JAVA Calculator Tutorial

Clay Gloster/Mustafa Dagtekin

Discussion

Java Calculator is a proof-of-concept demonstration that performs these functions: The addition of two signed 32-bit integers ( range: -32,766 to 32,767), the subtraction of two integers and the multiplication of two numbers. The user can choose to do this locally or remotely with standard software methods including Java and C methods. The remote and local hardware methods are not implemented yet.

If the user chooses to add locally, a simple java statement is executed to perform the operations using C native methods or Java methods. If a remote operation is chosen, things get a bit more complex: the java Calculator client uses the network to ask a JAVA server to execute, on its behalf, a method which takes the two integers as parameters and calls either Java method or C native method.

Download Source Files

Click here to download a zip file of the: 

You will also need the Java Development Kit 

Compiling and running the demo


Read the text file "readme.txt" in the distribution, or see below in Starting the system for instructions. 

The JAVA Client

The client is the portion of the system visible to the user. It is a simple interface that allows for entry of operands, selecting necessary functions, display of various messages, and range/error checking. In the example below, the client is using the "bowlingball" server. 
 

The interface was constructed using the JDK 1.1.5 AWT.

  • The first row is used to select operation type: addition, subtraction, or multiplication
  • The second row is to select either native methods(C) or Java methods to perform the operation. A hardware button is also presented but has not been implemented yet
  • The third row is to select either remote operations or local operations..

    • The JAVA Server

    Ther server is a console application that provides indications of its activities. In the example below, both server and client are running on "bowlingball" 
     

    The server was implemented using the JDK 1.1.5. 

    Starting the system

    A makefile is provided to make things easier. You can examine the makefile and see what is going on inside.
    • To make and run the system use "make HOSTNAME=your_machines_hostname"
    • "make compile" only makes the system
    • "make run" only runs the system
    • "make run_clientonly" only runs the client
    • "make run_serveronly" only runs the server
    Example:

    % cd Calculator 
    % make HOSTNAME=bowlingball.cacc.ncsu.edu 

    If you want to exit the system, use ctrl-c to close rmiregistry and server program, and use "Quit" to close the client.