Spring Semester, 2004
Server Intro
© 2004, All Rights Reserved, SDSU & Roger Whitney
San Diego State University -- This page last updated 19-Feb-04
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CS 580 Client-Server Spring Semester, 2004 Server Intro |
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© 2004, All Rights Reserved, SDSU & Roger Whitney San Diego State University -- This page last updated 19-Feb-04 |
while (true) {
Wait for an incoming request;
Perform whatever actions are requested;
}
| server |
server := SocketAccessor newTCPserverAtPort: 9009.
server listenFor: 5.
[ | acceptedSocket |
"wait for a new connection"
acceptedSocket := server accept.
"fork off processing of the new stream socket"
[ | stream char |
stream := acceptedSocket readAppendStream.
stream lineEndTransparent.
[ (char := stream next) isNil ] whileFalse: [
stream nextPut: char; commit ].
stream close.
] forkAt: Processor userSchedulingPriority -1.
] repeat.
public ServerSocket(int port) //port = 0 gives random port public ServerSocket(int port, int backlog) public ServerSocket(int port, int backlog, InetAddress bindAddress)public Socket accept() throws IOException
public InputStream getInputStream() throws IOException public OutputStream getOutputStream() throws IOException
public class DateServer {
private static Logger log = Logger.getLogger("dateLogger");
public static void main (String args[]) throws IOException {
ProgramProperties flags = new ProgramProperties( args);
int port = flags.getInt( "port" , 8765);
new DateServer().run(port);
}
public void run(int port) throws IOException {
ServerSocket input = new ServerSocket( port );
log.info("Server running on port " + input.getLocalPort());
while (true) {
Socket client = input.accept();
log.info("Request from " + client.getInetAddress());
processRequest(
client.getInputStream(),
client.getOutputStream());
client.close();
}
}
void processRequest(InputStream in,OutputStream out)
throws IOException {
BufferedReader parsedInput =
new BufferedReader(new InputStreamReader(in));
boolean autoflushOn = true;
PrintWriter parsedOutput = new PrintWriter(out,autoflushOn);
String inputLine = parsedInput.readLine();
if (inputLine.startsWith("date")) {
Date now = new Date();
parsedOutput.println(now.toString());
}
}
}
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rohan
16->
java
-jar DateServer.jar
Feb 19, 2004 10:56:59 AM DateServer run INFO: Server running on port 8765 |
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Al
13->
telnet
rohan.sdsu.edu 8765
Trying 130.191.3.100... Connected to rohan.sdsu.edu. Escape character is '^]'. |
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Feb
19, 2004 10:57:34 AM DateServer run
INFO: Request from /68.7.92.191 |
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date Thu Feb 19 10:57:39 PST 2004 Connection closed by foreign host. |
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newTCP “selects random port” newTCPserverAtPort: portNumber
accept Wait for a client connection and return it acceptNonBlock return any waiting client connection, return nil if no waiting client connections readAppendStream readStream writeStream Return a stream of the given type on the conection
Smalltalk defineClass: #SimpleDateServer
superclass: #{Core.Object}
indexedType: #none
private: false
instanceVariableNames: 'serverSocket '
classInstanceVariableNames: ''
imports: ''
category: 'SimpleServer'
SimpleDateServer class methodsFor: 'instance creation'
port: anInteger ^super new setPort: anInteger
setPort: anInteger
serverSocket := SocketAccessor newTCPserverAtPort: anInteger.
serverSocket
listenFor: 4;
soReuseaddr: true
run | childSocket clientConnection clientIOStream | [childSocket := serverSocket accept. clientIOStream := childSocket readAppendStream. clientIOStream lineEndTransparent. self processRequestOn: clientIOStream.] repeat
processRequestOn: anReadAppendStream
| clientRequest |
clientRequest := anReadAppendStream through: Character cr.
(clientRequest startsWith: 'date')
ifTrue: [anReadAppendStream nextPutAll:
Time dateAndTimeNow printString].
anReadAppendStream close
server := SimpleDateServer port: 5556. serverProcess := [server run] fork
Client A builds connection to server,
Client A goes to lunch
Client B builds connection to server and ... :-(
SocketAccessor>>listenFor: aNumber
public ServerSocket(int port)
public ServerSocket(int port, int backlog, InetAddress bindAddress)
SocketAccessor>> soReuseaddr: true
ServerSocket method setReuseAddress(boolean on)
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Platform |
End
of Line Convention
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Unix |
Line
Feed (LF)
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Macintosh |
Carriage
return (CR)
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Windows |
CR-LF |
BufferedExternalStream>> lineEndTransparent
BufferedReader parsedInput =
new BufferedReader(new InputStreamReader(in));
char[] message = new char[500]; int sizeRead = parsedInput.read(message, 0, 500);If