Java Network Programming Index

Symbols
& (ampersand) in query strings, 97
= (equal sign) in query strings, 97
% (percent sign) in encoded URLs, 94
# in URLs, 35
" (quotation marks) in tags, 37
/ (slash) for document root, 36

Numbers
128-bit addresses, 57

A
ABORT constant (ImageObserver), 121
ABORTED constant (MediaTracker), 130
absolute URLs, 36, 82
  getting from virtual paths, 392
Accept keyword (HTTP), 39
accept( ), 189-191
  SO_TIMEOUT option and, 193
addImage( ), 124
addresses (see IP addresses)
Admin servlet, 378
agents, intelligent, 9-11, 377
ALLBITS constant (ImageObserver), 120-121
allowUserInteraction field, 257
ampersand (&) in query strings, 97
analog-to-digital conversion, 15
anchors, named, 35, 85, 93
animation player (example application), 139
API, Java Server, 375-379
Applet class, downloading data with, 109-117
Applet Host security level, 54
<APPLET> tags (HTML), 51
AppleTalk, 13
AppletContext class, 110-111, 131-133
applets, 51-55, 109, 375
  downloading (example), 274
  URLs for, 110
  (see also servlets)
AppletStub class, 110
application/ content types, 45-48, 264
  application/octet-stream, 52
  application/x-time, 312
  application/x-www-form-urlencoded, 95, 276
application layer, 14, 17
application servers, 25
applications, 51
  client-server model, 25
  consumer, 7, 10
  future, 7-8
  search, 8
  (see also applets)
audio/ content types, 46, 48, 265
  (see also sounds)
AudioClip object, 115-117
authentication, 398

B
base directive, 379
billing (see electronic commerce)
binary data from HTTP connections, 267
BindException, 169
binding names to remote objects, 361-363
bind( ), 362, 368
BITPIX keyword (FITS), 314
_blank target string, 132
broadcasting, 325
buffering socket data, 168
bugs
  getContentLength( ), 249
  reverse DNS lookup, 67
ByteArrayInputStream object, 219

C
caching (see saving)
case sensitivity of tags, 37
CGI (Common Gateway Interface), 48-51
  programs, communicating with, 103
  servlets versus, 376
CgiServlet servlet, 378
channels, 43
Character Generator Protocol, 31
chargen protocol, 288-296
chat rooms, 6
checkAll( ), 126
checkID( ), 125-126
checking
  clients (example program), 195-198
  download status, 117-122, 125-126
  for errors (see errors)
  input, 5
  servers with telnet, 161-165
class A address blocks, 22
class B address blocks, 22
class C address blocks, 22
class D address blocks, 22, 329
class E address blocks, 22, 329
classes
  loading over networks, 269-276
  serialization and, 350
ClassLoader class, 269
ClassLoader object, 52-53
CLASSPATH variable, 53
clickable image maps, 141-147, 378
clients
  allowing input/output, 259
  remote, getting information on, 371
  RMI and, 352, 358
  testing (example program), 195-198
  UDP echo (example), 240-243
  UDP, examples of, 233-236
client-server model, 25
clone( ), 371, 373
close( )
  DatagramSocket class, 228
  ServerSocket class, 191
  Socket class, 165-166, 168
closing
  DatagramSocket objects, 228
  handling unsent datagrams, 168
  server sockets, 191
  sockets, 165-166
CODE attribute (<SERVLET> tag), 382
codebase, 110
CODEBASE attribute (HTML), 52
collaboration online, 6
commerce, online, 7, 10
Common Gateway Interface (see CGI)
Common Object Request Broker Architecture (CORBA), 351
communicating, 5
  with CGI programs, 103
  client-server, 25
  with multicast groups, 339-342
  peer-to-peer connections, 5, 26
comparing
  IP addresses, 65
  URLs, 91, 93
compiling servlets, 381
COMPLETE constant (MediaTracker), 130
connected field (URLConnection class), 257
ConnectException, 169
connection trees, 326
connections, 89
  accepting/closing server sockets, 189-191
  full-duplex, 150
  openConnection( ), 89, 245, 287
  peer-to-peer, 5, 26
  (see also sockets)
connect( ), 245-246
constants
  ImageObserver class, 120
  media status, 129
constructors
  for DatagramPacket objects, 214, 221-224
  for MediaClip object, 124
  for multicast sockets, 338
  for server sockets, 186-189
  for sockets, 152-158
  for URL objects, 79-83
consumer applications, 7, 10
content handlers, 303-306
  for application/x-time (example), 312
  headers and, 307
  for image/x-fits (example), 313-324
content types, 44-48
  determining, 264-267
  getContent( ) and, 89-91, 246
  obtaining, 249
ContentHandler class, 306-309
ContentHandlerFactory object, 53, 263, 304, 310-312
Content-length header line, 386
Content-type header line, 30, 90, 249, 386
converting
  digital/analog, 15
  IP addresses to names, 67-71
  MIME header field data, 254
  virtual to absolute paths, 392
copying objects, 349
CORBA (Common Object Request Broker Architecture), 351
Counter servlet (example), 383
createContentHandler( ), 310
createRegistry( ), 370
createURLStreamHandler( ), 292-296
creating URLs, 79-84
customizing
  HTTP servers, 198-211
  servers, 7

D
data link layer, 16
DatagramPacket( ), 215-217, 221-224
DatagramPacket class, 214-220
datagrams, 16, 149
  handling unsent, 168
  multicast, 334
  sending and receiving, 224-228
  size of, 215, 219, 226
  UDP (see UDP)
  (see also sockets)
DatagramSocket class, 213, 221-229
  socket options, 228
DataInputStream object, 87, 161
DataOutputStream object, 163, 248
date (see time and date)
daytime protocol, 20, 31, 161
  protocol handler for (example), 297-301
  UDP server for (example), 239
decoding encoded URLs, 96
defaultAllowUserInteraction field, 258
defaultUseCaches field, 263
defineClass( ), 52
destroy( ), 380, 391
DHCP (Dynamic Host Configuration Protocol), 330
digital-to-analog conversion, 15
disabling caching, 263
discard protocol, 20, 31
displaying data, 2
Distance Vector Multicast Routing Protocol (DVMRP), 330
DNS (Domain Name System), 19, 31, 56-57
document base, 110
document root (/), 36
doInput field, 259
domain name server, 57
Domain Name System (see DNS)
doOutput field, 260
double quotation marks (") in tags, 37
downloading, 2-4
  applets (example), 274
  with Applet class, 109-117
  binary data with HTTP, 267
  classes from network, 269-276
  document transmission date, 250
  images, 111-113
  from servers, 246
  sounds, 113-117
  status reports for, 117-122, 125-126, 129
  from URLs, 78, 86-91
  waiting for, 126
  Web pages, 87, 104-108, 247
draft standards, 28
drawImage( ), 118, 120
DVMRP (Distance Vector Multicast Routing Protocol), 330
Dynamic Host Configuration Protocol (DHCP), 330

E
echo protocol, 20, 31, 163
  UDP client/server for (example), 238, 240-243
elective RFCs, 29
electronic commerce, 7, 10
electronic mail, standards for, 30
  (see also MIME)
encapsulation, 17
encode( ), 95
encoding
  determining method of, 249
  URL characters, 94-97
equal sign (=) in query strings, 97
equals( )
  InetAddress class, 65
  RemoteObject class, 371
  URL class, 93
ERROR constant (ImageObserver), 121
error correction, 16
ERRORED constant (MediaTracker), 130
errors
  HTTP response codes for, 42, 401, 404
  Image object, 128
  setError( ), 404
Ethernet, 13
examples in book, xii
exceptions, 128
  java.rmi.server package, 373
  remote, 366-368
  socket-related, 169
  (see also under specific exception)
exec( ), 53
experimental protocols, 28
expiration dates, document, 250
ExportException, 373
exportObj( ), 373
extensions
  HTML, 38
  URL, and content types, 264
extra path information, 395

F
field name, MIME header, 253
file servers (see servers)
File Transfer Protocol) (see FTP)
filenames in URLs, 35
files
  binary, downloading, 267
  FITS, 313
  image (see images)
  server for only one, 198-202
  sound (see sounds)
  storing, 4
FileServlet servlet, 378
FileURLConnection object, 252
finalize( ), 229
finger protocol, 20, 30, 170-172
firewalls, 23-25
FITS (Flexible Image Transport System), 313-324
forms, 49, 276-280
  parsing with servlet (example), 405
  smart, 5
  (see also CGI)
fragments, URL, 35, 85, 93
FRAMEBITS constant (ImageObserver), 121
FTP (File Transfer Protocol), 20, 26
ftp-data protocol, 20
full-duplex connection, 150
future
  of HTML, 38
  of HTTP, 43
  of Java, 7-8
  supportable image formats, 112

G
games, 6
garbage collection, 229
GenericServlet class, 380, 389
GenericServlet( ), 389
GET keyword (HTTP), 39
GET method (CGI), 50, 259
getAddress( )
  DatagramPocket class, 218
  InetAddress class, 64-65
getAllByName( ), 61-62
getAllowUserInteraction( ), 257
getAudioClip( ), 115-117
getAuthType( ), 398
getByName( ), 59-61
getClientHost( ), 371
getClientPort( ), 371
getCodeBase( ), 83, 110
getContent( )
  URL class, 89-91, 104, 284
  URLConnection class, 246, 304, 307-309
getContentEncoding( ), 249
getContentLength( )
  ServletRequest interface), 386
  URLConnection class, 249
getContentType( )
  ServletRequest interface), 386
  URLConnection class, 249
getData( ), 218
getDate( ), 250
getDateHeader( ), 397
getDefaultAllowUserInteraction( ), 258
getDefaultRequestProperty( ), 255
getDefaultToolkit( ), xv
getDefaultUseCaches( ), 263
getDocumentBase( ), 83, 110, 113
getDoInput( ), 259
getDoOutput( ), 260
getErrorsAny( ), 129
getErrorsID( ), 129
getFile( ), 85
getHeader( ), 397
getHeaderField( ), 252-253
getHeaderFieldDate( ), 254
getHeaderFieldInt( ), 254
getHeaderFieldKey( ), 253
getHeaderName( ), 398
getHost( ), 84
getHostname( ), 63
getIfModifiedSince( ), 261
getImage( ), 111-113
getInetAddress( )
  ServerSocket class, 191
  Socket class, 158
getInitParameter( )
  GenericServlet interface, 382, 389
  ServerStub interface, 393
getInitParameters( )
  GenericServlet interface, 382, 389
  ServletStub interface, 393
getInputStream( )
  ServletRequest interface, 387
  Socket class, 161
  URLConnection class, 247
getInterface( ), 342
getIntHeader( ), 397
getLastModified( ), 250
getLength( ), 219
getLocalAddress( ), 160
getLocalHost( ), 62
getLocalPort( )
  DatagramSocket class, 227
  ServerSocket class, 192
  Socket class, 159
getLog( ), 372
getMethod( ), 394
getMimeType( ), 392
getOutputStream( ), 388
  Socket class, 163-165
  URLConnection class, 248
getParameter( ), 383, 387
getParameters( ), 383, 388
getPathInfo( ), 395
getPathTranslated( ), 395
getPort( )
  DatagramPacket class, 218
  Socket class, 159
  URL class, 84
getProperty( ), 53
getProtocol( )
  ServletRequest interface, 386
  URL class, 84
getQueryParameter( ), 395
getQueryParameters( ), 397
getQueryString( ), 395
getRealPath( ), 392
getRef( ), 85
getRegistry( ), 369
getRemoteAdr( ), 387
getRemoteHost( ), 387
getRemoteUser( ), 398
getRequestProperty( ), 255
getRequestURI( ), 394
getSecurityContext( ), 364
getServerInfo( ), 392
getServerName( ), 386
getServlet( ), 391
getServletContext( )
  GenericServlet interface, 391
  ServletStub interface, 393
getServletInfo( ), 390
getServletPath( ), 395
getServlets( ), 391
getSoLinger( ), 168
getSoTimeout( )
  DatagramSocket class, 229
  ServerSocket class, 193
  Socket class, 169
getTcpNoDelay( ), 168
getting (see downloading; obtaining)
getURL( ), 256
getUseCaches( ), 262
GIF image format, 44, 112
graphical whois client (example), 177
graphics (see images)
groups, multicast, 329, 339-342
guessContentTypeFromName( ), 264
guessContentTypeFromStream( ), 266

H
handling
  content (see content handlers)
  errors (see errors)
  protocols (see protocol handlers)
  unsent datagrams, 168
hashCode( )
  InetAddress class, 66
  RemoteObject class, 371
  URL class, 94
headers
  content handlers and, 307
  Content-length, 386
  Content-type, 30, 90, 249, 386
  datagram (packet), 16, 149
  FITS files, 314
  getting values of, 397
  MIME, 248-254, 264-267
  User-Agent, 39
HEIGHT constant (ImageObserver), 121
historic RFCs, 29
hostnames, 19, 56
  converting IP addresses to, 67-71
  versus network addresses, 61
  obtaining, 63
  specified in URLs, 35, 84
hosts, 12
  addresses (see IP addresses)
  multicast groups, 329, 339-342
  multihoming (see multihoming)
  networking between (see RMI)
host-to-network layer, 14-16
HotJava, 54
HTML (Hypertext Markup Language), 33, 36-38
  <APPLET> tags, 51
  CODE attribute, 382
  CODEBASE attribute, 52
  forms, 49
  NAME attribute, 382
  <PARAM> tags, 382
  <SERVLET> tags, 382
HTTP (Hypertext Transfer Protocol), 20, 33, 38-43
  custom servers, 198-211
  HTTP-NG (HTTP Next Generation), 43
  java.servlet.http package, 393-407
  redirector server, 202-207
  response codes, 41-43, 75, 399
  saving binary data over, 267
  standards for, 32
HttpServlet class, 380
HttpServletRequest interface, 394-398
HttpServletResponse interface, 399-405
HttpURLConnection object, 252
HttpUtils interface, 405
Hypertext Markup Language (see HTML)
Hypertext Transfer Protocol (see HTTP)

I
IANA (Internet Assigned Numbers Authority), 29, 330
identifiers (see numbers)
idioms, Java, xiii
IETF (Internet Engineering Taskforce), 27
  multicast addresses, 331
ifModifiedSince field, 261
IllegalAccessException, 256
ImagemapServlet servlet, 378
ImageObserver class, 117-122
  MediaTracker class versus, 122
ImageProducer object, 89
images
  content handler for (example), 313-324
  downloading, 111-113
  errors and Image objects, 128
  image/ content types, 46, 48, 265-266
    image/gif, 44
    image/jpeg, 44
  image maps, 141-147, 378
  multiple (see MediaTracker class)
  reporting download progress, 117-122
  sizing in advance, 134-139
  waiting to download, 126
imageUpdate( ), 118-120
implAccept( ), 194
includes, server-side, 382-384
index.html file, 35
InetAddress class, 57-67
  closed sockets and, 165
infoflags argument, imageUpdate( ), 120
informational RFCs, 29
init( ), 380, 390
init parameters, servlet, 382, 389, 393
input
  allowing to clients, 259
  checking, 5
InputStream object, 86, 161, 247
  guessing content type and, 266
installing
  ContentHandler class, 310
  servlets, 381
  URLStreamHandler class, 292-296
instantiation, xiii
intelligent agents, 9-11, 377
interacting with users, 257-259
Internet, 21-25
  addresses (see IP addresses)
  internets/intranets, 21
  layer, 14, 16
  multicasting on, 328-337
Internet Assigned Numbers Authority (IANA), 29, 330
Internet Drafts, 27
Internet Engineering Taskforce (see IETF)
Internet Network Information Center (InterNIC), 13, 22
Internet Protocol (see IP)
Internet Service Providers (ISPs), 22
InterNIC, 13, 22
InvokeServlet servlet, 378
IP addresses, 13, 19, 56-57
  address blocks, 22, 329
  applet security and, 53
  comparing, 65
  converting to names, 67-71
  versus hostnames, 61
  InterNIC, 13, 22
  IPv6 and 128-bit, 57
  local, 62
  local loopback address, 22
  multicast addresses, 328-334
  multiple per computer, 61, 147, 160
  obtaining, 59-62, 64-65, 218
  relating with sockets, 160
  remote, obtaining, 387
IP (Internet Protocol), 16-19
  addresses (see IP addresses)
  multicasting (see multicasting)
IPv6 addresses, 57
isErrorAny( ), 128
isErrorID( ), 129
ISPs (Internet Service Providers), 22

J
Java Electronic Commerce Framework (JECF), 11
Java programming language
  future of, 7-8
  idioms, xiii
  versions of, xi
Java Server API, 375-379
java.rmi package, 360-368
java.rmi.registry package, 368-370
java.rmi.server package, 370-374
java.servlet package, 385-393
java.servlet.http package, 393-407
JECF (Java Electronic Commerce Framework), 11
Jeeves, 21, 207, 378
jhttp (example server program), 207-211
joinGroup( ), 339
JPEG image format, 44, 112

K
key, MIME header fields, 253

L
last modification date, 250, 261
layers
  network, 14-17
  RMI model, 352
leaveGroup( ), 340
length (see size)
levels
  applet network security, 54
  network, 14-17
limited-use RFCs, 29
linking names to remote objects, 361-363
list( ), 363, 368
loadClass( ), 52
loading (see downloading)
LOADING constant (MediaTracker), 130
local
  caches, 262-263
  caching, 24
  filesystem, applets and, 53
  loopback address, 22
  network address, 62
  port number, getting, 159, 192, 227
localhost hostname, 22
LocateRegistry class, 369
log( )
  ServletContext interface, 392
  ServletResponse interface, 390
logging
  processing log files, 74-77
  remote communications, 372
  server events, 390
  to servlets, 392
lookup( ), 362, 368

M
machines on networks
  hosts (see hosts)
  nodes, 12
mailto: protocol, 285, 287
main( ), xiii
MalformedURLException, 79-83
mapping URLs to remote objects, 361-363
marshaling, 355
MBONE (Multicast Backbone), 333
media (see images; sounds)
MediaTracker class, 122-131
  downloading and, 125-127, 129
  Image object identifiers, 122, 124
MediaTracker( ), 124
messages
  error (see errors)
  mail (see electronic mail)
  message/ content types, 45, 266
methods, static, xiii
MIME (Multipurpose Internet Mail Extensions), 30, 33, 44-48
  content types (see content types)
  headers, 248-254, 264-267
modification times, 250, 261
Morris Internet worm, 9
mrouters, 336
Multicast Backbone (MBONE), 333
multicasting, xi, 31, 213, 326-337
  examples of multicast servers, 342-346
  multicast addresses, 328-334
  multicast datagrams, 334
  multicast groups, 329, 339-342
  multicast sockets, 337-342
  routers, 335
MulticastSocket( ), 338
MulticastSocket class, 337-342
multihoming, 61, 147
  DatagramSocket( ) for, 223
  multicast communications and, 341
  relating IP addresses with sockets, 160
multipart/ content types, 45
multiple
  images (see MediaTracker class)
  IP addresses per computer, 61, 147, 160
Multipurpose Internet Mail Extensions (see MIME)
multithreading, servlets and, 384

N
NAME attribute (<SERVLET> tag), 382
named anchors, 35, 85, 93
names
  binding to remote objects, 361-363
  guessing content type from, 264
  header, 398
  host (see hostnames)
  MIME header fields, 253
  server, obtaining, 386
  URNs (uniform resource names), 34
Naming class, 361-363
NAXIS header (FITS), 314
NBC multicast addresses, 332
nested HTML/SGML tags, 37
Network News Transfer Protocol (NNTP), 20
networks, 12-17
  addresses (see IP addresses)
  layers of, 14-17
  loading classes from, 269-276
  RMI and (see RMI)
NNTP (Network News Transfer Protocol), 20
nodes, 12
noise, signal, 16
None security level, 54
non-routable addresses, 22
NoRouteToHostException, 169
nslookup utility, 71
NullPointerException, xv
numbers
  address (see IP addresses)
  IANA, 29, 330
  MediaTracker image IDs (see MediaTracker class)
  port, 19-21

O
object serialization, 349-351
obtaining
  content type, 249
  data (see downloading)
  elements of URLs, 84-86, 284-287
  examples in book, xiii
  header values, 397
  hostnames, 63
  information about remote client, 371
  IP addresses, 59-62, 64-65, 218
  MIME header fields, 252-254
  Remote interface, 362
  servlet init parameters, 382
  socket information, 158-165
  URLs, 256
online collaboration, 6
online shopping, 7, 10
openConnection( ), 89, 245, 287
opening
  sockets, 89, 245, 287
  URLConection objects, 245
openStream( ), 86-88
operating systems and URLs, 94-97
options, socket, 168-169
  for DatagramSocket objects, 228
  for server sockets, 192
order, loading MediaTracker images, 124
OSI network model, 14
output, allowing to servers, 260
OutputStream object, 163, 248

P
packets, 13, 16, 149
  filtering, 23
  packet-switching, 13
  size of, 215, 219, 226
  (see also sockets)
Page Saver application (example), 98
parallel computing, 5
<PARAM> tags (HTML), 382
parameters, servlet, 383, 387
_parent target string, 132
parseQuery( ), 405
parseURL( ), 285-286
parsing
  forms, example servlet for, 405
  MIME headers, 248-252
  query strings, 405
  URLs, 84-86, 284-287
passing a reference, 352
paths
  extra path information, 395
  getRealPath( ), 392
  getting images by, 113
  servlet, obtaining, 395
  specified in URLs, 35, 85
payload, datagram, 149
peer-to-peer connections, 5, 26
percent sign (%) in encoded URLs, 94
permanent multicast addresses, 330
physical layer, 15
PlainSocketImpl object, 167
play( ), 114-115
playing
  animation (example application), 139
  sounds, 114-115
plug-ins, 303
PNG image format, 112
POP (Post Office Protocol), 20
portability, 9
ports, 19-21
  creating multicast socket on, 338
  for datagrams, 218
  local, getting number of, 159, 192, 227
  relating with sockets, 159
  specified in URLs, 35, 81, 84
POST method (CGI), 50, 260
  sending forms (example), 276-280
Post Office Protocol (POP), 20
pound sign (#) in URLs, 35
precedence, loading MediaTracker images, 124
println( ), toString( ) and, 92
print( ), toString( ) and, 92
priority, loading MediaTracker images, 124
processing Web server logs, 74-77
PROPERTIES constant (ImageObserver), 121
proposed standards, 28
protected constructors
  ServerSocket( ), 188
  Socket( ), 157
protocol handlers, 280-284
  examples of, 296-301
  mechanism for, 244
  writing, 288-291
protocols, 14, 17
  broadcasting and, 325
  chargen, 288
  daytime, 297-301
  development of, 27-32
  investigating with telnet, 150-152
  mailto:, 285, 287
  reliable versus unreliable, 16
  specified in URLs, 34, 84
  stateless, 40
  (see also encapsulation)
prototypes, 27
proxy servers, 24
PUT keyword (HTTP), 40

Q
query strings, 50, 97, 395, 405
quotation marks (") in tags, 37
Quote of the Day protocol, 31

R
read( ), SO_TIMEOUT option and, 169
rebind( ), 363, 368
receive( ), 225, 339
  SO_TIMEOUT option and, 228
receiving datagrams, 225-228
redirecting requests, 133, 202-207, 404
Refs., URL (see named anchors)
registries, server, 368-370
Registry interface, 368
REGISTRY_PORT field, 368
RegistryHandler interface, 369
registryImpl( ), 369
registryStub( ), 369
relative URLs, 36, 82
reliable protocols, 16
remote
  exceptions, 366-368
  objects, 348, 361-363
  reference layer, 352
Remote interface, 360
Remote Method Invocation (see RMI)
Remote Procedure Calls (RPC), 348
RemoteObject class, 370
RemoteServer( ), 371
RemoteServer class, 371
  UnicastRemoteObject subclass, 355, 371-372
RequestProperty methods, 255
requests for comments (see RFCs)
Resource Reservation Setup Protocol (RSVP), 330
response codes, HTTP, 41-43, 75, 399
retrieving (see downloading; obtaining)
reverse DNS lookup, 60, 67
RFCs (requests for comments), 27-32
RMI (Remote Method Invocation), xi, 20, 347-354
  java.rmi package, 360-368
  java.rmi.registry package, 368-370
  java.rmi.server package, 370-374
rmic utility, 357
RMISecurityManager( ), 364
RMISecurityManager class, 363-366
routers, multicasting and, 335
RPC (Remote Procedure Calls), 348
RSVP (Resource Reservation Setup Protocol), 330

S
sales (see electronic commerce)
sameFile( ), 91, 93
saving
  allowing caches, 262-263
  binary data from HTTP connections, 267
  document expiration dates, 250
  file data, 4
  local caching, 24
  Web pages, 98-103
SC_ response codes (HTTP), 399
schemes (see protocols)
SeaNet project, 331
search applications, 8
security
  applets and, 53-55
  authentication, 398
  firewalls, 23
  levels, applet network, 54
  logging remote communications, 372
  Morris Internet worm, 9
  object serialization and, 350
  proxy servers, 24
  RMI and, 348
  RMISecurityManager class, 363-366
  servlets, 376
  using Socket( ) to improve, 154
SecurityManager object, 53
__self target string, 132
send( )
  DatagramSocket class, 224-225
  MulticastSocket class, 340
sendError( ), 404
sending, 4, 326
  datagrams, 224-228
  forms, 276-280
  (see also multicasting)
sendRedirect( ), 404
serialization, 349-351
Server API, xii, 375-379
server sockets, 184, 195-211
  options for, 192
ServerCloneException, 374
ServerNotActiveException, 373
servers, 3, 6
  allowing output to, 260
  client-server model, 25
  customizing, 7, 198
  document expiration dates, 250
  domain name, 57
  downloading from, 246
  example program for, 207-211
  java.rmi.server package, 370-374
  life cycle of, 185
  multicast (see multicasting)
  one-file, 198-202
  proxy, 24
  redirector, 202-207
  RMI and, 352, 355-358
  RMI registries, 368-370
  testing with telnet, 161-165
  UDPServer class (example), 236-239
  Web, processing logs of, 74-77
server-side includes, 382-384
ServerSocket( ), 186-189
ServerSocket class, 185-194
service( ), 380, 388, 390
service providers (see ISPs)
Servlet interface, 385-393
<SERVLET> tag (HTML), 382
ServletContext interface, 391
ServletInputStream class, 385
ServletOutputStream class, 385
ServletRequest interface, 385-388
ServletResponse interface, 388
servlets, xii, 375-377
  java.servlet package, 385-393
  java.servlet.http package, 393-407
  Jeeves, 378
  server-side includes and, 382-384
  writing, 379-384
ServletStub interface, 391-392
setAllowUserInteraction( ), 257
setContentHandlerFactory( ), 263
setContentLength( ), 388, 403
setContentType( ), 388, 403
setDateHeader( ), 403
setDefaultAllowUserInteraction( ), 258
setDefaultRequestProperty( ), 255
setDefaultUseCaches( ), 263
setDoInput( ), 259
setDoOutput( ), 248, 260
setError( ), 404
setHeader( ), 403
setIfModifiedSince( ), 261
setInitHeader( ), 403
setInterface( ), 341
setLog( ), 372
setRequestProperty( ), 255
setSocketFactory( ), 194
setSocketImplFactory( ), 167
setSoLinger( ), 168
setSoTimeout( )
  DatagramSocket class, 228
  ServerSocket class, 193
  Socket class, 169
setStatus( ), 402
setStub( ), 391
setTcpNoDelay( ), 168
setURL( ), 287
setURLStreamHandlerFactory( ), 94
setUseCaches( ), 262
SGML (Standard Generalized Markup Language), 36
shopping online, 7, 10
showDocument( ), 131-133
signal noise, 16
Simple Mail Transfer Protocol (see SMTP)
size
  datagrams/packets, 215, 219, 226
  image, 134-139
SkeletonMismatchException, 374
SkeletonNotFoundException, 374
slash (/) for document root, 36
smart agents, 9-11, 377
smart forms, 5
SMTP (Simple Mail Transfer Protocol), 20, 30
SO_LINGER option, 168
SO_TIMEOUT option, 169, 192, 228
Socket( ), 152-158
Socket class, xi, 152-169
SocketException, 169, 338
SocketImpl class, 167
SocketImplFactory object, 53, 167, 194
sockets, 149-152, 228
  closing, 165-166, 168
  exceptions, 169
  multicast (see multicasting)
  obtaining information about, 158-165
  opening, 89, 245, 287
  options for, 168-169
  server sockets, 184-194
  for UDP traffic, 158
  unicast, 325
  (see also DatagramSocket class; ServerSocket class)
SocketSecurityException, 373
SOMEBITS constant (ImageObserver), 121
sounds
  audio/ content types, 46, 48, 265
  downloading, 113-117
spiders, 8
standards, development of, 27-32
stateless protocols, 40
static methods, xiii
status codes, HTTP, 41-43, 75, 399
status, downloading (see downloading)
statusAll( ), 130
statusID( ), 130
STD numbers, 28
storing (see saving)
streams, guessing content type from, 266
strings, 66
  query strings, 50, 395, 405
  URL (see URLs)
  (see also toString( ))
stubs (RMI), 352, 363
switching, 13

T
tags, HTML (and SGML), 37-38
TCP_DELAY option, 168
TCP (Transmission Control Protocol), 16, 18, 212
  sockets (see sockets)
telnet protocol, 20, 150-152
testing (see checking)
text/ content types, 44, 265-266
  text/html, 44
  text/plain, 44, 52
  text/tab-separated-values, 307-309
Thread object, 53
ThreadGroup object, 53
threads, 240
three-dimensional worlds, 8
time and date
  daytime protocol, 20, 31, 161, 239, 297-301
  document expiration dates, 250
  document transmission date, 250
  getDateHeader( ), 397
  last modification, 250, 261
  from MIME header fields, 250, 254
  setDateHeader( ), 403
  time protocol, 20, 312
  in Web server logs, 75
Time Server Protocol, 32
timeouts for reading from socket, 169, 192, 228
Time-To-Live (TTL) value, 328, 334, 340
toExternalForm( ), 92, 286
Toolkit class, xv
_top target string, 132
toString( )
  InetAddress class, 66
  print statements and, 92
  RemoteObject class, 371
  ServerSocket class, 194
  Socket class, 166
  URL class, 92
  URLConnection class, 267
Transmission Control Protocol (see TCP)
transmitting (see sending)
transport layer, 14, 16, 352
TTL (Time-To-Live) value, 328, 334, 340

U
UDP (User Datagram Protocol), 16, 18, 212-214
  multicast datagrams, 334
  simple clients (examples), 233-236
  sockets for, 158
UDPClient class (example), 230-233
UDPEchoClient class (example), 240-243
UDPServer class (example), 236-239
unbind( ), 362, 368
unicast sockets, 325
UnicastRemoteObject( ), 373
UnicastRemoteObject class, 355, 371-372
uniform resource locators (see URLs)
UnknownHostException, 59, 61
unmarshaling, 355
unreliable protocols, 16
Unrestricted security level, 54
URIs (uniform resource identifiers), 34, 394
URL( ), 79-83
URL class, 78-94, 280
URLClassLoader class (example), 270-276
URLConnection( ), 255
URLConnection class, 244-248, 255-267, 280-281
  allowing input/output, 259
  MIME headers and, 248-254, 264-267
  RequestProperty methods and, 255
URLConnection object, 89
URLEncoder class, 94-97
URLRequestor program (example), 104-108
URLs (uniform resource locators), 34-36
  applets and applet pages, 110
  comparing with sameFile( ), 91, 93
  converting from virtual to absolute, 392
  creating, 79-84
  displaying documents by, 131-133
  downloading from, 78, 86-91
  encoding and, 94-97
  extensions, guessing content type from, 264
  mapping to remote objects, 361-363
  obtaining, 256
  obtaining elements of, 84-86, 284-287
  protocols in (see protocol handlers)
  query strings, 50, 395
  redirecting requests for documents, 133, 202-207, 404
  relative URLs, 36
URLStreamHandler class, 280, 284-288, 292-296
URLStreamHandlerFactory object, 53, 94, 280-283, 291-296
URNs (uniform resource names), 34
useCaches field, 262
User-Agent header line, 39
User Datagram Protocol (see UDP)
username, remote, 398
users, interacting with, 257-259

V
verifying (see checking)
versions
  HTML, 37
  Java, xi
video/ content types, 46, 48, 266
virtual paths, converting, 392
VRML (Virtual Reality Modeling Language), 8

W
waitForAll( ), 127
waitforID( ), 127
waiting for media to download, 126
Web pages, 98
  downloading, 87, 104-108, 247
  saving, 98-103
  (see also World Wide Web)
whois protocol, 20, 173-183
  graphical client for (example), 177
whois++ protocol, 173
WIDTH constant (ImageObserver), 121
windows, displaying documents in new, 132
working groups, 27
World Wide Web, 25, 98
  CGI (see CGI)
  HTTP and (see HTTP)
  processing server log files, 74-77
  search applications for, 8
  URLs (see URLs)
  (see also Web pages)
writeErrorResponse( ), 404
writing
  protocol handlers, 288-291, 296-301
  servers, 184, 195-211
  servlets, 379-384
  URLs, 79-84
  URLStreamHandler class, 284-288

X
XBM image format, 112