CS 580 Client-Server Spring Semester, 2004 Some on Protocol
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Doc 21, Some on Protocol Slide # 2

Some low level Parsing

"cat;man;ran".split(";");

parts = new java.util.StringTokenizer("cat,man;ran;,fan", ",;");
while (parts.hasMoreElements()) 
   {
   System.out.println( parts.nextToken());
   }

cat
man
ran
fan

Doc 21, Some on Protocol Slide # 3

'cat;man;ran' tokensBasedOn: $;

OrderedCollection ('cat' 'man' 'ran')

'cat. man... ran.'
      piecesCutWhere: 
            [:each :next | each = $. and: [next = Character space]] 
      do: [:each | Transcript show: each printString; cr]

'cat.'
' man...'
' ran.'

Doc 21, Some on Protocol Slide # 4

'cat\man\ran' 
      runsFailing: [:each | each = $\] 
      do: [:each | Transcript show: each; cr]

cat
man
ran

'cat\man\ran' 
      runsSatisfying: [:each | each ~= $\] 
      do: [:each | Transcript show: each; cr]

cat
man
ran
Doc 21, Some on Protocol Slide # 5

Doc 21, Some on Protocol Slide # 6

Doc 21, Some on Protocol Slide # 7

read = new sdsu.io.ChunkReader("catEOMmatEOM", "EOM")
while (read.hasMoreElements() ) 
   {
   System.out.println( read.readChunk());
   }

cat
mat
Doc 21, Some on Protocol Slide # 8

Calendar System

• View the items in a calendar
• Do searches for particular events

• Date
• Title
• Location

• Enter new events
• Modify event they submitted earlier
• Cancel events they submitted earlier

• A Title
• A start time (day and time)
• A duration, which could be all day
• A short description
• A location, which could be a room in a building, a building or a general location like Aztec Green
• The name of a submitter
• <HR>

Doc 21, Some on Protocol Slide # 9

Doc 21, Some on Protocol Slide # 10

public class CalendarLogonRequest {
   private Hashtable data = new Hashtable();

   public void userName( String name) { data.put(“user”, name); }

   public String userName()  { return data.get(“user”); }

   public void password(String password) {
      data.put(“password”, password);
   }

   public String toString() {
      StringBuffer logon = new StringBuffer();
      logon.append(“login” ).
      logon.append(“\r\n” ).
      logon.append(“user=” ).
      logon.append( data.get(“user”) ).
      logon.append(“\r\n” ).
      logon.append(“password=” ).
      logon.append( data.get(“password”) ).
      logon.append(“\r\n” ).
      logon.append(“EOM\r\n).
      return logon.toString();
   }
   public static CalendarLogonRequest from(InputStream in) {
      parse in
      return CalendarLogonRequest object with username and password set}
Doc 21, Some on Protocol Slide # 11

Smalltalk defineClass: #CalendarLogonRequest
   superclass: #{Core.Object}
   indexedType: #none
   private: false
   instanceVariableNames: 'userName password '
   classInstanceVariableNames: ''
   imports: ''
   category: 'Protocol Examples'

from: aStringOrReadStream
   ^super new from: aStringOrReadStream readStream

userName: aNameString password: aPasswordString
   ^super new setUserName: aNameString password: aPasswordString 

setUserName: aNameString password: aPasswordString
   userName := aNameString.
   password := aPasswordString 

from: aReadStream
   | message lines |
   message := aReadStream upToAll: 'EOM\' withCRs.
   lines := message tokensBasedOn: Character cr.
   lines do: 
      [:each | (each includes: $=) ifTrue:[self addPairFrom: each]]
Doc 21, Some on Protocol Slide # 12

addPairFrom: aString
   | keyValue |
   keyValue := aString tokensBasedOn: $=.
   keyValue first asLowercase = 'password' 
      ifTrue:[ password := keyValue last].
   keyValue first asLowercase = 'user' 
      ifTrue:[ userName := keyValue last].

asString
   | aStream |
   aStream := WriteStream on: (String new: 16).
   self printOn: aStream.
   ^aStream contents

printOn: aStream
   aStream
      nextPutAll: 'login'; cr;
      nextPutAll: 'user=';
      nextPutAll: userName; cr;
      nextPutAll: 'password=';
      nextPutAll: password; cr;
      nextPutAll: 'EOM'; cr

password
   ^password

userName
   ^userName
Doc 21, Some on Protocol Slide # 13

logonRequest = new CalendarLogonRequest();
logonRequest.user( “whitney”);
logonRequest.password( “foo” );
   
clientSocket = new Socket(“127.0.0.1”, 9009);
toServer = clientSocket.getOutputStream();
   
request = logonRequest.toString();
toServer.write(request.getBytes());

Doc 21, Some on Protocol Slide # 14

clientSocket := SocketAccessor newTCPclientToHost: '127.0.0.1' port: 9009.
logon := CalendarLogonRequest userName: 'roger' password: 'foo'.
toServer := clientSocket readAppendStream.
toServer lineEndCRLF.
toServer nextPutAll: logon asString;flush.

server := SocketAccessor newTCPserverAtPort: 9009.
server listenFor: 5.
   
acceptedSocket := server accept.
[ | stream |
   stream := acceptedSocket readAppendStream.
   stream lineEndCRLF.
   request := CalendarLogonRequest from: stream.
   stream nextPutAll: 'Done'; commit.
      stream close. 
   ] forkAt: Processor userSchedulingPriority -1.
Doc 21, Some on Protocol Slide # 15

public class CalendarLogonRequest {

   public Result execute( CalenderHandler aCalender) {
      check to see if user name and password are correct
      return a result object
   }
Doc 21, Some on Protocol Slide # 16

• Read returns a Calendar request object

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( 
            new CalenderInputStream(client.getInputStream()),
            new CalenderOutPutStream(client.getOutputStream());
         client.close();
      }
   }

void processRequest(
            CalenderInputStream in, 
            CalenderOutPutStream out)
      throws IOException {
      CalenderRequest request = (CalenderRequest ) in.read();
      CalenderRequest response = request.execute( calender );
      out.write( response);
      }
   }
Doc 21, Some on Protocol Slide # 17

Socket client = input.accept();
   
in = client.getInputStream();

String firstLine = in.readLine();
if (firstLine = “login” )
   request = new CalendarLoginRequest();
else if (firstLine = “newEvent” )
   request = new CalendarNewEventRequest();
else if etc.

requests = new Hashtable();
requests.put( “login”, new CalendarLoginRequest());
requests.put(“newEvent”, new CalendarNewEventRequest());

Socket client = input.accept();
   
in = client.getInputStream();

String firstLine = in.readLine();
request = requests.get( firstLine).clone();

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