has-a relationship, example of, 211
hasAccess tag, example of, 158-159
hashes, role in Public Key Cryptography and digital signatures, 63
Header elements, role in Web services, 281
hierarchical site organization, example of, 32
home references, caching for EJBs, 244
HtmlTag, using with Struts, 99
HTTP messages, carrying SOAP messages in, 277
HTTPS, using, 155-156