Exception while reading from JSON

Question

I have this code

JSONObject obj;
try {
    obj = new JSONObject(readUrl("http://dleel.ps/ss.txt"));
    List<String> list = new ArrayList<String>();
    JSONArray array = obj.getJSONArray("data");

    for(int i = 0 ; i < array.length() ; i++) {
        if (array.getJSONObject(i).getString("link")!=null)
        System.out.println(array.getJSONObject(i).getString("link"));
    }
}

why I am getting exception when theres no link (JSONObject["link"] not found.) , what should I put in the if condition ? also I tried using instead of getJSONArray , optJSONArray but the same

you can see the JSON file in the txt shown in the readUrl function — Peril, Sep 19 '11 at 14:48
@Brain Roach java.util.NoSuchElementException: JSONObject["link"] not found. it reads the first one , but it fails to read the second one because its null — Peril, Sep 19 '11 at 14:49
@Salah: There's a *lot* of JSON there. Please do the work to find which bit of it is causing a problem, and also show us the exception you're having trouble with. Read http://tinyurl.com/so-hints for suggestions about how to write a good question. — Jon Skeet, Sep 19 '11 at 14:50

score 16 · Accepted Answer · answered Sep 19 '11 at 14:49

16

The getString() method throws exception if key not found. Instead use the has() method:

if (array.getJSONObject(i).has("link"))

answered Sep 19 '11 at 14:49

Suraj Chandran

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2

u might wanna accept it as the right answer, so it might help others with same problem :) – Suraj Chandran Sep 19 '11 at 14:51
4

You can also use the .optString("link") method, which returns null if the string doesn't exist instead of throwing an exception. – lucasmo Sep 19 '11 at 17:00
@SurajChandran just a quick question , how can compare the getJSONObject(i).getString("link") with another string ? – Peril Sep 19 '11 at 21:07

score 2 · Answer 2 · answered Sep 19 '11 at 14:51

2

To test if a key exists use,

array.getJSONObject(i).has("link")

answered Sep 19 '11 at 14:51

Andrew

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Exception while reading from JSON

2 Answers2

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