1. Developing XML Applications for Oracle WebLogic Server
  2. Introduction

1 Introduction

This chapter provides summary of WebLogic Server XML features and provides variety of code samples for XML developers.

Samples for the XML Developer

In addition to this document, Oracle provides a variety of code samples for XML developers. The examples and tutorials illustrate WebLogic Server XML in action, and provide practical instructions on how to perform key XML development tasks.

Oracle recommends that you run some or all of the XML examples before programming your own application that processes XML.

XML Examples in the WebLogic Server Distribution

WebLogic Server optionally installs API code examples in the ORACLE_HOME\wlserver\samples\server directory, where ORACLE_HOME represents the directory in which you installed WebLogic Server. For more information about the WebLogic Server code examples, see Sample Applications and Code Examples in Understanding Oracle WebLogic Server.

Summary of WebLogic Server XML Features

WebLogic Server consolidates XML technologies applicable to WebLogic Server and XML applications based on WebLogic Server. The WebLogic Server XML subsystem allows customers to use standard parsers, the WebLogic FastParser, XSLT transformers, and DTDs and XML Schemas to process and convert XML files.

The following topics, which describe the features included in the WebLogic Server XML subsystem, are presented in this section:

XML Document Parsers

WebLogic Server uses, by default, the XML parser that is included in the JDK.

You can also use any other XML parser of your choice by using the WebLogic Server Administration Console to configure it in the XML Registry. You can configure a single instance of WebLogic Server to use one parser for a particular application and use another parser for a different application.

For information about parsing XML documents, see Parsing XML Documents.

Difference In Default Parsers Between Versions 8.1 and 9.1 of WebLogic Server

The default parser in Versions 8.1and previous of WebLogic Server was one that was based on Apache's Xerces parser and whose package name started with weblogic.apache.xerces.*. In Version 9.1 of WebLogic Server, this parser has been deprecated. Instead, the default parser is the same one that is shipped in the JDK.

For backward compatibility, the weblogic.apache.xerces.* parser is still available in Version 9.1 of WebLogic Server, although it is deprecated and Oracle highly recommends you do not use it since it will not be available in future versions. If, however, you need to temporarily continue using this parser, you must use the WebLogic Server Administration Console to configure a parser other than the default for your WebLogic Server instance by updating, or creating, a new XML Registry and setting the default implementation classes for SAX and DOM parser factory interfaces, as indicated in Table 1-1.

Table 1-1 Default Implementation Classes for SAX and DOM Parser Factory Interfaces

Parser Factory Interface Implementation Class

DOM (DocumentBuilderFactory)

weblogic.apache.xerces.jaxp.DocumentBuilderFactoryImpl

SAX (SAXParserFactory)

weblogic.apache.xerces.jaxp.SAXParserFactoryImpl

For information about creating an XML Registry, see Administering WebLogic Server XML.

XML Document Transformer

WebLogic Server uses, by default, the XML transformer that is included in the JDK.

You can also use any other XML transformer of your choice by using the WebLogic Server Administration Console to configure it in the XML Registry. You can configure a single instance of WebLogic Server to use one transformer for a particular application and use another transformer for a different application.

For more information about transforming XML documents, see Transforming XML Documents.

Streaming API for XML (StAX) Implementation

WebLogic Server includes an implementation of the Streaming API for XML (StAX).

See Using the Streaming API for XML (StAX).

WebLogic XPath API

The WebLogic XPath API contains all of the classes required to perform XPath matching against a document represented as a DOM, an XMLInputStream, or an XMLOutputStream.

See Using the WebLogic XPath API.

JAXP Pluggability Layer Implementation

Java API for XML Processing (JAXP) 1.2 is a Java-standard, parser-independent API for XML. For more information on JAXP, see What Is JAXP?.

Note:

WebLogic Server uses the XML Registry, accessed through the WebLogic Server Administration Console, to plug in parsers and transformers. This is different from the JAXP 1.2 specification which specifies the use of system properties to plug in parsers and transformers.

WebLogic Servlet Attributes

WebLogic Server supports the following special Servlet attributes:

  • org.xml.sax.HandlerBase

  • org.xml.sax.helpers.DefaultHandler

  • org.w3c.dom.Document

Calling the setAttribute (for SAX parsing) and getAttribute (for DOM parsing) methods on a ServletRequest object with the preceding attributes will parse any given XML document.

See Parsing XML Documents in a Servlet.

XML Registry For Configuring Parsers and Transformers

The XML Registry simplifies administration and configuration tasks by separating these tasks from the XML application. Use the WebLogic Server Administration Console to configure the parsers and transformers for an instance of WebLogic Server.

See XML Parser and Transformer Configuration Tasks.

XML Registry for Configuring External Entity Resolution

WebLogic XML supports external entity resolution through the XML Registry. See External Entity Configuration Tasks.

Endorsed Standards Override Mechanism for DOM/SAX: Not Supported

WebLogic Server does not support switching the server's DOM and SAX interfaces using the endorsed standards override mechanism.

An endorsed standard is a Java API defined through a standards process other than the Java Community Process (JCP). See Endorsed Standards Override Mechanism at http://docs.oracle.com/javase/8/docs/technotes/guides/standards/.

Learning More About XML

To learn more about XML, see the following online courses and tutorials. XML Reference, provides links to additional information.