Question

I use the following class to send an http request and get the returning XML response in my android project.
But the UnknownHostException is thrown when it trying to send the request.
Please help me on this problem.

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;

import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;    
import org.xml.sax.Locator;
import org.xml.sax.SAXException;

import android.os.AsyncTask;
import android.util.Xml;

class RequestTask extends AsyncTask<String, String, String>{

@Override
protected String doInBackground(String... uri) {
    HttpClient httpclient = new DefaultHttpClient();
    HttpResponse response;
    String responseString = null;
    try {
        response = httpclient.execute(new HttpGet(uri[0]));
        StatusLine statusLine = response.getStatusLine();
        if(statusLine.getStatusCode() == HttpStatus.SC_OK){
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            response.getEntity().writeTo(out);
            out.close();                
            responseString = out.toString();
        } else{
            //Closes the connection.
            response.getEntity().getContent().close();
            throw new IOException(statusLine.getReasonPhrase());
        }
    } catch (ClientProtocolException e) {
        //TODO Handle problems..
    } catch (IOException e) {
        String s=e.toString();
        System.out.println(s);
        //TODO Handle problems..
    }
    return responseString;
}

@Override
protected void onPostExecute(String result) {
    super.onPostExecute(result);
    //Do anything with response..
    System.out.println(result);





}


}

Answer 1

Make sure you have declared the INTERNET permission in the AnroidManifest file, and have internet connection.

You should have this permission declared in AndroidManifest:

<uses-permission android:name="android.permission.INTERNET" />