The method: javax.xml.bind.DatatypeConverter#printBase64Binary(byte) encodes a byte into a Base64 encoded string.
To encode a String with JDK 1.6+ use the static method
String encodedDuke = DatatypeConverter.printBase64Binary("duke".getBytes("UTF-8"));
Java 8 comes with the java.util.Base64 class entirely dedicated to Basic, URL, Filenames and MIMEs encoding and decoding.
See you at Java EE Workshops at MUC Airport!
Java EE 7 Workshops: Bootstrap, Effective, Architectures, June, 13th-15th, Munich's Airport
On demand workshops: Java EE 7 Bootstrap, Effective Java EE 7, Java EE 7 Testing and NEW: Java EE 7 Microservices are available for streaming