Jonathan Lalou's blog

Case

I try to deploy a Mule ESB configuration, using this XML:

<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns:pattern="http://www.mulesoft.org/schema/mule/pattern"
 xsi:schemaLocation="http://www.mulesoft.org/schema/mule/core
 http://www.mulesoft.org/schema/mule/core/3.1/mule.xsd
 http://www.mulesoft.org/schema/mule/pattern
 http://www.mulesoft.org/schema/mule/pattern/3.1/mule-pattern.xsd
 ">
 <pattern:simple-service name="authenticationService"
 address="http://localhost:1234/authenticationService"
 component-class="lalou.jonathan.esb.components.AuthenticationComponent"
 type="direct" />
</mule>

I get the following error:

Ignored XML validation warning
org.xml.sax.SAXParseException: schema_reference.4: Failed to read schema document 'http://www.mulesoft.org/schema/mule/pattern/3.1/mule-pattern.xsd'

Extended Stacktrace

2011-11-22 16:10:25,375 WARN  xml.XmlBeanDefinitionReader         - Ignored XML validation warning
org.xml.sax.SAXParseException: schema_reference.4: Failed to read schema document 'http://www.mulesoft.org/schema/mule/pattern/3.1/mule-pattern.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:195)
 at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.warning(ErrorHandlerWrapper.java:96)
 at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:380)

Notice that Mule ESB files are similar to classic Spring files. Of course, I first checked the pointed XSD was actually reachable.
Anyway, this error should be raised when your application, for any reason -firewall, proxies, network interruption-, cannot access the remote site where the XSD is hosted.

Fix

• Copy the XSD to a local folder
• Create a file spring.schemas
• Make it available in the classpath in META-INF.
• Add the following line

• http\://www.mulesoft.org/schema/mule/pattern/3.1/mule-pattern.xsd=WEB-INF/classes/mule-pattern.xsd

  The pattern is: missing resource (beware of escaping colon) = path in classpath of the local XSD

• Rebuild, pack and run!