An Application Example That Deploys a Message-Driven Bean on Two Servers
This section, like the preceding one, explains how to write, compile, package, deploy, and run a pair of Java EE modules that use the JMS API and run on two Java EE servers. The modules are slightly more complex than the ones in the first example.
The modules use the following components:
- An application client that is deployed on the local server. It uses two connection factories--one ordinary one and one that is configured to communicate with the remote server--to create two publishers and two subscribers and to publish and to consume messages.
- A message-driven bean that is deployed twice: once on the local server, and once on the remote one. It processes the messages and sends replies.
In this section, the term local server means the server on which both the application client and the message-driven bean are deployed (
earth
in the preceding example). The term remote server means the server on which only the message-driven bean is deployed (jupiter
in the preceding example).The section covers the following topics:
You will find the source files for this section in
<
INSTALL
>/javaeetutorial5/examples/jms/sendremote/
. Path names in this section are relative to this directory.Overview of the Modules
This pair of modules is somewhat similar to the modules in An Application Example That Consumes Messages from a Remote Server in that the only components are a client and a message-driven bean. However, the modules here use these components in more complex ways. One module consists of the application client. The other module contains only the message-driven bean and is deployed twice, once on each server.
The basic steps of the modules are as follows.
- You start two Java EE servers, one on each system.
- On the local server (
earth
), you create two connection factories: one local and one that communicates with the remote server (jupiter
). On the remote server, you create a connection factory that has the same name.- The application client looks up the two connection factories--the local one and the one that communicates with the remote server--to create two connections, sessions, publishers, and subscribers. The subscribers use a message listener.
- Each publisher publishes five messages.
- Each of the local and the remote message-driven beans receives five messages and sends replies.
- The client's message listener consumes the replies.
Figure 33-4 illustrates the structure of this application. M1 represents the first message sent using the local connection factory, and RM1 represents the first reply message sent by the local MDB. M2 represents the first message sent using the remote connection factory, and RM2 represents the first reply message sent by the remote MDB.
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Figure 33-4 A Java EE Application That Sends Messages to Two Servers
Writing the Module Components
Writing the components of the modules involves two tasks:
Coding the Application Client: MultiAppServerClient.java
The application client class,
multiclient/src/java/MultiAppServerClient.java
, does the following.
- It injects resources for two connection factories and a topic.
- For each connection factory, it creates a connection, a publisher session, a publisher, a subscriber session, a subscriber, and a temporary topic for replies.
- Each subscriber sets its message listener,
ReplyListener
, and starts the connection.- Each publisher publishes five messages and creates a list of the messages the listener should expect.
- When each reply arrives, the message listener displays its contents and removes it from the list of expected messages.
- When all the messages have arrived, the client exits.
Coding the Message-Driven Bean: ReplyMsgBean.java
The message-driven bean class,
replybean/src/ReplyMsgBean.java
, does the following:
- Uses the
@MessageDriven
annotation:
@MessageDriven(mappedName="jms/Topic")
- Injects resources for the
MessageDrivenContext
and for a connection factory. It does not need a destination resource because it uses the value of the incoming message'sJMSReplyTo
header as the destination.- Uses a
@PostConstruct
callback method to create the connection, and a@PreDestroy
callback method to close the connection.The
onMessage
method of the message-driven bean class does the following:On both servers, the bean will consume messages from the topic
jms/Topic
.Creating Resources for the Modules
This example uses the connection factory named
jms/ConnectionFactory
and the topic namedjms/Topic
. These objects must exist on both the local and the remote servers.This example uses an additional connection factory,
jms/JupiterConnectionFactory
, which communicates with the remote system; you created it in Creating Administered Objects for Multiple Systems. This connection factory must exist on the local server.The
build.xml
file for themulticlient
module contains targets that you can use to create these resources if you deleted them previously.Using Two Application Servers
The Application Server must be running on both systems. You package, deploy, and run the modules from the local system.
If you are using NetBeans 5.5, you need to add the remote server in order to deploy the message-driven bean there. To do so, perform these steps:
- In NetBeans 5.5, click the Runtime tab.
- Right-click the Servers node and choose Add Server. In the Add Server Instance dialog, perform these steps:
- Select Sun Java System Application Server (the default) from the Server list.
- In the Name field, specify a name slightly different from that of the local server, such as
Sun Java System Application Server (1)
.- Click Next.
- For the Platform Folder location, you can either browse to the location of the Application Server on the remote system or, if that location is not visible from the local system, use the default location on the local system.
- Select the Register Remote Domain radio button.
- Click Next.
- Type the system name of the host in the Host field.
- Click Next.
- Type the administrative username and password for the remote system in the Admin Username and Admin Password fields.
- Click Finish.
There may be a delay while NetBeans 5.5 registers the remote domain.
Building, Deploying, and Running the Modules Using NetBeans 5.5
To package the modules using NetBeans 5.5, perform these steps:
- In NetBeans 5.5, choose Open Project from the File menu.
- In the Open Project dialog, navigate to
<
INSTALL
>/javaeetutorial5/examples/jms/sendremote/
.- Select the
replybean
folder.- Select the Open as Main Project checkbox.
- Click Open Project Folder.
- Right-click the
replybean
project and choose Build Project.This command creates a JAR file that contains the bean class file.
- Choose Open Project from the File menu.
- Select the
multiclient
folder.- Select the Open as Main Project checkbox.
- Click Open Project Folder.
- Right-click the
multiclient
project and choose Build Project.This command creates a JAR file that contains the client class file and a manifest file.
To deploy the
multiclient
module on the local server, perform these steps:To deploy the
replybean
module on the local and remote servers, perform these steps:
- Right-click the
replybean
project and choose Properties.- Select Run from the Categories tree.
- From the Server list, select Sun Java System Application Server 9 (the local server).
- Click OK.
- Right-click the
replybean
project and choose Deploy Project.- Right-click the
replybean
project again and choose Properties.- Select Run from the Categories tree.
- From the Server list, select Sun Java System Application Server (1) (the remote server).
- Click OK.
- Right-click the
replybean
project and choose Deploy Project.You can use the Runtime tab to verify that
multiclient
is deployed as an App Client Module on the local server and thatreplybean
is deployed as an EJB Module on both servers.To run the application client, right-click the
multiclient
project and choose Run Project.This command returns a JAR file named
multiclientClient.jar
and then executes it.On the local system, the output of the
appclient
command looks something like this:running application client container. Sent message: text: id=1 to local app server Sent message: text: id=2 to remote app server ReplyListener: Received message: id=1, text=ReplyMsgBean processed message: text: id=1 to local app server Sent message: text: id=3 to local app server ReplyListener: Received message: id=3, text=ReplyMsgBean processed message: text: id=3 to local app server ReplyListener: Received message: id=2, text=ReplyMsgBean processed message: text: id=2 to remote app server Sent message: text: id=4 to remote app server ReplyListener: Received message: id=4, text=ReplyMsgBean processed message: text: id=4 to remote app server Sent message: text: id=5 to local app server ReplyListener: Received message: id=5, text=ReplyMsgBean processed message: text: id=5 to local app server Sent message: text: id=6 to remote app server ReplyListener: Received message: id=6, text=ReplyMsgBean processed message: text: id=6 to remote app server Sent message: text: id=7 to local app server ReplyListener: Received message: id=7, text=ReplyMsgBean processed message: text: id=7 to local app server Sent message: text: id=8 to remote app server ReplyListener: Received message: id=8, text=ReplyMsgBean processed message: text: id=8 to remote app server Sent message: text: id=9 to local app server ReplyListener: Received message: id=9, text=ReplyMsgBean processed message: text: id=9 to local app server Sent message: text: id=10 to remote app server ReplyListener: Received message: id=10, text=ReplyMsgBean processed message: text: id=10 to remote app server Waiting for 0 message(s) from local app server Waiting for 0 message(s) from remote app server Finished Closing connection 1 Closing connection 2On the local system, where the message-driven bean receives the odd-numbered messages, the output in the server log looks like this (wrapped in logging information):
ReplyMsgBean: Received message: text: id=1 to local app server ReplyMsgBean: Received message: text: id=3 to local app server ReplyMsgBean: Received message: text: id=5 to local app server ReplyMsgBean: Received message: text: id=7 to local app server ReplyMsgBean: Received message: text: id=9 to local app serverOn the remote system, where the bean receives the even-numbered messages, the output in the server log looks like this (wrapped in logging information):
ReplyMsgBean: Received message: text: id=2 to remote app server ReplyMsgBean: Received message: text: id=4 to remote app server ReplyMsgBean: Received message: text: id=6 to remote app server ReplyMsgBean: Received message: text: id=8 to remote app server ReplyMsgBean: Received message: text: id=10 to remote app serverUndeploy the modules after you finish running the client. To undeploy the modules, perform these steps:
- Click the Runtime tab.
- Expand the Servers node.
- Expand the Sun Java System Application Server 9 node (the local system).
- Expand the Applications node.
- Expand the EJB Modules node.
- Right-click
replybean
and choose Undeploy.- Expand the App Client Modules node.
- Right-click
multiclient
and choose Undeploy.- Expand the Sun Java System Application Server (1) node (the remote system).
- Expand the Applications node.
- Expand the EJB Modules node.
- Right-click
replybean
and choose Undeploy.To remove the generated files, follow these steps:
Building, Deploying, and Running the Modules Using Ant
To package the modules, perform these steps:
- Go to the following directory:
<
INSTALL
>/javaeetutorial5/examples/jms/sendremote/multiclient/
- Type the following command:
ant
This command creates a JAR file that contains the client class file and a manifest file.
- Change to the directory
replybean
:
cd ../replybean
- Type the following command:
ant
This command creates a JAR file that contains the bean class file.
To deploy the
replybean
module on the local and remote servers, perform the following steps:
- Verify that you are still in the directory
replybean
.- Type the following command:
ant deploy
Ignore the message that states that the application is deployed at a URL.
- Type the following command:
ant deploy-remote -Dsys=
remote_system_name
Replace
remote_system_name
with the actual name of the remote system.To deploy and run the client, perform these steps:
On the local system, the output looks something like this:
running application client container. Sent message: text: id=1 to local app server Sent message: text: id=2 to remote app server ReplyListener: Received message: id=1, text=ReplyMsgBean processed message: text: id=1 to local app server Sent message: text: id=3 to local app server ReplyListener: Received message: id=3, text=ReplyMsgBean processed message: text: id=3 to local app server ReplyListener: Received message: id=2, text=ReplyMsgBean processed message: text: id=2 to remote app server Sent message: text: id=4 to remote app server ReplyListener: Received message: id=4, text=ReplyMsgBean processed message: text: id=4 to remote app server Sent message: text: id=5 to local app server ReplyListener: Received message: id=5, text=ReplyMsgBean processed message: text: id=5 to local app server Sent message: text: id=6 to remote app server ReplyListener: Received message: id=6, text=ReplyMsgBean processed message: text: id=6 to remote app server Sent message: text: id=7 to local app server ReplyListener: Received message: id=7, text=ReplyMsgBean processed message: text: id=7 to local app server Sent message: text: id=8 to remote app server ReplyListener: Received message: id=8, text=ReplyMsgBean processed message: text: id=8 to remote app server Sent message: text: id=9 to local app server ReplyListener: Received message: id=9, text=ReplyMsgBean processed message: text: id=9 to local app server Sent message: text: id=10 to remote app server ReplyListener: Received message: id=10, text=ReplyMsgBean processed message: text: id=10 to remote app server Waiting for 0 message(s) from local app server Waiting for 0 message(s) from remote app server Finished Closing connection 1 Closing connection 2On the local system, where the message-driven bean receives the odd-numbered messages, the output in the server log looks like this (wrapped in logging information):
ReplyMsgBean: Received message: text: id=1 to local app server ReplyMsgBean: Received message: text: id=3 to local app server ReplyMsgBean: Received message: text: id=5 to local app server ReplyMsgBean: Received message: text: id=7 to local app server ReplyMsgBean: Received message: text: id=9 to local app serverOn the remote system, where the bean receives the even-numbered messages, the output in the server log looks like this (wrapped in logging information):
ReplyMsgBean: Received message: text: id=2 to remote app server ReplyMsgBean: Received message: text: id=4 to remote app server ReplyMsgBean: Received message: text: id=6 to remote app server ReplyMsgBean: Received message: text: id=8 to remote app server ReplyMsgBean: Received message: text: id=10 to remote app serverUndeploy the modules after you finish running the client. To undeploy the
multiclient
module, perform these steps:To undeploy the
replybean
module, perform these steps:To remove the generated files, use the following command in both the
replybean
andmulticlient
directories: