biz.chitec.quarterback.gjsa.server
Class SocketLayer

java.lang.Object
  java.lang.Thread
      biz.chitec.quarterback.gjsa.server.SocketLayer

All Implemented Interfaces:

java.lang.Runnable

public class SocketLayer

extends java.lang.Thread

Lowest-level class in server-socket-communication A SocketLayer object is created by GJSAServer for each incoming connection. It always runs in its own thread. It does always the initial and the low-level stuff on the connection:

• Spawning into special handling thread for this connection.
• Wrapping the socket with the appropriate Stream objects
• Reading the first query from the socket
• Initiating the further handling.

SocketLayer has three possibilities what to do with the freshly read first query:

1. The query contains an ID of an already opened connectionless connection. In this case, the complete query is handed over to the CLBag (via GJSAServer) so that the appropriate handler can cope with it. The delivered answer is written back to the Socket which is closed afterwards.
2. The query begins with the NEWCONNECTIONLESS command. Then, a new ServerThreadBase object is created, put into CLBag, it is given the rest of the query (if available), the result is appended to the self-generated answer to the NEWCONNECTIONLESS command, and everything is finally written back to the Socket, which is closed afterwards.
3. The query begins with every other command and is not signed as "connectionless". In this case, a new ServerThreadBase is created, it gets the SocketLayer, and after that, it completely takes over the connection with the SocketLayer being the final instance on top of the Socket.

SocketLayer always survives the complete livetime of the open connection to the client. It is also the instance which incorporates the Thread under which the question of the client is answered (regardless of who actually handles the query).

Version:

$Id: e4e41bd5141a742f2424710024b7e447084a5214 $

Author:

Dirk Hillbrecht 2003. Distributed under the terms of the GNU LGPL.

See Also:

ServerThreadBase, GJSAServer, SessionConnector

Nested Class Summary

private class

SocketLayer.InternalHandlingException

Field Summary

private java.lang.String	clienthostip The client IP address
private java.lang.String	clienthostname The (DNS-)name of the client host
private int	connectionencoding What is the encoding of the connection?
private boolean	encrypted Is this connection encrypted?
static int	INITIALTIMEOUT Timeout used directly after opening the Socket.
private boolean	internalsocketclosing Marker whether the socket is closed internally
private Logger	mess
GJSAServer	myserv Reference to the Server object that has launched this ServerThreadBase
private java.net.InetAddress	remoteaddress The client InetAddress object
private java.net.Socket	socket Socket to the client
private java.io.ObjectInputStream	socketinputstream
private java.io.ObjectOutputStream	socketoutputstream
private java.io.BufferedReader	socketreader
private java.io.BufferedWriter	socketwriter

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

SocketLayer(GJSAServer gx, java.net.Socket sx, boolean ex, int codex)
Constructor for the SocketLayer.

Method Summary

boolean	clientMatchesPattern(java.lang.String pattern) Description of the Method
void	closeSocket() Closes the socket externally.
java.lang.String	getClientHostIP() Returns the IP address of the connected client.
java.lang.String	getClientHostName() Returns the symbolic name of the connected client.
java.net.InetAddress	getClientInetAddr() Returns the InetAddress object for the currently connected client This method will also work for connectionless connect.
boolean	isEncrypted() Returns whether this SocketLayer is on an encrypted connection or not.
boolean	isInternalSocketClosing() Returns whether the socket will be closed internally.
ServerEnvelope	readFromSocket() Reads data from socket.
ServerEnvelope	readFromSocket(ServerThreadBase stb) Read one query from the socket.
void	run() Main method to do something useful with the socket.
void	setInternalSocketClosing(boolean b) Toggles internal socket closing.
void	setSoTimeout(int millis) Set the socket's read timeout.
void	writeToSocket(ServerEnvelope se) Write one answer to the socket.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setName, setPriority, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

INITIALTIMEOUT

public static final int INITIALTIMEOUT

Timeout used directly after opening the Socket. The first query must arrive within this amount of time.

See Also:

Constant Field Values

myserv

public GJSAServer myserv

Reference to the Server object that has launched this ServerThreadBase

socket

private java.net.Socket socket

Socket to the client

encrypted

private boolean encrypted

Is this connection encrypted?

connectionencoding

private int connectionencoding

What is the encoding of the connection?

socketreader

private java.io.BufferedReader socketreader

socketwriter

private java.io.BufferedWriter socketwriter

socketinputstream

private java.io.ObjectInputStream socketinputstream

socketoutputstream

private java.io.ObjectOutputStream socketoutputstream

mess

private Logger mess

clienthostname

private java.lang.String clienthostname

The (DNS-)name of the client host

clienthostip

private java.lang.String clienthostip

The client IP address

remoteaddress

private java.net.InetAddress remoteaddress

The client InetAddress object

internalsocketclosing

private boolean internalsocketclosing

Marker whether the socket is closed internally

Constructor Detail

SocketLayer

public SocketLayer(GJSAServer gx,
                   java.net.Socket sx,
                   boolean ex,
                   int codex)

Constructor for the SocketLayer. Does only create the object. Everything else is done in the detached run() method.

Parameters:

gx - The GJSA server

sx - The socket to listen on (and write to)

ex - Encryption state of the connection (encrypted or not?)

codex - Encoding mode of the connection.

Method Detail

readFromSocket

public ServerEnvelope readFromSocket(ServerThreadBase stb)
                              throws java.io.IOException,
                                     java.lang.ClassNotFoundException

Read one query from the socket. Reads exactly one query from the socket. Handles differences between String and Object-based communication. This method blocks until something to be read is available (or the connection times out). It should be called by a caller who takes care of this behaviour.

Returns:

ServerEnvelope object containing the query.

Throws:

java.io.IOException

java.lang.ClassNotFoundException

readFromSocket

public ServerEnvelope readFromSocket()
                              throws java.io.IOException,
                                     java.lang.ClassNotFoundException

Reads data from socket.

Throws:

java.io.IOException

java.lang.ClassNotFoundException

writeToSocket

public void writeToSocket(ServerEnvelope se)
                   throws java.io.IOException

Write one answer to the socket. Writes exactly one answer to the socket. Handles differences between String and Object-based communication. This method blocks until the recipient has read the stuff (or the connection times out). It should be called by a caller who takes care of this behaviour.

Parameters:

se - The ServerEnvelope to write to the socket

Throws:

java.io.IOException

setSoTimeout

public void setSoTimeout(int millis)
                  throws java.net.SocketException

Set the socket's read timeout.

Throws:

java.net.SocketException

clientMatchesPattern

public boolean clientMatchesPattern(java.lang.String pattern)

Description of the Method

Parameters:

pattern - Description of the Parameter

Returns:

Description of the Return Value

getClientInetAddr

public java.net.InetAddress getClientInetAddr()

Returns the InetAddress object for the currently connected client This method will also work for connectionless connect.

Returns:

Info about the currently connected client

getClientHostName

public java.lang.String getClientHostName()

Returns the symbolic name of the connected client. May be null.

Returns:

The clientHostName value

getClientHostIP

public java.lang.String getClientHostIP()

Returns the IP address of the connected client. May be null though this is rather unlikely.

Returns:

The clientHostIP value

isEncrypted

public boolean isEncrypted()

Returns whether this SocketLayer is on an encrypted connection or not.

setInternalSocketClosing

public void setInternalSocketClosing(boolean b)

Toggles internal socket closing. Normally, SocketLayer closes the socket automatically if the connection is gone. However, if an asynchronous writing thread is operating on the socket, it must be ensured that everything is written to the socket in advance to closing it. Therefore, socket closing control can be passed to that writing thread. To activate this pass-over, internal socket closing must be disabled by calling this method. Warning: Socket closing should only be disabled if the external socket closing mechanism will close the socket properly. Under all circumstances no orphaned opened sockets should linger around and eat up resources.

Parameters:

b - Flag whether sockets should be closed internally

isInternalSocketClosing

public boolean isInternalSocketClosing()

Returns whether the socket will be closed internally.

closeSocket

public void closeSocket()

Closes the socket externally. Must be called by any accordingly qualified entity of the program to close the socket if this is not done internally. All exceptions are caught internally. If internal socket closing is enabled, this method does nothing.

run

public void run()

Main method to do something useful with the socket. The main method initializes the Socket appropriately, then reads the first query and does whatever is needed.