Parsing json object in java, object not found

Question

I'm trying to parse the following (expected) json response to return an array of id

{
   "establishments":[
      {
         "establishment":{
            "id":21,
            "name":"Quick Bites"
         }
      },
      {
         "establishment":{
            "id":16,
            "name":"Casual Dining"
         }
      },
      {
         "establishment":{
            "id":7,
            "name":"Bar"
         }
      },
      {
         "establishment":{
            "id":6,
            "name":"Pub"
         }
      },
      {
         "establishment":{
            "id":5,
            "name":"Lounge"
         }
      },
      {
         "establishment":{
            "id":31,
            "name":"Bakery"
         }
      },
      {
         "establishment":{
            "id":18,
            "name":"Fine Dining"
         }
      },
      {
         "establishment":{
            "id":275,
            "name":"Pizzeria"
         }
      },
      {
         "establishment":{
            "id":1,
            "name":"Caf\u00e9"
         }
      },
      {
         "establishment":{
            "id":24,
            "name":"Deli"
         }
      },
      {
         "establishment":{
            "id":285,
            "name":"Fast Casual"
         }
      },
      {
         "establishment":{
            "id":271,
            "name":"Sandwich Shop"
         }
      },
      {
         "establishment":{
            "id":282,
            "name":"Taqueria"
         }
      },
      {
         "establishment":{
            "id":283,
            "name":"Brewery"
         }
      },
      {
         "establishment":{
            "id":161,
            "name":"Microbrewery"
         }
      },
      {
         "establishment":{
            "id":23,
            "name":"Dessert Parlour"
         }
      },
      {
         "establishment":{
            "id":101,
            "name":"Diner"
         }
      },
      {
         "establishment":{
            "id":286,
            "name":"Coffee Shop"
         }
      },
      {
         "establishment":{
            "id":81,
            "name":"Food Truck"
         }
      },
      {
         "establishment":{
            "id":91,
            "name":"Bistro"
         }
      },
      {
         "establishment":{
            "id":272,
            "name":"Cocktail Bar"
         }
      },
      {
         "establishment":{
            "id":284,
            "name":"Juice Bar"
         }
      },
      {
         "establishment":{
            "id":281,
            "name":"Fast Food"
         }
      },
      {
         "establishment":{
            "id":8,
            "name":"Club"
         }
      },
      {
         "establishment":{
            "id":20,
            "name":"Food Court"
         }
      },
      {
         "establishment":{
            "id":278,
            "name":"Wine Bar"
         }
      }
   ]
}

I'm using the following code:

private static void parseEstablishments (JSONObject r) {

    System.out.println("in parseEstablishments");
    System.out.println(r.length()); 


    JSONArray array = r.getJSONArray("establishment");

    List<String> list = new ArrayList<String>();

    for (int i = 0; i < array.length(); i++) {
        list.add(array.getJSONObject(i).getString("id"));
    }


    System.out.println("done");

}

r.length prints out 1 and r.toString prints out {"encoding":"UTF8"}. I'm also getting the following error: JSONObject["establishment"] not found.

Not really sure what's wrong. Can anyone help? Thanks.

@guillaumegirod-vitouchkina what's the syntax for accessing establishments then establishment? sorry, very new at this. — 1.mkn
– 1.mkn, Commented Dec 4, 2015 at 15:24

Mibac · Accepted Answer · 2015-12-04 14:39:03Z

1

You can't access establishment if you didn't go into establishments. For example we have class A which has field with class B. You can't access B until you get A. Another example: When you eat orange you first eat what's inside or remove the skin?

You might also consider checking is your JSON what you expect it to be.

answered Dec 4, 2015 at 14:39

Mibac

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3 Comments

1.mkn Over a year ago

how can I check my json? when it print it out with toString() I get the UTF8 code though I don't think that's correct. If i convert the response to a string buffer > toString() and print that it's the response that I expect it to be. How do I go into establishments? sorry, pretty new at this.

Mibac Over a year ago

Try something like string == expectedString.

1.mkn Over a year ago

the json response > String Buffer isn't the same as the json response itself...I don't understand why this is or what I should do about.

Sanjeev H · Accepted Answer · 2015-12-04 17:06:37Z

0

Hope this code snippet helps you..!!

private static void parseEstablishments (JSONObject r) throws JSONException {
        System.out.println("in parseEstablishments");
        System.out.println(r.length()); 

        JSONArray array = r.getJSONArray("establishments");
        List<String> list = new ArrayList<String>();

        for (int i = 0; i < array.length(); i++) {
             JSONObject establishmentObj=new JSONObject(array.get(i).toString());
            list.add(String.valueOf(new JSONObject(establishmentObj.get("establishment").toString()).get("id")));
        }
        System.out.println("List Of Ids:"+list);
        System.out.println("done");

    }

answered Dec 4, 2015 at 17:06

Sanjeev H

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1 Comment

Sanjeev H Over a year ago

As @mibac said first need to access establishments then loop through all establishment and get ids, before using this code think about performance(object creation in loop and toString operation..!!)

meda · Accepted Answer · 2015-12-04 17:24:48Z

0

First of all , it should be

JSONArray array = r.getJSONArray("establishments");

The JSON array key is establishments with the s

Then because your object is nested in another object :

 {
     "establishment":{
        "id":21,
        "name":"Quick Bites"
     }
  }

Your loop needs to change :

for (int i = 0; i < array.length(); i++) {
    JSONObject establishmentObj=array.getJSONObject(i)
                                     .getJSONObject("establishment");
    list.add(establishmentObj.getString("id"));
}

edited Dec 4, 2015 at 17:24

answered Dec 4, 2015 at 17:13

meda

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2 Comments

1.mkn Over a year ago

my code doesn't even make it to the loop, event after changing the array key to "establishments" with the s it still says "[establishments] not found."

meda Over a year ago

Then something is else is not correct, I suggest you log r.toString()

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