Download a file from the internet using java : How to authenticate?

Question

Thanks to this thread How to download and save a file from Internet using Java? I know how to download a file, now my problem is that I need to authenticate on the sever fro

Answer 1

This is some code I wrote that fetches a website and displays the contents to System.out. It uses Basic authentication:

import java.net.*;
import java.io.*;

public class foo {
    public static void main(String[] args) throws Exception {

   URL yahoo = new URL("http://www.MY_URL.com");

   String passwdstring = "USERNAME:PASSWORD";
   String encoding = new 
          sun.misc.BASE64Encoder().encode(passwdstring.getBytes());

   URLConnection uc = yahoo.openConnection();
   uc.setRequestProperty("Authorization", "Basic " + encoding);

   InputStream content = (InputStream)uc.getInputStream();
   BufferedReader in   =   
            new BufferedReader (new InputStreamReader (content));

   String line;
   while ((line = in.readLine()) != null) {
      System.out.println (line);
   }   

   in.close();
}

Problems with the above code:

1. This code isn't production-ready (but it gets the point across.)

2. The code yields this compiler warning:

foo.java:11: warning: sun.misc.BASE64Encoder is Sun proprietary API and may be removed in a future release
      sun.misc.BASE64Encoder().encode(passwdstring.getBytes());
              ^ 1 warning

One really should use the Authenticator class, but for the life of me, I could not figure out how and I couldn't find any examples either, which just goes to show that the Java people don't actually like it when you use their language to do cool things. :-P

So the above isn't a good solution, but it does work and could easily be modified later.