ActiveMQ.xml文件的主要配置

佘小宝的爹

　　ActiveMQ.xml文件默认位置位于 activemq/conf/目录下，主要的配置及解析如下:
<beans  
  xmlns="http://www.springframework.org/schema/beans"  
  xmlns:amq="http://activemq.org/config/1.0"  
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd   
  http://activemq.org/config/1.0 http://activemq.apache.org/schema/activemq-core.xsd   
  http://activemq.apache.org/camel/schema/spring>  
   
  <!-- persistent="true"表示要持久化存储消息，和子元素persistenceAdapter结合使用 -->  
  <!-- dataDirectory默认的存储持久化数据的目录 -->  
  <!-- brokerName 设置broker的name，在注意在网络上必须是唯一的-->  
  <!-- 更多参考http://activemq.apache.org/xbean-xml-reference-50.html#XBeanXMLReference5.0-brokerelement -->  
  <broker xmlns="http://activemq.org/config/1.0" brokerName="192.168.1.148" persistent ="true" dataDirectory="${activemq.base}/data" useShutdownHook="false">  
   
    <!-- Destination specific policies using destination names or wildcards -->  
    <!-- wildcards意义见http://activemq.apache.org/wildcards.html -->  
    <destinationPolicy>  
      <policyMap>  
        <policyEntries>  
       <!-- 这里使用了wildcards，表示所有以EUCITA开头的topic -->  
          <policyEntry topic="EUCITA.>" producerFlowControl="false" memoryLimit="10mb">  
            <!-- 分发策略 -->  
        <dispatchPolicy>  
          <!-- 按顺序分发 -->  
              <strictOrderDispatchPolicy/>  
            </dispatchPolicy>  
        <!--  恢复策略-->  
            <subscriptionRecoveryPolicy>  
          <!-- 只恢复最后一个message -->  
              <lastImageSubscriptionRecoveryPolicy/>  
            </subscriptionRecoveryPolicy>  
          </policyEntry>  
        </policyEntries>  
      </policyMap>  
    </destinationPolicy>  
  
    <!-- The transport connectors ActiveMQ will listen to -->  
    <transportConnectors>  
       <transportConnector name="openwire" uri="tcp://192.168.1.148:61616" discoveryUri="multicast://default"/>  
       <transportConnector name="ssl"     uri="ssl://192.168.1.148:61617"/>  
       <transportConnector name="stomp"   uri="stomp://192.168.1.148:61613"/>  
       <transportConnector name="xmpp"    uri="xmpp://192.168.1.148:61222"/>  
    </transportConnectors>  
      
    <!-- 消息持久化方式 -->  
    <persistenceAdapter>  
      <amqPersistenceAdapter directory="${activemq.base}/data"/>  
    </persistenceAdapter>  
</broker>  
  
  <!-- lets create a command agent to respond to message based admin commands on the ActiveMQ.Agent topic -->  
    <commandAgent xmlns="http://activemq.org/config/1.0"/>  
     
  <!-- An embedded servlet engine for serving up the Admin console -->  
  <jetty xmlns="http://mortbay.com/schemas/jetty/1.0">  
    <connectors>  
      <nioConnector port="8161" />  
    </connectors>  
  
    <handlers>  
      <webAppContext contextPath="/admin" resourceBase="${activemq.base}/webapps/admin" logUrlOnStart="true" />        
      <webAppContext contextPath="/demo" resourceBase="${activemq.base}/webapps/demo" logUrlOnStart="true" />         
    </handlers>  
  </jetty>   
</beans>  
　　【DispathPolicy】
ActiveMQ支持3中不同的分发策略（避免翻译了以后误解，这里用原文）：
　　1.<roundRobinDispatchPolicy>：Simple dispatch policy that sends a message to every subscription that matches the message.
2.<simpleDispatchPolicy>：Simple dispatch policy that sends a message to every subscription that matches the message.
3.<strictOrderDispatchPolicy>：Dispatch policy that causes every subscription to see messages in the same order.

【SubscriptionRecoveryPolicy】
ActiveMQ支持6种恢复策略，可以自行选择使用不同的策略:
　　<fixedCountSubscriptionRecoveryPolicy>： keep a fixed count of last messages.
        <fixedSizedSubscriptionRecoveryPolicy>： keep a fixed amount of memory available in RAM for message history which is
          evicted in time order.
        <lastImageSubscriptionRecoveryPolicy>：only keep the last message.
        <noSubscriptionRecoveryPolicy>：disable recovery of messages.
        <queryBasedSubscriptionRecoveryPolicy>：perform a user specific query mechanism to load any messages they may have missed.
        <timedSubscriptionRecoveryPolicy>：keep a timed buffer of messages around in memory and use that to recover new subscriptions.
　　
【PersistenceAdapter】
http://activemq.apache.org/persistence 讲解了关于persistence的信息。ActiveMQ5.2使用AMQ Message Store 持久化消息，这种方式提供了很好的性能（The AMQ Message Store is an embeddable transactional message storage solution that is extremely fast and reliable.） 默认使用该存储方式即可，如果想使用JDBC来存储，可以查找文档配置。