list add error without activity in android

RequestActivity.java

package com.example.netrequest;



import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
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.apache.http.message.BasicNameValuePair;

import android.app.Activity;
import android.util.Log;

public class RequestActivity {
	//extends Activity{

	//protected void onCreate(android.os.Bundle savedInstanceState) {
		//super.onCreate(savedInstanceState);


		// Creating HTTP client
		HttpClient httpClient = new DefaultHttpClient();
		// Creating HTTP Post
		HttpPost httpPost = new HttpPost(
				"http://www.example.com/login");

		// Building post parameters
		// key and value pair
		List<NameValuePair> nameValuePair = new ArrayList<NameValuePair>(2);
		nameValuePair.add(new BasicNameValuePair("email", "user@gmail.com"));
		nameValuePair.add(new BasicNameValuePair("message",
				"Hi, trying Android HTTP post!"));

		// Url Encoding the POST parameters
		try {
			httpPost.setEntity(new UrlEncodedFormEntity(nameValuePair));
		} catch (UnsupportedEncodingException e) {
			// writing error to Log
			e.printStackTrace();
		}

		// Making HTTP Request
		try {
			HttpResponse response = httpClient.execute(httpPost);

			// writing response to log
			Log.d("Http Response:", response.toString());
		} catch (ClientProtocolException e) {
			// writing exception to log
			e.printStackTrace();
		} catch (IOException e) {
			// writing exception to log
			e.printStackTrace();

		}
	}
}