This class is the point of contact between the applet and the server's business logic. It receives and sends on each demand of the applet a Communication-object. There a several types of demands: a logon-, graph-, refresparameters- and present-demand. Each type of demand is delegated to a separate method of the FsmManager class.

public void doPost(HttpServletRequest request, HttpServletResponse response)

This method overrides the doPost method of the HttpServlet. It provides the communication between te applet and the server

public void destroy()

This method overrides the destroy-method of the HttpServlet and is

executed when the servlet is unloaded. It stops the Graph-caching

of the mangager.

Provides a helper method for determining the serialized size of an object.

Calculates the serialized size of an object by writing it into a byte array and the returning the array size.

public synchronized long getElapsedTime()

public synchronized void reset()

public synchronized void start()

public synchronized void stop()

This class manages all actions to be taken on the server. It can also start and stop the automatic graph caching thread.

his constructor starts the AutoGraphCaching-thread.

public Communication logon(SessionBean session)

This method logs on a user using a SessionBean. It will set the graph- and preference attribute of the SessionBean, and redirect it to the ClientState. If the graph is customized, it will not cache the sessionbean.

public Communication refresh(SessionBean session)

This method treats a refresh-demand for the applet. It will set only the Graph attribute of the SessionBean, it will take this value out of the ClientState except for a customized graph, there it will regenerate the Graph value.

public Communication refreshParameters(SessionBean session)

This method reloads the preferences in the ClientState for that session. This is usefull because the automatic graph caching gets it preferences out of the ClientState.

public Communication detail(SessionBean session, String comm_desc)

Not yet implemented

public Communication activateSession(SessionBean session)

Activates or reactivates a session.

public Graph generateGraph(SessionBean session)

Based on the groupname and graphnr, this method will give the FsmReader the command to generate a graph

public void stopManager()

This method stops the AutoGraphCaching-thread and the ClientMaintenance-thread. It deletes all instances of the ClientState, AutoGraphCaching and Reader

AutoGraphCaching regenerates for every session that is present in the cachevector of the ClientState, a graph. This Graph-object will be put in a SessionBean and will be afterwards saved in the cachevector. This is done every 5 minutes.

The constructor makes a link with the Manager (FsmManager), ClientState (FsmClientState) and the Reader (FsmReader)

public void run()

Starts the AutoGraphCaching-thread

private void pause(int sec)

The ClientState (FsmClientState) is responsible for the caching of actively logged-on users. This cache is a vector of SessionBeans. A SessionBean is a self-written class that contains userinfo, Preferences and a Graph. The ClientState has several methods to retrieve, modify, add or delete information from its cache

public FsmClientState()

The contructor creates a new cache-vector for storing SessionBeans and it creates and starts an instance of the ClientStateMaintenance-class.

public void stopMaintenance()

Used to stop the instance of the ClientStateMaintenance-class that was started in the constructor of FsmClientState. The sessionvector, used for caching SessionBeans, will be emptied.

public synchronized Object executeOperation(int operation, SessionBean b)

Main-method to perform synchronized operations on the sessionvector. Use a semaphore to accomplish an operation.

private int indexOf(SessionBean b)

private void activateBean(SessionBean b)

private void deactivateBean(SessionBean b)

The ClientStateMaintance, that is a Thread, has the duty to maintain the cachevector of the ClientState. This maintenance consists out of finding and deleting users that currently are not logged on. It uses this principle: Every minute the applet sends a command to the server that indicated the applet/user is logged-on. Every 2 minutes the ClientStateMaintance considers all sessions in-active. When an applet/user resends it "i'm present"-command, ClientStateMaintance considers it active. The next time the pause of 2 minutes has elapsed, ClientStateMaintance tracks the sessions that were not back set to active. Those sessionbeans will then be unregistered.

public void run()

Start the ClientStateMaintance-thread.

private void pause(int sec)

The AuthorisationReader is responsible to return data that ensures the security-policy of the GEM (A-130) and FSM (A-140).

public ArrayList getGraph_nrs(String group)

Ensures FSM's security-policy

public ArrayList getAutorisedCzs(String user)

Ensures GEM's security-policy

private ArrayList getAllCzs()

This class houses a large number of constants, used in the base classes for generating graphs: GraphComposer and VectorTool. The motherVector is vector of Strings. These Strings have a common structure. The constants of this class defines that structure. It defines the start (_S) and end position (_E)of every field in a String of the motherVector.

The GraphComposer has several methods that are used in the Reader to generate a Graph-object. It's a low-level component that contains most of the business-logic for designing a Graph-object. The data for this class is supplied by the VectorTool in the shape of a motherVector. Different than the Vectortool, the GraphComposer performs it's operations solely with Java-objects and doesn't has to read from the mainframe. That's why, once a motherVector is built, a Graph-object can be so quickly generated.

constructor, creates a new instance of the Constants-class

public Vector addTrainInfo(Vector XmotherVector, Vector beanVector, Vector infrastructure, Preferences p, Date startDate)

This method adds TrainMovements to the infrastructure

public Vector addOperationInfo(Vector XmotherVector, Vector beanVector, Vector infrastructure, Preferences p, Date startDate)

This method adds TrackOperations to the infrastructure

public Vector addWagonQuantityInfo(Vector XmotherVector, Vector beanVector, Vector infrastructure, Preferences p, Date startDate)

This method adds WagonQuantities to the infrastructure

The InfrastructureBuilder is specialised in infrastructure building and consultations

public Vector buildInfrastructure(Vector cl)

This method determines the infrastructure (tracks and hill) for one or more requested communicationzones.

public boolean displayTrack(Vector cz_list, String track, String cz)

This method checks if a specified track in a specified cz is present in the list of displayed tracks in the current Preferences

public boolean displayHill(Vector cz_list, String hill, String cz

This method checks if a specified hill in a specified cz is present in the list of displayed hills in the current Preferences

public ArrayList getZoneComposition(String cz)

public void generateNetwork()

public void generateZone(String cz)

The PreferenceReader combines reading mainframetables Grafiek_Weergave and Grafiek_Opbouw so that it becomes the only class that can read the preferences stored on the mainframe

public Preferences getPreferences(SessionBean session)

This method is used when the Preferences for a group + graphnr is needed

public Vector buildCz_list(String key)

Used for retrieving the list of displayed tracks and hills for a communicationzone

The Reader is a low-level delegating class that gives instructions to the VectorTool, InfrastructureBuilder, GraphComposer for ultimately returning a Graph-object. Therefore it becomes the point-of contact of other management-classes such as ClientState and Manager

The constructor establishes a link to the ClientState, creates instances of the InfrastructureBuilder, VectorTool and GraphComposer.

public Graph generateGraph(SessionBean session)

This method will give instructions to the other low-level components (InfrastructureBuilder, VectorTool and GraphComposer)in order to become a Graph-object as return value

This is the low-level class to build the motherVector. It uses ergonomic methods to unburden the mainframe. It reads the mainframetables Operatie, Op_Loc and Trein_Op_Loc. The mothervector is in fact a "de-normalised" table of the three earlier named mainframetables. This table is a Vector with String-objects as a record. The structure of a record is defined in FsmConstants. A field can be retrieved by the method substring(). Because of the lack of a language such as SQL, I have written several methods where you can give a single condition to select records such as get(), search(), exclude(), include() etc...

Constructor establishes a link between the VectorTool and the InfraStructurebuilder It creates also an instance of FsmConstants.

public Vector buildMotherVector(Vector clv, Date start, int duration)

Builds the mothervector

public Vector convertMotherVector(Vector result)

This method converts a flat String-table into a Object-Oriented Table. In fact the Strings are converted to a SuperBean. Every field will be stocked into a attribute of that SuperBean. It's easier to access an attribute than retrieving the fields content using the substring()-method.

public Vector returnSortedMotherVector(Vector bvx)

This method sorts the beanVector using the fields 'begindatum' + 'einddatum'.

public void setZoneComposition(String cz, ArrayList composition)

public ArrayList getZoneComposition(String cz)

A Sessionbean contains all necessary information about a session of a user/group. It stores info like username, groupname, graph_nr, Preferences, Graph and an indication if the session is still active. Note that if there are more than 1 user from a same group only 1 sessionbean for that group will be stored in the cachevector from the ClientState.

public boolean equals(SessionBean sb)

Compare current sessionbean with a specified sessionbean. If both groupname and graph_nr are the same. Both sessionbeans are consired as equal and a true-value is returned.

A SuperBean is the OO-version of a flat String-record from the motherVector. Sometimes it's easier to work with attributes of an object instead of using substring() methods.

public int compareTo(Object bx)

Method to sort SuperBeans in a BeanVector. It is sorted by begindatum then by einddatum