Reading JSON double dimensional array in Java

Question

Each news entry has three things : title,contentand date.

The entries are retrieved from a database and I would like to read them in my application using JSONObject and JSONArray. However, I do not know how to use these classes.

Here is my JSON string:

[
   {
      "news":{
         "title":"5th title",
         "content":"5th content",
         "date":"1363197493"
      }
   },
   {
      "news":{
         "title":"4th title",
         "content":"4th content",
         "date":"1363197454"
      }
   },
   {
      "news":{
         "title":"3rd title",
         "content":"3rd content",
         "date":"1363197443"
      }
   },
   {
      "news":{
         "title":"2nd title",
         "content":"2nd content",
         "date":"1363197409"
      }
   },
   {
      "news":{
         "title":"1st title",
         "content":"1st content",
         "date":"1363197399"
      }
   }
]

To start, make a class called News with 3 fields: title, content, and date. — Sotirios Delimanolis
– Sotirios Delimanolis, Commented Mar 14, 2013 at 14:16

Michael Celey · Accepted Answer · 2013-03-14 14:50:22Z

8

Your JSON string is a JSONArray of JSONObject which then contain an inner JSONObject called "news".

Try this for parsing it:

JSONArray array = new JSONArray(jsonString);

for(int i = 0; i < array.length(); i++) {
    JSONObject obj = array.getJSONObject(i);
    JSONObject innerObject = obj.getJSONObject("news");

    String title = innerObject.getString("title");
    String content = innerObject.getString("content");
    String date = innerObject.getString("date");

    /* Use your title, content, and date variables here */
}

edited Mar 14, 2013 at 14:50

Michael Celey

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answered Mar 14, 2013 at 14:18

Pragnani Kinnera

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1 Comment

Michael Celey Over a year ago

@JonathanHugh I'm glad you were able to find an answer to your question. Remember that if an answer given meets your needs, you should accept that answer by clicking the check mark under the voting arrows so that people viewing this question in the future will be able to tell which answer solved the problem.

Michael Celey · Accepted Answer · 2013-03-14 14:36:05Z

2

First of all, your JSON structure is not ideal. You have an array of objects, with each object having a single object in it. However, you could read it like this:

JSONArray jsonArray = new JSONArray (jsonString);
int arrayLength = jsonArray.length ();

for (int counter = 0; counter < arrayLength; counter ++) {
    JSONObject thisJson = jsonArray.getJSONObject (counter);

    // we finally get to the proper object
    thisJson = thisJson.getJSONObject ("news");

    String title = thisJson.getString ("title");
    String content = thisJson.getString ("content");
    String date = thisJson.getString ("date");

}

However!

You could do better if you change your JSON to look like the following:

[
    {
        "title": "5th title",
        "content": "5th content",
        "date": "1363197493"
    },
    {
        "title": "4th title",
        "content": "4th content",
        "date": "1363197454"
    }
]

Then, you could parse it as follows:

JSONArray jsonArray = new JSONArray (jsonString);
int arrayLength = jsonArray.length ();

for (int counter = 0; counter < arrayLength; counter ++) {
        // we don't need to look for a named object any more
    JSONObject thisJson = jsonArray.getJSONObject (counter);    

    String title = thisJson.getString ("title");
    String content = thisJson.getString ("content");
    String date = thisJson.getString ("date");
}

edited Mar 14, 2013 at 14:36

Michael Celey

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answered Mar 14, 2013 at 14:18

Shade

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5 Comments

Pragnani Kinnera Over a year ago

You got wrong date is a string you won't get it using getLong(), check the quotes

323go Over a year ago

"Your json is bad" is opinion. The array might contain other objects besides "news", so the format of the json is actually pretty descriptive.

Shade Over a year ago

@323go he actually says it's a two-dimensional array in the title and in the first line of the question he says "Each news has three things : title,contentand date". I think he doesn't really understand the syntax of JSON arrays and objects, so I tried to help with an example.

Alex Over a year ago

I think Shade is right, my json is not as good as he advised, it's just because i'm encoding it using php and this is what i got, i couldn't make it just like you did but i'll try. thank you anyway for your help! :)

Shade Over a year ago

No problem. You could ask another question for your PHP code that generates the JSON.

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