CSE 4/586 Distributed Systems Fall 2004Project 1: Designing and deploying a Web ServicePurpose: 1. To understand the components, the core technologies, the architecture and the protocols enabling a Web Services-based distributed system.2. To design and implement a Web Service. 3. To understand the elaborate and complex process of preparing and deploying a remote service.Preparation before lab:1. Read and study the Web Services architecture and the associated protocols: http://www.w3.org/2002/ws/There is another article available as a first chapter of the Web Services tutorial offered by Sun Microsystems at http://java.sun.com/webservices/tutorial.html2. Learn how to use the XML-based build tool Ant at http://ant.apache.org/3. Understand the role of deployment descriptors. The deployment descriptors are XML files used to configure runtime properties of an application thus relieveing application to deal only with the programmatic details. A simple reading on deployment descriptors can be found at http://java.sun.com/webservices/docs/ea1/tutorial/doc/WebApp4.html4. Learn to use the application interface to the Oracle database using embedded SQL andJDBC.5. Finally, you must have a clear understanding of a client-server system operation.Web Services Technology:Web Services technology provides a standard means of buidling a distributed systemover the Internet. In simple terms, it provides a means for a sophisticated remoteprocedure call. The sophistication arises out of the elegant mechanisms it supports forenabling (i) various transparencies (platform, language, and hardware) (ii) application toapplication data exchange and interoperability, and (iii) composability of complex webservices from a set of simple web services. The significant difference between theregurlar HTTP-based technologies and Web Servcies is the standardization realizedthrough the XML and SOAP ( SOAP, XML over HTTP). Web Services DefinitionLanaguage (WSDL) is an important standard supported that allows for standarddefinition of services. All these make Web Services technology ideally suited for large-scale enterprise level application integration. Web Servcies specification is defined by World Wide Web (W3) consortium in terms of(i) Web Servcies architecture requirements, (ii) Web Services architecture, (iii) WebServices glossary, and (iv) Web Services architecture usage services. Many vendorsincluding Sun Microsystems (Sun One) and Microsoft (.net) have frameworks forbuilding and deploying Web Services.Assignment:Build a multi-tier distributed system comprising two major sub-system (i) an RMI andsimple data acquisition system and (ii) a Web Services based web application processingand serving the data collected. The two sub-systems are loosely coupled via a database.The block diagram of the system you will implement is given in Figure 1. The RMI partof the project is adapted from the Weather servcie problem described in the fourth editionof Java: How to Program? By Deitel and Deitel.Figure 1: System Architecture of the Weather ServiceThe national weather bureau updates the weather condiions at various cities once everyon its web site (box 1 in Figure 1) at http://iwin.nws.noaa.gov/iwin/us/traveler.html . TheRMI Server (box 2) streams in the page and parses it for the relevant data and stores it ina persistent storage. (The details of the RMI and existing code base and a simple framework were discussed during the lecture and are available athttp://www.cse.buffalo.edu/gridforce/CSE486fall2004.htm) The persistent storage in thesample code is a simple file and the data stored is just the weather data for one day. Youare required to update the code to accumulate the data for a period of over at least 1 week(or any 7 days). The data collected will be stored in a relational data base (box 4) onOracle 9i. The daily data in the sample code is served to an RMI client (box 3) whichNational Weather Service Web Site RMI WeatherInfo ServerRMI WeatherInfo ClientApplication RMIIP Socket APIWeather Web Service Web ClientWeather Web ServiceContainer/ServerRelation DatabaseOracle 9ihttphttpSOAPXMLLAN123456simply renders the ASCII data provided by the weather bureau by transforming it usingvisually appealing graphics. In the Web Services part of the system in Figure 1, the data collected in the data base willbe processed by the server (box 5) for such information as average temperature for agiven city, and the temperature for a particular date for a city. The Web Services client(box 6) will be able to query the server for various information related to the datacollected. Your task is to design and implement the complete Web Services-based systemindicated by boxes 4, 5 and 6 of Figure 1 and study the operation of the integrated systemdepicted in Figure 1.Project Implementation Details and Steps:1. Getting used to building client-server systems: When you implement a simplecient side application program there are just two steps involved: compile andexecute the code. In a client-server system, you will have to take care the serverside as well as the client side. On the server side, you will compile the code,generate stubs or proxies using special compilers, deploy the service, register andpublicize the service for the clients to use. On the client side you will prepare theclient code with appropriate stubs, and during excution lookup the service neededand use it. To understand the process study the RMI-based system code andimplementation. Deploy it and make sure it works and you understand the variousoperations. You will notice that besides simple compile and execute, configurationand deployment of a service are important issues to be reckoned with. Use thelatest version of RMI.2. Working with the relational database and embedded SQL: In this project youwill store the data in a relational table and access it using SQL statementsembedded in Java lanaguage. Work on a simple java program to refresh yourknowledge about accessing the Oracle database. Seehttp://www.cse.buffalo.edu/local/Consulting/UNIX/Oracle.html for examples andaccess details.3. Building systems using build tools such as Ant: In order to tackle complexitiesin configuration and