This document contains code for a simple client-server calculator application that performs arithmetic operations over TCP. The client code allows a user to enter equations like "operand1 operator operand2" and sends them to the server. The server code receives the equations, uses StringTokenizer to split them into operands and operators, performs the calculation, and sends the result back to the client. The client then displays the answer to the user. Both the client and server use DataInputStream and DataOutputStream for communication and Socket for the TCP connection.

1. Assignmentmultithread
Clientside
// Javaprogram to illustrate ClientSideProgramming
// forSimple CalculatorusingTCP
importjava.io.DataInputStream;
importjava.io.DataOutputStream;
importjava.io.IOException;
importjava.net.InetAddress;
importjava.net.Socket;
importjava.util.Scanner;
publicclassCalc_Client
{
publicstaticvoidmain(String[] args) throwsIOException
{
InetAddressip=InetAddress.getLocalHost();
intport = 4444;
Scannersc = newScanner(System.in);
// Step1: Open the socketconnection.
Sockets = newSocket(ip,port);
// Step2: Communication-getthe inputandoutputstream
DataInputStreamdis= new DataInputStream(s.getInputStream());
DataOutputStreamdos= new DataOutputStream(s.getOutputStream());
while (true)

2. {
// Enterthe equationinthe form-
// "operand1operationoperand2"
System.out.print("Enterthe equationinthe form:");
System.out.println("'operandoperatoroperand'");
Stringinp= sc.nextLine();
if (inp.equals("bye"))
break;
// sendthe equationtoserver
dos.writeUTF(inp);
// waittill requestisprocessedandsentbackto client
Stringans = dis.readUTF();
System.out.println("Answer="+ans);
}
}
}
=====================================================================================
serverside
// Javaprogram to illustrate ServerSide Programming
// forSimple CalculatorusingTCP
importjava.io.DataInputStream;

3. importjava.io.DataOutputStream;
importjava.io.IOException;
importjava.net.ServerSocket;
importjava.net.Socket;
importjava.util.StringTokenizer;
publicclassCalc_Server
{
publicstaticvoidmain(Stringargs[]) throwsIOException
{
// Step1: Establishthe socketconnection.
ServerSocketss= newServerSocket(4444);
Sockets = ss.accept();
// Step2: Processingthe request.
DataInputStreamdis= new DataInputStream(s.getInputStream());
DataOutputStreamdos= new DataOutputStream(s.getOutputStream());
while (true)
{
// waitforinput
Stringinput= dis.readUTF();
if(input.equals("bye"))
break;
System.out.println("Equationreceived:-"+input);
intresult;

4. // Use StringTokenizertobreakthe equationintooperandand
// operation
StringTokenizerst= new StringTokenizer(input);
intoprnd1 = Integer.parseInt(st.nextToken());
Stringoperation= st.nextToken();
intoprnd2 = Integer.parseInt(st.nextToken());
// performthe requiredoperation.
switch(operation) {
case "+":
result= oprnd1 + oprnd2;
break;
case "-":
result= oprnd1 - oprnd2;
break;
case "*":
result= oprnd1 * oprnd2;
break;
default:
result= oprnd1 / oprnd2;
break;
}
System.out.println("Sendingthe result...");
// sendthe resultbackto the client.
dos.writeUTF(Integer.toString(result));
}

5. }
}