Sem3CA1

This is the repository for the CA1 project 2017 Group 5

• Thomas Staal, Mads Ibsen & Christian Øst-Jacobsen

The plan for the next four days:

• Day 1-2: Concentrate on developing a chat server which can handle at least two clients. Before the end of day 2 you should demonstrate your server to us!
• Day 3: Concentrate on writing your client and make sure you can connect to your server with multiple clients.
• Day 4: Re-visit your Tomcat server and Nginx proxy and setup the reverse proxy from Nginx to Tomcat. Try to get to a point where you can deploy your chat server to Digital Ocean.

Protocol

This protocol was defined by the students in the class on the 13th of February. You are expected to implement this protocol both on the server and the client, to allow them to communicate. In the client -> server section, the client sends commands to the server which the server reacts upon. In the server -> client section, the server sends messages to all the clients currently logged in.

Convention

1. All commands must be in one line and end with a newline \n character¹
2. No names with # and no messages with #

In the text below the values inside [] is meant to be replaced by a variable. So LOGIN#[USERNAME] would be LOGIN#Lars if your user name is "Lars".

Client -> Server

These messages should arrive to the server from the client.

Command	Description	Definition	Examples
Login	Logs in the client by adding it to the list of participants in the chat room	LOGIN#[USERNAME]	LOGIN#Lars
Message	Sends a message to either everyone the chat room (ALL) or a single client (in this case USERNAME is the receiver)	``MSG#[USER	ALL]#[MESSAGE]``

Logging out a client should be discovered by the server when the TCP connection breaks. That should trigger a DELETE message sent from the server to all the remaining clients.

Server -> Client

These messages should arrive to the client from the server.

Command	Description	Definition	Examples
Ok	Successful login followed by list of active user names	OK#[USER1]#[USER2]#...	OK#Lars#Jens#Donald
Fail	Failed login if user name is already taken or connection error	FAIL	FAIL
Update client list	Update all clients when a single new user logs in	UPDATE#[USERNAME]	UPDATE#Lars
Forward message	Forwards message from a client (USERNAME is now the sender)	MSG#[USERNAME]#[MESSAGE]	MSG#Jens#Hej
Delete user from chat	Tells all clients that a user has disconnected	DELETE#[USERNAME]	DELETE#Lars

¹ Protip: Use a PrintWriter to output your data to the socket OutputStream. It has the println method which prints your message in a single line, ending with a newline character (\n). Similarly you can use a BufferedReader in the receiving end which has the readLine() method, which reads text from the socket until a newline character (\n).

Rapport

Link til rapportskrivning: https://docs.google.com/document/d/12Tht8kcxQ3heicYRQ8Lzg7ZVpxrQObpsN-dpfmtUQFQ/edit