Can someone please explain to me ASAP??import java.io.*; import java.net.*; class SimpleTextClient { public static void main(String argv[]) throws Exception { BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in)); Socket clientSocket = new Socket("127.0.0.1", 8000); DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream()); BufferedReader inFromServer = new BufferedReader(new InputStreamReader( clientSocket.getInputStream())); while (true) { System.out.println("
You are connected to the Server."); System.out.println("
0. Log in to the server
1. Get the user list
2. Send a message
3. Get my messages
4. Exit"); System.out.print("
Enter your option: "); String option = inFromUser.readLine(); outToServer.writeBytes(option + "
"); switch (option) { case "0": System.out.print("Enter your username: "); String username = inFromUser.readLine(); System.out.print("Enter your password: "); String password = inFromUser.readLine(); outToServer.writeBytes(username + "
"); outToServer.writeBytes(password + "
"); String response = inFromServer.readLine(); System.out.println(response); break; case "1": System.out.println("User List:"); String user = inFromServer.readLine(); System.out.println(user); break; case "2": System.out.print("Enter the receiver's username: "); String receiver = inFromUser.readLine(); System.out.print("Enter your message: "); String message = inFromUser.readLine(); outToServer.writeBytes(receiver + "
"); outToServer.writeBytes(message + "
"); break; case "3": System.out.println("Your messages:"); String answer = inFromServer.readLine(); System.out.println(answer); break; case "4": clientSocket.close(); } if (option.equals("4")) { break; } } } }import java.io.*; import java.net.*; class SimpleTextServer { public static void main(String argv[]) throws Exception { ServerSocket welcomeSocket = new ServerSocket(8000); System.out.println("SERVER is running ... "); while(true) { Socket connectionSocket = welcomeSocket.accept(); BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream())); DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream()); String option; while (true) { System.out.println("waiting..."); option = inFromClient.readLine(); switch (option) { case "0": System.out.println("The option is " + option); String username = inFromClient.readLine(); System.out.println("The username is " + username); String password = inFromClient.readLine(); System.out.println("The password is " + password); outToClient.writeBytes("Access Granted
"); break; case "1": System.out.println("The option is " + option); outToClient.writeBytes("Alice Bob
"); System.out.println("Alice Bob"); break; case "2": System.out.println("The option is " + option); String receiver = inFromClient.readLine(); System.out.println("The receiver is " + receiver); String message = inFromClient.readLine(); System.out.println("The message is " + message); break; case "3": System.out.println("The option is " + option); outToClient.writeBytes("No message
"); break; case "4": connectionSocket.close(); break; } if (option.equals("4")) { break; } } } }} 2. InstructionWrite a server program and a client program. The server manages a number ofclient accounts, each having a username and a password. The server programstarts first. When a client process is started, it repeatedly shows the followingmenu to the user and asks the user for an option:0. Connect to the server1. Get the user list2. Send a message3. Get my messages4. ExitIf the user chooses Option 0, the client program establishes a TCP connectionwith the server. Then, it prompts the user for their username and password tolog in. The client program then sends the credentials to the server to verify. Ifwhat the user entered matches the username and password stored at the server,grant the user access by printing "Access Granted" at the client. Otherwise, print"Access Denied - Username/Password Incorrect", and keep asking the user forthe credentials until the user gets them correct to successfully log onto theserver.If the user chooses Option 1, the client program receives the list of usernamesfrom the server and print them out to the user.If the user chooses Option 2, the user can leave text message to another user.The client program sends this text message to the server and the server will storeit.If the user chooses Option 3, the user can retrieve their own text messages thatwere left by other users at the server. The client program will display thosemessages to the user.If the user chooses Option 4, the client program terminates the TCP connectionwith the server and exit.3. Sample CodeWe provide sample code for a simple server program and a client program. Theclient establishes a TCP connection with the server, and sends a message to theserver, which will send a capitalized message back to the client for display.Essentially, it gives you a programming template that you can follow to writeyour own networking program.4. TestingUse the following scenario for testing. The server maintains two client accounts:One is for Alice and the password is "1234"; the other is Bob and thepassword is "5678". Alice logs onto the server first. She gets the user list from theserver and sees Bob. She sends a text message to Bob and exit from the clientprogram. Next, Bob logs onto the server. He then retrieves his text messages leftby Alice, and exits from the client program.

Question

Can someone please explain to me ASAP??import java.io.*; import java.net.*; class SimpleTextClient {   public static void main(String argv[]) throws Exception    {      BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));      Socket clientSocket = new Socket(&#34;127.0.0.1&#34;, 8000);       DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());       BufferedReader inFromServer = new BufferedReader(new InputStreamReader( clientSocket.getInputStream()));            while (true) {         System.out.println(&#34;
You are connected to the Server.&#34;);         System.out.println(&#34;
0. Log in to the server
1. Get the user list
2. Send a message
3. Get my messages
4. Exit&#34;);         System.out.print(&#34;
Enter your option: &#34;);         String option = inFromUser.readLine();         outToServer.writeBytes(option + &#34;
&#34;);                  switch (option) {               case &#34;0&#34;:                  System.out.print(&#34;Enter your username: &#34;);                  String username = inFromUser.readLine();                  System.out.print(&#34;Enter your password: &#34;);                  String password = inFromUser.readLine();                  outToServer.writeBytes(username + &#34;
&#34;);                  outToServer.writeBytes(password + &#34;
&#34;);                  String response = inFromServer.readLine();                  System.out.println(response);                  break;               case &#34;1&#34;:                  System.out.println(&#34;User List:&#34;);                  String user = inFromServer.readLine();                                    System.out.println(user);                  break;               case &#34;2&#34;:                  System.out.print(&#34;Enter the receiver's username: &#34;);                  String receiver = inFromUser.readLine();                  System.out.print(&#34;Enter your message: &#34;);                  String message = inFromUser.readLine();                  outToServer.writeBytes(receiver + &#34;
&#34;);                  outToServer.writeBytes(message + &#34;
&#34;);                  break;               case &#34;3&#34;:                  System.out.println(&#34;Your messages:&#34;);                  String answer = inFromServer.readLine();                  System.out.println(answer);                  break;               case &#34;4&#34;:                  clientSocket.close();         }         if (option.equals(&#34;4&#34;)) {            break;         }      }   } }import java.io.*; import java.net.*; class SimpleTextServer {   public static void main(String argv[]) throws Exception    {      ServerSocket welcomeSocket = new ServerSocket(8000);       System.out.println(&#34;SERVER is running ... &#34;);      while(true) {         Socket connectionSocket = welcomeSocket.accept();         BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));          DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());         String option;                  while (true) {            System.out.println(&#34;waiting...&#34;);            option = inFromClient.readLine();            switch (option) {               case &#34;0&#34;:                  System.out.println(&#34;The option is &#34; + option);                  String username = inFromClient.readLine();                  System.out.println(&#34;The username is &#34; + username);                  String password = inFromClient.readLine();                  System.out.println(&#34;The password is &#34; + password);                  outToClient.writeBytes(&#34;Access Granted
&#34;);                  break;               case &#34;1&#34;:                  System.out.println(&#34;The option is &#34; + option);                  outToClient.writeBytes(&#34;Alice Bob
&#34;);                  System.out.println(&#34;Alice Bob&#34;);                        break;               case &#34;2&#34;:                  System.out.println(&#34;The option is &#34; + option);                  String receiver = inFromClient.readLine();                  System.out.println(&#34;The receiver is &#34; + receiver);                  String message = inFromClient.readLine();                  System.out.println(&#34;The message is &#34; + message);                       break;               case &#34;3&#34;:                  System.out.println(&#34;The option is &#34; + option);                  outToClient.writeBytes(&#34;No message
&#34;);                        break;               case &#34;4&#34;:                  connectionSocket.close();                  break;            }            if (option.equals(&#34;4&#34;)) {               break;            }         }      }   }} 2. InstructionWrite a server program and a client program. The server manages a number ofclient accounts, each having a username and a password. The server programstarts first. When a client process is started, it repeatedly shows the followingmenu to the user and asks the user for an option:0. Connect to the server1. Get the user list2. Send a message3. Get my messages4. ExitIf the user chooses Option 0, the client program establishes a TCP connectionwith the server. Then, it prompts the user for their username and password tolog in. The client program then sends the credentials to the server to verify. Ifwhat the user entered matches the username and password stored at the server,grant the user access by printing &#34;Access Granted&#34; at the client. Otherwise, print&#34;Access Denied - Username/Password Incorrect&#34;, and keep asking the user forthe credentials until the user gets them correct to successfully log onto theserver.If the user chooses Option 1, the client program receives the list of usernamesfrom the server and print them out to the user.If the user chooses Option 2, the user can leave text message to another user.The client program sends this text message to the server and the server will storeit.If the user chooses Option 3, the user can retrieve their own text messages thatwere left by other users at the server. The client program will display thosemessages to the user.If the user chooses Option 4, the client program terminates the TCP connectionwith the server and exit.3. Sample CodeWe provide sample code for a simple server program and a client program. Theclient establishes a TCP connection with the server, and sends a message to theserver, which will send a capitalized message back to the client for display.Essentially, it gives you a programming template that you can follow to writeyour own networking program.4. TestingUse the following scenario for testing. The server maintains two client accounts:One is for Alice and the password is &#34;1234&#34;; the other is Bob and thepassword is &#34;5678&#34;. Alice logs onto the server first. She gets the user list from theserver and sees Bob. She sends a text message to Bob and exit from the clientprogram. Next, Bob logs onto the server. He then retrieves his text messages leftby Alice, and exits from the client program.

Accepted Answer

In this question we have to understand and explain the provided Java Code with description and…