Package cruise.umple

Class AbstractServer

java.lang.Object
cruise.umple.AbstractServer
All Implemented Interfaces:
java.lang.Runnable
Direct Known Subclasses:
PlaygroundMain
public abstract class AbstractServer
extends java.lang.Object
implements java.lang.Runnable
This file contains material derived from "Object Oriented Software Engineering" by Lethbridge and Laganiere and is issued under the open-source license found at www.lloseng.com This is a framework for a server that can read and write characters

  • Constructor Summary

    Constructors 
    Constructor Description
    AbstractServer​(int port)
    CONSTRUCTOR ****************************************************** Constructs a new server.
    AbstractServer​(java.lang.Thread aConnectionListener, int aPort, java.lang.ThreadGroup aClientThreadGroup)  

  • Method Summary

    Modifier and Type Method Description
    protected void clientConnected​(ConnectionToClient client)
    METHODS DESIGNED TO BE OVERRIDDEN BY CONCRETE SUBCLASSES --------- Hook method called each time a new client connection is accepted.
    protected void clientDisconnected​(ConnectionToClient client)  
    protected void clientException​(ConnectionToClient client, java.lang.Throwable exception)  
    void close()
    Closes the server socket and the connections with all clients.
    void delete()  
    int getBacklog()
    The maximum queue length; i.e.
    java.lang.Thread[] getClientConnections()  
    java.lang.ThreadGroup getClientThreadGroup()
    The thread group associated with client threads.
    java.lang.Thread getConnectionListener()
    The connection listener thread.
    int getNumberOfClients()
    Counts the number of clients currently connected.
    int getPort()
    The port number
    boolean getReadyToStop()
    Indicates if the listening thread is ready to stop.
    java.net.ServerSocket getServerSocket()
    INSTANCE VARIABLES ********************************************* The server socket: listens for clients who want to connect.
    int getTimeout()
    The server timeout while for accepting connections.
    protected abstract void handleMessageFromClient​(java.lang.String msg, ConnectionToClient client)
    Handles a command sent from one client to the server.
    boolean isClosed()
    Returns true if the server is closed.
    boolean isListening()
    ACCESSING METHODS ------------------------------------------------ Returns true if the server is ready to accept new clients.
    void listen()
    INSTANCE METHODS ************************************************* Begins the thread that waits for new clients.
    protected void listeningException​(java.lang.Throwable exception)
    Hook method called when the server stops accepting connections because an exception has been raised.
    void run()
    RUN METHOD ------------------------------------------------------- Runs the listening thread that allows clients to connect.
    void sendToAllClients​(java.lang.String msg)
    Sends a message to every client connected to the server.
    protected void serverClosed()
    Hook method called when the server is clased.
    protected void serverStarted()
    Hook method called when the server starts listening for connections.
    protected void serverStopped()
    Hook method called when the server stops accepting connections.
    boolean setBacklog​(int aBacklog)  
    boolean setClientThreadGroup​(java.lang.ThreadGroup aClientThreadGroup)  
    boolean setConnectionListener​(java.lang.Thread aConnectionListener)  
    boolean setPort​(int aPort)  
    boolean setReadyToStop​(boolean aReadyToStop)  
    boolean setServerSocket​(java.net.ServerSocket aServerSocket)  
    boolean setTimeout​(int aTimeout)  
    void stopListening()
    Causes the server to stop accepting new connections.
    java.lang.String toString()  

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • AbstractServer

      public AbstractServer​(java.lang.Thread aConnectionListener, int aPort, java.lang.ThreadGroup aClientThreadGroup)

    • AbstractServer

      public AbstractServer​(int port)
      CONSTRUCTOR ****************************************************** Constructs a new server.
      Parameters:
      port - the port number on which to listen.

  • Method Details

    • setServerSocket

      public boolean setServerSocket​(java.net.ServerSocket aServerSocket)

    • setConnectionListener

      public boolean setConnectionListener​(java.lang.Thread aConnectionListener)

    • setPort

      public boolean setPort​(int aPort)

    • setTimeout

      public boolean setTimeout​(int aTimeout)

    • setBacklog

      public boolean setBacklog​(int aBacklog)

    • setClientThreadGroup

      public boolean setClientThreadGroup​(java.lang.ThreadGroup aClientThreadGroup)

    • setReadyToStop

      public boolean setReadyToStop​(boolean aReadyToStop)

    • getServerSocket

      public java.net.ServerSocket getServerSocket()
      INSTANCE VARIABLES ********************************************* The server socket: listens for clients who want to connect.

    • getConnectionListener

      public java.lang.Thread getConnectionListener()
      The connection listener thread.

    • getPort

      public int getPort()
      The port number

    • getTimeout

      public int getTimeout()
      The server timeout while for accepting connections. After timing out, the server will check to see if a command to stop the server has been issued; it not it will resume accepting connections. Set to half a second by default.

    • getBacklog

      public int getBacklog()
      The maximum queue length; i.e. the maximum number of clients that can be waiting to connect. Set to 10 by default.

    • getClientThreadGroup

      public java.lang.ThreadGroup getClientThreadGroup()
      The thread group associated with client threads. Each member of the thread group is a ConnectionToClient .

    • getReadyToStop

      public boolean getReadyToStop()
      Indicates if the listening thread is ready to stop. Set to false by default.

    • delete

      public void delete()

    • listen

      public void listen() throws java.io.IOException
      INSTANCE METHODS ************************************************* Begins the thread that waits for new clients. If the server is already in listening mode, this call has no effect.
      Throws:
      java.io.IOException - if an I/O error occurs when creating the server socket.

    • stopListening

      public void stopListening()
      Causes the server to stop accepting new connections.

    • close

      public void close() throws java.io.IOException
      Closes the server socket and the connections with all clients. Any exception thrown while closing a client is ignored. If one wishes to catch these exceptions, then clients should be individually closed before calling this method. The method also stops listening if this thread is running. If the server is already closed, this call has no effect.
      Throws:
      java.io.IOException - if an I/O error occurs while closing the server socket.

    • sendToAllClients

      public void sendToAllClients​(java.lang.String msg)
      Sends a message to every client connected to the server. This is merely a utility; a subclass may want to do some checks before actually sending messages to all clients. This method can be overriden, but if so it should still perform the general function of sending to all clients, perhaps after some kind of filtering is done. Any exception thrown while sending the message to a particular client is ignored.
      Parameters:
      msg - Object The message to be sent

    • isListening

      public boolean isListening()
      ACCESSING METHODS ------------------------------------------------ Returns true if the server is ready to accept new clients.
      Returns:
      true if the server is listening.

    • isClosed

      public boolean isClosed()
      Returns true if the server is closed.
      Returns:
      true if the server is closed.
      Since:
      version 2.2

    • getNumberOfClients

      public int getNumberOfClients()
      Counts the number of clients currently connected.
      Returns:
      the number of clients currently connected.

    • run

      public void run()
      RUN METHOD ------------------------------------------------------- Runs the listening thread that allows clients to connect. Not to be called.
      Specified by:
      run in interface java.lang.Runnable

    • clientConnected

      protected void clientConnected​(ConnectionToClient client)
      METHODS DESIGNED TO BE OVERRIDDEN BY CONCRETE SUBCLASSES --------- Hook method called each time a new client connection is accepted. The default implementation does nothing. This method does not have to be synchronized since only one client can be accepted at a time.
      Parameters:
      client - the connection connected to the client.

    • listeningException

      protected void listeningException​(java.lang.Throwable exception)
      Hook method called when the server stops accepting connections because an exception has been raised. The default implementation does nothing. This method may be overriden by subclasses.
      Parameters:
      exception - the exception raised.

    • serverStarted

      protected void serverStarted()
      Hook method called when the server starts listening for connections. The default implementation does nothing. The method may be overridden by subclasses.

    • serverStopped

      protected void serverStopped()
      Hook method called when the server stops accepting connections. The default implementation does nothing. This method may be overriden by subclasses.

    • serverClosed

      protected void serverClosed()
      Hook method called when the server is clased. The default implementation does nothing. This method may be overriden by subclasses. When the server is closed while still listening, serverStopped() will also be called.

    • handleMessageFromClient

      protected abstract void handleMessageFromClient​(java.lang.String msg, ConnectionToClient client)
      Handles a command sent from one client to the server. This MUST be implemented by subclasses, who should respond to messages. This method is called by a synchronized method so it is also implcitly synchronized.
      Parameters:
      msg - the message sent.
      client - the connection connected to the client that sent the message.

    • toString

      public java.lang.String toString()
      Overrides:
      toString in class java.lang.Object

    • getClientConnections

      public final java.lang.Thread[] getClientConnections()

    • clientDisconnected

      protected void clientDisconnected​(ConnectionToClient client)

    • clientException

      protected void clientException​(ConnectionToClient client, java.lang.Throwable exception)