Java programming and networking

Programming Assignment

Client-Server

1) Write a client socket program to communicate with EchoServer.java program from chapter 9 of Java Network Programming.

2) Modify the Chat program to use multithreading.

3) Write a phone book server, and a client that goes along with it.

The server should wait on a well-known port, waiting for a connection from a client. The server understands two commands, "PUT name phoneNumber" and "GETname". The PUT operation adds the name and phone number to a hashtable. 

The server read information (name, phone#) from a file “phone.txt” and store them in a hash. This means that the phonebook server will start off with entries from the file, and have entries added to it as users interact with the phonebook. When the server shuts down, all the entries should be saved in the file.

The client should add several entries to the phonebook, then retrieve a few. It should also attempt to retrieve an entry that doesn't exist, and send a command that the server does not understand. (That is, something besides GET or PUT.)