hostage/src/de/tudarmstadt/informatik/hostage/commons/GetExternalIPTask.java

package de.tudarmstadt.informatik.hostage.commons;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONObject;

import android.os.AsyncTask;
/**
 * A {@link android.os.AsyncTask} that determines and returns the external IP address of the device.
 * Therefore it uses a given URL to get a JSON Object containing the external IP address.
 * @author Lars Pandikow
 *
 */
public class GetExternalIPTask extends AsyncTask<String, Void, String> {
	 @Override
    protected String doInBackground(String... url) {
   	 String ipAddress = null;
			try {
				HttpClient httpclient = new DefaultHttpClient();
				HttpGet httpget = new HttpGet(url[0]);
				HttpResponse response;

				response = httpclient.execute(httpget);

				HttpEntity entity = response.getEntity();
				entity.getContentLength();
				String str = EntityUtils.toString(entity);
				JSONObject json_data = new JSONObject(str);
				ipAddress = json_data.getString("ip");
			} catch (Exception e) {
				e.printStackTrace();
			}
	return ipAddress;
    }
}