簡易實作 Java TCP, UDP 的客戶端與服務端（計算機網路）
With a TCP Server provided to you, we’re going to construct a client to communicate with it. Fig. 1:1 describes the messages sent between client and server.
This code can 1) read the message sent from server and 2) send the user:input message to the server. There will be 5 messages from server and 4 messages sent to the server alternatively like Fig 1:1.
In this experiment, we consider a UDP server and a UDP client. If the client sends 10000 packets back to back to the server (i.e. continually send 10000 packets), we discuss about how many packets will the server receive, and how many of them are lost.