org.apache.xerces.jaxp.SAXParserFactoryImpl not found when importing Gears API in GWT

Question

I've created a GWT project using Eclipse which was working perfectly (I was able to run it in both Hosted Mode and on Google App Engine) until I tried to import the Gears API for Google Web Toolkit. After adding the following line to my java source file:

import com.google.gwt.gears.client.geolocation.Geolocation;

I get the following error when I try to compile:

19-Jun-2009 3:36:09 AM com.google.apphosting.utils.jetty.JettyLogger warn
WARNING: failed com.google.apphosting.utils.jetty.DevAppEngineWebAppContext@1c7d682{/,C:\Documents and Settings\Geoff Denning\workspace\TaskPath\war}
javax.xml.parsers.FactoryConfigurationError: Provider org.apache.xerces.jaxp.SAXParserFactoryImpl not found

I've already added the gwt-gears.jar file to my \war\WEB-INF\lib directory, and I've referenced it in Eclipse as follows:

I've even opened the gwt-gears.jar file and confirmed that org/apache/xerces/jaxp/SAXParserFactoryImpl.class does exist. Can anyone give me any pointers as to why I'm getting the above error?

Densimeter

what version of java are you using? Have you recently changed the version from 1.4 to 1.5 ? – Unfledged

Answer 1

Apparently this is a bug in jre 1.5. I was able to resolve the problem by switching my default JRE in Eclipse from 1.5.0_06 to 1.6.0_03, as shown below:

Thanks to Jon and Rahul for pointing me in the right direction.

Densimeter

Answer 2

Check that Xerces exists in:

$JAVA_HOME/lib/endorsed

Sounds like a Java 5 issue. Also check the Java system property for:

javax.xml.parsers.SAXParserFactory

It should be:

org.apache.xerces.jaxp.SAXParserFactoryImpl

If not then that's your issue, make sure you set the system property.

Natheless

In practice, how to do that? – Ignorant

Answer 3

This happened to me. I had conflicting JARs in my workspace. I removed one and boom it worked. The message didn't lend very well to the root of the error.

Meade

In my case, after days fighting with the exact same problem, I found I had a SAXParserFactoryImpl class in a xercesImpl-2.8.1.jar in one of my uses library. I just had to copy this jar into the WEB-INF/lib and add it to the .settings\com.google.appengine.eclipse.core.prefs Works like a charm now. – Lodge

Answer 4

My SAXParserFactoryImpl problem was caused by gwt-gadgets.jar I had in my boot class path. Removing this JAR from the boot class path solved the problem for me. Basically you have to remove any JAR containing a SAXParserFactoryImpl class from your build path (user libs).

Mauldin

Answer 5

Remove the $JAVA_HOME/jre/lib/jaxp.properties fixed the issue.

Mechanotherapy

Answer 6

Take a look at Trouble with Selenium (XercesImpl) and Google App Engine. I had a similar problem with GWT / GAE (SAXParserFactoyImpl not found) and solved it by;

1. Importing the jar to war/WEB-INF/lib
2. Adding the jar to the build path

Filibeg