[CAMEL-11000] Property 'accessExternalDTD' is not recognized by (all) Xerces

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.17.5, 2.18.3
• Fix Version/s: 2.17.7, 2.18.4, 2.19.0
• Component/s: camel-validator
• Estimated Complexity: Unknown
• Regression: Regression
• Assignee: Andrea Cosentino
• Reporter: Bernard Ligny
• Created: 13/Mar/17 11:43
• Updated: 18/Apr/17 08:59
• Resolved: 14/Mar/17 09:05

Description

When upgrading from v2.18.1 to 2.18.3, we encounter a (blocking) regression, preventing routes involving validator component to successfully start.

Indeed, one of the recent validation-related changes is not fully compatible with all versions of Xerces. Especially when deployed on JBoss Wildlfy 10.1.0.Final

Stack trace:

Caused by: java.lang.IllegalStateException: org.xml.sax.SAXNotRecognizedException: Property 'http://javax.xml.XMLConstants/property/accessExternalDTD' is not recognized.
	at org.apache.camel.processor.validation.SchemaReader.createSchemaFactory(SchemaReader.java:181)
	at org.apache.camel.processor.validation.SchemaReader.getSchemaFactory(SchemaReader.java:152)
	at org.apache.camel.processor.validation.SchemaReader.createSchema(SchemaReader.java:192)
	at org.apache.camel.processor.validation.SchemaReader.loadSchema(SchemaReader.java:84)
	at org.apache.camel.component.validator.ValidatorEndpoint.createProducer(ValidatorEndpoint.java:119)
	at org.apache.camel.impl.ProducerCache.doGetProducer(ProducerCache.java:574)
	... 78 more
Caused by: org.xml.sax.SAXNotRecognizedException: Property 'http://javax.xml.XMLConstants/property/accessExternalDTD' is not recognized.
	at org.apache.xerces.jaxp.validation.XMLSchemaFactory.setProperty(XMLSchemaFactory.java:436)
	at __redirected.__SchemaFactory.setProperty(__SchemaFactory.java:143)
	at org.apache.camel.processor.validation.SchemaReader.createSchemaFactory(SchemaReader.java:178)
	... 83 more

In particular, in the following code:

protected SchemaFactory createSchemaFactory() {
   ...
	try {
		factory.setProperty(XMLConstants.ACCESS_EXTERNAL_DTD, "");
	} catch (SAXException e) {
		LOG.error(e.getMessage(), e);
		throw new IllegalStateException(e);
	} 
 
}   

Would it be possible to issue a simple warning, rather then raising an exception ?
(>see Oracle recommandations: https://docs.oracle.com/javase/tutorial/jaxp/properties/error.html)

Issue Links

• links to: GitHub Pull Request #1533