Re: Android LAN access problem

From:
Steve Sobol <sjsobol@JustThe.net>
Newsgroups:
comp.lang.java.programmer
Date:
Thu, 10 Mar 2011 09:26:53 -0800
Message-ID:
<MPG.27e2a9b72aecf1dc98985a@news.justthe.net>
In article <8tsddsFordU1@mid.individual.net>, dirk.bruere@gmail.com
says...

Like I said, I'm using the emulator and can clearly access the Net


bah, you did say that... I am undercaffeinated right now, it's only 9am

Everything on the same LAN
One piece of code running on Windows works, identical piece running via
emulator does not


Here's what I am trying:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView
    android:id="@+id/myText"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/hello"
    />
</LinearLayout>

package test.inettest;

import java.net.InetAddress;
import java.net.UnknownHostException;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class Activity1 extends Activity {

    String myHostname = "testarossa";

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        TextView t = (TextView)findViewById(R.id.myText);
        try {
         t.setText(InetAddress.getByName(myHostname).toString());
        } catch(UnknownHostException exc) {
         t.setText("UNKNOWN HOST EXCEPTION");
        }
    }
}

When I run the app in the emulator, it says UNKNOWN HOST EXCEPTION.

Now, consider that I'm trying to resolve the NetBIOS name of my laptop.
My guess is that Android can't automatically resolve the NetBIOS name of
the computer. Running on the desktop, Java SE will receive the call to
getByName, pass the hostname on to Windows and Windows will pass back
the LAN address. Windows has ability to resolve NetBIOS names. But in an
Android app, there is no built-in facility to resolve NetBIOS hostnames
(as far as I know :>)

If you set serverNameStr to some globally resolvable hostname like
www.google.com or www.lobosstudios.com, what happens?

(I'm still not sure why you're getting 81.200.64.50, but that's mostly
because I haven't seen your code, other than that one line that you
already gave us)

--
Steve Sobol - Programming/Web Dev/IT Support
Apple Valley, CA
sjsobol@JustThe.net

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