Java reading json :reading data from json array which present inside json object

Question

I want read json file using java . content of my json files are as below

{
  "ServiceData": {
    "ServiceInfo": [     
      {
        "trav": "20200131T173017Z",
        "real": "MyService",
        "lintruntime": "7",
        "upload": "184",
        "build": "1717",
        "buildproductruntime": "1709",
        "EXITCODE": "0",
        "totaltime": "3610"
      },
      {
        "trav": "20200131T173024Z",
        "real": "ERSampleService1",
        "lintruntime": "38",
        "upload": "381",
        "build": "1765",
        "buildproductruntime": "1767",
        "EXITCODE": "0",
        "totaltime": "3913"
      }
    ]
  }
}

How can do it using simple json I tried below but it's not working

public static void main(String args[])
    {
         try {
              Object obj = new JSONParser().parse(new FileReader("metricDataFinal.json"));  
              JSONObject jo = (JSONObject) obj; 
              Map ServiceData = ((Map)jo.get("ServiceData")); 
              Iterator<Map.Entry> itr1 = ServiceData.entrySet().iterator(); 
                while (itr1.hasNext()) { 
                     JSONArray ja = (JSONArray) jo.get("ServiceInfo"); 
                     Iterator itr2 = ja.iterator(); 

                     while (itr2.hasNext())  
                     { 
                         itr1 = ((Map) itr2.next()).entrySet().iterator(); 
                         while (itr1.hasNext()) { 
                             Map.Entry pair = itr1.next(); 
                             System.out.println(pair.getKey() + " : " + pair.getValue()); 
                         } 
                     } 
                    Map.Entry pair = itr1.next(); 
                   // System.out.println(pair.getKey() + " : " + pair.getValue()); 



                } 

         }catch(Exception e)
         {

         }
}

how to read data from for json I wanted to do processing on this data Please let me know if anyone knows how to do it

Answer 1

Try the code below:

Object obj = new JSONParser().parse(new FileReader("metricDataFinal.json"));
            JSONObject jo = (JSONObject) obj;
            Map ServiceData = ((Map) jo.get("ServiceData"));
            Iterator<Map.Entry> itr1 = ServiceData.entrySet().iterator();
            while (itr1.hasNext()) {
                JSONArray ja = (JSONArray) ServiceData.get("ServiceInfo");
                Iterator itr2 = ja.iterator();
                while (itr2.hasNext()) {
                    itr1 = ((Map) itr2.next()).entrySet().iterator();
                    while (itr1.hasNext()) {
                        Map.Entry pair = itr1.next();
                        System.out.println(pair.getKey() + " : " + pair.getValue());
                    }
                }
                Map.Entry pair = itr1.next();
                // System.out.println(pair.getKey() + " : " + pair.getValue());


            }

        } catch (Exception e) {
            e.printStackTrace();
        }

You have done a mistake in the iterator where you are trying to get ServiceInfo object. you are mistakenly trying to get that object from jo object but that object is in ServiceData object.