此代码样本显示了部署描述符中有关 EJB 2.0 消息驱动的 bean 的描述:
<message-driven id="Mdb20"> <ejb-name>Mdb</ejb-name> <ejb-class>ejbs.MdbBean</ejb-class> <transaction-type>Bean</transaction-type> <message-selector>mdbMessage</message-selector> <acknowledge-mode>Auto-acknowledge</acknowledge-mode> <message-driven-destination> <destination-type>javax.jms.Topic</destination-type> <subscription-durability>Durable</subscription-durability> </message-driven-destination> </message-driven>
此代码样本显示了部署描述符中有关 EJB 2.1 消息驱动的 bean 的描述:
<message-driven id="Mdb21"> <ejb-name>Foo</ejb-name> <ejb-class>ejbs.FooBean</ejb-class> <messaging-type>javax.jms.MessageListener</messaging-type> <transaction-type>Bean/transaction-type> <message-destination-type>javax.jms.Topic</message-destination-type> <activation-config> <activation-config-property> <activation-config-property-name>destinationType</activation-config-property-name> <activation-config-property-value>javax.jms.Topic</activation-config-property-value> </activation-config-property> <activation-config-property> <activation-config-property-name>subscriptionDurability</activation-config-property-name> <activation-config-property-value>Durable</activation-config-property-value> </activation-config-property> <activation-config-property> <activation-config-property-name>acknowledgeMode</activation-config-property-name> <activation-config-property-value>AutoAcknowledge</activation-config-property-value> </activation-config-property> <activation-config-property> <activation-config-property-name>messageSelector</activation-config-property-name> <activation-config-property-value>fooSelector</activation-config-property-value> </activation-config-property> </activation-config> </transaction-type> </ejb-name> </message-driven>
在 EJB 2.1 中,规范定义了 <activation-config-property> 元素,它可用来定义应答方式、消息选择器、预订持久性和目标类型等属性。使用非 JMS 消息传递类型时,向导允许定义需要用于 bean 的 <activation-config-property> 名称和值对。对于 JMS 消息传递系统,向导提供了 JMS 所需的缺省配置属性,例如预订持久性和应答方式。