Android HttpUrlConnection InputStream reading error(JSONException: Unterminated array)

Question

I am using an HttpUrlConnection to GET a very large JSON array from the web. I am reading the data 500 bytes at a time as so:

 public String getJSON(String myurl) throws IOException {

    URL url = new URL(myurl);

    HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
    try {
        InputStream in = new BufferedInputStream(urlConnection.getInputStream());
        String result = readIt(in, 500) ;

        return result ;
        //Log.d(TAG, result);
    }
    finally {
        urlConnection.disconnect();
    }
}

public String readIt(InputStream stream, int len) throws IOException, UnsupportedEncodingException {
    StringBuilder result = new StringBuilder();
    InputStreamReader reader = null;
    reader = new InputStreamReader(stream, "UTF-8");
    char[] buffer = new char[len];

    while(reader.read(buffer) != -1)
    {
        System.out.println("!@#: " + new String(buffer)) ;
        result.append(new String(buffer)) ;
        buffer = new char[len];
    }
    System.out.println(result.length()) ;
    return result.toString();
}

This works fine on some phones, but not on newer phones. On newer phones I realized that the result JSON string was starting to contain garbage characters once it got to character 2048.

Some of my garbage return data:
ST AUGUSTINE, FL","2012050

And the full error is: Error: org.json.JSONException: Unterminated array at character 40549 of {"COLUMNS":["IMAGELI

Answer 1

Probably you append a wrong buffer to your string. You should count the number of char you get when reading and append them to the string but no more:

String str = new String(); // or use a StringBuilder if you prefer
char[] buffer = new char[len];

while ((count = reader.read(buffer, 0, len)) > 0) 
{ str += new String(buffer, 0, count); }

Avoid recreate your buffer each time ! You allocate a new one for each loop... Reuse the buffer, as you have flushed it in str.

Be carreful when debugging: you cannot print a too long string in logcat (it will be cut if too long). But your str should be fine and should not contain any garbage data anymore.