DWREngine is undefined

[Inge]

I get this Java error in the browser when adding a song to the current playlist.

The song is added to the list, but the browser shows the Java error either verbose or as the !-yellow-warningsign in the lower left corner of the browser window, dependent on the browser configuration.

Details:
---------------------
Line: 22
Char: 10
Error: DWREngine is undefined
Code: 0
URL: http://myipaddress:8080/subsonic/playlist.jsp?add=%2F%Home.....

Running on Tomcat 5.0.28, Java SDK 1.5.0.06 on my RedHat 8.

Tested with IE 6 browser on XP Clients with Java JRE 1.5.0 and 1.4.2.

Seen this before?

Inge.

[sindre_mehus]

Hm, the problem seems to be that a JavaScript library is not loaded.

Can you please try to open this link: http://myipaddress:8080/subsonic/dwr/engine.js

It should return something like this:

Code: Select all

function DWREngine() { }

DWREngine.setErrorHandler = function(handler) {
DWREngine._errorHandler = handler;
};
...


Do you get the same error on other browsers (Opera, Firefox)?

Regards, Sindre

[Inge]

I don't see the error using Opera 8.52, haven't tested with Firefox. I don't know if this is because Opera doesn't display script error by default, or not...

Whichever browser I use, the URL below throws an 500 Exception with the following text (+ a logner Root Cause):

http://myipaddress:8080/subsonic/dwr/engine.js

Code: Select all

exception

javax.servlet.ServletException: Servlet.init() for servlet dwr-invoker threw exception
   org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
   org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
   org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
   org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
   org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
   org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
   java.lang.Thread.run(Thread.java:595)



That's the same exception I get when trying a random url that doesn't exist, such as:
http://myipaddress:8080/subsonic/dwr/someotherpage.js

Inge.

[sindre_mehus]

Does the root exception look similar to this?

Code: Select all

javax.xml.transform.TransformerFactoryConfigurationError: Provider org.apache.xalan.processor.TransformerFactoryImpl not found
     javax.xml.transform.TransformerFactory.newInstance(Unknown Source)
     uk.ltd.getahead.dwr.convert.DOMConverter.<init>(DOMConverter.java:134)

If that's the case, then the problem is most likely some conflicting xml-parser libraries in Java 1.5 and Tomcat 5.0.

You can either upgrade to a later Tomcat version, or delete TOMCAT_HOME/common/endorsed/xml-apis.jar.

Here are some links with more info:
http://www.jivesoftware.com/jive/thread ... eID=107225
http://www.junlu.com/msg/166072.html

Thanks for letting me know! Please tell me how it goes.
Sindre

[Inge]

I removed xml-apis.jar for now, and the problem is gone. It also made adding songs to the current playlist a lot faster

I'll try to upgrade Tomcat later.

Thanks for your help, and for a great product!

regards,

Inge.

[nishanth]

Hey sindre,

I was facing the same problem while using DWR for my application. Thanks a lot for ur suggestions. It saved me a lot of time. And the links were really helpful. Initially I had removed xmlParserAPIs.jar from common/endorsed. This also worked but the Tomcat is a shared one, so we were not allowed to remove jar files. Hence had to add xalan.jar to common/endorsed which also works perfectly. Thanks again

Regards

Nish

Does the root exception look similar to this?

Code: Select all

javax.xml.transform.TransformerFactoryConfigurationError: Provider org.apache.xalan.processor.TransformerFactoryImpl not found
     javax.xml.transform.TransformerFactory.newInstance(Unknown Source)
     uk.ltd.getahead.dwr.convert.DOMConverter.<init>(DOMConverter.java:134)

If that's the case, then the problem is most likely some conflicting xml-parser libraries in Java 1.5 and Tomcat 5.0.

You can either upgrade to a later Tomcat version, or delete TOMCAT_HOME/common/endorsed/xml-apis.jar.

Here are some links with more info:
http://www.jivesoftware.com/jive/thread ... eID=107225
http://www.junlu.com/msg/166072.html

Thanks for letting me know! Please tell me how it goes.
Sindre

[linuxman]

Copy that jar and then restart tomcat5 and your problems go away. I was running tomcat 5.5 on fc7 and apparently tomcat can't find a common library in the system somehow and it produces all the errors trying to write the tags. Soon as I got this in the system is much faster and the java errors in IE7 have disappeared and can write the tags.