我遇到了一个非常烦人的问题，即 Jboss AS 7.1 中的 de ojdbc6 驱动程序加载了两次类。我已经通过谷歌进行了研究，但没有找到任何答案。
这就是问题所在：我在 JBoss 中部署了两只耳朵，其中一只在它的 jboss-deployment-structure 中具有与 JBoss 中的 oracle 模块的依赖关系，它依赖于 javax.api 和 javax.transaction.api。另一只耳朵通过使用 ant 任务在其启动时执行一些 liquibase 更改控制，该 ant 任务具有运行 liquibase 所需的 jar 作为类路径（oracle 驱动程序与 JBoss 模块中的相同）。在standalone-full.xml 中，我定义了第一只耳朵所需的一些 xa:datasources。
现在，问题是，当服务器启动并在 liquibase 更改控件之后，正确执行与 xa:datasources 的连接时，由于此错误而无法创建：
11:56:00,029 WARN [org.jboss.jca.core.connectionmanager.pool.strategy.PoolBySubject] (MSC service thread 1-6) IJ000604: Throwable while attempting to get a new connection: null: javax.resource.ResourceException: Could not create connection
at org.jboss.jca.adapters.jdbc.xa.XAManagedConnectionFactory.getXAManagedConnection(XAManagedConnectionFactory.java:447) [ironjacamar-jdbc-1.0.9.Final.jar:1.0.9.Final]
at org.jboss.jca.adapters.jdbc.xa.XAManagedConnectionFactory.createManagedConnection(XAManagedConnectionFactory.java:385) [ironjacamar-jdbc-1.0.9.Final.jar:1.0.9.Final]
at org.jboss.jca.core.connectionmanager.pool.mcp.SemaphoreArrayListManagedConnectionPool.createConnectionEventListener(SemaphoreArrayListManagedConnectionPool.java:761)
at org.jboss.jca.core.connectionmanager.pool.mcp.SemaphoreArrayListManagedConnectionPool.getConnection(SemaphoreArrayListManagedConnectionPool.java:343)
at org.jboss.jca.core.connectionmanager.pool.AbstractPool.getSimpleConnection(AbstractPool.java:397)
at org.jboss.jca.core.connectionmanager.pool.AbstractPool.getConnection(AbstractPool.java:365)
at org.jboss.jca.core.connectionmanager.AbstractConnectionManager.getManagedConnection(AbstractConnectionManager.java:329)
at org.jboss.jca.core.connectionmanager.tx.TxConnectionManagerImpl.getManagedConnection(TxConnectionManagerImpl.java:368)
at org.jboss.jca.core.connectionmanager.AbstractConnectionManager.allocateConnection(AbstractConnectionManager.java:464)
at org.jboss.jca.adapters.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:129) [ironjacamar-jdbc-1.0.9.Final.jar:1.0.9.Final]
at org.hibernate.service.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:141) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcServicesImpl.java:253) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:119) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.service.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:75) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:159) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:131) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:71) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2270) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2266) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1735) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1775) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
at saes.util.HibernateDB.init(HibernateDB.java:1047) [session.jar:]
at saes.admin.init.servlet.InitServlet.init(InitServlet.java:105) [session.jar:]
at saes.admin.init.servlet.REISInitServlet.init(REISInitServlet.java:57) [session.jar:]
at javax.servlet.GenericServlet.init(GenericServlet.java:242) [jboss-servlet-api_3.0_spec-1.0.0.Final.jar:1.0.0.Final]
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1202) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1102) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:3655) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardContext.start(StandardContext.java:3873) [jbossweb-7.0.13.Final.jar:]
at org.jboss.as.web.deployment.WebDeploymentService.start(WebDeploymentService.java:90) [jboss-as-web-7.1.1.Final.jar:7.1.1.Final]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_21]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_21]
at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0_21]
Caused by: java.lang.LinkageError: loader constraint violation in interface itable initialization: when resolving method "oracle.jdbc.xa.client.OracleXAConnection.getXAResource()Ljavax/transaction/xa/XAResource;" the class loader (instance of org/jboss/modules/ModuleClassLoader) of the current class, oracle/jdbc/xa/client/OracleXAConnection, and the class loader (instance of <bootloader>) for interface javax/sql/XAConnection have different Class objects for the type ransaction/xa/XAResource; used in the signature
at oracle.jdbc.xa.client.OracleXADataSource.getPooledConnection(OracleXADataSource.java:469)
at oracle.jdbc.xa.client.OracleXADataSource.getXAConnection(OracleXADataSource.java:156)
at oracle.jdbc.xa.client.OracleXADataSource.getXAConnection(OracleXADataSource.java:130)
at org.jboss.jca.adapters.jdbc.xa.XAManagedConnectionFactory.getXAManagedConnection(XAManagedConnectionFactory.java:430) [ironjacamar-jdbc-1.0.9.Final.jar:1.0.9.Final]
... 34 more
经过一些调试，我得出的结论是，当 liquibase 执行 jboss 第一次加载 oracle 驱动程序并使用（加载）来自 jre 的 rt.jar 的 XAResource 但在此之后，当另一只耳朵尝试创建与数据源的连接时在 jboss 模块中使用从 javax.transaction.api 模块加载 XAResource 类的 oracle，因此服务器抛出异常。
有没有办法使用另一个类加载器来执行 liquibase 或告诉它不能从 rt.jar 加载 XAResource 类？有没有人遇到过这个问题或知道如何解决它？
感谢您提供的任何帮助