blackberry programming with Java ME

hi friends I am new to blackberry programming, I am getting problem while making HTTPConnection to send GET request to a php web service, following is the code I am trying,

    HttpConnection conn = null;
    InputStream in = null;
    StringBuffer buff = new StringBuffer();
    String result = null;
    String url = "http://localhost/blackberry/locations.php?device_id="+id+"&lat="+lat+"&lon="+lon
    try{
        conn = (HttpConnection) Connector.open(url,Connector.READ_WRITE, true);
        conn.setRequestMethod(HttpConnection.GET);
        conn.setRequestProperty("User-Agent", "Profile/MIDP-1.0 Confirguration/CLDC-1.0");
        if(conn.getResponseCode() == HttpConnection.HTTP_OK){
            in = conn.openInputStream();
            int chr;
            //xp.parse(in, handler);
            while((chr = in.read()) != -1){
                buff.append((char)chr);
            }
            result = buff.toString();
        }
        else{
            result = "Error in connection";
            return result;
        }

    } catch(Exception ex){
        System.out.println(ex.getMessage());
    } finally{
        try {
            in.close();
            conn.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

please suggest me solution, Thanks

Regard开发者_Go百科.

A few comments:

• If you are using OS 5.0+, use the network API instead. For more details, please see this answer
• You cannot connect to localhost from BlackBerry.
• Use IOUtilities.streamToBytes instead of that while loop to read the data to a byte array.

Sorry, my reputation does not allow me to comment. My guess is: you cannot connect to localhost, therefore the response code is different from HTTP_OK, therefore the input stream 'in' never gets opened and the variable 'in' is still null when the stream is about to be closed in the finally-block. Hence the NullPointerException.

Try to use if (in != null) in.close(); instead.