How to use base64 to add a basic authentication to an HTTP request.

Use the "Authorization", "basic "+encodedpassword like below.
import org.apache.commons.codec.binary.Base64;

String userpasswd = username+":"+password;
String encodedString = new String(Base64.encodeBase64(userpasswd.getBytes()));
....
and in ur httpconnection object add the below
conn.setRequestProperty("Authorization","Basic "+encodedString);

...

URL url = new URL("https://fyi.com");
conn = (HttpURLConnection) url.openConnection();
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setRequestProperty("Authorization"....


if (conn instanceof HttpsURLConnection)
((HttpsURLConnection) conn).setHostnameVerifier(DNV);
conn.connect();