In Java to encode Base64 in Java

• Base64 is a straight forward encoding for binary data into readable characters.
• The Java class is the javax.xml.bind.DatatypeConverter, which is part of the XML package (JAXB) and has a method called printBase64Binary() that takes in a byte array and returns a encoded BASE64 string.
• The following is a code snippet that encoding the user name and password for BASIC Authentication for Web applications.
• It combines a user name and corresponding password with “:” as delimiter, and converts it to an byte array that can be feed into the printBase64Binary(). Once the encoded string is ready, just set it as value to the Authorization header. 

The following code is how to do the encoding and set it as a HTTP header in request to server:

     

import javax.xml.bind.DatatypeConverter; String encoding =  DatatypeConverter.printBase64Binary((username + ":" + password).getBytes("UTF-8"));    urlConn.setRequestProperty("Authorization", "Basic " + encoding);

Depending the client library, your API to set the header could be different. For example, if you use Apache Thrift’s HTTP transport, the code may look like the following:

import org.apache.thrift.transport.THttpClient;   transport.setCustomHeader("Authorization", "Basic " + encoding);