遠程機器未運行時如何初始化遠程JMS隊列的ConnectionFactory？

Question

使用JBoss 4.0.5，JBossMQ和Spring 2.0.8，我試圖配置Spring來實例化依賴於遠程JMS隊列資源的bean。我遇到的所有示例都依賴於使用JNDI來查找遠程ConnectionFactory對象等內容。

我的問題是，當試圖啓動一個將消息放入遠程隊列的機器時，如果遠程機器沒有啓動，JNDI查找失敗，導致部署失敗。有沒有辦法讓Spring繼續嘗試在後臺查找此對象，同時不阻止剩餘的部署？

Answer 1

Iit很難確定沒有看到您的spring配置，但假設您使用Spring的JndiObjectFactoryBean來執行JNDI查找，那麼您可以將lookupOnStartup屬性設置爲false，這允許上下文即使在JNDI目標不在那裏。 JNDI解析將在第一次使用ConnectionFactory時完成。

但是，這只是將問題進一步轉移到鏈上，因爲如果某個其他組件試圖在啓動時獲得JMS Connection，那麼您又回到了開始的位置。您可以在其他bean上使用lazy-init="true"屬性來防止在部署時發生這種情況，但是很容易在您的配置中意外放入一些東西，這會強制所有內容初始化。

Answer 2

你是對的。我試着將lookupOnStartup設置爲false並且lazy-init = true。這只是首次嘗試使用隊列時的問題。然後拋出如下異常：

[org.jboss.mq.il.uil2.SocketManager] Failed to handle: org.jboss.mq.il.uil2.msgs.CloseMsg29702787[msgType: m_connectionClosing, msgID: -2147483606, error: null] 
java.io.IOException: Client is not connected 

此外，它看起來像查找再也不會嘗試。當帶有遠程隊列的機器恢復運行時，隨後不會處理任何消息。這確實看起來好像應該在J2EE廢話的用例範圍內，然而我沒有太多的運氣......感覺它應該甚至可能是解決了問題。

爲了完成的緣故，以下是我的Spring配置的相關部分。

<bean id="jndiTemplate" class="org.springframework.jndi.JndiTemplate"> 
     <property name="environment"> 
      <props> 
      <prop key="java.naming.provider.url">localhost:1099</prop> 
      <prop key="java.naming.factory.url.pkgs">org.jnp.interfaces:org.jboss.naming</prop> 
      <prop key="java.naming.factory.initial">org.jnp.interfaces.NamingContextFactory</prop> 
      </props> 
     </property> 
    </bean> 

    <bean id="connectionFactory" class="org.springframework.jndi.JndiObjectFactoryBean"> 
     <property name="jndiTemplate"> 
      <ref bean="jndiTemplate"/> 
     </property> 
     <property name="jndiName"> 
      <value>ConnectionFactory</value> 
     </property> 
    </bean> 

    <bean id="remoteJndiTemplate" class="org.springframework.jndi.JndiTemplate" lazy-init="true"> 
     <property name="environment"> 
      <props> 
      <prop key="java.naming.provider.url">jnp://10.0.100.232:1099</prop> 
      <prop key="java.naming.factory.url.pkgs">org.jnp.interfaces:org.jboss.naming</prop> 
      <prop key="java.naming.factory.initial">org.jnp.interfaces.NamingContextFactory</prop> 
      </props> 
     </property> 
    </bean> 

    <bean id="remoteConnectionFactory" class="org.springframework.jndi.JndiObjectFactoryBean" lazy-init="true"> 
     <property name="jndiTemplate" ref="remoteJndiTemplate"/> 
     <property name="jndiName" value="ConnectionFactory" /> 
     <property name="lookupOnStartup" value="false" /> 
     <property name="proxyInterface" value="javax.jms.ConnectionFactory" /> 
    </bean> 

    <bean id="destinationResolver" class="com.foo.jms.FooDestinationResolver" /> 

    <bean id="localVoicemailTranscodingDestination" class="org.springframework.jndi.JndiObjectFactoryBean"> 
     <property name="jndiTemplate" ref="jndiTemplate"/> 
     <property name="jndiName" value="queue/voicemailTranscoding" /> 
    </bean> 

    <bean id="globalVoicemailTranscodingDestination" class="org.springframework.jndi.JndiObjectFactoryBean" lazy-init="true" > 
     <property name="jndiTemplate" ref="remoteJndiTemplate" /> 
     <property name="jndiName" value="queue/globalVoicemailTranscoding" /> 
    </bean> 

    <bean id="jmsTemplate" class="org.springframework.jms.core.JmsTemplate" > 
     <property name="connectionFactory" ref="connectionFactory"/> 
     <property name="defaultDestination" ref="localVoicemailTranscodingDestination" /> 
    </bean> 

    <bean id="remoteJmsTemplate" class="org.springframework.jms.core.JmsTemplate" lazy-init="true"> 
     <property name="connectionFactory" ref="remoteConnectionFactory"/> 
     <property name="destinationResolver" ref="destinationResolver"/> 
    </bean> 

    <bean id="globalQueueStatus" class="com.foo.bar.recording.GlobalQueueStatus" /> 

    <!-- Do not deploy this bean for machines other than transcoding machine --> 
    <condbean:cond test="${transcoding.server}"> 
     <bean id="voicemailMDPListener" 
       class="org.springframework.jms.listener.adapter.MessageListenerAdapter" lazy-init="true"> 
      <constructor-arg> 
       <bean class="com.foo.bar.recording.mdp.VoicemailMDP" lazy-init="true"> 
        <property name="manager" ref="vmMgr" /> 
       </bean> 
      </constructor-arg> 
     </bean> 
    </condbean:cond> 

    <bean id="voicemailForwardingMDPListener" 
      class="org.springframework.jms.listener.adapter.MessageListenerAdapter" lazy-init="true"> 
     <constructor-arg> 
      <bean class="com.foo.bar.recording.mdp.QueueForwardingMDP" lazy-init="true"> 
       <property name="queueStatus" ref="globalQueueStatus" /> 
       <property name="template" ref="remoteJmsTemplate" /> 
       <property name="remoteDestination" ref="globalVoicemailTranscodingDestination" /> 
      </bean> 
     </constructor-arg> 
    </bean> 

    <bean id="prototypeListenerContainer" 
      class="org.springframework.jms.listener.DefaultMessageListenerContainer" 
      abstract="true" 
      lazy-init="true"> 
     <property name="concurrentConsumers" value="5" /> 
     <property name="connectionFactory" ref="connectionFactory" /> 
     <!-- 2 is CLIENT_ACKNOWLEDGE: http://java.sun.com/j2ee/1.4/docs/api/constant-values.html#javax.jms.Session.CLIENT_ACKNOWLEDGE --> 
     <!-- 1 is autoacknowldge --> 
     <property name="sessionAcknowledgeMode" value="1" /> 
     <property name="sessionTransacted" value="true" /> 
    </bean> 

    <!-- Do not deploy this bean for machines other than transcoding machine --> 
    <condbean:cond test="${transcoding.server}"> 
     <bean id="voicemailMDPContainer" parent="prototypeListenerContainer" lazy-init="true"> 
      <property name="destination" ref="globalVoicemailTranscodingDestination" /> 
      <property name="messageListener" ref="voicemailMDPListener" /> 
     </bean> 
    </condbean:cond> 

    <bean id="voicemailForwardMDPContainer" parent="prototypeListenerContainer" lazy-init="true"> 
     <property name="destination" ref="localVoicemailTranscodingDestination" /> 
     <property name="messageListener" ref="voicemailForwardingMDPListener" /> 
    </bean>