Linkage error wile using custom Oracle Driver(xa-datasource-class) in standalone.xml

[jtiwari]

Hi All,

    I am trying to configure datasource in wildfly and for that I am using custom drive xa-datasource-class in standalone.xml. My custom class is using  XAResource/XACopnnection and other Javax classes.

  To configure the custom driver, I created a module for example com.oracle.jdbc and created a module.xml as below

<module xmlns="urn:jboss:module:1.3" name="com.oracle.jdbc">

    <resources> 

       <resource-root path="ojdbc6-11.jar"/>

       <resource-root path="xmz.jar"/> //custom driver jar

    </resources>

    <dependencies>

        <module name="javax.api"/>

        <module name="javax.transaction.api"/>

    <module name="org.jboss.ironjacamar.jdbcadapters"/>

    </dependencies>

</module>

    While starting server  I am facing the linkage error while doing so.

Caused by: java.lang.LinkageError: loader constraint violation: loader (instance of <bootloader>) previously initiated loading for a different type with name "javax/transaction/xa/XAResource".

Can somebody help me regarding the above issue. It would be a great help.

Thanks

Jtiwari

[pmm]

What are the contents of xmz.jar? You you have a javax.transaction.xa.XAResource class in there?

[jtiwari]

Thank you Philippe for the quick reply,

Yes,  xmz.jar is using javax.transaction.xa.XAResource . Actually, I have written a wrapper which is internally using  avax.transaction.xa.XAResource .

I tried to debug it bit more detail level using  -verbose:class  and I  found that javax.transaction.xa.XAResource is being loaded from jdk\rt.jar. Since, Wildfly also loads javax module(javax.transaction.api), so, I believe  this may be the primary reason for the  Linkage Error.

[Loaded javax.transaction.xa.XAResource from D:\Java\jdk\jre\lib\rt.jar]

Any help will be highly appreciated.

Thank you

Jitendra Tiwari

[pmm]

Is it just using javax.transaction.xa.XAResource or do you package it into the JAR?

[jtiwari]

yes , I packaged it as a jar, let me explain by the example

import javax.transaction.xa.XAResource

class xyz(){

   // using XAResource/XAConnection

}

packaged it into a jar called xmz.jar

Thanks

Jitendra Tiwari

[pmm]

You must not have any javax.transaction.* classes in the xmz.jar. It is ok to have classes there that use javax.transaction.* classes.

        <module name="javax.api"/>

        <module name="javax.transaction.api"/>

Will provide the javax.transaction.* classes to you at runtime.

[jtiwari]

Hello Philippe,

    I am using many custom wrapper classes inside xmz.jar,

MYConnection.java uses javax.transaction..xa.XAConnection.

Mydatasource.java uses javax.transaction..xa.XADatasource

Please suggest, how can I get rid of this issue.

Thanks.

Jitendra Tiwari

[pmm]

Having custom classes that use javax.transaction.* classes in xmz.jar is totatlly fine. Packing javax.transaction.* into xmz.jar is an issue. Just build xmz.jar containing your custom wrapper classes but do not include javax.transaction.* classes in the JAR.

[jtiwari]

Hello Philippe,

Thanks a lot for your suggestions.

      I verified the xmz.jar,  This jar does not contain any  javax.transaction.*  classes, only internally my custom classes are using those classes .  But yes, since my code is depend on ironjacamar-jdbc-1.1.5.Final.jar and ojdbc6.jar. I used these two jar just to compile my code.

Apart from that, I tried to remove all the jar from my application having javax package.

One more thing I observed that XAResource is getting loaded by the JDK rt.jar

[Loaded javax.transaction.xa.XAResource from <JAVA_HOME>\jre\lib\rt.jar].

That I believe may be the root cause.

I am not sure how to avoid class loading from rt.jar.

I tried almost every possible options. Any help on this issue would really be appreciated .

Thank You.

Jitendra Tiwari

[rhodan76]

[Loaded javax.transaction.xa.XAResource from <JAVA_HOME>\jre\lib\rt.jar].

Can someone explain why javax.transaction.xa.XAResource is also loaded from JDK? As far as i understand the javax.transaction package is NOT getting exported from jboss "sun.jdk" module (and also nowhere else) and thus should not be accessible by any classloader in Jboss/Wildfly?

<?xml version="1.0" encoding="UTF-8"?>

<!--

  ~ JBoss, Home of Professional Open Source.

  ~ Copyright 2010, Red Hat, Inc., and individual contributors

  ~ as indicated by the @author tags. See the copyright.txt file in the

  ~ distribution for a full listing of individual contributors.

  ~

  ~ This is free software; you can redistribute it and/or modify it

  ~ under the terms of the GNU Lesser General Public License as

  ~ published by the Free Software Foundation; either version 2.1 of

  ~ the License, or (at your option) any later version.

  ~

  ~ This software is distributed in the hope that it will be useful,

  ~ but WITHOUT ANY WARRANTY; without even the implied warranty of

  ~ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

  ~ Lesser General Public License for more details.

  ~

  ~ You should have received a copy of the GNU Lesser General Public

  ~ License along with this software; if not, write to the Free

  ~ Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA

  ~ 02110-1301 USA, or see the FSF site: http://www.fsf.org.

  -->

<module xmlns="urn:jboss:module:1.3" name="sun.jdk">

    <resources>

        <!-- currently jboss modules has not way of importing services from

        classes.jar so we duplicate them here -->

        <resource-root path="service-loader-resources"/>

    </resources>

    <dependencies>

        <system export="true">

            <paths>

                <path name="com/sun/script/javascript"/>

                <path name="jdk/nashorn/api/scripting"/>

                <path name="com/sun/image/codec/jpeg"/>

                <path name="com/sun/imageio/plugins/bmp"/>

                <path name="com/sun/imageio/plugins/common"/>

                <path name="com/sun/imageio/plugins/gif"/>

                <path name="com/sun/imageio/plugins/jpeg"/>

                <path name="com/sun/imageio/plugins/png"/>

                <path name="com/sun/imageio/plugins/wbmp"/>

                <path name="com/sun/imageio/spi"/>

                <path name="com/sun/imageio/stream"/>

                <path name="com/sun/jndi/dns"/>

                <path name="com/sun/jndi/ldap"/>

                <path name="com/sun/jndi/url"/>

                <path name="com/sun/jndi/url/corbaname"/>

                <path name="com/sun/jndi/url/dns"/>

                <path name="com/sun/jndi/url/iiop"/>

                <path name="com/sun/jndi/url/iiopname"/>

                <path name="com/sun/jndi/url/ldap"/>

                <path name="com/sun/jndi/url/ldaps"/>

                <path name="com/sun/media/sound"/>

                <path name="com/sun/crypto/provider"/>

                <path name="com/sun/org/apache/xml/internal/security/transforms/implementations"/>

                <path name="com/sun/security/auth"/>

                <path name="com/sun/security/auth/login"/>

                <path name="com/sun/security/auth/module"/>

                <path name="com/sun/tools/internal/xjc"/>               

                <path name="sun/awt"/>

                <path name="sun/awt/color"/>

                <path name="sun/awt/datatransfer"/>

                <path name="sun/awt/dnd"/>

                <path name="sun/awt/event"/>

                <path name="sun/awt/geom"/>

                <path name="sun/awt/im"/>

                <path name="sun/awt/image"/>

                <path name="sun/awt/image/codec"/>

                <path name="sun/awt/motif"/>

                <path name="sun/awt/resources"/>

                <path name="sun/awt/shell"/>

                <path name="sun/awt/util"/>

                <path name="sun/awt/windows"/>

                <path name="sun/awt/X11"/>

                <path name="sun/dc"/>

                <path name="sun/print"/>

                <path name="sun/print/resources"/>

                <path name="sun/security/action"/>

                <path name="sun/security/pkcs"/>

                <path name="sun/security/x509"/>

                <path name="sun/jdbc/odbc"/>

                <path name="sun/jdbc/odbc/ee"/>

                <path name="sun/font"/>

                <path name="sun/misc"/>

                <path name="sun/io"/>

                <path name="sun/nio"/>

                <path name="sun/nio/ch"/>

                <path name="sun/nio/cs"/>

                <path name="sun/nio/cs/ext"/>

                <path name="sun/security"/>

                <path name="sun/security/util"/>

                <path name="sun/security/krb5"/>

                <path name="sun/util"/>

                <path name="sun/util/calendar"/>

                <path name="sun/util/locale"/>

                <path name="sun/util/resources"/>

                <path name="sun/security/pkcs11"/>

                <path name="sun/security/provider"/>

                <path name="sun/text"/>

                <path name="META-INF/services"/>

            </paths>

            <exports>

                <include-set>

                    <path name="META-INF/services"/>

                </include-set>

            </exports>

        </system>

    </dependencies>

</module>

[pmm]

Is it really loaded from the JDK and not from the javax.transaction.api module?

[rhodan76]

To be correct, the XAResource class is loaded from javax.transaction.api module

[Loaded javax.transaction.xa.XAResource from jar:file:/C://wildfly-8.1.0.Final/modules/system/layers/base/javax/transaction/api/main/jboss-transaction-api_1.2_spec-1.0.0.Final.jar!/]

but later in deployment there is an attempt to load XAResource class also from JDK (i think because we defined a datasource in standalone.xml using jdbcdslog) but the loader rejects this:

[Loaded javax.transaction.xa.XAResource from C:\Program Files\Java\jdk1.7.0_60\jre\lib\rt.jar]

[Constraint check failed for name javax/transaction/xa/XAResource, loader <bootloader>: the presented class object differs from that stored ]

We have jdbcdslog included as a module,

<module xmlns="urn:jboss:module:1.1" name="org.jdbcdslog">

    <resources>

        <resource-root path="jdbcdslog-1.0.5.jar"/>

    </resources>

    <dependencies>

        <module name="org.slf4j"/>     

        <module name="javax.api"/>

        <module name="javax.transaction.api"/>     

        <!-- TODO: add other database modules as other optional dependencies like h2 -->

        <module name="com.oracle.ojdbc6" optional="true" />     

    </dependencies>

</module>

which runs into loader constraint violation trouble with XAResource class:

Caused by: java.lang.LinkageError: loader constraint violation: loader (instance of <bootloader>) previously initiated loading for a different type with name "javax/transaction/xa/XAResource"

    at java.lang.Class.getDeclaredMethods0(Native Method) [rt.jar:1.7.0_60]

    at java.lang.Class.privateGetDeclaredMethods(Class.java:2570) [rt.jar:1.7.0_60]

    at java.lang.Class.privateGetPublicMethods(Class.java:2690) [rt.jar:1.7.0_60]

    at java.lang.Class.getMethods(Class.java:1467) [rt.jar:1.7.0_60]

    at sun.misc.ProxyGenerator.generateClassFile(ProxyGenerator.java:426) [rt.jar:1.7.0_60]

    at sun.misc.ProxyGenerator.generateProxyClass(ProxyGenerator.java:323) [rt.jar:1.7.0_60]

    at java.lang.reflect.Proxy$ProxyClassFactory.apply(Proxy.java:671) [rt.jar:1.7.0_60]

    at java.lang.reflect.Proxy$ProxyClassFactory.apply(Proxy.java:591) [rt.jar:1.7.0_60]

    at java.lang.reflect.WeakCache$Factory.get(WeakCache.java:244) [rt.jar:1.7.0_60]

    at java.lang.reflect.WeakCache.get(WeakCache.java:141) [rt.jar:1.7.0_60]

    at java.lang.reflect.Proxy.getProxyClass0(Proxy.java:454) [rt.jar:1.7.0_60]

    at java.lang.reflect.Proxy.newProxyInstance(Proxy.java:736) [rt.jar:1.7.0_60]

    at org.jdbcdslog.XAConnectionLoggingProxy.wrap(XAConnectionLoggingProxy.java:10)

    at org.jdbcdslog.DataSourceProxyBase.getXAConnection(DataSourceProxyBase.java:126)

    at org.jboss.jca.adapters.jdbc.xa.XAManagedConnectionFactory.getXAManagedConnection(XAManagedConnectionFactory.java:497)

    ... 12 more

jdbcdslog problematic source seems to be:

package org.jdbcdslog;

import java.lang.reflect.Proxy;

import javax.sql.XAConnection;

public class XAConnectionLoggingProxy {

    public static XAConnection wrap(XAConnection con) {

       return (XAConnection)Proxy.newProxyInstance(con.getClass().getClassLoader() , new Class[]{XAConnection.class}, new GenericLoggingProxy(con));

   }

}

XAConnection.getClass().getClassLoader seems to reference a classloader which tries to load another version of javax.transaction.xa.XAResource than provided by javax.transaction.api module =  java.lang.LinkageError: loader constraint violation?

Am i correct?

[rhodan76]

Philipe Marschall schrieb:

Is it really loaded from the JDK and not from the javax.transaction.api module?

Rhodan76 schrieb:

To be correct, the XAResource class is loaded from javax.transaction.api module

[Loaded javax.transaction.xa.XAResource from jar:file:/C://wildfly-8.1.0.Final/modules/system/layers/base/javax/transaction/api/main/jboss-transaction-api_1.2_spec-1.0.0.Final.jar!/]

but later in deployment there is an attempt to load XAResource class also from JDK (i think because we defined a datasource in standalone.xml using jdbcdslog) but the loader rejects this:

[Loaded javax.transaction.xa.XAResource from C:\Program Files\Java\jdk1.7.0_60\jre\lib\rt.jar]

[Constraint check failed for name javax/transaction/xa/XAResource, loader <bootloader>: the presented class object differs from that stored ]

The question is, why is there a second attempt to load javax/transaction/xa/XAResource but from a different library (rt.jar of JDK) insteadof "javax.transaction.api" module. All modules only have declared dependencies to "javax.transaction.api" module.

[pmm]

Which classloader does

org.jdbcdslog.XAConnectionLoggingProxy.wrap(XAConnectionLoggingProxy.java:10)

pass to Proxy.newProxyInstance?

[rhodan76]

Philippe Marschall schrieb:

Which classloader does

org.jdbcdslog.XAConnectionLoggingProxy.wrap(XAConnectionLoggingProxy.java:10)

pass to Proxy.newProxyInstance?

The classloader of another module ("com.oracle.ojdbc6"):

ModuleClassLoader for Module "com.oracle.ojdbc6:main" from local module loader @38f4f222 (finder: local module finder @5944b364 (roots: C:\wildfly-8.1.0.Final\modules,C:\wildfly-8.1.0.Final\modules\system\layers\base))

module definition:

<?xml version="1.0" encoding="UTF-8"?>
<module xmlns="urn:jboss:module:1.0" name="com.oracle.ojdbc6">
    <resources>
        <resource-root path="com.oracle.ojdbc6-11.2.0.jar"/>
    </resources>
    <dependencies>
        <module name="javax.api"/>
        <module name="javax.transaction.api"/>
    </dependencies>
</module>