DOCSLIB.ORG

Active Server Pages Architecture

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Active Server Pages Architecture Active Server Pages Architecture Li Yi South Bank University Contents 1. Introduction ...................................................................................................................................... 2 1.1 Host-based databases ............................................................................................................... 2 1.2 Client/server databases ............................................................................................................ 2 1.3 Web databases........................................................................................................................... 3 2. Active Server Pages ........................................................................................................................ 5 2.1 ASP Components ...................................................................................................................... 6 2.2 ADO and Database................................................................................................................... 7 2.3 The steps of executing a query ............................................................................................. 11 3 ASP Attributes ................................................................................................................................ 12 References:.......................................................................................................................................... 13 1 1. Introduction The development of databases always comes with the newer and better hardware and the demand for applications that match the new hardware. In the past 20 years, we have seen the development of databases not only in DBMS, but also in the evolution of database connectivity, which is from centralised computing to Client/Server computing. These client/server structure databases have a great impact to the use of databases. 1.1 Host-based databases The host-based databases are performed on one computer system with attached unintelligent, "dumb," terminals. A limited number of users can only connect to the databases running on the monolithic mainframe through the dumb monitors. There is no friendly interface at all for the users. When the users want to do queries, they must know schema of the databases clearly. What they have typed in will send to the mainframe without any processing. The application of databases will do everything. As a result, the users of the databases will be limited because each user occupies resource of the mainframe independently, even worse the mainframe will be easily overloaded because it will do everything from any trivial things to complicated businesses queries. The performance of the databases will be very poor when the users climbs up to a certain number. 1.2 Client/server databases When the number of users accessing a database grows too high or when too many features are integrated into the database, it is increasingly possible that the centralising database model fails. And with the proliferation of low-cost hardware, especially the advent of cheap PCs, client/server databases have gained popularity in the recent years. 2 Client/server has revolutionised the way of designing and building databases applications. It splits the processing load between clients and servers to get the best of both worlds. A database application is two-tier or three-tier based on the separation of the application logic from the Graphic User Interface (GUI) and the database. In a two-tier client/server database, the application logic is buried either inside GUI on the client (fat client) or within the database on the server (fat server) or both. A user runs a GUI on the client, and then sends queries over a network to a database server. The database server processes the request and returns a result. Simplicity is a good feature of two-tier databases, the two-tier databases are easier to develop than the three-tier or N-tier for small databases. But the databases do not scale well. Many SQL statements are sent over the network and selected data must be downloaded for analysis on the client. When new and more stringent requirements must be introduced into databases, two-tier databases become exponentially harder to develop and normally failed. Three-tier was designed to meet this new challenge. In a three-tier or N-tier (more than three tiers) client/server database, the application logic (or process) lives in the middle-tier. Instead of interacting with the database server directly, the client calls business logic on the server. The business logic then accesses the database on the client's behalf. Only service requests and responses are sent between the client and server, so it performs much well than two-tier. It also provides better security by not exposing the database schema to the client and by enabling more fine-grained authorisation on the server. 1.3 Web databases Web technology is a very special case in client/server computing world. Almost every database vendor is rushing to support this technology at the moment. There are two reasons to explain this, one is that enterprise web servers need powerful databases to support, and the other reason is that 3 databases need to be extended their services to the biggest wide range group, web group. The typical web databases are three-tier or N-tier. The users run standard browsers on the client side and the requests are transferred over the Internet to HTTP servers. The HTTP servers then interact with database servers and change the result into HTML files to send back to the browsers. Because HTTP is a stateless connection protocol, web databases need find a way to "remember" each user's operations. They also should have capability of handling with enormous users concurrently. If the web databases support Java, or ODBC/JDBC, they are platform independent because they can connect with different web servers or the Internet directly. It does not need to care about server platform, client platform and network protocol. Performance is a big problem of web databases. Users concern the response time of the databases and the web masters concern the throughput. Optimisation is always used at web server. When a web server receives a service request from a client, it first looks up a result in its cache to see if it is there already. If it does, the result will send back to the client directly without connecting to a database server. If it can not find the result in the cache, it will connect to the database server and fetch the result. The result will normally stored in the server cache and send back to the client. When there are more than one user's request coming into the web server, a queue will be built on web server and optimisation will make them use the server resource reasonably. Web databases can be two-tie, three-tie or N-tie. The two-tie web databases are the simplest to develop and may gain some good performance from this simple structure. However, they are lack of flexibility to deal with other web things and normally they are vendor dependence. The three-tie or N-tie web databases are powerful and flexible. But the middle tie may add the overhead because the databases are not connected with the Internet directly. 4 2. Active Server Pages Active Server Pages (ASP) is an Internet Server Application Programming Interface (ISAPI) extension which builds on top of the ISAPI infrastructure to provide a server-side application framework, making it even easier to build dynamic Web applications. ISAPI is an alternative approach to Common Gateway Interface (CGI) and is adopted by Internet Information Server (IIS) because each CGI invocation of process is very resource intensive and a busy Web server could have severe performance problems. If web technologies are used to deal with database via HTTP, then the data and its state need to be kept track of, as it flies around the world. ASP is an excellent tool to help developers do that on the Windows NT world. ASP is supplied with ActiveX Data Objects (ADO) that provides a high performance interface to databases that are Open Database Connectivity (ODBC) or OLE DB compliant. Fig. 1 shows the general structure of how ASP to connect the databases. Server: Windows NT Internet Information Server CGI Client Scripts Browser Internet ASP WWW SQL ADO Server ODBC Or Oracle ActiveX HTML MTS files Fig. 1 The connectivity of ASP with the database on the web 5 *ADO is a high-level interface, which is a wrapper around OLE DB. OLE DB is a COM- based, low-level programming interface that provides access to data from all parts of an organisation (relational, access, file). * If there is a native OLE DB provider for the database, it does not have to go through ODBC - the extra layer of processing. 2.1 ASP Components Active Server Pages allows the developer to include VBScript or JScript code in the HTML pages, which is executed on the server. ASP has its own object model, which is exposed for the above scripting languages. Its built-in objects give the way to integrate code with the requests sent from the browser, and the web pages, or responses, sent back from the server. There are six built-in objects provided by the Active Server Pages core engine. These objects are Application, Session, Response, Request and ObjectContext. They only relate to each other logically, not in a hierarchy object models. The diagram below shows how these objects fit together. Server Request Object Server Client Response Application ObjectContext Session Fig. 2 The built-in objects
Load more

Recommended publications
  • Active Server Pages (ASP)
    Active Server Pages (ASP) Outline 11.1 Introduction 11.2 How Active Server Pages Work 11.3 Client-side Scripting versus Server-side Scripting 11.4 Using Personal Web Server or Internet Information Server 11.5 A Simple ASP Example 11.6 Server-side ActiveX Components 11.7 File System Objects 11.8 Session Tracking and Cookies 11.9 Accessing a Database from an Active Server Page 11.10 Case Study: A Product Catalog 11.1 Introduction • Active Server Pages (ASP) – Processed in response to client request – ASP file contains HTML and scripting code – VBScript de facto language for ASP scripting • Other languages can be used – JavaScript – .asp file extension – Microsoft-developed technology – Send dynamic Web content • HTML • DHTML • ActiveX controls • Client-side scripts • Java applets 11.2 How Active Server Pages Work • Client sends request – Server receives request and directs it to ASP – ASP processes, then returns result to client • HTTP request types – Request methods • GET – Gets (retrieves) information from server – Retrieve HTML document or image • POST – Posts (sends) data to server – Send info from HTML form » Client-entered data » Info to search Internet » Query for a database » Authentication info 11.2 How Active Server Pages Work (II) • Browsers often cache Web pages – Cache: save on disk – Typically do not cache POST response • Next POST request may not return same result • Client requests ASP file – Parsed (top to bottom) by ActiveX component asp.dll • ActiveX component: server-side ActiveX control that usually does not have GUI
    [Show full text]
  • Implementing OGC Web Map Service Client Applications Using JSP, JSTL and XMLC
    Implementing OGC Web Map Service Client Applications Using JSP, JSTL and XMLC Hao Ding , Richard Pascoe & Neville Churcher Department of Computer Science University of Canterbury. Christchurch, New Zealand Phone: +64 3 364-2362 Fax: +64 3 364-2569 Email: [email protected] , {richard, neville}@cosc.canterbury.ac.nz Presented at SIRC 2002 – The 14th Annual Colloquium of the Spatial Information Research Centre University of Otago, Dunedin, New Zealand th December 3-5 2002 ABSTRACT Java technologies are widely used in web application development. In this paper are described three approaches to developing Java-based web applications and our experiences with applying each to the development of client that interact with servers implementing the OGC (Open GIS Consortium) Web Map Service (WMS) specification. Also described is the installation and configuration of open source software that implements the WMS specification. The paper is concluded with some preliminary insights into when one of the three approaches to WMS client implementation is more suited to another. Keywords and phrases: WMS, JSP, JSTL, XMLC, map layer, web map server 1.0 INTRODUCTION Of the many technologies, such as Common Gateway Interface (CGI), Active Server Pages (ASP), JavaServer Pages (JSP), that are used to develop web applications, three are of particular interest to the research presented here. These three technologies or approaches to developing clients that utilise web services are JavaServer Pages (JSP), JSP with the use of tags from the JSP Standard Tag Library (JSTL), and the eXtensible Markup Language Compiler (XMLC). JSP is a more convenient way to write Java servlets, and allows the insertion of Java code directly into static HTML (Hypertext Markup Language) pages.
    [Show full text]
  • Tool Support for Computer Role-Playing Game Programming: Foundations, Guidelines and Applications
    Tampereen teknillinen yliopisto. Julkaisu 1237 Tampere University of Technology. Publication 1237 Juha-Matti Vanhatupa Tool Support for Computer Role-Playing Game Programming: Foundations, Guidelines and Applications Thesis for the degree of Doctor of Science in Technology to be presented with due permission for public examination and criticism in Tietotalo Building, Auditorium TB222, at Tampere University of Technology, on the 17th of October 2014, at 12 noon. Tampereen teknillinen yliopisto - Tampere University of Technology Tampere 2014 ISBN 978-952-15-3341-9 (printed) ISBN 978-952-15-3393-8 (PDF) ISSN 1459-2045 Abstract Computer role-playing games (CRPGs) are a genre of computer games, which aim at providing similar player experience than their ancestors, paper-and- pen role-playing games. For a type of digital games, their evolution is already rather long, as the first ones were created in 1980s. Typically CRPGs em- phasize character development and to support this huge fantasy worlds and sophisticated storylines are also present. CRPG development has unique challenges, which derive from these typical features. Content creation is a continuous issue, since huge virtual worlds and long storylines must be filled with content. Personalization is also an important issue, because all fun of creating personalized character is lost if it has no effect into the game. Low starting threshold is important for successful game. It is becoming essential that the player can start playing quickly and she is not required to spent time waiting the installation to be completed. This can be achieved by web-based approach, since web-based games do not require installations.
    [Show full text]
  • Developing an E-Commerce System Using Active Server Pages
    Developing an E-Commerce System Using Active Server Pages Robert W. Ingram Ross-Culverhouse Chair Culverhouse School of Accountancy University of Alabama Box 870220 Tuscaloosa, AL 35487 (205) 348-2907 [email protected] Dale L. Lunsford Assistant Professor Culverhouse School of Accountancy University of Alabama Box 870220 Tuscaloosa, AL 35487 (205) 348-5780 [email protected] August 2002 Developing an E-Commerce System Using Active Server Pages Abstract: This paper describes a case to illustrate analysis, design, and implementation issues involving a multi-tier e-commerce system. The case is designed for use in advanced accounting systems or systems analysis and design courses. The case involves analysis of a sales order system that will be implemented using a web interface and relational database, conceptual design of the system, and implementation of the system. A variety of tasks are involved in the case, but an instructor can select the tasks of relevance in a particular course. Key Words: E-commerce, systems analysis and design, systems development, security. Data Availability: All data and programs described are available from the authors. 1 Developing an E-Commerce System Using Active Server Pages I. Introduction Web-based applications are an important means of accessing business information. E-commerce represents an increasingly important part of the economy and is an obvious source of demand for web-based systems. In addition, companies may use the Internet for internal communications because of the ability of employees to access data from locations throughout the world. Companies like Oracle and SAP are increasingly focusing on the Web as a means of deploying their software products.
    [Show full text]
  • Web Based Applications, Tomcat and Servlets - Lab 3
    CMPUT 391 Database Management Systems Web based Applications, Tomcat and Servlets - Lab 3 - CMPUT 391 – Database Management Systems Department of Computing Science University of Alberta The Basic Web Server Lab 3 CMPUT 391 – Database Management Systems 2 Tomcat and Servlets CGI CGI – Common Gateway Interface Processing forms & Generating dynamic content (early solution ) Spawning an external program, pass the data from the HTML form to the program Limitation: An expensive process (Spawning an external program) Lab 3 CMPUT 391 – Database Management Systems 3 Tomcat and Servlets CGI: Illustration Browser Browser Browser Browser GET Response Form.cgi Web Server Web Server Web Server Web Server Spawn an Read environment external program variables Response Start form.cgi CGfoI rPmr.ocggria m CGI Program CGI Program CteGrIm Pinroagterasm time Lab 3 CMPUT 391 – Database Management Systems 4 Tomcat and Servlets ASP ASP – Active Server Pages Microsoft’s answers to CGI programming ASP page - a Web page with code embedded inside, interpreted by the Web server Using special HTML tags, VBScript/JavaScript code can be inserted Lab 3 CMPUT 391 – Database Management Systems 5 Tomcat and Servlets Servlets Java technology's answer to CGI programming A Java class handling forms on Java Web servers Applet -- a little piece of program (client side) Servlet -- a little piece of program (server side) A servlet can do everything that a CGI program can Running inside the JVM along with the Web server itself Lab 3 CMPUT 391 – Database Management
    [Show full text]
  • Computer Information Systems: Web Applications (CISW) 1
    Computer Information Systems: Web Applications (CISW) 1 CISW 24 Secure Web Server Programming in Python COMPUTER INFORMATION 3 Units (Degree Applicable) Lecture: 54 SYSTEMS: WEB Corequisite: CISW 24L Secure web programming to create user interfaces, extract information APPLICATIONS (CISW) and manage databases, manage files, format reports, and access web CISW 15 Web Site Development servers using Python programming language. Student must be enrolled in 3.5 Units (Degree Applicable, CSU) CISW 24L, a concurrent lab co-requisite. Lecture: 54 Lab: 27 CISW 24L Secure Web Server Programming in Python Laboratory Advisory: CISB 15 or CISB 16 0.5 Units (Degree Applicable) Lab: 27 Plan, develop, implement, publish, and maintain Web sites with a Corequisite: CISW 24 professional visual Web-authoring application, includes working with text and images, internal and external hyperlinks, image maps, tables, Laboratory for secure web programming to create user interfaces, extract Cascading Style Sheets (CSS), Web page content, Web forms, multimedia information and manage databases, manage files, format reports, and objects (Flash text, Flash buttons, sounds, and video), interactions and access web servers using Python programming language. Student must behaviors, and Web page templates. Principles of Web site structures, be enrolled in CISW 24, a concurrent lecture co-requisite. documentation, management, and maintenance will be discussed. CISW 31 Secure Web Server Programming in PHP CISW 17 HTML, CSS, and JavaScript Programming 3 Units (Degree Applicable) 3 Units (Degree Applicable, CSU) Lecture: 54 Lecture: 54 Corequisite: CISW 31L Advisory: CISB 11 Advisory: (CISN 34 and CISN 34L) or (CISW 24 and CISW 24L) Plan, program, implement, publish, and maintain web sites using Plan, install, and manage secure Apache Web servers using server Hypertext Markup Language version 5 (HTML5), Cascading Style Sheets side programming language like PHP (PHP: Hypertext Preprocessor) to version 3 (CSS3), and JavaScript.
    [Show full text]
  • NIST SP 800-28 Version 2 Guidelines on Active Content and Mobile
    Special Publication 800-28 Version 2 (Draft) Guidelines on Active Content and Mobile Code Recommendations of the National Institute of Standards and Technology Wayne A. Jansen Theodore Winograd Karen Scarfone NIST Special Publication 800-28 Guidelines on Active Content and Mobile Version 2 Code (Draft) Recommendations of the National Institute of Standards and Technology Wayne A. Jansen Theodore Winograd Karen Scarfone C O M P U T E R S E C U R I T Y Computer Security Division Information Technology Laboratory National Institute of Standards and Technology Gaithersburg, MD 20899-8930 March 2008 U.S. Department of Commerce Carlos M. Gutierrez, Secretary National Institute of Standards and Technology James M. Turner, Acting Director GUIDELINES ON ACTIVE CONTENT AND MOBILE CODE Reports on Computer Systems Technology The Information Technology Laboratory (ITL) at the National Institute of Standards and Technology (NIST) promotes the U.S. economy and public welfare by providing technical leadership for the nation’s measurement and standards infrastructure. ITL develops tests, test methods, reference data, proof of concept implementations, and technical analysis to advance the development and productive use of information technology. ITL’s responsibilities include the development of technical, physical, administrative, and management standards and guidelines for the cost-effective security and privacy of sensitive unclassified information in Federal computer systems. This Special Publication 800-series reports on ITL’s research, guidance, and outreach efforts in computer security and its collaborative activities with industry, government, and academic organizations. National Institute of Standards and Technology Special Publication 800-28 Version 2 Natl. Inst. Stand. Technol. Spec. Publ.
    [Show full text]
  • Theme JEE and .Net OMA Implementations (Part 1)
    Application Servers Session 4 – Main Theme JEE and .Net OMA Implementations (Part 1) Dr. Jean-Claude Franchitti 1 Icons / Metaphors Information Common Realization Knowledge/Competency Pattern Governance Alignment Solution Approach 22 Web Application Servers Architectures (Evolution) Traditional client-server technology CGI frameworks Page-based extended HTML environments Distributed object computing platforms Java-Based Object Management Architectures (OMAs) Component-based computing environments Web Services platforms Next generation application servers (reflective, multimedia- and agent enabled, MDA-compliant, etc.) 3 Web Application Servers Architectures (Page-Based Extended HTML Environments Details) Application Servers for Enhanced HTML (traditional) a.k.a., Page-Based Application Servers Tag-Oriented (e.g., Macromedia ColdFusion 5.0 Server) Script Oriented (e.g., Microsoft IIS with ASP, PHP) Mostly Used to Support Standalone Web Applications Typically less expensive than standalone and IDE-based servers HTML-based development New Generation Page-Based Script-Oriented App. Servers First Generation Extensions (e.g., Microsoft IIS with COM+/ASP) Servlet/JSP Environments XSP Environment Can now be used as front-end to enterprise applications Hybrid development environments 4 Web Application Servers Architectures (Beyond Page-Based Extended HTML Environments Details) Distributed Object Computing Platforms Provide an infrastructure for distributed communications enabling Still need to merge traditional web-oriented
    [Show full text]
  • Surface Contents Author Index
    Surface Contents Author Index Mu-Lin WU, Chiou-Hsiung CHEN & Chih-Hsin CHEN DESIGN AND OPERATION OF SPATIAL DECISION SUPPORT SYSTEMS FOR WATER RESOURCE PROTECTION a b b Mu-Lin WU , Chiou-Hsiung CHEN , Chih-Hsin CHEN aCivil Engineering Dept., National Pingtung Univ. of Science and Technology, 39-13 TongZong Road, Dali, Taichung County, 41244, Taiwan [email protected] bTaipei Watershed Management Bureau, WRA, MOEA, 5, Lane 45, Sec. 1, Peihsin Road, Hsien-Ten, Taipei 231, Taiwan [email protected] Commission II, WG IC II /5 KEY WORDS: Spatial decision support systems, Water resource protection ABSTRACT: Spatial decision support systems for water resource protection at Taipei Watershed Management Bureau (TWMC) have been pursued for more than a decade. There are five townships and two watersheds under jurisdiction of TWMC. The whole area under management of water resource protection is 717 square kilometres. The management objective is to provide sustainable drinking water for a population about four millions in Taipei. Management prescriptions for water resource protection at TWMC are not confined to traditional approaches. Design of spatial decision support systems for water resource protection was mainly focused on integration of techniques such as remote sensing, geographic information systems (GIS), and global positioning systems (GPS). The major ingredients of spatial decision support systems are web-based GIS which can bring relevant information for management of water resource protection for a given location say, x and y coordinates, a single sheet of map, a township, even a watershed. All maps, satellite images, and orthophoto maps were stored in scalable vector graphics (SVG) format.
    [Show full text]
  • Best Practices for Securing E-Commerce Special Interest Group PCI Security Standards Council
    Standard: PCI Data Security Standard (PCI DSS) Date: April 2017 Authors: Best Practices for Securing E-commerce Special Interest Group PCI Security Standards Council Information Supplement: Best Practices for Securing E-commerce Information Supplement • Best Practices for Securing E-commerce • April 2017 Document Changes Date Document Version Description Pages January 2013 1.0 Initial release All January 2017 1.1 Expanded and revised Various content based upon the Securing e-Commerce Special Interest Group April 2017 1.2 Corrected entries in table, Various Section 2.7 typographical and grammatical errors The intent of this document is to provide supplemental information. Information provided here does ii not replace or supersede requirements in any PCI SSC Standard. Information Supplement • Best Practices for Securing E-commerce • April 2017 Table of Contents Document Changes ................................................................................................................................................. ii 1 Introduction ........................................................................................................................................................ 5 1.1 Background ................................................................................................................................................... 5 1.2 Intended Audience ........................................................................................................................................ 7 1.3 Terminology .................................................................................................................................................
    [Show full text]
  • Parametric Web-CAD for Box Culvert Design
    147 Parametric Web-CAD for Box Culvert Design Julian H. Kang1, Byeong-Cheol Lho2 and Sang-Rung Choi3 1Texas A&M University, [email protected] 2Sangji University, [email protected] 3Hanseok Engineering Co., Ltd., [email protected] ABSTRACT This paper presents a development of Web applications to improve the process of a box culvert design and document management using XML and SVG. The box culvert is one of the simple and common structures employed repetitively in road construction. Although parametric computer applications have demonstrated a significant amount of time savings in designing simple and repetitive structures, circulating resultant electronic documents among project participants has not been fully integrated with these applications. We developed a parametric Web application in order to facilitate not only engineering design of the box culvert but also management of resultant documents over the Web. This paper presents how XML Data Island and SVG were utilized to generate engineering drawings and display them in the Web page. Keywords: Design Automation, Web-CAD, XML, SVG projects. Web-based project management, which stores 1. INTRODUCTION information in the central repository, therefore has A box culvert is one of the common structures employed attracted many AEC firms because of its potential ability in road construction. Over the last decade, many box of building a project legacy database by collecting culverts have been constructed in Korea. The shape of electronic documents in the central repository. The these box culverts is fairly simple and typical no matter frequency and cost of the bridge repairs made a public where they were built.
    [Show full text]
  • O'reilly & Associates)
    JavaServer Pages Hans Bergsten First Edition, December 2000 ISBN: 1-56592-746-X, 572 pages JavaServer Pages shows how to develop Java-based web applications without having to be a hardcore programmer. The author provides an overview of JSP concepts and illuminates how JSP fits into the larger picture of web applications. There are chapters for web authors on generating dynamic content, handling session information, and accessing databases, as well as material for Java programmers on creating Java components and custom JSP tags for web authors to use in JSP pages.JavaServer Pages shows how to develop Java-based web applications without having to be a hardcore programmer. The author provides an overview of JSP concepts and illuminates how JSP fits into the larger picture of web applications. There are chapters for web authors on generating dynamic content, handling session information, and accessing databases, as well as material for Java programmers on creating Java components and custom JSP tags for web authors to use in JSP pages. Release Team[oR] 2001 Preface 1 What's in This Book Audience Organization About the Examples Conventions Used in This Book How to Contact Us Acknowledgments i JSP Application Basics This part of the book describes the fundamentals of HTTP (the protocol used by all web applications), how servlets and JSP are related, and how to set up a JSP development environment and install the book examples. 1 Introducing JavaServer Pages 8 1.1 What Is JavaServer Pages? 1.2 Why Use JSP? 1.3 What You Need to Get Started 2
    [Show full text]