Description
Purpose: Writing the Client and Server code
The purpose of Assignment 2 is to build a simple socket based client/server application.
In Part 1 of the assignment you have built the client GUI. In Part 2 of the assignment
you are to write the client and the server code. The server will be a TCP/IP
multithreaded console based application. The application must behave exactly as
specified below and shown in the ClientServerScreenCaptures_F17 .pdf.
Requirements Specification:
Server Implementation
The server implementation must satisfy the following requirements and must behave
as shown in ClientServerScreenCaptures_F17 .pdf.
Requirements:
The server implementation consists of two separate classes: Server and
ServerSocketRunnable.
Class Server
The Server class is responsible for creating a server socket and starting a service
thread responsible for serving each individual client.
The main() method should perform the following tasks:
If command line string is supplied at launch, the method converts the string to an
integer port number. Otherwise, the server must use 65535 as a default port
number.
The method creates a TCP/IP server socket bound to the specified port.
In an endless loop the method calls accept() on the server socket instance.
Once a connection with the client is established, the accept() method will return a
Socket instance. The main() method prints an appropriate message on the
console screen and proceeds (see ClientServerScreenCaptures_F17 .pdf).
In the same loop the main() method creates an instance of
ServerSocketRunnable class passing the socket instance to its constructor.
Finally, in the same loop the main method uses the ServerSocketRunnable
object to create a Thread instance and to start a service thread.
The server does not have a GUI. It must started at the command prompt. In order to
stop the server the user must terminate the Java Virtual Machine (JVM).
CST8221 – JAP, Assignment 2, Part 2, MMXVII Page 2 of 4
Class ServerSocketRunnable
The ServerSocketRunnable class is responsible for communicating with the client and
responding to the command strings sent by the client. The class must implement the
Runnable interface. The class must have a single constructor taking a reference to a
Socket object as a parameter.
The server request line (string) sent by the client must have the following syntax:
-COMMAND-optional command string
In this implementation, the only supported COMMANDs are: quit, echo, time,
date, help and clrs. The commands are case sensitive. Any command can have
an optional string. Allcommand must start with a dush – (minus sign). If the command
conatins an optional string the command must end with a dash – .
Command examples (see ClientServerScreenCaptures_F17.pdf):
-time
-echo- Testing connection
-help-asking for help
The run() method should perform the following tasks:
It opens input and output streams.
Note: I have used ObjectOutputStream and ObjectInputStream in my
implementation, but you are free to use any stream of your choosing.
In a loop that repeats until the quit command is sent by the client, the run()
method first reads the command string sent by the client.
The method extracts the COMMAND from the command string and depending
on the COMMAND it writes back to the client.
(See ClientServerScreenCaptures_F17.pdf).
If the COMMAND is echo, the method writes back the following string:
ECHO: optional command parameter string
If the COMMAND is time, the method writes back the following string:
TIME: current hour:current minutes:current seconds AM or PM
If the COMMAND is date, the method writes back the following string:
DATE: day number month name year number
If the COMMAND is help, the method writes back the following string:
Available Services:
quit
echo
time
date
help
clrs
If the COMMAND is clrs, the method writes back the string clrs. If the Client
receives the clrs string from the server, it must clear the terminal screen.
If the COMMAND is quit, the method exits the loop, prints a message, notifies
the client, closes the streams and the client socket, and terminates
At the end of each of the loop iterations, the tread sleeps for 100 milliseconds.
CST8221 – JAP, Assignment 2, Part 2, MMXVII Page 3 of 4
The run() method must handle all possible exceptions and display an appropriate
message on the console screen. The Server and the run() method must not crash.
Client Implementation
In this part of the assignment you must implement the event handling part the client
GUI application. Before writhing the code, read the requirements and see the Client
screen captures in ClientServerScreenCaptures_F17.pdf.
The server implementation must satisfy the following requirements and must behave as
shown in ClientServerScreenCaptures_F17.pdf.
Requirements:
All messages generated by the client must be displayed in the display area of the
GUI. No messages must be displayed on the Console screen.
At launch, the Connect button must be red and enabled, and the Send button
must be disabled. The display area must be empty.
When the user clicks the Connect button, the client should try to connect to the
server using the specified host and port number. To avoid making your GUI
irresponsive a timeout socket connection must be used.
If the connection is successful, input and output streams should be open, an
appropriate message should be displayed (ClientServerScreenCaptures_F17
.pdf), the Connect button should be disabled and changed to blue in color, and
the Send button should be enabled.
If for some reason the connection to the server is unavailable or becomes
unavailable (for example, the server receives the quit command), an
appropriate message should be displayed (ClientServerScreenCaptures_F17
.pdf), the Connect button should be enabled, and the Send button should be
disabled.
When the user types a command line string (see above the expected syntax of
the command string) and clicks the Send button, the command line string must
be sent to the server, and the server response string must be displayed
(ClientServerScreenCaptures_F17.pdf) in the display area of the GUI.
When the connection session is terminated, the Connect button should be
enabled, and the Send button should be disabled.
The event handler must handle all possible exceptions and display an
appropriate message in the display area of the GUI.
(ClientServerScreenCaptures_F17.pdf). The Client must not crash and the
event handler generate exceptions in the Console window.
Note: If you use only one event handler that implements the ActionListener interface,
you should use getSelectedItem() to get the port number from the combo box.
CST8221 – JAP, Assignment 2, Part 2, MMXVII Page 4 of 4
Bonus Task 1 (1% of your course mark):
Use an appropriate thread pool and the Executor Framework to manage the server
threads.
Reference: Textbook, Chapter 23, Section 26.3
Bonus Task 2 (2.0% of your course mark):
Use a thread to manage the client part of the connection. The implementation must
comply with Rule #1 and Rule #2 outlined in HybridAct 11.
For full bonus mark you must use a BlockingQueue to send the client’s command to the
communication thread.
Reference: Textbook, Chapter 23, Section 23.11, HybridAct 11, and Lab 12.
Note: In order to have the bonus marks added to your assignment
mark your application must work as specified and must not crash or
generate uncaught exceptions. The bonus implementation must be
documented in a text file named README_FIRST.txt
What to Submit:
Paper submission:
No paper submission is required for this assignment.
Code submission:
Compress in one .zip file all relevant to the assignment .java and .class files (plus
the README_FIRST.txt for the bonus(es)). Upload the assignment zip file to
Blackboard prior to or on the due date. The name of the zip file must have the
following structure: Student’s family name followed by the last three digits of the
student ID number followed by _JAP_A2P2. For example, Ranev_JAP_A2P2.zip.
The submission must follow the course submission standards. The Assignment
Submission Standard and the Assignment Marking Guide are posted on
Blackboard.
.
Enjoy the assignment. And do not forget that:
“To serve a client you ought to have a server first.” Business Rule #2
