Name: Homework 4 -Message Broker
SKU: 23955
Price: 24.99 USD
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Description

5/5 – (2 votes)

Description

In this assignment, you are going to extend your program in homework 2 and 3 in order to implement a Messenger-like function via message broker.

Example Architecture

NP-Client and NP-Server serve as project 2 & 3. Additionally, there are 6 commands added this time.

This is just an example architecture for your reference. If you have a better design, then you don’t have to follow this architecture.

Requirement

The server accept the following requests. For client side, like project 2 & 3, client program will help user to store their access token.

Therefore, users only need to type their username.

Request Format	Description	Request	Client Output ( usernames or groupnames are
		Status	examples, please output the correct names)

login <id><password>	When user login, your client program	Success	Success!
	should subscribe to all the related
	channels, such as user’s personal
	channel and the groups’ channels that
	user has joined.
	When request fail, your program
	should have the same output message
	as project 2 & 3.

send <token> <friend> <message>	Send message to your friend via	Success	Success!
	message broker.
	● <message> allow spaces

		Fail-A	Not login yet
	The request will success only when
	passing the following rules: (A has the
	highest priority, E has the lowest)

A. You cannot send message with

Fail-B

Usage: send <user> <friend> <message>

an invalid token

B. Correct request format

C. You cannot send to an user who

Fail-C

No such user exist

doesn’t exist.

D. You can only send to your

friend.

Fail-D

userA is not your friend

E. You can only send to online

user, which means that the user

already login, but not logout yet.

Fail-E

userA is not online

create-group <token> <group>

Create a group named <group>

Success

Success!

●

<group> is unique

Fail-A

Not login yet

●

<group> not allowed spaces

Fail-B

Usage: create-group <user> <group>

The request will success only when

Fail-C

EXAMPLE_GROUP already exist

passing the following rules: (A has the

highest priority, C has the lowest)

A. You cannot send message with

an invalid token

B. Correct request format

C. The group name must be

unique.

list-group <token>

List all the groups

Success

group_hello

The request will success only when

group_world

passing the following rules: (A has the

Success

No groups

highest priority, B has the lowest)

(No

groups

A. You cannot send message with

created)

an invalid token

Fail-A

Not login yet

B. Correct request format

Fail-B

Usage: list-group <user>

list-joined <token>

List the groups you already added

Success

group_hello

The request will success only when

group_world

Success (

No groups

passing the following rules: (A has the

No groups

highest priority, B has the lowest)

created)

A. You cannot send message with

Fail-A

Not login yet

an invalid token

Fail-B

Usage: list-joined <user>

B. Correct request format

join-group <token> <group>

Become the member of the group

Success

Success!

The request will success only when

Fail-A

Not login yet

passing the following rules: (A has the

Fail-B

Usage: join-group <user> <group>

highest priority, D has the lowest)

Fail-C

EXAMPLE_GROUP does not exist

A. You cannot send message with

Fail-D

Already a member of EXAMPLE_GROUP

an invalid token

B. Correct request format

C. You cannot join a non-exist

group

D. You cannot join the same group

multiple times

send-group <token> <group>

Send message to onlinegroup

Success

{

members, including yourself.

“status”: 0,

● <message> allow spaces

}

“message”:

“Success!”

The request will success only when

passing the following rules: (A has the

Fail-A

Not login yet

highest priority, D has the lowest)

A. You cannot send message with

Fail-B

Usage: send-group <user> <group> <message>

an invalid token

Fail-C

No such group exist

B. Correct request format

Fail-D

You are not the member of EXAMPLE_GROUP

C. You cannot send message to a

non-exist group

D. You cannot send message to a

group that you didn’t join

General

All the commands in project 2 & 3 must work as before.

You have to setup an ActiveMQ server to forward the messages.

You may have to modify the login feature to integrate with the message broker. For the failing cases, output the same message as project 2 & 3.

You need to implement the rest of the features,to handle all the successful request and failing request.

Your client program must output the correct message according to different commands and different situations.

You server should reply the correct message according to the priorities.

Output format of receiving message from other users

- When USER_A send message “HELLO WORLD” to USER_B, your client program should show the message with following format to USER_B.
  - <<<USER_A->USER_B: HELLO WORLD>>>

- When USER_A send message “HELLO WORLD” to GROUP_A, your client program should show the message with following format with all the group members, including USER_A.
  - <<<USER_A->GROUP<GROUP_A>: HELLO WORLD>>>

Grade (100%)

Receiving send message from other users – (20%)

Receiving send-group message from groups – (20%)

Every commands above except login10% – (60%)

Demo

It’s your responsibility to prepare the demo environment. TA will not help you prepare the environment, including the ActiveMQ. You can either bring your laptop, desktop, or using remote control to run the server.

When it’s your turn to demo, we will ask you to download the version you uploaded to new-e3.

Launch server (ip and port may change during demo): ./server 0.0.0.0 8888

Run with testcase: ./client TARGET_IP TARGET_PORT < testcase > output

Please learn how to run the above commands in your shell, no matter on Windows, Mac, or Linux.

Submit

Please upload a zip file called “hw4_{$student_id}.zip” that includes your source code. Submission that don’t follow the rule will get 20% punishment on the grade.

Demo time will be announced before the deadline. You are not allowed to modify your code after demo. Please submit your code on time.

If you have any questions, please ask your questions on course forum(https://e3new.nctu.edu.tw/)

Reference