Question

i have done up a method to return a string values of a textfile which is hosted on a site

but i cant seem to get the value out when i call the method

private String DownloadFromUrl() //this is the downloader method
{  
    String strFileContents = null;
    try 
    {
            String webURL = "http://www.example.net/test/file.txt";
            URL url = new URL(webURL);

            /* Open a connection to that URL. */
            URLConnection ucon = url.openConnection();

            /*
             * Define InputStreams to read from the URLConnection.
             */
            InputStream is = ucon.getInputStream();
            BufferedInputStream bis = new BufferedInputStream(is);

            //create a byte array
            byte[] contents = new byte[1024];

            int bytesRead=0;

            while( (bytesRead = bis.read(contents)) != -1){

                strFileContents += new String(contents, 0, bytesRead);
            }

       }

    catch (IOException e) 
    {

    }
    return strFileContents;        
}

i got a null pointer exception thrown from the stringreader

 //Read text from file
    StringBuilder text = new StringBuilder();

    String test = DownloadFromUrl();

    try {
        StringReader sr = new StringReader(test);
        String line="";
        int c,counter =0;
        while ((c = sr.read()) != -1) 
        {
            line+=(char)c;
            counter++;
        }

        char[] singleText = line.toCharArray();

        for (int i = 0; i < counter; i++)
        {
            classifier(singleText[i]);
        }
        text.append(line);

    }
    catch (IOException e) {
        //You'll need to add proper error handling here
    }

i tested my code and the error was thrown form the stringreader with a null pointer

but works correctly when i test with a string text.

so the problem would lie on the DownloadFromUrl method not returning the string of text from the online .txt file

added the error message hope this helps

Answer 1

Try This to convert InputStream to String

public static String convertStreamToString(InputStream is) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
  sb.append(line + "\n");
}
is.close();
return sb.toString();

}
}