In a previous article (XML Basics Part One);we had a brief look at XML. However, as stated in the article, XML itself is worth nothing without the set of APIs that are generated-it would simply be just another fancy form of CSV, that is, a proprietary data format! My aim in this set of articles is not to actually reveal XML in its every detail, but rather have a look at the implications of XML in today’s technologies. That’s why the previous article only sheds a little light into the insights of XML, which included some terms and technologies you will be confronted with the moment you step in the XML arena.
Java and XML Basics, Part 1 - Appendix: Installing Xerces-J 2.0.0 under JDK 1.4 (Page 5 of 5 )
As stated above, just by loading XercesJ into the class path doesn't solve the problem, as both Crimson and XercesJ are JAXP compliant, and the javax.xml.parsers factories, when loaded, will load the first JAXP provider found which is always Crimson (as this is included in the rt.jar runtime jar). In order to allow XercesJ to "override" Crimson, you’ll have to use the Java Endorsed API mechanism--this means creating a directory (the recommended method is to create it in your <JAVA_HOME>\lib directory and call it "endorsed"--therefore the full path would be <JAVA_HOME>\lib\endorsed) and in the command line that starts the Java interpreter add the following option:
(Or the path to the directory where you have placed the XercesJ jars.) If you have more than one directory, you can separate them with “;” on Windows or “:” or UNIX. This will allow the Java interpreter, when starting up, to load the JAXP API providers form this directory first, and therefore the XercesJ classes will be loaded rather than Crimson. One easy way to test it is with the following code:
.xml.parsers.*; .... /*** Checkout the parser ***/ DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); System.out.println( "Factory: " + dbf ); DocumentBuilder db = dbf.newDocumentBuilder(); System.out.println( "Builder: " + db ); /***/ ....
If the output shows a class name in the package org.apache.xerces.jaxp... then Xerces is loaded, otherwise, you should check your class path, endorsed API path and make sure that it's all set correctly for XercesJ to load.
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