Traverse, delete, judge whether JSON data is empty, and recursion

newest fastjson jar package

 JSONObject backDish = JSONObject.parseObject(val);
 			//  obtain data data ："data"：{"list":[{},{}]}
            JSONObject da = backDish.getJSONObject("data");
            //  obtain list data  [{},{}]
            JSONArray list = da.getJSONArray("list");
            
            JSONObject quanbu = new JSONObject();
            quanbu.put("dishesType","");
            quanbu.put("dishesTypeName"," All the dishes ");
            quanbu.put("shopId","");
            System.out.println("quanbu:"+quanbu.toString());

            arrayDishType = new JSONArray();
            //JSONArray Add JSONObject
            arrayDishType.add(quanbu);
            //  Traverse JSONArray Array 
            for (int i = 0;i<list.size();i++){
    
                System.out.println("list The content of "+(list.getJSONObject(i).toString()));

                arrayDishType.add(list.getJSONObject(i));
            }
            System.out.println("22222"+arrayDishType.toString());

---

Back to json The data are as follows ：

---

{
    
    "msg": " According to successful ",
    "code": 0,
    "data": {
    
        "list": [
            {
    
                "deptCreate": "2020/12/14-15:19:57",
                "deptName": " jiangsu ",
                "leader": "2",
                "deptModified": "2020/12/14-15:20:33",
                "son": "Y",
                "children": [
                    {
    
                        "deptCreate": "2020/12/21-09:13:00",
                        "deptName": " Suzhou store ",
                        "leader": "2",
                        "son": "N",
                        "children": [],
                        "phone": "2",
                        "deptId": 15,
                        "orderNum": 0,
                        "email": "2",
                        "parentId": 9
                    },
                    {
    
                        "deptCreate": "2020/12/14-15:20:09",
                        "deptName": " Nanjing store ",
                        "leader": "3",
                        "deptModified": "2020/12/21-09:12:46",
                        "son": "N",
                        "children": [],
                        "phone": "3",
                        "deptId": 10,
                        "orderNum": 1,
                        "email": "3",
                        "parentId": 9
                    }
                ],
                "phone": "2",
                "deptId": 9,
                "orderNum": 0,
                "email": "2",
                "parentId": 0
            },
            {
    
                "deptCreate": "2020/12/14-15:20:42",
                "deptName": " Zhejiang ",
                "leader": "3",
                "deptModified": "2020/12/14-15:21:43",
                "son": "Y",
                "children": [
                    {
    
                        "deptCreate": "2020/12/14-15:21:08",
                        "deptName": " Ningbo store ",
                        "leader": "23",
                        "son": "Y",
                        "children": [
                            {
    
                                "deptCreate": "2021-01-25 10:21:51",
                                "deptName": "wqqww",
                                "leader": "qw",
                                "son": "N",
                                "children": [],
                                "phone": "qwqw",
                                "deptId": 17,
                                "orderNum": 0,
                                "email": "w",
                                "parentId": 13
                            }
                        ],
                        "phone": "31",
                        "deptId": 13,
                        "orderNum": 0,
                        "email": "12",
                        "parentId": 11
                    },
                    {
    
                        "deptCreate": "2020/12/14-15:20:54",
                        "deptName": " Hangzhou store ",
                        "leader": "4",
                        "deptModified": "2020/12/14-15:21:40",
                        "son": "N",
                        "children": [],
                        "phone": "34",
                        "deptId": 12,
                        "orderNum": 1,
                        "email": "43",
                        "parentId": 11
                    }
                ],
                "phone": "3",
                "deptId": 11,
                "orderNum": 1,
                "email": "3",
                "parentId": 0
            }
        ]
    }
}

requirement ： take children:[ ] To remove

1. take data Corresponding value

JSONObject baseInfo = jsonSuccess.getJSONObject("data");
		System.out.println("base:"+baseInfo);

result ：{“list”:[{},{},{}…]}
2、 take list Corresponding value

JSONArray value = null;
		for (Map.Entry<String, Object> entry : baseInfo.entrySet()) {
    
            System.out.println(entry.getKey() + " : " + entry.getValue());//list : [{"children":[{"children":[],"name":"hh"}],"name":"ls"}]
            value = (JSONArray) entry.getValue();// [{"children":[{"children":[],"name":"hh"}],"name":"ls"}]
        }

result ： [{},{}…]

---

Call recursive traversal method

---

recursive.json(value);

3、 Traverse jsonArray Array 、 Delete json Key value pair , Judge whether it is 【】 And recursion

public class recursive {
    
	
	
	public static void json(JSONArray value32) {
    
		
		JSONArray value3 = null;
		     //  An array 【】  Traverse 
		for (int i = 0; i < ((JSONArray) value32).size(); i++) {
    
			//  Get array's   data 
        	JSONObject house = (JSONObject) ((JSONArray) value32).get(i);
        	
        	//  Traverse the key value pairs of the array 
            for (Map.Entry<String, Object> entry : house.entrySet()) {
    
                System.out.println(entry.getKey() + " : " + entry.getValue());
                //  If key ==children
                if(entry.getKey().equals("children")) {
    
                	//  take children  The value of value3
                	value3 = (JSONArray) entry.getValue(); //[{"children":[],"name":"hh"}]
                	
                }
                
            }
            //  Judge  children  Value   Is it right? 【】
            if(("[]".equals(value3.toString()))) {
    
        		System.out.println(" It's empty ");
        		//  Delete  children Key value pair   Delete... Here  json The original data   Also delete 
        		house.remove("children");
            		
            		
            }else {
    
            	//  If it's not empty , explain children Still worth it , recursive   Call yourself , Traverse the next layer again children
            	json(value3);
            }
        }
		        
		   
		        
		
	}

Straw paper

package menu_crud;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;

public class rt {
    

	public static void main(String[] args) {
    
		  String originalStr = "{'data':{'list':[{'name':'ls','children':[{'name':'hh','children':[]}]}]}}";
	        JSONObject jsonObject = JSON.parseObject(originalStr);
	        System.out.println(jsonObject);
	        
	        JSONObject baseInfo = jsonObject.getJSONObject("data");
	        System.out.println("base:"+baseInfo); //{"list":[{"children":[{"children":[],"name":"hh"}],"name":"ls"}]}
	        Object value = null;
	        for (Map.Entry<String, Object> entry : baseInfo.entrySet()) {
    
	            System.out.println(entry.getKey() + " : " + entry.getValue());//list : [{"children":[{"children":[],"name":"hh"}],"name":"ls"}]
	            value = entry.getValue();// [{"children":[{"children":[],"name":"hh"}],"name":"ls"}]
	        }
	        System.out.println("value:"+value);
	        if(value instanceof JSONArray) {
    
	        	System.out.println("11111");
	        }
	        //  An array 【】  Traverse 
	        Object value2 = null;
	        for (int i = 0; i < ((JSONArray) value).size(); i++) {
    

	        	JSONObject house = (JSONObject) ((JSONArray) value).get(i);
	        	
	        
	            for (Map.Entry<String, Object> entry : house.entrySet()) {
    
	                System.out.println(entry.getKey() + " : " + entry.getValue());
	                if(entry.getKey().equals("children")) {
    
	                value2 = entry.getValue(); //[{"children":[],"name":"hh"}]
	                }
	            }
	        }
	        System.out.println("value2:"+value2);
	        Object value3 = null;
	     //  An array 【】  Traverse 
	        for (int i = 0; i < ((JSONArray) value2).size(); i++) {
    

	        	JSONObject house = (JSONObject) ((JSONArray) value2).get(i);
	        	
	            for (Map.Entry<String, Object> entry : house.entrySet()) {
    
	                System.out.println(entry.getKey() + " : " + entry.getValue());
	                if(entry.getKey().equals("children")) {
    
	                	value3 = entry.getValue(); //[{"children":[],"name":"hh"}]
	                	
	                }
	                
	            }
	            if(("[]".equals(value3.toString()))) {
    
            		System.out.println(" It's empty ");
            		house.remove("children");
            		
            }
	        }
	        
	        System.out.println("value3:"+value3);
	        System.out.println("jsonObject:"+jsonObject);
	        
	        }
		

	
}

Reference resources ：https://blog.csdn.net/AttleeTao/article/details/104414739?ops_request_misc=%25257B%252522request%25255Fid%252522%25253A%252522161162527916780264086665%252522%25252C%252522scm%252522%25253A%25252220140713.130102334…%252522%25257D&request_id=161162527916780264086665&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2_allfirst_rank_v2~rank_v29-2-104414739.pc_search_result_hbase_insert&utm_term=%E6%80%8E%E4%B9%88%E9%81%8D%E5%8E%86%E5%B5%8C%E5%A5%97%E7%9A%84JSONObject