UDP ( User Datagram Protocol) 2nd connections, managing DatagramChannel class DatagramPacket class datagrams, sending and receiving DatagramSocket class discard server file transfer protocols using Java classes implementing multicasting and 2nd multicasting, compared to packet size ports per host simple clients TCP channels versus datagram channels TCP, compared to Traffic class UDP echo client UDPServer class UDP datagrams and sockets code examples DatagramPacket, constructing for receipt of data high-performance UDP discard server local UDP port scanning ReceiverThread class SenderThread class UDP daytime server UDP discard client UDP discard server UDP echo client based on channels UDP echo server UDP time client UDPDiscardServer UDPDiscardServer based on channels UDPEchoClient class UDPEchoServer based on channels UDPPoke class UDPServer class UDPDiscardClient class UDPEchoClient class UDPPoke class private fields UDPServer class fields unbind( ) methods Naming class Registry interface unicast sockets UnicastRemoteObject class 2nd uniform resource names (URNs) unread( ) methods (PushbackInputStream class) URI class constructing URIs getPort( ) method getter methods isAbsolute( ) method isOpaque( ) method parseServerAuthority( ) method resolving relative URIs relativize( ) method resolve( ) method resolveURI( ) method URL class, compared to 2nd utility methods compareTo( ) method equals( )method hashCode( ) method toASCIIString( ) method toString( ) method URIs (Uniform Resource Identifiers) absolute and relative URIs hierarchical and non-hierarchical URIs parts schemes URL class character encoding and constructing relative URLs constructing URLs from strings constructing URLs from thier parts constructors creating new URLs GET method server-side input processing HTTP authentication inaccessible but supported protocols methods for protocol handlers object methods equals( ) hashCode( ) method toString( ) method protocol handlers, usage in retrieving data getContent( ) method openConnection( ) method openStream( ) method overloaded getContent( ) method server-side programs, communicating with reverse engineering server-side input processing splitting URLs into pieces getAuthority( ) method getDefaultPort( ) method getFile( ) method getHost( ) method getPath( ) method getPort( ) method getProtocol( ) method getQuery( ) method getRef( ) method getUserInfor( ) method supported protocols URI class, compared to URLConnection class, compared to URLStreamHandler objects utility methods sameFile( ) method toExternalForm( ) method toURI method URLConnection class 2nd API caching client request HTTP headers, configuring code examples CacheRequest class CacheResponse class CacheResponse subclass downloading and saving binaries from web sites get time of URL's last change in-memory ResponseCache posting a form printing URL of URLConnection to www.oreilly.com returning headers set ifModifiedSince to 24 hours ago SourceViewer with response code and message web pages, downloading with correct character sets connections, configuring allowUserInteraction instance field connected instance field doinput instance field doOutput instance field getter and setter methods ifModifiedSince instance field POST method versus GET for long URLs protected instance fields timeouts url instance field useCaches instance field constructor content handlers ContentHandlerFactory getContent( ) methods getContentEncoding( ) method getContentLength( ) method getContentType( ) method getDate( ) method getExpiration( ) method getHeaderField( ) method getInputStream( ) method getLastModified( ) method headers, reading HTTP dependency HttpURLConnection subclass [See HttpURLConnection subclass] JarURLConnection class MIME content types, guessing object methods opening connections header querying methods reading headers retrieving arbitrary header fields servers, reading data from protocol handlers, usage in security servers, writing data to POST versus GET post( ) method URL class, compared to URLConnection object URLDecoder class URLEncoder class encode( ) method Java 1.3 versus Java 1.4 versions URLName class constructors parsing methods URLs (Uniform Resource Locators) character encodinging distributed computing technologies EJB piece-by-piece encoding relaitve URLs relative schemes IANA list structure this book URLs and URIs code examples A URL relative to the web page comparing http://www.oreilly.com/ and http://www.ora.com/ download a web page downloading password-protected web pages GUI authenticator Open Directory searches parts of a URI parts of a URL protocol tester ProxySelectors that remember connections QueryString class -x-www-form-urlencoded strings URLStreamHandler and URLStreamHandlerFactory URLStreamHandler class connecting method constructor new protocols and protecting hash code protocol handlers, usage in proxy server specification URL parsing methods URLStreamHandlerFactory interface protocol handlers, usage in URNs (Uniform Resource Names) Usenet news and JavaMail API usernames