echo client, UDP implementation EchoClient elements email applications 2nd [See also JavaMail API] attachments mail providers and protocols receiving IMAP protocol 2nd POP protocol protocols, comparison remote mailboxes, reading sending from applets from applications encode( ) method (URLEncoder class) Java 1.3 versus Java 1.4 versions encoding of characters in URLs encrypting streams encryption system overhead required by encryption software 2nd [See also JSSE] equals( ) methods Address class Buffer classes InetAddress class 2nd NetworkInterface class RemoteObject class URI class URL class URLStreamHandler class exists( ) method (Folder class) exportObject( ) methods (UnicastRemoteObject class) Extensible Markup Language [See XML]