THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
Enterprise messaging has become an increasingly important component of loosely coupled, reliable enterprise frameworks. This is due in large part to the proliferation of enterprise applications and disparate enterprise resources, and the increasing need to integrate these applications into cohesive systems. Over the years Messaging and Message Oriented Middleware (MOM) has provided this integration propritery way. Introduction of Java Messaging Service (JMS) standard has eliminated many of the disadvantages in propritery MOM based products. In addition to that Message Driven Beans (MDBs) introduced with Enterprise Java Beans 2.0 have served to get the best out of existing investments in J2EE application servers. Most of the J2EE application servers in modern era are acting as a MOM with a whole lot of value added services to JMS. Apache Geronimo comes in to the party with support of JMS integrating one of the best breed open source messaging frameworks ActiveMQ. This article will guide you a way to use JMS/MDBs for in enterprise application scenario in both as a locally and remotely reffered enviroments with Geronimo and ActiveMQ.
The company reffered in this sample application sales one specific item in both retail and whole sale markets. All the placed orders in the application has to be autorized by a company sales employee before delevering goods to the customer. To the whole sale market, company has placed their agents all over the country. They send their orders as a bunch at once which is called as a consignment. End users place their orders using company web site while agents send their consignments with a special software insalled in their premises. All the cosignments must be approved by the comany GM before it handed over to a sales employee. This is a typical application to JMS/MDBs as a solution because both cosignment and order requests are processed in asynchronous manner.
After reading this article you should be able to define Message Queues and their Connection Factories in Geronimo/ActiveMQ enviroment, send and recieve messages them using different kinds of client applications in your Enterprise Application with ease.
This article is organized in to following sections.
- Overview of JMS in Geronimo/ActiveMQ Enviroment
- Application Overview
- Configuring, Building and Deploying the Sample Application
- Testing of the Sample Application
- Summary
Overview of JMS in Geronimo/ActiveMQ Enviroment
Geronimo server comes with JMS server and application components can access JMS resources like connection factories, topics and queues from it. This JMS server also known as message broker too. Default message broker supports by ActiveMQ, usually does not need to be changed since it is a mature and feature-rich JMS server. This implementations uses inbuilt Derby database for the message persistent.
ActiveMQ supports a large variety of transports (such as TCP, SSL, UDP, multicast, intra-JVM, and NIO) and client interactions (such as push, pull, and publish/subscribe). In Geronimo enviroment ActiveMQ supports MDBs, which are EJBs that consume JMS messages. It allows enterprise application to take J2EE specific features from Geronimo. Application components such as JSPs, Servlets or EJBs utilizing JMS must access message broker through a library that implements the JMS API. This API has been implemented in an abstract layer to support any JMS provider. Geronimo has achieved this this feature using supporting J2EE Connector (JCA) specification. The JCA 1.5 specification details the contracts required between the application server (Geronimo) and the driver supplied by ActiveMQ (resource adapter) Applications deployed in the Geronimo access ActiveMQ message broker only through this resource adapter(RA).
Application Overview
Order processing application has two defined Queues as to recieve orders and consignments. Order requests can be generated and send by the Order Sender web application. When order requests are reached to the order queue, the Order recv MDB will be triggered. Those order requests are saved in the server repository for the later authorization by a company employee. Compnay's sales agents are using the Consignment Sender application to send consignment requests from their locations. First they will prepare consignments as XML files, then it will be given it to that application. Consignment Sender application will read the content of the consignment and send it to the Consignment queue. Senior manager in the company uses Consignment Reciever application to find out the consignment requests. When a consignment request reached to the Consignment queue, Consignment Reciever listener application will download those requests to the responsible manager's computer.
Following figure gives the overall architecture of the order processing application.
Application contents
The order placement application consist of following list of packages and classes.
- org.apache.geronimo.samples.order.client
- ConsignmentReciever - Listening on recieving of consignment requests to a defined queue.
- ConsignmentSender - Send consignment requests to their queue.
- org.apache.geronimo.samples.order.ejb
- OrderRecvMDB - Listening on recieving of order requests to a defined queue.
- org.apache.geronimo.samples.order.util
- PropertyLoader - Loads configuration properties to application.
- org.apache.geronimo.samples.order.web
- OrderSenderServlet - Creates order requests based on the user input and send them to respective queue.
Finally order placement application will be deployed as an EAR to the application server. Overview of the contents of EAR is given in the following.
|-Order.ear
|-OrderEjb.jar
|-META-INF
|- ejb-jar.xml
|- openejb-jar.xml
|-OrderWeb.war
|-jsp
|- index.jsp
|- error.jsp
|-WEB-INF
|- web.xml
|- geronimo-web.xml
|- classes
|-META-INF
|- application.xml
|- geronimo-application.xml
First we will look at how to define connection factories and queues in the Geronimo server using jms-resource-plan.xml. It defines two JMS queues and a common queue connection factory to access them.
jms-resource-plan.xml
<?xml version="1.0" encoding="UTF-8"?>
<connector xmlns="http://geronimo.apache.org/xml/ns/j2ee/connector-1.1">
<dep:environment xmlns:dep="http://geronimo.apache.org/xml/ns/deployment-1.1">
<dep:moduleId>
<dep:groupId>samples</dep:groupId>
<dep:artifactId>jms-resources</dep:artifactId>
<dep:version>1.0</dep:version>
<dep:type>rar</dep:type>
</dep:moduleId>
<dep:dependencies>
<dep:dependency>
<dep:groupId>geronimo</dep:groupId>
<dep:artifactId>activemq-broker</dep:artifactId>
<dep:type>car</dep:type>
</dep:dependency>
</dep:dependencies>
</dep:environment>
<resourceadapter>
<resourceadapter-instance>
<resourceadapter-name>CommonConnectionFactory</resourceadapter-name>
<config-property-setting name="Password">geronimo</config-property-setting>
<config-property-setting name="UserName">geronimo</config-property-setting>
<nam:workmanager xmlns:nam="http://geronimo.apache.org/xml/ns/naming-1.1">
<nam:gbean-link>DefaultWorkManager</nam:gbean-link>
</nam:workmanager>
</resourceadapter-instance>
<outbound-resourceadapter>
<connection-definition>
<connectionfactory-interface>javax.jms.QueueConnectionFactory</connectionfactory-interface>
<connectiondefinition-instance>
<name>CommonConnectionFactory</name>
<connectionmanager>
<xa-transaction>
<transaction-caching/>
</xa-transaction>
<single-pool>
<match-one/>
</single-pool>
</connectionmanager>
</connectiondefinition-instance>
</connection-definition>
</outbound-resourceadapter>
</resourceadapter>
<adminobject>
<adminobject-interface>javax.jms.Queue</adminobject-interface>
<adminobject-class>org.activemq.message.ActiveMQQueue</adminobject-class>
<adminobject-instance>
<message-destination-name>OrderQueue</message-destination-name>
<config-property-setting name="PhysicalName">OrderQueue</config-property-setting>
</adminobject-instance>
<adminobject-instance>
<message-destination-name>ConsignmentQueue</message-destination-name>
<config-property-setting name="PhysicalName">ConsignmentQueue</config-property-setting>
</adminobject-instance>
</adminobject>
<adminobject>
<adminobject-interface>javax.jms.Topic</adminobject-interface>
<adminobject-class>org.activemq.message.ActiveMQTopic</adminobject-class>
</adminobject>
</connector>
Corresponding openejb-jar.xml defines Geronimo specific features of MDBs. It links OrderRecv MDB with OrderQueue via CommonConnectionFactory.
openejb-jar.xml
<openejb-jar xmlns="http://www.openejb.org/xml/ns/openejb-jar-2.1" xmlns:naming="http://geronimo.apache.org/xml/ns/naming-1.1" xmlns:security="http://geronimo.apache.org/xml/ns/security-1.1" xmlns:sys="http://geronimo.apache.org/xml/ns/deployment-1.1">
<sys:environment>
<sys:moduleId>
<sys:groupId>samples</sys:groupId>
<sys:artifactId>OrderEjb</sys:artifactId>
<sys:version>1.0</sys:version>
<sys:type>car</sys:type>
</sys:moduleId>
<sys:dependencies>
<sys:dependency>
<sys:groupId>geronimo</sys:groupId>
<sys:artifactId>activemq-broker</sys:artifactId>
<sys:version>1.1</sys:version>
<sys:type>car</sys:type>
</sys:dependency>
<sys:dependency>
<sys:groupId>samples</sys:groupId>
<sys:artifactId>jms-resources</sys:artifactId>
<sys:version>1.0</sys:version>
<sys:type>rar</sys:type>
</sys:dependency>
</sys:dependencies>
<sys:hidden-classes/>
<sys:non-overridable-classes/>
</sys:environment>
<enterprise-beans>
<message-driven>
<ejb-name>OrderRecvMDB</ejb-name>
<resource-adapter>
<resource-link>CommonConnectionFactory</resource-link>
</resource-adapter>
<activation-config>
<activation-config-property>
<activation-config-property-name>destination</activation-config-property-name>
<activation-config-property-value>OrderQueue</activation-config-property-value>
</activation-config-property>
<activation-config-property>
<activation-config-property-name>destinationType</activation-config-property-name>
<activation-config-property-value>javax.jms.Queue</activation-config-property-value>
</activation-config-property>
</activation-config>
</message-driven>
</enterprise-beans>
</openejb-jar>
geronimo-application.xml and application.xml define the main components of the EAR. Both EJB component and Web archive information are given in this files as usual.
geronimo-application.xml
<application xmlns="http://geronimo.apache.org/xml/ns/j2ee/application-1.1">
<dep:environment xmlns:dep="http://geronimo.apache.org/xml/ns/deployment-1.1">
<dep:moduleId>
<dep:groupId>samples</dep:groupId>
<dep:artifactId>Order</dep:artifactId>
<dep:version>1.0</dep:version>
<dep:type>car</dep:type>
</dep:moduleId>
<dep:dependencies/>
<dep:hidden-classes/>
<dep:non-overridable-classes/>
</dep:environment>
</application>
application.xml
<?xml version="1.0" encoding="UTF-8"?>
<application
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/application_1_4.xsd"
version="1.4">
<module>
<ejb>OrderEjb.jar</ejb>
</module>
<module>
<web>
<web-uri>OrderWeb.war</web-uri>
<context-root>/Order</context-root>
</web>
</module>
</application>
Web application of the Order Processing system sends messages to the Order Queue. OrderSenderServlet will handle the relevant order request generation and sending. web.xml of the archive has the relevant configurations for the both queue connection factory and the queue, which is essential to refer resources in a local enviroment.
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4"> <servlet> <display-name>OrderSenderServlet</display-name> <servlet-name>OrderSenderServlet</servlet-name> <servlet-class>org.apache.geronimo.samples.order.web.OrderSenderServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>OrderSenderServlet</servlet-name> <url-pattern>/order</url-pattern> </servlet-mapping> <resource-ref> <res-ref-name>jms/CommonConnectionFactory</res-ref-name> <res-type>javax.jms.QueueConnectionFactory</res-type> <res-auth>Container</res-auth> <res-sharing-scope>Shareable</res-sharing-scope> </resource-ref> <message-destination-ref> <message-destination-ref-name>jms/OrderQueue</message-destination-ref-name> <message-destination-type>javax.jms.Queue</message-destination-type> <message-destination-usage>Produces</message-destination-usage> <message-destination-link>OrderQueue</message-destination-link> </message-destination-ref> <welcome-file-list> <welcome-file>/jsp/index.jsp</welcome-file> </welcome-file-list> </web-app>
Please note this web application supports Servlet 2.4 specification. These cofigurations in other versions are bit different than given in the above web.xml.
geronimo-web.xml will act as the defined JMS resources in the application server and the web.xml. It links both parties giving relavant information to the connection factory and the queue.
geronimo-web.xml
<web-app xmlns="http://geronimo.apache.org/xml/ns/j2ee/web-1.1" xmlns:naming="http://geronimo.apache.org/xml/ns/naming-1.1">
<dep:environment xmlns:dep="http://geronimo.apache.org/xml/ns/deployment-1.1">
<dep:moduleId>
<dep:groupId>samples</dep:groupId>
<dep:artifactId>OrderWeb</dep:artifactId>
<dep:version>1.0</dep:version>
<dep:type>car</dep:type>
</dep:moduleId>
<dep:dependencies>
<dep:dependency>
<dep:groupId>geronimo</dep:groupId>
<dep:artifactId>activemq-broker</dep:artifactId>
<dep:version>1.1</dep:version>
<dep:type>car</dep:type>
</dep:dependency>
<dep:dependency>
<dep:groupId>samples</dep:groupId>
<dep:artifactId>jms-resources</dep:artifactId>
<dep:version>1.0</dep:version>
<dep:type>rar</dep:type>
</dep:dependency>
</dep:dependencies>
<dep:hidden-classes/>
<dep:non-overridable-classes/>
</dep:environment>
<context-root>/Order</context-root>
<resource-ref>
<ref-name>jms/CommonConnectionFactory</ref-name>
<resource-link>CommonConnectionFactory</resource-link>
</resource-ref>
<resource-env-ref>
<ref-name>jms/OrderQueue</ref-name>
<admin-object-link>OrderQueue</admin-object-link>
</resource-env-ref>
</web-app>
The whole order processing application will load external resource using order_mgmt.properties. To send order requests to the queue, web application will use the Order Sender Properties in the given file.
order_mgmt.properties
########################################################### ## Order Sender(Web Application) Properties # Connection Factory Name. jms.connection=java:comp/env/jms/CommonConnectionFactory # Queue Name. jms.queue=java:comp/env/jms/OrderQueue ########################################################### ## Order Reciever(EJB Application) Properties # Change a directory in server to store order requests. order.repo=/home/lsf/Lasantha/Temp/order ########################################################### ## Consignment Sender Properties # Queue connection factory type. java.naming.factory.initial=org.activemq.jndi.ActiveMQInitialContextFactory # Server location, change according to your enviroment. java.naming.provider.url=tcp://localhost:61616 # Connection factory names. connectionFactoryNames=CommonConnectionFactory # Queue name. queue.ConsignmentQueue=ConsignmentQueue ########################################################### ## Consignment Reciever Properties # Provider url, change according to your enviroment. provider.url=tcp://localhost:61616 # Queue name. queue.name=ConsignmentQueue # Change a directory in client machine to store consignment requests. consignment.dir=/home/lsf/Lasantha/Temp/consignment
The next important part of this sample application is how to send messages and listen them from out side the application server context. Consignment sender and reciever will demonstrate those features in the application.
Tools used
The tools used for developing and building the order placement application are:
XDoclet
XDoclet is an open source code generation engine. It enables Attribute-Oriented Programming for java. In short, this means that you can add more significance to your code by adding meta data (attributes) to your java sources. This is done in special JavaDoc tags.
Although XDoclet originated as a tool for creating EJBs, it has evolved into a general-purpose code generation engine. XDoclet consists of a core and a constantly growing number of modules. It is fairly straightforward to write new modules if there is a need for a new kind of component.
http://xdoclet.sourceforge.net/xdoclet/index.html
Eclipse
The Eclipse IDE was used for development of the sample application. This is a very powerful and popular open source development tool. It has integration plug-ins for the Geronimo too. Eclipse can be downloaded from the following URL:
http://www.eclipse.org
Apache Ant
Ant is a pure Java build tool. It is used for building the war files for the Inventory application. Ant can be downloaded from the following URL:
http://ant.apache.org
Configuring, Building and Deploying the Sample Application
Download the order processing application from the following link:
Order
After decompressing the given file, the Order directory will be created.
Configuring
Configuration of the application consists of creating JMS resources and accessing them via defferent sorts of enviroments.
Creating JMS Specific Resources
All JMS specific resource information can be found in the config/jms-resource-plan.xml file. Please follow given to deployment after logged in to the Geronimo console.
- Select Deploy New link from the Console Navigation in the left.
- Load the <geronimo_home>/repository/geronimo/ge-activemq-rar/1.1/ge-activemq-rar-1.1.rar file to the Archive field.
- Load the Order/config/jms-resource-plan.xml file to the Plan input field.
- Press Install button. Make sure Start app after install is selected when this deployment happens
- After you get the successful installation message, verify the deployment traversing JMS resources link. It will display the connection factory and two JMS queues.
Modify Property Files
This application has two different property files in the config folder namely build.properties and order_mgmt.properties. Build process of the application is entirely depends on the build.propeties while application will use order_mgmt.properties to load application related properties.
Set the correct paths to the xdoclet.home and geronimo.home directories to work application build process correctly.
This build script depends on XDoclet version 1.2.3 and Geronimo 1.1.
order_mgmt.properties file given is shared among four defferent application components. If you deploy one of these application components out side of application server, make sure to change the relevant network property in the above mentioned property file.
Building
Use a command prompt to navigate into the Order directory and just give ant command to build. It will create the Order.ear, recvclient.jar and sendclient.jar under the Order/releases folder. Also note it will create a lib folder and copy list of jar files refered by the remote client applications. Now you are ready to deploy order processing application in to the Geronimo Application server.
Deploying
Deploying Order processing sample application is pretty same as the deployment of JMS resources.
- Travel Deploy New from the Console Navigation.
- Load Order.ear from Order/releases folder in to the Archive input box.
- Press Install button to deploy application in the server.
Testing of the Sample Application
Core business functionality of the order processing application is shared among the three different client applications.
Order Placement Web Application
To test the sample web application open a browser and type http://localhost:8080/Order
. It will forward you in to the Order Management Welcome page. Then user has to fill the necessary information for the order placement and submit it.
Consignment Placement Remote Application
This application will send consignment requests to the consignment queue. It will take consignment file as a command line argument. Sample consignment has been given with the appication archive as Order/config/sample-consignment.xml. First travel to the Order/releases from a command prompt and give the following command.
java -jar sendclient.jar <home>/Order/config/sample-consignment.xml
Consignment Listener Remote Application
Listener application to the consignment queue. It will download the consignment requests in the local repository. As in the above mentioned application first travel to the Order/releases from a command prompt. After that issue following command to start listening on the consignment queue.
java -jar recvclient.jar
Always consider lib folder inside of releases are a part of this client application.Check your Operating Sytem's security configuration when you are connecting from a remote machine.
Summary
This article has demontrated how to use JMS features in Apache Geronimo with the ActiveMQ JMS server.It provides a hypothical example which extensively used JMS features to application processing.
Following are some of the highlights.
- Apache Geronimo is a J2EE 1.4 Certified application server and it provides all the necessary features support asynchronous mode of communication.
- Define JMS connection factories and related queues.
- Message Driven Beans are the components are listener application components provides by J2EE container. This article has shown how to define them effective manner.
- Sending and recieving data to a defined queue as a remote client to the application server