Chapter 1 - Technologies for Web Applications

Abstract

This chapter provides an overview of the technologies constituting the foundations for building data-intensive Web applications. The chapter begins by surveying the basic protocols and languages for the Web, such as hypertext transfer protocol (HTTP), hypertext markup language (HTML), and client-side scripting. Then, extensible markup language (XML) and the collateral extensible stylesheet language (XSL) technology are introduced as the new paradigm for content definition and exchange. To address the “data” part of data-intensive Web applications, a brief compendium on relational databases, structured query language (SQL), the most popular relational query language, and on the open database connectivity (ODBC) and Java database connectivity (JDBC) database interoperability standards, are included. The chapter then discusses the architectures for constructing HTML pages on the fly, including common gateway interface (CGI), Java servlets, server-side scripting, with a special mention of Java server pages (JSP) and Microsoft .NET custom tag libraries, and application servers. The challenging requirements of multi-device application development are addressed. The use of XML as an intermediate data format, and of SQL and XSL as the declarative languages for expressing the queries and transformations necessary to publish database content for multiple devices, are also reviewed.