Atomikos，Tomcat，JTA java.lang.ClassCastException

Question

试图让事务使用Tomcat、Atomikos、ActiveMQ和MySql工作。遵循这些例子：Tomcat 7与Atomikos 3.5.2的集成和Tomcat 7.0.27与Atomikos 3.7.1的集成没有成功.

ERROR: com.atomikos.icatch.jta.UserTransactionManager cannot be cast to javax.transaction.TransactionManager
java.lang.ClassCastException: com.atomikos.icatch.jta.UserTransactionManager cannot be cast to javax.transaction.TransactionManager

使用：

• 猫7.0.29
• Atomikos 3.7.1
• ActiveMQ 5.8.0
• MySQL 5.5.31

将下面的jars放在$TOMCAT_HOME/lib下面

• atomikos-integration-extension-3.7.1-20120529.jar
• atomikos-util-3.7.1.jar
• transactions-3.7.1.jar
• transactions-api-3.7.1.jar
• transactions-jdbc-3.7.1.jar
• transactions-jms-3.7.1.jar
• transactions-jta-3.7.1.jar
• geronimo-jta_1.0.1B_spec-1.0.jar
• activemq-all-5.8.0.jar
• mysql-connector-java-5.1.25.jar

以下是transactions.properties的内容

com.atomikos.icatch.service=com.atomikos.icatch.standalone.UserTransactionServiceFactory
com.atomikos.icatch.automatic_resource_registration=true
com.atomikos.icatch.output_dir=../work/atomikos
com.atomikos.icatch.log_base_dir=../work/atomikos/log
com.atomikos.icatch.enable_logging=true
com.atomikos.icatch.console_log_level=TRACE

context.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <Context>
    <WatchedResource>WEB-INF/web.xml</WatchedResource>
    <Transaction factory="com.atomikos.icatch.jta.UserTransactionFactory" />

    <Resource name="TransactionManager"
          auth="Container"
          type="com.atomikos.icatch.jta.UserTransactionManager"
          factory="org.apache.naming.factory.BeanFactory" />

    <Resource name="UserTransaction"
          auth="Container"
          type="com.atomikos.icatch.jta.UserTransactionImp"
          factory="org.apache.naming.factory.BeanFactory" />                 

    <Resource name="jms/ConnectionFactory"
            auth="Container"
            description="JMS Connection Factory"
            type="com.atomikos.jms.AtomikosConnectionFactoryBean"
            factory="com.atomikos.tomcat.EnhancedTomcatAtomikosBeanFactory"
            uniqueResourceName="jms/ConnectionFactory"
            xaConnectionFactoryClassName="org.apache.activemq.ActiveMQXAConnectionFactory"
            xaProperties.brokerURL="vm://localhost"
            xaProperties.transportType="1"
            localTransactionMode="true" />

    <Resource name="jms/WsTopic" 
          auth="Container"
          type="org.apache.activemq.command.ActiveMQTopic" 
          factory="org.apache.activemq.jndi.JNDIReferenceFactory"
          physicalName="WS.TOPIC" />

    <Resource name="jms/WsQueue" 
          auth="Container"
          type="org.apache.activemq.command.ActiveMQQueue"
          factory="org.apache.activemq.jndi.JNDIReferenceFactory" 
          physicalName="WS.QUEUE" />


   <!--  MySQL -->
   <Resource name="jdbc/DB"
          auth="Container"
          type="com.atomikos.jdbc.AtomikosDataSourceBean"
          factory="com.atomikos.tomcat.EnhancedTomcatAtomikosBeanFactory"
          uniqueResourceName="jdbc/DB"
          minPoolSize="5"
          maxPoolSize="10"
          testQuery="SELECT 1 FROM DUAL"             
          xaDataSourceClassName="com.mysql.jdbc.jdbc2.optional.MysqlXADataSource"
          xaProperties.databaseName="db"
          xaProperties.serverName="localhost"
          xaProperties.port="3306"
          xaProperties.user="user"
          xaProperties.password="password"
          xaProperties.url="jdbc:mysql://localhost:3306/db"
          xaProperties.pinGlobalTxToPhysicalConnection="true"
          xaProperties.autoReconnect="true"
          xaProperties.autoReconnectForConnectionPools="true"
          xaProperties.autoReconnectForPools="true" />
</Context>

相关的java代码：

import javax.transaction.Transaction;
import javax.transaction.TransactionManager;
import javax.transaction.UserTransaction;
...

Hashtable<String, String> hashTable = new Hashtable<String, String>();
try {
    Context ctx = new InitialContext(hashTable);
    ctx = (Context) jndiContext.lookup("java:comp/env");

    TransactionManager transactionManager = (TransactionManager) ctx.lookup("TransactionManager");
} catch (Exception e) {
    e.printStackTrace();
}

我做错了什么？

编辑：

在从$TOMCAT_HOME/lib中删除activemq-all-5.8.0.jar之后，我能够通过最初的错误，但现在我得到了：

com.atomikos.jms.AtomikosJMSException: Error in proxy
at com.atomikos.jms.AtomikosJMSException.throwAtomikosJMSException(AtomikosJMSException.java:54)
at com.atomikos.jms.ConsumerProducerSupport.handleException(ConsumerProducerSupport.java:61)
at com.atomikos.jms.AtomikosJmsMessageConsumerProxy.receive(AtomikosJmsMessageConsumerProxy.java:73)
at com.atomikos.jms.AtomikosJmsMessageConsumerProxy.receive(AtomikosJmsMessageConsumerProxy.java:137)
...
at java.lang.Thread.run(Thread.java:619)
Caused by: com.atomikos.jms.AtomikosTransactionRequiredJMSException: The JMS session you are using requires a JTA transaction context for the calling thread and none was found.
Please correct your code to do one of the following: 
1. start a JTA transaction if you want your JMS operations to be subject to JTA commit/rollback, or
2. increase the maxPoolSize of the AtomikosConnectionFactoryBean to avoid transaction timeout while waiting for a connection, or
3. create a non-transacted session and do session acknowledgment yourself, or
4. set localTransactionMode to true so connection-level commit/rollback are enabled.
    at com.atomikos.jms.AtomikosTransactionRequiredJMSException.throwAtomikosTransactionRequiredJMSException(AtomikosTransactionRequiredJMSException.java:38)
    at com.atomikos.jms.ConsumerProducerSupport.enlist(ConsumerProducerSupport.java:107)
    at com.atomikos.jms.AtomikosJmsMessageConsumerProxy.receive(AtomikosJmsMessageConsumerProxy.java:70)
    ... 5 more

Answer 1

Tomcat使用多类装载器。参见它们的定义，它是如何工作的，哪个优先(引导、系统、webapp、公共)。我假设您将geronimo-jta_1.0.1B_spec-1.0.jar和/或transactions-jta-3.7.1.jar放在WAR文件webapp.war/WEB-INF/lib/以及$TOMCAT_HOME/lib/之外。这可能会导致问题，因为不同的类加载器将多次加载javax.transaction.TransactionManager类。即使类具有相同的名称，如果由不同的类加载器加载，转换也会失败。

1. 当Tomcat初始化由TransactionManager实现的context.xml中定义的容器范围的com.atomikos.icatch.jta.UserTransactionManager资源时，它首先使用公共类加载器($Tomcat_HOME/lib/*..jar)加载。(Tomcat目前不使用任何webapp类加载程序。)
2. 在web应用程序中使用javax.transaction.TransactionManager类，现在它将从位于WAR文件中的webapp.war/WEB-INF/lib/文件夹中的JAR文件的副本中加载webapp类加载器。

尝试从javax.transaction.TransactionManager类中删除包含webapp.war/WEB-INF/lib/类的JAR文件，并尝试重新部署应用程序。

或者，在CLASSPATH系统变量中列出这些JAR文件，这样这些类将由在Tomcat中具有优先级的系统类加载器加载。