5.2.3Java =>High-level Language:
A high-level programming language developed by Sun Microsystems. Java was originally called OAK, and was designed for handheld devices and set-top boxes. Oak was unsuccessful so in 1995 Sun changed the name to Java and modified the language to take advantage of the burgeoning World Wide Web.
Java is an object-oriented language similar to C++, but simplified to eliminate language features that cause common programming errors. Java source code files (files with a .java extension) are compiled into a format called bytecode (files with a .class extension), which can then be executed by a Java interpreter. Compiled Java code can run on most computers because Java interpreters and runtime environments, known as Java Virtual Machines (VMs), exist for most operating systems, including UNIX, the Macintosh OS, and Windows. Bytecode can also be converted directly into machine language instructions by a just-in-time compiler (JIT).
Java is a general purpose programming language with a number of features that make the language well suited for use on the World Wide Web. Small Java applications are called Java applets and can be downloaded from a Web server and run on your computer by a Java-compatible Web browser, such as Netscape Navigator or Microsoft Internet Explorer.
Object-oriented software development matured significantly during the past several years. The convergence of object-oriented modeling techniques and notations, the development of object-oriented frameworks and design patterns, and the evolution of object-oriented programming languages have been essential in the progression of this technology.
Object-Oriented Software Development using Java: Principles, Patterns, and Frameworks contains a very applied focus that develops skills in designing software-particularly in writing well-designed, medium-sized object-oriented programs. It provides a broad and coherent coverage of object-oriented technology, including object-oriented modeling using the Unified Modeling Language (UML) object-oriented design using Design Patterns, and object-oriented programming using Java.
TheÂ NetBeans PlatformÂ is a reusableÂ frameworkÂ for simplifying the development ofÂ Java SwingÂ desktop applications. The NetBeans IDE bundle for Java SE contains what is needed to start developing NetBeans plugins and NetBeans Platform based applications; no additional SDK is required.
Applications can install modules dynamically. Any application can include the Update Center module to allow users of the application to downloadÂ digitally-signedÂ upgrades and new features directly into the running application. Reinstalling an upgrade or a new release does not force users to download the entire application again.
The platform offers reusable services common to desktop applications, allowing developers to focus on the logic specific to their application. Among the features of the platform are:
User interface management (e.g. menus and toolbars)
User settings management
Storage management (saving and loading any kind of data)
Wizard framework (supports step-by-step dialogs)
NetBeans Visual Library
Integrated Development Tool
WAMPs are packages of independently-created programs installed on computers that use aÂ Microsoft WindowsÂ operating system. WAMP is an acronym formed from the initials of the operating system Microsoft Windows and the principal components of the package:Apache,Â MySQLÂ and one ofÂ PHP,Â PerlÂ orÂ Python. Apache is aÂ web server. MySQL is an open-source database. PHP is a scripting language that can manipulate information held in a database and generate web pages dynamically each time content is requested by a browser. Other programs may also be included in a package, such asÂ phpMyAdminÂ which provides a graphical user interface for the MySQL database manager, or the alternative scripting languages Python or Perl. Equivalent packages areÂ MAMPÂ (for the Apple Mac) andÂ LAMPÂ (for the Linux operating system).
5.3 MODULE DESCRIPTION
5.3.1 Client-Server Initiation:
In this module,first present the protocol for communication between a single client and a server . In the subsequent section, we describe the BIGWHEEL algorithm that enables multiparty communication. Without loss of generality, one server is considered throughout the presentation for readability issues. For the situation of multiclient and multiserver, clients and servers follow the algorithms for the clients and servers, respectively.
Client in the contact initiation part is, Client has succeeded in finding the first port to contact Server, without the need of having Server keep some “wellknown” ports open, nor Client relying on a third party to get the port information; and Client gets the seed from Server for the pseudorandom function to compute the port sequence. After the contact-initiation part, the application data from Client to S is sent out to the open ports of Server that change every time.
Client server initiation can be done by port hopping algorithm. Here sending and receiving time of contact initiation message is stored in the server.Intervals of Port number select randomly. Send contact initiation message to each of the port in the chosen interval.The data to be transferred is selected from the existing files.One of the encryption algorithm, that is RSA is used to encrypt the data into unknown format.Then the encrypted data will be send through different port and it reach server.
In this Module, Client sends data messages to the worker ports of Server. After Client gets the reply from the server in the contact-initiation part, Client has the seed for the pseudorandom function to generate the sequence of the worker ports. The open interval of the worker ports is time unit. The new worker port will be opened time units earlier than the closing time of the old one.
When Server receives the contact-initiation messages from Client, it will send the reply message at the time when the next worker port is opened,and then generating next port.When client gets the reply from server immediately it aill send the data. The encrypted data is chosen to send from the client to the server.During data transfer client port number automatically change with respect to the time interval.The data is transferred through various ports and reaches the server.