当前节点作为根节点进行递归，检查是否还有子节点。
+                recur(node, children);
+            }
+        }
     }
 
+
     /**
      * 新增商品分类
      *