|Oracle8i Application Developer's Guide - XML
Release 3 (8.1.7)
Part Number A86030-01
Introduction to Oracle XML, 7 of 27
Oracle8i provides an integrated suite of tools for building e-business applications:
This suite of tools ensure that exchanging data and document objects is simplified for application development and that multiple serializations is eliminated.
Oracle JDeveloper 3.2 is an integrated environment for building, deploying, and debugging applications leveraging Java and XML on Oracle8i. It facilitates working in Java 1.1 or 1.2 with CORBA, EJB, and Java Stored Procedures. With it you can do the following:
Examples of applications built using Oracle JDeveloper include:
See Chapter 14, "Using JDeveloper to Build Oracle XML Applications" for more information on JDeveloper and XML applications.
Business Components for Java (BC4J) is an Oracle8i application framework for encapsulating business logic into reusable libraries of Java components and reusing the business logic through flexible, SQL-based views of information.
Access to Oracle8i Internet File System (iFS) facilitates organizing and accessing documents and data using a file- and folder-based metaphor through standard Windows & Internet protocols such as SMB, HTTP, FTP, SMTP, and IMAP4.
iFs facilitates building and administering web-based applications. It is an application interface for Java and can load a document, such as a Powerpoint .PPT file, into Oracle8i (O817) and display the document from a web server, such as iAS or Apache Web Server. See also Chapter 15, "Using Internet File System (iFS) to Build XML Applications".
iFS is a simple way for developer's to work with XML, where iFS serves as the repository for XML. iFS automatically parses XML and stores content in tables and columns. iFS renders the content when a file is requested delivering select information, for example, on the web.
Portal can for example input XML-based Rich Site Summary (RSS) format documents, then merge the information with an XSL stylesheet so that it can be rendered in a browser. This design efficiently separates the rendition of information from the information itself and allows for easy customization of the look-and-feel without risk to data integrity.
Oracle Portal is software for building and deploying enterprise portals, the Web sites that power an e-business. The browser interface delivers an organized, personalized view of business information, web content, and applications needed by each user. It includes site-building and self-service Web publishing functionality of WebDB 2.2 and adds new enterprise portal features such as single sign-on, personalization, and content classification. Oracle Portal uses Oracle8i and is deployed on Oracle iAS. It is packaged with iAS.
Portlets are reusable interface components that provide access to web-based resources. Any web page, application, business intelligence report, syndicated content feed, hosted software service or other resource can be accessed through a portlet, allowing it to be personalized and managed as a service of Oracle Portal. Companies can create their own portlets and select portlets from third-party portlet providers. Oracle provides a Portal Developer's Kit (PDK) for developers to easily create portlets using PL/SQL, Java, HTML, or XML.
The Oracle Exchange platform is based on Oracle8i. It offers all necessary business transactions to support an entire industry's or a company's supply chain. Oracle Exchange is based on Oracle's e-Business Suite, which supports a supply chain from the initial contact with the prospect, to manufacturing planning and execution, to post sales on-going service and support.
Oracle Exchange uses XML as its data exchange format and message payload, and Advanced Queueing.
Besides these tools, the following initiatives are underway:
Support for XML Metadata Interchange (XMI) specification proposed by Oracle, IBM, and Unisys. This enables application development tools and data warehousing tools from Oracle and others to exchange common metadata, insuring that you can choose any tool without having to modify your application and warehouse design.
Oracle Advanced Queueing (AQ) will allow reliable propagation of asynchronous messages, including messages with XML documents or document sections or fragments as their "payload", over (Secure) HTTP. This enables dynamic trading and eliminates delays and startup costs to establish inter-company or inter-agency links.
interMedia Text provides powerful search and retrieval options for XML stored in CLOBs and other documents. It can index and search XML documents and document 'sections' of any size up to 4 Gigabytes each stored in a column in a table.
interMedia Text XML document searches include hierarchical element containership, doctype discrimination, and searching on XML attributes. These XML document searches can be used in combination with standard SQL query predicates or with other powerful lexical and full-text searching options.
XML documents or document sections saved into "text CLOBs" in the database can be enabled for indexing by Oracle8i interMedia Text's text-search engine. Developer's can pinpoint searches to data within a specific XML hierarchy as well as locate name-value pairs in attributes of XML elements.
Since interMedia Text is seamlessly integrated into the database and the SQL language, developers can easily use SQL to perform queries that involve both structured data and indexed document sections.
Also included in the Oracle XML are the following components:
Built from the ground up on Oracle Multi-threaded Server (MTS) architecture, Oracle8i JVM (Jserver) is a Java 1.2 compliant virtual machine that data server shares memory address space. This allows the following:
Oracle8i JVM supports native CORBA and EJB standards as well as Java Stored Procedures for easy integration of Java with SQL and PL/SQL.
Oracle Integration Server sends and receives XML payload messages using Oracle Advanced Queueing. Oracle Message Broker packages and delivers the XML messages using JMS wrappers.
Oracle Internet Application Server 8i (Oracle iAS), offers services for both intranet and Internet web applications. It is integrated with Oracle8i and offers advanced services like data caching and Oracle Portal.
A key development challenge is integrating back-end ERP and CRM systems from multiple vendors, with systems from partners in their supply chain, and with customized Data Warehouses.
Such data exchange between different vendors' relational and object-relational databases is simpler using XML. One example of a data exchange implementation using XML and AQ is provided in Chapter 13, "B2B XML Application: Step by Step".
Oracle XML and Oracle XML-enabled tools, interfaces, and servers provide building blocks for most data and application integration challenges.
Not only are these building blocks available, but their use implicates higher performance implementations for the following reasons:
Hence developers can build XML-based web solutions that integrate Java and database data and facilities in many ways.
Oracle XML Parser is implemented in four languages, Java, C, C++, and PL/SQL. The Java version runs directly on Oracle8i JVM (Java virtual machine). It supports the XML 1.0 specification and is used as a validating or non-validating parser.
The Parser provides the two most common APIs that developers need for processing XML documents:
For more information, see Chapter 17, "Using XML Parser for Java"". See Appendix B, "Comparing Oracle XML Parsers and Class Generators by Language", for a comparison of the Oracle XML parsers and generators.
Hence writing custom applications that process XML documents can be simpler in an Oracle8i environment. This enables you to write portable standards-based applications and components in your language of choice that can be deployed on any tier.
The XML parser is part of the Oracle8i platform on every operating system where Oracle8i is ported.
Oracle XML Parser is also implemented in PL/SQL. Hence, existing PL/SQL applications can be extended to take advantage of Oracle XML technology.
You can to use the following options to load XML data or DTD files into Oracle8i:
You can also use Internet File System (iFS) to put an XML document into the database. However, it does not support DTDs. It will however be supporting XML Schema which is the standard that will replace DTD.