Android and PHP connection to MySQL Database

Question

i have the following code and i am struggling to get it working . There are 2 errors in the java file and i can not find a fix.

here is my MySQLData.java file

package com.example.qosmetre2;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.net.ParseException;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
import java.util.ArrayList; 
import java.util.HashMap; 
import java.util.List; 

import org.apache.http.NameValuePair; 
import org.json.JSONArray; 
import org.json.JSONException; 
import org.json.JSONObject; 

import android.app.ListActivity; 
import android.app.ProgressDialog; 
import android.content.Intent; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ListAdapter; 
import android.widget.ListView; 
import android.widget.SimpleAdapter; 
import android.widget.TextView;

public class MySQLData extends ListActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    String result = null;
    InputStream is = null;
    StringBuilder sb=null;
    String result=null;
    //http post

    try{
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://localhost/android_test/fetch_data2.php");
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
        HttpResponse response = httpclient.execute(httppost);
        HttpEntity entity = response.getEntity();
        is = entity.getContent();
    }catch(Exception e){
        Log.e("log_tag", "Error in http connection"+e.toString());
    }

    //convert response to string

    try{
        BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
        sb = new StringBuilder();
        sb.append(reader.readLine() + "\n");
        String line="0";
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }

        is.close();
        result=sb.toString();

    }catch(Exception e){

        Log.e("log_tag", "Error converting result "+e.toString());
    }
    //paring data

    String nam;
    int rec_pow;
    int tow;
    int stat;

    try{
    JSONArray jArray = new JSONArray(result);
    JSONObject json_data=null;

    for(int i=0;i<jArray.length();i++){
            json_data = jArray.getJSONObject(i);
            nam=json_data.getString("name");
            rec_pow=json_data.getInt("recieved_power");
            tow=json_data.getInt("tower");
            stat=json_data.getInt("status");

    }

    }catch(JSONException e1){
        Toast.makeText(getBaseContext(), "Could not Parse Data", Toast.LENGTH_LONG).show();
    }catch (ParseException e1){
        e1.printStackTrace();

    }

}

}

There is an error on the following 2 lines:

String result=null;
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

The first error says duplicate local variable result, and the second error says nameValuePairs cannot be resolved to a variable.

i also have a php file that i put in my wamp server and i would like the infro thats showing up on my local server to be in the application. I read somewhere that i might have to port forward so that i could acces from the app over the internet, but i don't know. The app wont run until the errors are fixed.

Here is my PHP file fetch_data2.php

  <?php
mysql_connect("888888","8888888","*******");
mysql_select_db("*******");
$q=mysql_query("SELECT * FROM users");


 while($row=mysql_fetch_assoc($q))
 $output[]=$row;

  print(json_encode($output));

  mysql_close();

?>

Answer 1

In reviewing your code, I do see the variable result defined twice and I don't see nameValuePairs defined anywhere. I think the compiler is correct :})