CEP 与 JMS 结合的参考文章

http://docs.oracle.com/cd/E13213_01/wlevs/docs30/create_apps/jms.html#wp1021114

Application Development Guide

Using the Java Message Service (JMS) Adapters

This section contains information on the following subjects:

• Overview of Using the JMS Adapters
• Using JMS Adapters: Typical Steps

 

Overview of Using the JMS Adapters

Oracle CEP provides two JMS adapters that you can use in your event applications to send and receive messages to and from a JMS queue, respectively, without writing any Java code. In particular:

• The inbound JMS adapter receives map messages from a JMS queue and automatically converts them into events by matching property names with a specified event type. You can optionally customize this conversion by writing your own Java class to specify exactly how you want the incoming JMS messages to be converted into one or more event types.
• The outbound JMS adapter sends events to a JMS queue, automatically converting the event into a JMS map message by matching property names with the event type. You can optionally customize this conversion by writing your own Java class to specify exactly how you want the event types to be converted into outgoing JMS messages.

Oracle CEP supports the following two JMS providers: Oracle WebLogic JMS and TIBCO EMS JMS.

When connecting to Oracle WebLogic server, Oracle CEP uses the T3 client by default. You can use the IIOP WebLogic client by starting Oracle WebLogic Server with the -useIIOP command-line argument. This is a server-wide setting that is independent of the JMS code being used (whether it is one of the provided adapters or custom JMS code). It is not possible to mix T3 and IIOP usage within a running Oracle CEP server.

For general information about JMS, see Java Message Service on the Sun Developer Network.

 

Using JMS Adapters: Typical Steps

The following procedure describes the typical steps to use the JMS adapters provided by Oracle CEP.

Note:

It assumed in this section that you have already created an Oracle CEP application along with its EPN assembly file and and component configuration files, and that you want to update the application to use an inbound or outbound JMS adatper. If you have not, refer to Overview of Creating Oracle Complex Event Processing Applications for details.

1. Optionally create a converter Java class if you want to customize the way JMS messages are converted into event types, or vice versa in the case of the outbound JMS adapter. This step is optional because you can let Oracle CEP make the conversion based on mapping property names between JMS messages and a specified event type.

   See Creating a Custom Converter Between JMS Messages and Event Types.

2. Update the EPN assembly file of the application by adding a <wlevs:adapter> tag for each inbound and outbound JMS adapter you want to use in your application.

   See Updating the EPN Assembly File With JMS Adapters

3. Configure the JMS properties of the JMS adapter by updating the component configuration file.

   See Configuring the JMS Adapters.

Creating a Custom Converter Between JMS Messages and Event Types

If you want to customize the way a JMS message is converted to an event type, or vice versa, you must create your own converter bean.

The custom converter bean for an inbound JMS must implement the com.bea.wlevs.adapters.jms.api.InboundMessageConverter interface. This interface has a single method:

public List convert(Message message) throws MessageConverterException, JMSException;

The message parameter corresponds to the incoming JMS message and the return value is a List of events that will be passed on to the next stage of the event processing network.

The custom converter bean for an outbound JMS must implement the com.bea.wlevs.adapters.jms.api.OutboundMessageConverter interface. This interface has a single method:

public List<Message> convert(Session session, Object event) throws MessageConverterException, JMSException;

The parameters correspond to an event received by the outbound JMS adapter from the source node in the EPN and the return value is a List of JMS messages.

See the Javadoc for a full description of these APIs.

The following example shows the Java source of a custom converter bean that implements both InboundMessageConverter and OutboundMessageConvert; this bean can be used for both inbound and outbound JMS adapters:

package com.customer;

import com.bea.wlevs.adapters.jms.api.InboundMessageConverter;
import com.bea.wlevs.adapters.jms.api.MessageConverterException;
import com.bea.wlevs.adapters.jms.api.OutboundMessageConverter;

import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.Session;
import javax.jms.TextMessage;
import java.util.ArrayList;
import java.util.List;

public class MessageConverter implements InboundMessageConverter, OutboundMessageConverter {

    public List convert(Message message) throws MessageConverterException, JMSException {
        TestEvent event = new TestEvent();
        TextMessage textMessage = (TextMessage) message;
        event.setString_1(textMessage.getText());
        List events = new ArrayList(1);
        events.add(event);
        return events;
    }

    public List<Message> convert(Session session, Object inputEvent) throws MessageConverterException, JMSException {
        TestEvent event = (TestEvent) inputEvent;
        TextMessage message = session.createTextMessage("Text message: " + event.getString_1());
        List<Message> messages = new ArrayList<Message>();
        messages.add(message);
        return messages;
    }
}

Updating the EPN Assembly File With JMS Adapters

For each JMS adapter in your event processing network, you must add a corresponding <wlevs:adapter> tag to the EPN assembly file of your application; use the provider attribute to specify whether the JMS adapter is inbound or outbound. Follow these guidelines:

• If you are specifying an inbound JMS adapter, set the provider attribute to jms-inbound, as shown:

  <wlevs:adapter id="jmsInbound" provider="jms-inbound"/>

  The value of the id attribute, in this case jmsInbound, must match the name specified for this JMS adapter in its configuration file. The configuration file configures the JMS queue from which this inbound JMS adapter gets its messages.

  Because no converter bean is specified, Oracle CEP automaticallys converts the inbound message to the event type specified in the component configuration file by mapping property names.

• If you are specifying an outbound JMS adapter, set the provider attribute to jms-outbound, as shown:

  <wlevs:adapter id="jmsOutbound" provider="jms-outbound"/>

  The value of the id attribute, in this case jmsOutbound, must match the name specified for this JMS adapter in its configuration file. The configuration file configures the JMS queue to which this outbound JMS adapter sends messages messages.

  Because no converter bean is specified, Oracle CEP automatically converts the incoming event types to outgoing JMS messages by mapping the property names.

• For both inbound and outbound JMS adapters, if you have created a custom converter bean to customize the converstion between the JMS messages and event types, first use the standard <bean> Spring tag to declare it in the EPN assembly file. Then pass a reference of the bean to the JMS adapter by specifying its id using the <wlevs:instance-property> tag, with the name attribute set to converterBean, as shown:

  <bean id="myConverter"
         class="com.customer.MessageConverter"/>

  <wlevs:adapter id="jmsOutbound" provider="jms-outbound">  
    <wlevs:instance-property name="converterBean" ref="myConverter"/>
  </wlevs:adapter>

  In this case, be sure you do not specify an event type in the component configuration file because it is assumed that the custom converter bean takes care of specifying the event type.

As with any other stage in the EPN, add listeners and sources to the <wlevs:adapter> tag to integrate the JMS adapter into the event processing network. Typically, an inbound JMS adapter is the first stage in an EPN (because it receives messages) and an outbound JMS adapter would be in a later stage (because it sends messages). However, the requirements of your own Oracle CEP application define where in the network the JMS adapters fit in.

The following sample EPN assembly file shows how to configure an outbound JMS adapter. The network is simple: a custom adapter called getData receives data from some feed, converts it into an event type and passes it to myProcessor, which in turn sends the events to the jmsOutbound JMS adapter via the streamOne stream. Oracle CEP automatically converts these events to JMS messages and sends the messages to the JMS queue configured in the component configuration file associated with the jmsOutbound adapter.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:osgi="http://www.springframework.org/schema/osgi"
       xmlns:wlevs="http://www.bea.com/ns/wlevs/spring"
       xsi:schemaLocation="
  http://www.springframework.org/schema/beans
  http://www.springframework.org/schema/beans/spring-beans.xsd
  http://www.springframework.org/schema/osgi
  http://www.springframework.org/schema/osgi/spring-osgi.xsd
  http://www.bea.com/ns/wlevs/spring
  http://www.bea.com/ns/wlevs/spring/spring-wlevs.xsd">

    <wlevs:event-type-repository>
        <wlevs:event-type type-name="JMSEvent">
            <wlevs:class>com.customer.JMSEvent</wlevs:class>
        </wlevs:event-type>
    </wlevs:event-type-repository>

    <!-- Custom adapter that gets data from somewhere and sends it to myProcessor -->
    <wlevs:adapter id="getData" 
                     class="com.customer.GetData">
        <wlevs:listener ref="myProcessor"/>
    </wlevs:adapter>

    <wlevs:processor id="myProcessor" />

     <!-- Stream for events flowing from myProcessor to outbound JMS adapter -->

    <wlevs:stream id="streamOne">
       <wlevs:listener ref="jmsOutbound"/>
       <wlevs:source ref="myProcessor"/>
    </wlevs:stream>

</beans>

The following sample EPN assembly file shows how to configure an inbound JMS adapter. The network is simple: the inbound JMS adapter called jmsInbound receives messages from the JMS queue configured in its component configuration file. The Spring bean myConverter converts the incoming JMS messages into event types, and then these events flow to the mySink event bean.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:osgi="http://www.springframework.org/schema/osgi"
       xmlns:wlevs="http://www.bea.com/ns/wlevs/spring"
       xsi:schemaLocation="
  http://www.springframework.org/schema/beans
  http://www.springframework.org/schema/beans/spring-beans.xsd
  http://www.springframework.org/schema/osgi
  http://www.springframework.org/schema/osgi/spring-osgi.xsd
  http://www.bea.com/ns/wlevs/spring
  http://www.bea.com/ns/wlevs/spring/spring-wlevs.xsd">

    <wlevs:event-type-repository>
        <wlevs:event-type type-name="JMSEvent">
            <wlevs:class>com.customer.JMSEvent</wlevs:class>
        </wlevs:event-type>
    </wlevs:event-type-repository>

    <!-- Event bean that is an event sink -->
    <wlevs:event-bean id="mySink" 
                         class="com.customer.MySink"/>

    <!-- Inbound JMS adapter with custom converter class; adapter sends events to mySink event bean-->
   <bean id="myConverter" class="com.customer.MessageConverter"/>
   <wlevs:adapter id="jmsInbound" provider="jms-inbound">
       <wlevs:instance-property name="converterBean" ref="myConverter"/>
       <wlevs:listener ref="mySink"/>
    </wlevs:adapter>

</beans>

Configuring the JMS Adapters

You configure the JMS adapters in their respective configuration files, similar to how you configure other components in the event processing network, such as processors or streams. For general information about these configuration files, see Component Configuration Files.

The root element for configuring a JMS adapter is <jms-adapter>. The <name> child element for a particular adapter must match the id attribute of the corresponding <wlevs:adapter> tag in the EPN assembly file that declares this adapter.

The following table describes the additional child elements of <jms-adapter> you can configure for both inbound and outbound JMS adapters.

Table 4-1 Child Elements of <jms-adapter> for Inbound and Outbound Adpaters

Child Element	Description
event-type	Event type whose properties match the JMS message properties. Specify this child element only if you want Oracle CEP to automatically perform the conversion between JMS messages and events. If you have created your own custom convert bean, then do not specify this element.
jndi-provider-url	Required. The URL of the JNDI provider.
jndi-factory	Optional. The JNDI factory name. Default value is weblogic.jndi.WLInitialContextFactory, for Oracle WebLogic Server JMS.
connection-jndi-name	Optional. The JNDI name of the JMS connection factory. Default value is weblogic.jms.ConnectionFactory, for Oracle WebLogic Server JMS.
destination-jndi-name, destination-name	Required. Either the JNDI name, or actual name, of the JMS destination. Specify one or the other, but not both.
user	Optional. The username for the external resource.
password	Optional The password for the external resource.
encrypted-password	Optional. The encrypted password for the external resource.

The following table lists the optional child elements of <jms-adapter> you can configure for inbound JMS adapters only.

Table 4-2 Optional Child Elements for Inbound JMS Adapters

Child Element	Description
work-manager	Name of a work manager, configured in the server’s config.xml file. This name corresponds to the value of the <name> child element of the <work-manager> element in config.xml.
concurrent-consumers	Number of consumers to create.
message-selector	JMS message selector to use to filter messages.
session-ack-mode-name	Use session acknowledgement mode.
session-transacted	Boolean value that specifies whether to use transacted sessions.

The following table lists the optional child elements of <jms-adapter> you can configure for outbound JMS adapters only.

Table 4-3 Optional Child Elements for Outbound JMS Adapters

Child Element	Description
delivery-mode	Specifies whether the delivery mode: persistent (default value) or nonpersistent.

For the full schema for the configuration of JMS adapters, see the XSD Schema.

The following configuration file shows a complete example of configuring both an inbound and outbound JMS adapter.

<?xml version="1.0" encoding="UTF-8"?>
<n1:config
 xsi:schemaLocation="http://www.bea.com/ns/wlevs/config/application wlevs_application_config.xsd"
 xmlns:n1="http://www.bea.com/ns/wlevs/config/application"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

    <jms-adapter>
        <name>jmsInbound</name>
        <jndi-provider-url>t3://localhost:7001</jndi-provider-url>
        <destination-jndi-name>Queue1</destination-jndi-name>
        <user>weblogic</user>
        <password>weblogic</password>
        <work-manager>JettyWorkManager</work-manager>
        <concurrent-consumers>1</concurrent-consumers>
        <session-transacted>false</session-transacted>
    </jms-adapter>

    <jms-adapter>
        <name>jmsOutbound</name>
        <event-type>JMSEvent</event-type>
        <jndi-provider-url>t3://localhost:7001</jndi-provider-url>
        <destination-jndi-name>Topic1</destination-jndi-name>
        <delivery-mode>nonpersistent</delivery-mode>
    </jms-adapter>

</n1:config>

The following snippet shows how to configure an inbound JMS adapter connecting to TIBCO EMS JMS:

<jms-adapter>
  <name>myJmsAdapter</name>
  <jndi-provider-url>t3://localhost:7222</jndi-provider-url>
  <jndi-factory>com.tibco.tibjms.naming.TibjmsInitialContextFactory</jndi-factory>
  <connection-jndi-name>TibcoQueueConnectionFactory</connection-jndi-name>
  <destination-jndi-name>MyQueue</destination-jndi-name>
</jms-adapter>