递归树结构封装

 

递归sql

select t3.* from (
select t1.*,
       if(find_in_set(pid, @pids) > 0, @pids := concat(@pids, ',', id),
                 if (t1.id = @pids,@pids,0)) as ischild
           from (
                 select <include refid="columns"/>,cast(shape as char(1000) character set utf8)shapeData from t3d_wss_port t
            ) t1,
       (select @pids := #{id}) t2
    ) t3 where ischild != 0 order by ischild, id

递归还原

@PostMapping(value = "/Hy",produces = "application/json;charset=utf-8")
public  Object Hy(){
    List<T3dWssPort> data = this.wssPortMapper.getPortTree(1);
    List<Map<String, Object>> tree = getree(data, 0,0);
    List<Map<String, Object>> hy = getHy(tree, 0);
    System.out.println(hy);
    return 1;
}


private static List<Map<String, Object>> getHy(List<Map<String, Object>> data, Integer parentId){
    List<Map<String, Object>> l=new ArrayList<>();
    for (Map<String, Object> stringObjectMap : data) {
         if(parentId == stringObjectMap.get("pid")){
             boolean children = stringObjectMap.containsKey("children");
             if (children) {
                 if(!ObjectUtils.isEmpty(stringObjectMap.get("children")))
                 getHy((List) stringObjectMap.get("children"), Integer.valueOf(stringObjectMap.get("id")+""));
             }
             stringObjectMap.entrySet().forEach((e)->{
                 String key = e.getKey();
                 Object value = e.getValue();
                 if(!key.equalsIgnoreCase("children")&&key.contains("pid")){
                     System.out.println(value+"====="+parentId);
                 }
             });

         }
    }
    return l;

}

 

/**
* 递归控制层级
*/
 

@PostMapping(value = "/Port",produces = "application/json;charset=utf-8")
public Object pselect(@RequestBody JSONObject object){
    List<Map> objects = Lists.newArrayList();
    List<Map> in = object.getObject("IN", List.class);
    in.forEach(item->{
        Map map=new HashMap();
        int id =(int) item.get("ID");
        int level =(int) item.get("Level");
        LEV=level;
        int pid = this.portService.getOne(new QueryWrapper<T3dWssPort>().eq("id", id)).getPid();
        List<T3dWssPort> data = this.wssPortMapper.getPortTree(id);
        List<Map<String, Object>> tree = getree(data, pid,0);
        map.put("tree_id_"+id,tree);
        objects.add(map);
    });
     return  objects;
}


private static List<Map<String, Object>> getree(List<T3dWssPort> data, Integer parentId, int count){
    if(LEV>=count||LEV<0) {
        List<Map<String, Object>> list = new ArrayList<>();
        for (int i = 0; i < data.size(); i++) {
            if (data.get(i).getPid().equals(parentId)) {
                try {
                    Map map = PropertyUtils.describe(data.get(i));
                    count=i+1;
                    List<Map<String, Object>> ds = getree(data, data.get(i).getId(),count);//i
                    if(!CollectionUtils.isEmpty(ds)){
                        map.put("children", ds);
                    }
                    list.add(map);
                } catch (Exception e) {
                    e.printStackTrace();
                }

            }
        }
        return list;
    }
    return  null;
}

 

/**
* 根据父级节点获取所有的子集节点
* @param parentNode
* @param allList
* @return
*/
public static List<Map<String, Object>> getJava8Children(Map<String,Object> parentNode, List<Map<String, Object>> allList){
return allList.stream()
.filter(curNode -> ObjectUtils.isNotEmpty(curNode.get("parentId")) && Objects.equals(curNode.get("parentId"),parentNode.get("id")))
.peek(m -> m.put("children", getJava8Children(m,allList))).collect(Collectors.toList());
}

 

 

 

 

public class Sheng {

private String name;

private int id;

private Integer pid;

private static List<Sheng> shenList;
private List<Shi> shiList;
private List<Xian> xianList;
static {
shenList=new ArrayList() {{
add(new Sheng("河南省",1,0));
add(new Sheng("郑州市",2,1));
add(new Sheng("开封市",3,1));
add(new Sheng("洛阳市",4,1));
add(new Sheng("洛阳市-1",5,4));
add(new Sheng("洛阳市-2",6,4));
add(new Sheng("洛阳市-3",7,4));
add(new Sheng("洛阳市-4",8,4));
}};
}

public static List<Map<String, Object>> bulidTree(List<Sheng> sheng, int pid_) {
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
for (Sheng item : sheng) {
Sheng shen = item;
//第一次temp.getParentId()=-1 parentId=-1 判断进入重新递归方法
//第二次temp.getParentId()=-1 parentId=1 不递归不进判断
//第二次temp.getParentId()=2 parentId=1 不递归不进判断
if (pid_ == shen.getPid()) {
Map<String, Object> map = new HashMap<>();
map.put("menuName", shen.getName());
map.put("menuIcon", "icon");
map.put("menuUrl", "login/test");
map.put("subMenus", bulidTree(sheng, shen.getId()));
list.add(map);
}
}
return list;
}

public static void main(String[] args) {
Sheng sheng = new Sheng();
System.out.println(bulidTree(sheng.getShenList(), 0));
}
}

https://blog.csdn.net/qq_36476972/article/details/75089927