递归的使用-- 国民经济行业类别集合递归树

controller

private static DCCommUtil commUtil; 
1 
@RequestMapping("/getALLIndustryTotree")
 2     public Result getALLIndustryTotree() {
 3         Result result = new Result();
 4         //1、查询所有国民经济行业类别
 5         List<industry> industryList=codeService.getALLIndustry();
 6         List<industry> returnIndustryList = new ArrayList<industry>();
 7         //2、遍历国民经济行业类别
 8         for (industry industry : industryList) {
 9             if (industry.getPid().equals("0")) {
10                 //3、调用递归组装树
11                 industry = commUtil.buildTree(industryList, industry);
12                 returnIndustryList.add(industry);
13             }
14         }
15         try {
16             result = result.buileSuccess();
17             result.setData(returnIndustryList);
18         } catch (Exception e) {
19             result = result.buileFailure();
20             result.setData(e.getMessage());
21         }
22         return result;
23     }

DCCommUtil.java

 1 public class DCCommUtil {
 2     /**
 3      * 国民经济行业类别集合递归树
 4      * @param list
 5      * @param industry
 6      * @return
 7      */
 8     public static industry buildTree(List<industry> list, industry industry){
 9         List<industry> children = new ArrayList<industry>();
10         for (industry item : list) {
11             if (item.getPid().equals(industry.getId())) {
12                 children.add(buildTree(list, item));
13             }
14         }
15         industry.setChildren(children);
16         return industry;
17     }

industry.java

1 public class industry {
2     private String id;
3     private String pid;
4     private String singlehyname;
5     private List<industry> children=new ArrayList();

mapper.xml         CASE  WHEN

1 <!-- 查询所有国民经济行业类别 -->
2     <select id="getALLIndustry" resultType="com.mapuni.datacenter.entity.industry">
3         select 
4             id,
5             (CASE pid WHEN '' THEN '0' WHEN NULL THEN '0' ELSE pid END) as pid, 
6             singlehyname 
7         from t_cod_industry
8     </select>

 

posted @ 2020-11-03 16:26  小菜bxb  阅读(126)  评论(0)  编辑  收藏  举报