COMP4320 Objective of this assignment: Solution

What you need to do:
1. Implement a simple UDP Client-Server application (Programming Assignment 2) 2. Implement a simple TCP Client-Server application (Programming Assignment 3)

Objective:
For this programming assignment, you are advised to start from the Friend client and server application to implement the calculator server. You will first implement the calculator server using UDP (Programming Assignment 2), and then TCP (Programming Assignment 3).

Part A: Datagram socket programming (Programming Assignment 2)
The objective is to design a Calculating Server (CS). This calculating server performs bitwise boolean and arithmetic computations requested by a client on 16-bit signed integers. Your server must offer the following operations: 1) addition (+), 2) subtraction (-), 3) bitwise OR (|), 4) bitwise AND (&), 5) Shift Right (>>), and 6) Shift Left (<<). A client request will have the following format:
Field TML Request ID Op Code Number Operands Operand 1 Operand 2
Size (bytes) 1 1 1 1 2 2

Where
1) TML is the Total Message Length (in bytes) including TML. It is an integer representing the total number of bytes in the message.
3) Op Code is a number specifying the desired operation following this table
Operation + - | & >> << ~
OpCode 0 1 2 3 4 5 6

4) Number Operands is the number of operands: 2 for (+, -, |, &) and shifts. It is 1 for ~ (NOT).
5) Operand 1: this number is the first or unique operand for all operations.
6) Operand 2: this number is the second operand for operations (+, -, |, &, <<, >>). It is the number of bits to shift by for the shift operations. This operand does NOT exist for the ~ (NOT) operation.

Operands are sent in the network byte order (i.e., big endian).
Hint: create a class object Request like "Friend", but with the information needed for a request.....

Below are two examples of requests

Request 1: suppose the Client requests to perform the operation 240 >> 4, i.e., shift the number 240 right by 4 bits (if this is the 7th request):
0x08 0x07 0x04 0x02 0x00 0xF0 0x00 0x04

Request 2: suppose the Client requests to perform the operation 240 – 160 (if this is the 9th request):
0x08 0x09 0x01 0x02 0x00 0xF0 0x00 0xA0

The Server will respond with a message with this format:
Total Message Length (TML) Request ID Error Code Result
one byte 1 byte 1 byte 4 bytes

Where
1) TML is the Total Message Length (in bytes) including TML. It is an integer representing the total numbers of bytes in the message.
2) Request ID is the request ID. This number is the number that was sent as Request ID in the request sent by the client.
3) Error Code is 0 if the request was valid, and 127 if the request was invalid (Length not matching TML). 4) Result is the result of the requested operation.


In response to Request 1 below
0x08 0x07 0x04 0x02 0x00 0xF0 0x00 0x04

the server will send back:
0x07 0x07 0x00 0x00 0x00 0x00 0x0F

In response to Request 2,
0x08 0x09 0x01 0x02 0x00 0xF0 0x00 0xA0

the server would send back:
0x07 0x09 0x00 0x00 0x00 0x00 0x50

a) Repetitive Server: Write a datagram Calculating Server (ServerUDP.java) in java. This server must respond to requests as described above. The server must run on port (10010+GID) and could run on any machine on the Internet. GID is your Canvas team #. The server must accept a command line of the form: java ServerUDP portnumber where portnumber is the port where the server should be working. For example, if your Group ID (GID) is 13 then your server must listen on Port # 10023.
Whenever a server gets a request, it must:
i. print the request one byte at a time in hexadecimal (for debugging and grading purpose)
ii. print out the request in a manner convenient for a typical Facebook user: the request ID and the request (operands and required operation)

b) Write a datagram client (ClientUDP.java) in java:
i. Accepts a command line of the form: java ClientUDP servername PortNumber where servername is the server name and PortNumber is the port number of the server. Your program must prompt the user to ask for an Opcode, an Operand1 and if needed an Operand2 where OpCode is the opcode of the requested operation (See the opcode table). Operand1 and Operand2 (if applicable) are the operands. For each entry from the user, your program must perform the following operations: ii. form a message as described above iii. send the message to the server and wait for a response
iv. print the message one byte at a time in hexadecimal (for debugging and grading purpose)
v. print out the response of the server in a manner convenient for a typical Facebook user: the request ID and the response
vi. print out the round trip time (time between the transmission of the request and the reception of the response)
vii. prompt the user for a new request.
Repeat part A using TCP sockets to produce (ServerTCP.java, ClientTCP.java).



How to get started?
1) Download all files (UDP sockets) to run the "Friend" application used in Module 2 to illustrate how any class object can be exchanged: Friend.java, FriendBinConst.java, FriendDecoder.java, FriendDecoderBin.java, SendUDP.java, and RecvUDP.java.
2) Compile these files and execute the UDP server and client. Make sure they work
3) Create a new folder called Request and duplicate inside it ALL files related to the Friend class object
4) Inside the Folder Request, change ALL occurrences of "Friend" with "Request" including the file names.
3) Adapt each file to your calculator application. Replace the fields used by Friend with the fields used by a request. 4) Aim to have the client send one request and have the server understand it (just like what we did with a friend object).
5) When your server will receive and print out correctly a request, then you need to send back a response... 6) Create a class object Response....



Report
• Write a report. The report should not exceed two pages.
• Your report state: whether your programs work or not (this must be just ONE sentence). If your program does not work, explain the obstacles encoutered.

What you need to turn in:
• Electronic copy of all your source programs (standalone). In addition, put all the source programs in a folder that you name with your concatenated last name and first name. Zip the folder and submit it TOO. The grader should see on Canvas all your source programs separately AND a zip folder containing all the source programs needed to compile and execute your program.
• Electronic copy of the report (including your answers) (standalone). Submit the file as a Microsoft Word or PDF file.

Grading
1) UDP/TCP client is worth 40% if it works well: communicates with YOUR server. Furthermore, screenshots of your client and server running on Tux machines must be provided. The absence of screenshots or screenshots on machines other than the Tux machines will incur a 15% penalty.

2) UDP/TCP client is worth 10% extra if it works well with a working server from any of your classmates.

1) UDP/TCP server is worth 40% if it works well: communicates with YOUR client. Furthermore, screenshots of your client and server running on Tux machines must be provided. The absence of screenshots or screenshots on machines other than the Tux machines will incur a 15% penalty.

2) UDP/TCP server is worth 10% extra if it works well with a working client from any of your classmates.