Addison Wesley XML And Java Developing Web Applications May 1999 ISBN 0201485435

8.6 Evolution of Web Applications The potential of XML-enabled Web applications can be illustrated by the very simple Travel Planning application that we developed in this chapter Airline and hotel companies have invested a lot to make their existing backend systems (typically based on Lotus Notes, SAP, and so on) accessible from Web browsers This has been a tremendous success, now exerting greater reach to end users all over the world However, that reach is limited to browsers (and thus to human users) because HTML is good only for displaying on the screen For example, a travel agent who wants to put the flight information in a spreadsheet to combine it with other information for a customer must manually cut and paste individual pieces of information between the Web browser and the spreadsheet application 8.6.1 Browser Clients Figure 8.10 depicts a possible scenario of the evolution of a Web site powered by XML Existing Web applications are typically designed to generate HTML pages directly from a database The first step to establish an XML-enabled Web site is to generate a logical and presentationneutral representation in XML/DOM, which is to be converted into HTML, as shown in case (1) in Figure 8.10 This covers all of the browserbased clients Figure 8.10 XML-powered Web site 8.6.2 office Clients The second step is to convert the presentation-neutral representation into a format that is supported by office products For example, if the travel agent receives the flight inrormation in XML that is compatiable with office products, that information can be fed into a spreadsheet, thereby eliminating tedious cut-and-paste operations This is shown in case (2) in Figure 8.10 Microsoft and Lotus are quickly moving towards supporting XML in their office products For example, Lotus e-Suite is already XMLenabled, so you can create an XML document that is directly loadable to an e-Suite spreadsheet 8.6.3 Integrated B2B Applications As the third step, the travel agency can connect the XML-enabled airline Web site to its backend system (such as SAP), thereyby allowing agents to automatically check the flight availability and to issue orders This is shown in case (3) in Figure 8.10 In this way, the XML-enabled Web site can be integrated into the agency's enterprise system as one of its components All of these transactions are made on the Internet using SSL, so maximum security is maintained, with no need for an expensive leased line (VAN) In addition, digital signatures build trust among business partners We believe many Web sites will be increasingly used as componenets of a more-or-less similar architecture in the near future the technologies described in this book-XML, Java, XML processors, LMX processor, servlets, SQLX, SSL, digital signatures, and Javabeans_are essential for realizing the coming world of Web applications  ... Figure 8.10 Microsoft and Lotus are quickly moving towards supporting XML in their office products For example, Lotus e-Suite is already XMLenabled, so you can create an XML document that is directly loadable to... We believe many Web sites will be increasingly used as componenets of a more-or-less similar architecture in the near future the technologies described in this book -XML, Java, XML processors, LMX processor,... described in this book -XML, Java, XML processors, LMX processor, servlets, SQLX, SSL, digital signatures, and Javabeans_are essential for realizing the coming world of Web applications