How do i solve this Apache POI XSSFReader LinkageException?

[Balazs]

Hello,  
the exception is the following:

java.lang.LinkageError: loader constraint violation: when resolving method "org.apache.poi.xssf.eventusermodel.XSSFReader.<init>(Lorg/apache/poi/openxml4j/opc/OPCPackage;)V" the class loader (instance of org/apache/felix/framework/BundleWiringImpl$BundleClassLoader) of the current class, com/...., and the class loader (instance of org/apache/catalina/loader/ParallelWebappClassLoader) for the method's defining class, org/apache/poi/xssf/eventusermodel/XSSFReader, have different Class objects for the type org/apache/poi/openxml4j/opc/OPCPackage used in the signature

We have a support plugin, the pom.xml looks like that:

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.15</version>
    <exclusions>
        <exclusion>
          <groupId>commons-logging</groupId>
          <artifactId>commons-logging</artifactId>
        </exclusion>
        <exclusion>
          <groupId>log4j</groupId>
          <artifactId>log4j</artifactId>
        </exclusion>
        <exclusion>
          <groupId>commons-codec</groupId>
          <artifactId>commons-codec</artifactId>
        </exclusion>
        <exclusion>
          <groupId>org.hamcrest</groupId>
          <artifactId>hamcrest-core</artifactId>
        </exclusion>
        <exclusion>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
        </exclusion>
        <exclusion>
          <groupId>org.apache.commons</groupId>
          <artifactId>commons-collections4</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.15</version>
    <exclusions>
        <exclusion>
            <groupId>stax</groupId>
            <artifactId>stax-api</artifactId>
        </exclusion>
        <exclusion>
            <groupId>xml-apis</groupId>
            <artifactId>xml-apis</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>ooxml-schemas</artifactId>
    <version>1.4</version>
</dependency>

<Export-Package>
    liquibase*,
    org.apache.poi.*,
    org.apache.fop.*,
    org.openxmlformats.schemas.spreadsheetml.*
</Export-Package>
<Import-Package>
    !com.sun.javadoc,
    !com.sun.tools.javadoc,
    !junit.framework,
    !org.apache.commons.cli,
    !org.apache.batik.extension.svg,
    !org.apache.fontbox.cff.charset,
    !org.apache.fontbox.cff.encoding,
    !org.apache.jcp.xml.dsig.internal.dom,
    !org.apache.log,
    !org.apache.log.format,
    !org.apache.log.util,
    !org.apache.poi.hslf.blip,
    !org.apache.poi.hsmf,
    !org.apache.poi.hsmf.datatypes,
    !org.apache.poi.hsmf.extractor,
    !org.apache.poi.hwpf.extractor,
    !org.apache.tools.ant,
    !org.apache.tools.ant.taskdefs,
    !org.apache.tools.ant.types,
    !org.apache.tools.ant.types.resources,
    !org.apache.tools.ant.util,
    !org.apache.xml.security,
    !org.apache.xml.security.c14n,
    !org.apache.xml.security.utils,
    !org.junit,
    !org.junit.internal,
    !org.junit.runner,
    !org.junit.runner.notification,
    *;version="0.0"
</Import-Package>

The pom.xml of the actual plugin: 

<Import-Package>
    ...
    org.apache.poi;version="0.0.0",
    org.apache.poi.openxml4j.*;version="0.0.0",
    *;version="0.0"
</Import-Package>

I need the XSSFReader class in order to stream-read potential large xlsx files. The exception is thrown at line: 

XSSFReader r = new XSSFReader(pkg);

XSSFReader resides in the package 

org.apache.poi.xssf.eventusermodel

If I try to use the ReadOnlySharedStringsTable which class also resides in the same package I get:

java.lang.NoClassDefFoundError: org/apache/poi/xssf/eventusermodel/ReadOnlySharedStringsTable

If I search for poi on my container I get these results: 

/var/lib/confluence/plugins-osgi-cache/felix/felix-cache/bundle228/version0.0/OfficeConnector-7.0.8.jar-embedded/META-INF/lib/poi-scratchpad-3.5-FINAL.jar

/var/lib/confluence/plugins-osgi-cache/felix/felix-cache/bundle228/version0.0/OfficeConnector-7.0.8.jar-embedded/META-INF/lib/poi-ooxml-3.5-FINAL.jar

/var/lib/confluence/plugins-osgi-cache/felix/felix-cache/bundle228/version0.0/OfficeConnector-7.0.8.jar-embedded/META-INF/lib/poi-3.5-FINAL.jar

...

The poi version 3.5-FINAL does not include the ReadOnlySharedStringsTable class, which makes me believe that at runtime somehow this older version will be used.

Please note I can use the regular poi classes (XSSFWorkbook, SXSSFWorkbook...) without any problems.