ActiveMQ.xml文件的主要配置

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。