I have the following class:

public class getURLData extends AsyncTask<String, Integer, String>{

@Override
protected String doInBackground(String... params) {
    String line;
    try {
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost(params[0]);

        HttpResponse httpResponse = httpClient.execute(httpPost);
        HttpEntity httpEntity = httpResponse.getEntity();
        line = EntityUtils.toString(httpEntity);

    } catch (UnsupportedEncodingException e) {
        line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
    } catch (MalformedURLException e) {
        line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
    } catch (IOException e) {
        line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
    }
    return line;
}

@Override
protected void onPostExecute(String result) {
    super.onPostExecute(result);
}

}

And I am trying to call it like this:

String output = null;
output = new getURLData().execute("http://www.domain.com/call.php?locationSearched=" + locationSearched);

But the output variable isn't getting data, instead I am getting an error:

Type mismatch: cannot convert from AsyncTask<String,Integer,String> to String

The method execute returns the AynscTask itself, you need to call get:

output =
    new getURLData()
        .execute("http://www.domain.com/call.php?locationSearched=" + locationSearched)
        .get();

However, if you do that you just turned your async task into a sync one, as get waits if needed for the result to be avilable.

Reference: AsyncTask.get