java.net.UnknownHostException

package com.moser.ticker;
import java.net.URL;
import android.app.Activity;
import android.os.Bundle;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.InputStreamReader;
import java.net.URLConnection;
import android.widget.TextView;

public class SturmGrazLiveTickerActivity extends Activity {
	private TextView contentView;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        contentView = (TextView)findViewById(R.id.lbl_content);        
        
        try {            
            URL url_ = new URL("http://www.google.de/");
            URLConnection conn = url_.openConnection();
            DataInputStream in = new DataInputStream ( conn.getInputStream (  )  ) ;
            BufferedReader d = new BufferedReader(new InputStreamReader(in, "iso-8859-15"));
            String content = "";
            while(d.ready()) {
                content += d.readLine();
            }
            
            contentView.setText("Hallo" + content);
            
        }
        catch(Exception ex) {
            contentView.setText("Exception:" + ex.toString() + " = " +  ex.getMessage());
        }
        
        
    }
    
}

Exception:java.net.UnknownHostException www.google.de = www.google.de