java.lang.LinkageError: loader constraint violation in Grails project

Question

I've built a Grails project with POI (include poi-3.7 and poi-ooxml-3.7). I've added these 2 external libraries to dependencies block in BuildConfig.groovy file of my project. There's nothing strange when I compiled it. But when I called the command "run-app" for that project, an error occured with below stacktrace:

Base Directory: <path-to-my-project>
Resolving dependencies...
Dependencies resolved in 5546ms.
Running script D:\_TOOLS\STS\grails-1.3.5\scripts\RunApp.groovy
Environment set to development
Running Grails application..
2011-05-23 18:51:01,225 [main] ERROR context.GrailsContextLoader  - Error executing bootstraps: java.lang.LinkageError: loader constraint violation: loader (instance of <bootloader>) previously initiated loading for a different type with name "org/w3c/dom/DOMConfiguration"
org.codehaus.groovy.runtime.InvokerInvocationException: java.lang.LinkageError: loader constraint violation: loader (instance of <bootloader>) previously initiated loading for a different type with name "org/w3c/dom/DOMConfiguration"
    at grails.spring.BeanBuilder.invokeBeanDefiningClosure(BeanBuilder.java:723)
    at grails.spring.BeanBuilder.beans(BeanBuilder.java:573)
    at grails.spring.BeanBuilder.invokeMethod(BeanBuilder.java:519)
    at org.grails.tomcat.TomcatServer.start(TomcatServer.groovy:212)
    at grails.web.container.EmbeddableServer$start.call(Unknown Source)
    at RunApp$_run_closure5_closure12.doCall(RunApp:158)
    at RunApp$_run_closure5_closure12.doCall(RunApp)
    at _GrailsSettings_groovy$_run_closure10.doCall(_GrailsSettings_groovy:280)
    at _GrailsSettings_groovy$_run_closure10.call(_GrailsSettings_groovy)
    at RunApp$_run_closure5.doCall(RunApp:149)
    at RunApp$_run_closure5.call(RunApp)
    at RunApp.runInline(RunApp:116)
    at RunApp.this$4$runInline(RunApp)
    at RunApp$_run_closure1.doCall(RunApp:59)
    at RunApp$_run_closure1.doCall(RunApp:33)
    at gant.Gant$_dispatch_closure5.doCall(Gant.groovy:381)
    at gant.Gant$_dispatch_closure7.doCall(Gant.groovy:415)
    at gant.Gant$_dispatch_closure7.doCall(Gant.groovy)
    at gant.Gant.withBuildListeners(Gant.groovy:427)
    at gant.Gant.this$2$withBuildListeners(Gant.groovy)
    at gant.Gant$this$2$withBuildListeners.callCurrent(Unknown Source)
    at gant.Gant.dispatch(Gant.groovy:415)
    at gant.Gant.this$2$dispatch(Gant.groovy)
    at gant.Gant.invokeMethod(Gant.groovy)
    at gant.Gant.executeTargets(Gant.groovy:590)
    at gant.Gant.executeTargets(Gant.groovy:589)

Caused by: java.lang.LinkageError: loader constraint violation: loader (instance of <bootloader>) previously initiated loading for a different type with name "org/w3c/dom/DOMConfiguration"
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2427)
    at java.lang.Class.getDeclaredMethods(Class.java:1791)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.codehaus.groovy.util.LazyReference.getLocked(LazyReference.java:46)
    at org.codehaus.groovy.util.LazyReference.get(LazyReference.java:33)
    at grails.spring.DynamicElementReader.invokeMethod(DynamicElementReader.groovy:121)
    ... 26 more  

And here is my configuration:

dependencies {  
        provided ('com.oracle:ojdbc6_g:11.2.0.1.0')  
        runtime ('org.apache.poi:poi:3.7', 'org.apache.poi:poi-ooxml:3.7')  
    }  

How can I do to make solve this? Thank you so much!

Answer 1

Here's the fix we finally came around to after several hours of going back and forth. In short, exclude xmlbeans from poi and create another xmlbeans jar with the offending class removed. Here's the incantation to exorcise the evil linkage error.

• Modify BuildConfig.groovy

    dependencies {
       compile ('org.apache.poi:poi-ooxml:3.6') {excludes "xmlbeans"}
    }

• Extract xmlbeans

  cd ~
  mkdir xmlbeantmp
  cd xmlbeantmp
  cp ~/.ivy2/cache/org.apache.xmlbeans/xmlbeans/jars/xmlbeans-2.3.0.jar .
  jar xf xmlbeans-2.3.0.jar
  

• Remove offending class package

  cd org
  rm -rf w3c/
  

• Recreate the jar

  cd ../
  rm xmlbean-2.3.0.jar
  jar cf xmlbean-2.3.0.jar *
  

• Copy jar into your projects lib

  cp xmlbean-2.3.0.jar your_grails_project/lib/.
  

• Show the love

  click answer up arrow. :)

Answer 2

There's a conflict between one of POI's dependencies (xmlbeans) and grails. You can exclude it as follows:

dependencies {
    compile('org.apache.poi:poi-ooxml:3.7') { excludes "xmlbeans" }
}

The following links were useful in tracking down the problem:

• http://markmail.org/message/ojglzgft57ts4dgw
• http://jira.grails.org/browse/MAVEN-22