Cannot instantiate DocumentBuilderFactory in JDK 5
Few months back I moved to JDK 5. After this move, recently, I tried running some Acceptance tests using an old fitnesse.jar, which was compiled using JDK 1.4. And guess what? I get the following exception :
javax.xml.parsers.FactoryConfigurationError:
Provider com.sun.org.apache.xerces.internal.jaxp.
DocumentBuilderFactoryImpl could not be instantiated: java.lang.NullPointerException
[java] at javax.xml.parsers.DocumentBuilderFactory.newInstance
(DocumentBuilderFactory.java:104)
[java] at fitnesse.util.XmlUtil.<clinit>
[java] at fitnesse.wiki.WikiPageProperties.loadFromXmlStream
[java] at fitnesse.wiki.FileSystemPage.attemptToReadPropertiesFile
[java] at fitnesse.wiki.FileSystemPage.loadAttributes
[java] at fitnesse.wiki.FileSystemPage.makePageData
[java] at fitnesse.wiki.CachingPage.getData
[java] at fitnesse.responders.run.FitClientResponder.readyToSend
[java] at fitnesse.responders.run.PuppetResponse.readyToSend
[java] at fitnesse.FitNesseExpediter.sendResponse
[java] at fitnesse.FitNesseExpediter.start
[java] at fitnesse.FitNesseServer.serve
[java] at fitnesse.FitNesseServer.serve
[java] at fitnesse.socketservice.SocketService$ServerRunner.run
[java] at java.lang.Thread.run(Thread.java:595)
If I use JDK 1.4, everything works fine. But there seems to be some backward compatibility issues with JDK 1.5.
After trying different things for a while, I came across a site that stated that “The J2SE 1.4 platform included the ‘Crimson‘ reference implementation for JAXP 1.1. The J2SE 5 platform includes a reference implementation for JAXP 1.3 based on the Apache ‘Xerces‘ library.â€
In JDK 1.4, xerces and xalan are embedded in the JDK. In JDK 1.5 too, but the packages are under com/sun (so com.sun.org.apache….).
So you would think all this should be transparent to developers. But no.
To verify the above statement, I opened up the DocumentBuilderFactory in JDK 1.5 and I found
public static DocumentBuilderFactory newInstance() {
try {
return (DocumentBuilderFactory) FactoryFinder.find(
/* The default property name according to the JAXP spec */
"javax.xml.parsers.DocumentBuilderFactory",
/* The fallback implementation class name */
"com.sun.org.apache.xerces.internal.jaxp.
DocumentBuilderFactoryImpl");
} catch (FactoryFinder.ConfigurationError e) {
throw new FactoryConfigurationError(e.getException(),
e.getMessage());
}
}
while the JDK 1.4‘s DocumentBuilderFactory class had:
public static DocumentBuilderFactory newInstance()
throws FactoryConfigurationError
{
try {
return (DocumentBuilderFactory) FactoryFinder.find(
/* The default property name according to the JAXP spec */
"javax.xml.parsers.DocumentBuilderFactory",
/* The fallback implementation class name */
"org.apache.crimson.jaxp.
DocumentBuilderFactoryImpl");
} catch (FactoryFinder.ConfigurationError e) {
throw new FactoryConfigurationError (e.getException(),
e.getMessage());
}
}
After all this research I still don‘t know what is the exact problem. But I have a solution.
Solution: Luckily adding the xerces.jar to the classpath solved the problem.
Would appreciate if someone would let me know the answer.
