dist1.acb.common.transport
Class AbstractClientSocket

java.lang.Object
  java.lang.Thread
      dist1.acb.common.transport.AbstractClientSocket

All Implemented Interfaces:

java.lang.Runnable

Direct Known Subclasses:

AdminSocket, Backup, ClientSocket, DownloadFile

public abstract class AbstractClientSocket

extends java.lang.Thread

Abstract class for threaded model of client socket. The class manages outcoming requests.

Version:

$Revision: 1.44 $

Author:

Alexander Stasiv

Nested Class Summary

static class

AbstractClientSocket.SocketAndStreams Container for three objects: Socket, ObjectOutputStream and ObjectInputStream

Field Summary

protected boolean	isShutdowned
protected java.util.logging.Logger	log
protected ObjectStreamFactory	objectStreamFactory
protected java.net.Socket	socket

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

AbstractClientSocket(java.lang.ThreadGroup group)
Creates a new instance of AbstractClientSocket

AbstractClientSocket(java.lang.ThreadGroup group, boolean doNotConnectInParentThread)
Creates a new AbstractClientSocket object.

Method Summary

void	connect() Connect to the next server
static AbstractClientSocket.SocketAndStreams	connect(java.net.InetSocketAddress serverAddr, java.lang.String className, java.util.logging.Logger log) Create connected socket and related streams
static AbstractClientSocket.SocketAndStreams	connect(java.net.InetSocketAddress serverAddr, java.lang.String className, java.util.logging.Logger log, ObjectStreamFactory osf) Create connected socket and related streams
Response	getResponse(Request request) Get respons to the request.
java.net.InetSocketAddress	getServerAddr() Getter for property serverAddr.
java.util.LinkedList	getServersAddresses() Getter for property serversAddresses.
protected abstract void	handleConnectionEstablished()
protected abstract boolean	handleConnectionLost()
protected void	handleResponseToNoRequest(Response response)
protected abstract void	handleUnrecoverableError(java.lang.Throwable e)
boolean	isConnected() Returns the connection state of the socket.
protected Response	receiveResponse() Private static function for receiving a response.
Response	request(Request request) Send the request and receive a response from the server in same thread.
static Response	request(Request request, java.io.ObjectInputStream in, java.io.ObjectOutputStream out, java.util.logging.Logger log) Used by a modles which use direct exchange of messages
void	run() Main processing method for the ConnectionServer object
void	scheduleRequest(Request request) Schedules equest to the server.
void	setServersAddresses(java.util.LinkedList serversAddresses) Setter for property serversAddresses.
void	start() Initiate connection to the server and if succeed, causes this thread to begin execution; the Java Virtual Machine calls the run method of this thread.

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, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

log

protected java.util.logging.Logger log

objectStreamFactory

protected ObjectStreamFactory objectStreamFactory

socket

protected java.net.Socket socket

isShutdowned

protected boolean isShutdowned

Constructor Detail

AbstractClientSocket

public AbstractClientSocket(java.lang.ThreadGroup group)

Creates a new instance of AbstractClientSocket

Parameters:

group - Thread group to which current thread will be related

AbstractClientSocket

public AbstractClientSocket(java.lang.ThreadGroup group,
                            boolean doNotConnectInParentThread)

Creates a new AbstractClientSocket object.

Parameters:

group - DOCUMENT ME!

doNotConnectInParentThread - DOCUMENT ME!

Method Detail

isConnected

public boolean isConnected()

Returns the connection state of the socket.

Returns:

true if the socket successfuly connected to a server

getResponse

public Response getResponse(Request request)

Get respons to the request. The method checks list of responses in order to find requered response. If found, delete the response from the list and return it.

Parameters:

request - A request to search for response

Returns:

A response to the request. NULL if no response received yet.

getServerAddr

public java.net.InetSocketAddress getServerAddr()

Getter for property serverAddr.

Returns:

Value of property serverAddr.

setServersAddresses

public void setServersAddresses(java.util.LinkedList serversAddresses)
                         throws java.lang.RuntimeException

Setter for property serversAddresses.

Parameters:

serversAddresses - New value of property serversAddresses.

Throws:

java.lang.RuntimeException - if contains less then 1 element

getServersAddresses

public java.util.LinkedList getServersAddresses()

Getter for property serversAddresses.

Returns:

Value of property serversAddresses.

connect

public static AbstractClientSocket.SocketAndStreams connect(java.net.InetSocketAddress serverAddr,
                                                            java.lang.String className,
                                                            java.util.logging.Logger log)
                                                     throws java.lang.ClassNotFoundException,
                                                            java.io.IOException

Create connected socket and related streams

Parameters:

serverAddr - Destination

className - Requester of the connection

log - A logger

Returns:

socket and related streams

Throws:

java.lang.ClassNotFoundException - if class with name className was not found

java.io.IOException - if some input-output exception occured

connect

public static AbstractClientSocket.SocketAndStreams connect(java.net.InetSocketAddress serverAddr,
                                                            java.lang.String className,
                                                            java.util.logging.Logger log,
                                                            ObjectStreamFactory osf)
                                                     throws java.lang.ClassNotFoundException,
                                                            java.io.IOException

Create connected socket and related streams

Parameters:

serverAddr - Destination

className - Requester of the connection

log - A logger

osf - ObjectStreamFactory for constructing streams

Returns:

socket and related streams

Throws:

java.lang.ClassNotFoundException - if class with name className was not found

java.io.IOException - if some input-output exception occured

connect

public void connect()

Connect to the next server

request

public Response request(Request request)
                 throws java.lang.InterruptedException,
                        java.lang.ClassNotFoundException,
                        java.io.IOException

Send the request and receive a response from the server in same thread. So the method is blocking. The method tries to hide some errors like link breaks or crashes of the server.

Parameters:

request - Request to send

Returns:

A response from a server

Throws:

java.lang.InterruptedException - The thread was interrupted.

java.lang.ClassNotFoundException - if received from the server class was not found

java.io.IOException - if handleConnectionLost() returns false

request

public static Response request(Request request,
                               java.io.ObjectInputStream in,
                               java.io.ObjectOutputStream out,
                               java.util.logging.Logger log)
                        throws java.lang.InterruptedException,
                               java.lang.ClassNotFoundException,
                               java.io.IOException,
                               java.lang.ClassCastException

Used by a modles which use direct exchange of messages

Parameters:

request - Request

in - Input stream from where to receive a Response

out - Output stream where to send a Request

log - A logger

Returns:

Received response

Throws:

java.lang.InterruptedException - Current thread was interrupted

java.lang.ClassNotFoundException - If we received a class that we haven't localy

java.io.IOException - An input exception

java.lang.ClassCastException - if received object can not be casted to Response

run

public void run()

Main processing method for the ConnectionServer object

Throws:

java.lang.InterruptedException - DOCUMENT ME!

scheduleRequest

public void scheduleRequest(Request request)

Schedules equest to the server. The method does not wait for Response from the server (non-blocking metod). Use getResponse() function to resive the response.

Parameters:

request - Request to send

start

public void start()

Initiate connection to the server and if succeed, causes this thread to begin execution; the Java Virtual Machine calls the run method of this thread.

handleConnectionEstablished

protected abstract void handleConnectionEstablished()

handleConnectionLost

protected abstract boolean handleConnectionLost()

handleResponseToNoRequest

protected void handleResponseToNoRequest(Response response)

handleUnrecoverableError

protected abstract void handleUnrecoverableError(java.lang.Throwable e)

receiveResponse

protected Response receiveResponse()
                            throws java.lang.InterruptedException,
                                   java.io.IOException,
                                   java.lang.ClassNotFoundException

Private static function for receiving a response. Used by static request().

Returns:

Received response

Throws:

java.lang.InterruptedException - Current thread was interrupted

java.io.IOException - An input exception

java.lang.ClassNotFoundException - If we received a class that we haven't localy