Android fetch data from mySql
I need to get some data from MySQL database on server. I have the following code. But the application starts when I launch it. I also get permission denied (INTERNET permission missing?) In my Logcat even though I have specified Internet access permission in my android manifest. Any idea what might be wrong here?
Java file
import android.app.Activity;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends Activity {
TextView text;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
connect();
}
private void connect() {
String data;
List<String> r = new ArrayList<String>();
ArrayAdapter<String>adapter=new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1,r);
ListView list=(ListView)findViewById(R.id.listView1);
try {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://xxxxx/data.php");
HttpResponse response = client.execute(request);
HttpEntity entity=response.getEntity();
data=EntityUtils.toString(entity);
Log.e("STRING", data);
try {
JSONArray json=new JSONArray(data);
for(int i=0;i<json.length(); i++)
{
JSONObject obj=json.getJSONObject(i);
String name=obj.getString("name");
String desc=obj.getString("description");
// String lat=obj.getString("lat");
Log.e("STRING", name);
r.add(name);
r.add(desc);
// r.add(lat);
list.setAdapter(adapter);
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (ClientProtocolException e) {
Log.d("HTTPCLIENT", e.getLocalizedMessage());
} catch (IOException e) {
Log.d("HTTPCLIENT", e.getLocalizedMessage());
}
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.diana.menu" >
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<uses-permission android:name="android.permission.INTERNET"/>
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
data.php
<?php
$conn=mysql_connect('localhost', 'xxxx', 'xxxxx','u199776286_pois');
if(!$conn )
{
die('Could not connect: ' . mysql_error());
}
$sql = 'SELECT name, description FROM pois';
mysql_select_db('u199776286_pois');
$retval = mysql_query( $sql, $conn );
if(! $retval )
{
die('Could not get data: ' . mysql_error());
}
while($row = mysql_fetch_array($retval, MYSQL_ASSOC))
{
echo "NAME : {$row['name']} <br> ".
"DESCRIPTION : {$row['description']} <br> ".
"--------------------------------<br>";
}
echo "Fetched data successfully\n";
mysql_close($conn);
?>
my logarithm
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StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
Writing the above code is not at all the best way to get rid of the NetworkOnMainThreadException . You should use any background thread for networking in android above api 11 like Asynch Task , Intent Service , etc.
How to fix android.os.NetworkOnMainThreadException?
You can also use Executors for network task
Executors.newSingleThreadExecutor().submit(new Runnable() {
@Override
public void run() {
//You can performed your task here.
}
});
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Add internet permission to AndroidManifest.xml
<uses-permission android:name="android.permission.INTERNET" />
Use Asynck Task like
List<String> r = new ArrayList<String>();
Must be declared from connect ();
from Oncreate
new LongOperation().execute("");
now create
private class LongOperation extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... params) {
connect();
return "Executed";
}
@Override
protected void onPostExecute(String result) {
ArrayAdapter<String>adapter=new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1,r);
ListView list=(ListView)findViewById(R.id.listView1);
list.setAdapter(adapter);
}
@Override
protected void onPreExecute() {}
@Override
protected void onProgressUpdate(Void... values) {}
}
// need to remove the Ui control from connect();
and require a value bind it toonPostExecute
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