Get data from mysql to android with php - php

Question

I am currently trying to develop an app that among other things can send and receive data from a mysql server.
The app calls a php script which makes the connection to the mysql server. I have successfully developed the sending part and now I want to retrieve data from mysql and display it on an android phone.
The mysql table consists of 5 columns:
bssid
building
floor
lon
lat
The php file getdata.php contains:
<?php
$con = mysql_connect("localhost","root","xxx");
if(!$con)
{
echo 'Not connected';
echo ' - ';
}else
{
echo 'Connection Established';
echo ' - ';
}
$db = mysql_select_db("android");
if(!$db)
{
echo 'No database selected';
}else
{
echo 'Database selected';
}
$sql = mysql_query("SELECT building,floor,lon,lat FROM ap_location WHERE bssid='00:19:07:8e:f7:b0'");
while($row=mysql_fetch_assoc($sql))
$output[]=$row;
print(json_encode($output));
mysql_close(); ?>
This part is working fine, when tested in a browser.
The java code for connecting to php:
public class Database {
public static Object[] getData(){
String db_url = "http://xx.xx.xx.xx/getdata.php";
InputStream is = null;
String line = null;
ArrayList<NameValuePair> request = new ArrayList<NameValuePair>();
request.add(new BasicNameValuePair("bssid",bssid));
Object returnValue[] = new Object[4];
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpContext localContext = new BasicHttpContext();
HttpPost httppost = new HttpPost(db_url);
httppost.setEntity(new UrlEncodedFormEntity(request));
HttpResponse response = httpclient.execute(httppost, localContext);
HttpEntity entity = response.getEntity();
is = entity.getContent();
}catch(Exception e){
Log.e("log_tag", "Error in http connection" +e.toString());
}
String result = "";
try
{
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result=sb.toString();
}catch(Exception e){
Log.e("log_tag", "Error in http connection" +e.toString());
}
try
{
JSONArray jArray = new JSONArray(result);
JSONObject json_data = jArray.getJSONObject(0);
returnValue[0] = (json_data.getString("building"));
returnValue[1] = (json_data.getString("floor"));
returnValue[2] = (json_data.getString("lon"));
returnValue[3] = (json_data.getString("lat"));
}catch(JSONException e){
Log.e("log_tag", "Error parsing data" +e.toString());
}
return returnValue;
}
}
This is a modified code used to send data to the mysql server, but something is wrong.
I've tried to test it by setting different returnValues in the code and this shows me that the part with the httpclient connection does not run.
Can you guys help me?
I hope this is not too confussing, and if you want I can try to explain it futher.

Answer 1

Use HttpGet instead of HttpPost and parse your url.

Answer 2

Here is a class I always use to GET
public JSONObject get(String urlString){
URL currentUrl;
try {
currentUrl = new URL(currentUrlString);
} catch (MalformedURLException e) {
e.printStackTrace();
return null;
}
HttpURLConnection urlConnection = null;
InputStream in;
BufferedReader streamReader = null;
StringBuilder responseStrBuilder = new StringBuilder();
String inputStr;
try {
urlConnection = (HttpURLConnection) currentUrl.openConnection();
in = new BufferedInputStream(urlConnection.getInputStream());
streamReader = new BufferedReader(new InputStreamReader(in, "UTF-8"));
while ((inputStr = streamReader.readLine()) != null) {
responseStrBuilder.append(inputStr);
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
urlConnection.disconnect();
if(null != streamReader){
try {
streamReader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
try {
return new JSONObject(responseStrBuilder.toString());
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
Try to test with get("http://echo.jsontest.com/key/value");