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An entity bean is defined as a representation of persistent data that has the ability to read from database and populate its fields with data. It can be updated and stored back to the database. There are two types: Bean-Managed Persistence(BMP) and Container-Managed Persistent(CMP). This article covers the migration of a BMP sample application. For this type of entity bean, actual code must be written to handle persistent operations such as loading, saving and finding data. The developer must use persistence API such as JDBC to select, insert, update, delete from a database.
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BMP implementation may vary from one vendor to another. The purpose of this section is to provide a BMP specific feature-to-feature comparison between JBoss v4 and Apache Geronimo so you can clearly identify the differences and plan accordingly before migration.
Features | JBoss v4 | Apache Geronimo |
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EJB Container | JBoss comes with its own EJB Container implementation. | Geronimo uses OpenEJB as its EJB Container. |
JMS implementation | JBoss is packaged with JBoss MQ. | Geronimo uses ActiveMQ as its JMS implementation. |
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Sample application
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The Loan BMP application is very simple. When the command line client is run, an entry is made into the database. The findByPrimaryKey() method of the CustomerHomeRemote interface is called and the field values of the returned CustomerRemote object are printed to the console. This is followed by a call to the findBySssNo() method after which the field values of the returned CustomerRemote object are printed to the console.
The following figure illustrates the application flow:
The user runs the command line client which then either creates an entity bean (which then adds itself to the datasource) or asks for one, by primary key, which is created from information that is stored in the database.
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- com.ibm.demo.entity.client
- BMPClient
- contains the main class that is called from the console.
- BMPClient
- com.ibm.demo.entity.bmp
- CustomerBean
- Implements javax.ejb.EntityBean fields of the bean are defined here.
- Contains business methods corresponding to the methods exposed by the CustomerRemote interface.
- Conatins callback methods that are called by the container to manage the bean. These methods include the create and find methods which use jdbc to make entries to the database and to search the database.
- Has a helper method that looks up the datasource through jndi.
- CustomerRemote
- Interface that extends javax.ejb.EJBObject.
- Exposes the setter and getter methods of the EJB.
- CustomerHomeRemote
- Interface that extends javax.ejb.EJBHome.
- Exposes the create and find methods of the EJB.
- CustomerBean
In addition to these classes, the Loan BMP sample application provides a Web Application client with two JSPs (create.jsp and list.jsp).
Tools used
The tools used for developing and building the loan Loan BMP sampple application are:
Eclipse
The Eclipse IDE was used for development of the sample application. This is a very powerful and popular open source development tool. Integration plug-ins are available for both JBoss and Geronimo. Eclipse can be downloaded from the following URL:
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- Download and install JBoss v4 as explained in the product documentation guides. From now on the installation directory will be referred as <jboss_home>
- Create a copy of the default JBoss v4 application server. Copy recursively <jboss_home>\server\default to <jboss_home>\server\<your_server_name>
- Start the new server by running the
run.sh -c <your_server_name>
command from the <jboss_home>\bin directory. - Once the server is started, you can verify that it is running by opening a Web browser and pointing it to this URL: http://localhost:8080. You should see the JBoss Welcome window and be able to access the JBoss console.
- Once the application server is up and running, the next step is to install and configure all the remaining prerequisite software required by the sample application. This step is described in the following section.
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This application is using the HSQL database that comes as part of the JBoss bundle. Open the hsqldb-ds.xml located in the <jboss_home>/server/. You need to modify the script for creating the database. Edit the localDB.script file located in the following directory:
<jboss_home>\server\<your_server_name>/deploy directory and which sets up the default datasource. Near the \data\hypersonic
Add at the top of the localDB.script file , look for the <connection-url> element. Uncomment this element and make sure the value is set to jdbc:hsqldb:hsql://localhost:1701 and that any other connection-url elements are commented out.
Now you need to modify the script for creating the database. Edit the localDB.script file located in the following directory:
<jboss_home>\server\<your_server_name>\data\hypersonic
Add at the top of the localDB.script file the content of the following example in order to create the sample HSQL database.
Note |
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Make sure JBoss is not running at the time of modifying this file. |
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CREATE MEMORY TABLE CUSTOMER(ID INTEGER NOT NULL PRIMARY KEY,NAME VARCHAR(45),BIRTHDATE DATE,SSS_NO VARCHAR(25),ADDRESS VARCHAR(60),ANNUAL_SALARY DOUBLE,LOAN_AMOUNT DOUBLE) |
Configure Maven
As mentioned before, Apache Maven is used to build the binaries for the Loan BMP application. If you do not have Maven installed this is a good time for doing it.
Apache Maven can be downloaded from the following URL:
Build the sample application
In order to build the loan application a Maven script has been provided. Download the Loan application from the following URL:
http://opensource2.atlassian.com/confluence/oss/download/attachments/1148/loan-bmp.zip
After extracting the zip file, a loan-bmp directory will be created. From now on, this directory will be referred as <bmp_home>. In that directory open the project.properties file. Edit the maven.jboss.home property to match your environment. It is important that you use "//" on the windows platform as is done below.
maven.jboss.home=Z://JBoss-4.0.2
From a command prompt or shell go to the <bmp_home> directory and run the following command:
maven ejb:ejb
This will build the jar file and put it in the <bmp_home>/apps/target folder. The jar created by the Maven build contains a JBoss specific deployment descriptor, the jboss.xml file in located the META-INF directory of the JAR is shown in the following example:
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<?xml version="1.0"?>
<jboss>
<enterprise-beans>
<entity>
<ejb-name>CustomerEJB</ejb-name>
<jndi-name>CustomerHomeRemote</jndi-name>
</entity>
</enterprise-beans>
</jboss>
the content of the following example in order to create the sample HSQL database.
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Make sure JBoss is not running at the time of modifying this file. |
CREATE MEMORY TABLE CUSTOMER(ID INTEGER NOT NULL PRIMARY KEY,NAME VARCHAR(45),BIRTHDATE DATE,SSS_NO VARCHAR(25),ADDRESS VARCHAR(60),ANNUAL_SALARY DOUBLE,LOAN_AMOUNT DOUBLE)
Configure Maven
As mentioned before, Apache Maven is used to build the binaries for the Loan BMP application. If you do not have Maven installed this is a good time for doing it.
Apache Maven can be downloaded from the following URL:
Build the sample application
In order to build the loan application a Maven script has been provided. Download the Loan application from the following link:
After extracting the zip file, a loan-bmp directory will be created. From now on, this directory will be referred as <bmp_home>. In that directory open the project.properties file. Edit the maven.jboss.home property to match your environment.
maven.jboss.home=<jboss_home>
From a command prompt or shell go to the <bmp_home> directory and run the following command:
maven
This will build the jar and war files and put them in the <bmp_home>/target directory. The jar created by the Maven build contains a JBoss specific deployment descriptor, the jboss.xml file in located the META-INF directory of the JAR is shown in the following example:
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<?xml version="1.0"?>
<jboss>
<enterprise-beans>
<entity>
<ejb-name>CustomerEJB</ejb-name>
<jndi-name>CustomerHomeRemote</jndi-name>
</entity>
</enterprise-beans>
</jboss> |
The jndi-name element is used to bind the CustomerEJB to the name CustomerHomeRemote in JNDI.
Deploy the sample application
To deploy the Loan BMP application in JBoss, copy the entity-ejb-SNAPSHOT.jar and entity-ejb.war files you just built with Maven to the following directory:
<jboss_home>\server\<your_server_name>\deploy
If JBoss is already started, it will automatically deploy and start the application; otherwise, the application will be deployed and started at the next startup.
Test the sample application
To test the sample client application type the following command from the <bmp_home> directory:
maven run:client
When you run this command, you will receive a list of all the loans that were retireved from the database, you should see a screen similar to the one shown in the following example:
No Format bgColor #000000 borderStyle solid
E:\loan-bmp>maven run:client
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build:start:
run:client:
[java] creating customer...
[java] done.findByPrimaryKeyTest... 1
[java] customer name: Customer 1
[java] customer sss no: 2323232
[java] customer loan amount: 0.0
[java] customer annual salary: 0.0
[java] customer birthdate: Fri Oct 21 15:40:39 EDT 2005
[java] updating ejb...
[java] done.findBySssNoTest... 2323232
[java] customer name: Customer 2
[java] customer sss no: 2323232
[java] customer loan amount: 0.0
[java] customer annual salary: 0.0
The jndi-name element is used to bind the CustomerEJB to the name CustomerHomeRemote in JNDI.
Deploy the sample application
To deploy the Loan BMP application in JBoss, copy the entity-ejb-SNAPSHOT.jar file you just built with Maven to the following directory:
<jboss_home>\server\<your_server_name>\deploy
If JBoss is already started, it will automatically deploy and start the application; otherwise, the application will be deployed and started at the next startup.
Test the sample application
To test the sample client application type the following command from the <bmp_home> directory:
maven run: client
The result of this command is a list of loans that were retrieved from the database similar to the list shown following in the follow:
When you run this command, you will receive a list of all the loans that were retireved from the database, you should see a screen similar to the one shown in the following example:
No Format bgcolor #FFFFFF borderStyle solid
E:\loan-bmp>maven run:client
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build:start:
run:client:
[java] creating customer...
birthdate: Fri Oct [java] done.findByPrimaryKeyTest... 1
[java] customer name: Customer 1
[java] customer sss no: 2323232
[java] customer loan amount: 0.0
[java] customer annual salary: 0.0
[java] customer birthdate: Fri Oct 21 15:40:39 EDT 2005
[java] updating ejb...
[java] done.findBySssNoTest... 2323232
[java] customer name: Customer 2
[java] customer sss no: 2323232
[java] customer loan amount: 0.0
[java] customer annual salary: 0.0
[java] customer birthdate: Fri Oct 21 15:40:39 EDT 2005
BUILD SUCCESSFUL
Total time: 3 seconds
Finished at: Fri Oct 21 15:40:39 EDT 2005
E:\loan-bmp>
...
21 15:40:39 EDT 2005
BUILD SUCCESSFUL
Total time: 3 seconds
Finished at: Fri Oct 21 15:40:39 EDT 2005
E:\loan-bmp>
To test the sample Web application point your browser to:
http://localhost:8080/entity-ejb
You should see the following screen:
Click on Add Customer. Enter the new customer information then click Create, this will take you to the first page showing the updated list of customers.
The Geronimo environment
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Download and install Geronimo from the following URL:
http://geronimo.apache.org/downloads.html
The release notes available there provide clear instructions on system requirements and how to install and start Geronimo. Throughout the rest of this article we will refer to the Geronimo installation directory as <geronimo_home>.
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If you are planning to run JBoss and Geronimo on the same machine consider to change the default service ports on, at least, one of these servers. |
Configure resources
For this scenario the Loan BMP will use directly the SystemDatabase from Geronimo. In this case there is no need to set up a new connector for the SystemDatabase since it is already configured as the DefaultDatasource.
Start the Geronimo server
Ensure that Geronimo is up and running. If the server has not been started yet, do so by typing the following command:
<geronimo_home>/bin/startup.sh
Once the server is started you should see a screen similar as the one illustrated in the following example:
No Format bgColor #000000 borderStyle solid
E:\geronimo\bin>startup
Booting Geronimo Kernel (in Java 1.4.2_09)...
Starting Geronimo Application Server
[*************] 100% 32s Startup complete
Listening on Ports:
1099 0.0.0.0 RMI Naming
1527 0.0.0.0 Derby Connector
4201 0.0.0.0 ActiveIO Connector EJB
4242 0.0.0.0 Remote Login Listener
8019 0.0.0.0 Tomcat Connector AJP
8080 0.0.0.0 Jetty Connector HTTP
8090 0.0.0.0 Tomcat Connector HTTP
8443 0.0.0.0 Jetty Connector HTTPS
8453 0.0.0.0 Tomcat Connector HTTPS
61616 0.0.0.0 ActiveMQ Message Broker Connector
Started Application Modules:
EAR: org/apache/geronimo/Console
WAR: org/apache/geronimo/applications/Welcome
Web Applications:
http://hcunico:8080/
http://hcunico:8080/console
http://hcunico:8080/console-standard
Geronimo Application Server started
Configure database via Geronimo Console
Access the Geronimo Console by pointing your Web browser to the following URL:
Enter the following system as the username and manager as the password, click Login.
Once logged in, on the bottom left corner from the left navigation panel click on DB Manager. In the text area labeled SQL Command/s enter the following SQL statement and click Run SQL; this will create the table used by the Entity Bean.
CREATE TABLE CUSTOMER(ID INTEGER NOT NULL PRIMARY KEY,NAME VARCHAR(45),BIRTHDATE DATE,SSS_NO VARCHAR(25),ADDRESS VARCHAR(60),ANNUAL_SALARY DOUBLE,LOAN_AMOUNT DOUBLE)
Configure Maven
You should set the maven.geronimo.home property in project.properties to point to your <geronimo_home> directory.
Step-by-step migration
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The same EJB jar file that was created and deployed in jboss may be deployed in Geronimo with no changes to its contents but you still need to edit the jndi properties of sample application. Edit the jndi.properties file located in in the <bmp_home>/jndi directory as shown in the following example:
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####################################################################
### JBoss Settings
####################################################################
#java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory
#java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces
#java.naming.provider.url=localhost
####################################################################
### Geronimo Settings
####################################################################
java.naming.factory.initial=org.openejb.client.RemoteInitialContextFactory
java.naming.provider.url=localhost:4201
java.naming.security.principal=username
java.naming.security.credentials=passwd |
The following example shows the customer-ejb.xml deployment plan used for deploying the EJB application, this deployment plan in located in the <bmp_home>/dd directory.
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<?xml version="1.0" encoding="UTF-8"?>
<openejb-jar
xmlns="http://www.openejb.org/xml/ns/openejb-jar"
xmlns:naming="http://geronimo.apache.org/xml/ns/naming"
xmlns:security="http://geronimo.apache.org/xml/ns/security"
xmlns:sys="http://geronimo.apache.org/xml/ns/deployment"
configId="geronimo/CustomerEJB/1.0/car"
parentId="geronimo/system-database/1.0/car">
<enterprise-beans>
<entity>
<ejb-name>CustomerEJB</ejb-name>
<jndi-name>CustomerHomeRemote</jndi-name>
<local-jndi-name>CustomerRemote</local-jndi-name>
<resource-ref>
<ref-name>jdbc/ibm-demo</ref-name>
<resource-link>SystemDatasource</resource-link>
</resource-ref>
</entity>
</enterprise-beans>
</openejb-jar> |
This plan sets geronimo/system-database/1.0/car as the parent. What follows is the definition of the entity bean. The jndi-name element indicates the jndi name of the entity bean's home interface CustomerHomeRemote. This is the name that the Loan BMP sample application will lookup in the jndi context. The element local-jndi-name indicates the jndi name of the local interface, which in this case happens to be a remote interface, CustomerRemote. Next, a reference to the SystemDatasource is defined giving the application access to the database.
The Web Application client can be directly deployed in Geronimo. This is because the build step packages both the JBoss jboss-web.xml and Geronimo geronimo-web.xml specific deployment plans in the war file. You can see both of these files in the <bmp_home>\src\webapp\WEB-INF directory.
The geronimo-web.xml deployment plan should look like the following example.
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<web-app xmlns="http://geronimo.apache.org/xml/ns/web"
xmlns:naming="http://geronimo.apache.org/xml/ns/naming"
configId="geronimo/EntityDemoWebApp/1.0/car"
parentId="geronimo/CustomerEJB/1.0/car">
<context-root>entity-ejb</context-root>
<ejb-ref>
<ref-name>ejb/CustomerHome</ref-name>
<target-name>
geronimo.server:EJBModule=geronimo/CustomerEJB/1.0/car,
J2EEApplication=null,J2EEServer=geronimo,
j2eeType=EntityBean,name=CustomerEJB
</target-name>
</ejb-ref>
</web-app> |
Build the Loan BMP application by typing maven from the <bmp_home> directory. This will create the entity-ejb-SNAPSHOT.jar and entity-ejb.war in the <bmp_home>/target directory.
Deploy the migrated application
To deploy the migrated Loan BMP application, make sure the Geronimo server is up and running.
From a command line, change directory to <geronimo_home> and type the following command:
java -jar bin/deployer.jar --user system --password manager deploy <bmp_home>/target/entity-ejb-SNAPSHOT.jar <bmp_home>/dd/customer-ejb.xml
With this command you first tell the deployer tool where is the module to deploy, then you tell the deployer tool how to deploy the application by specifying the deployment plan.
Deploy the Web Application by typing the following command:
java -jar bin/deployer.jar --user system --password manager deploy <bmp_home>/target/entity-ejb.war
From the command line change the the <bmp_home> directory and type the following command:
maven run:client
You should see something similar to the following example:
No Format bgColor #000000 borderStyle solid
E:\loan-bmp>maven run:client
__ __
| \/ |__ _Apache__ ___
| |\/| / _` \ V / -_) ' \ ~ intelligent projects ~
|_| |_\__,_|\_/\___|_||_| v. 1.0.2
build:start:
run:client:
[java] creating customer...
[java] done.findByPrimaryKeyTest... 1
[java] customer name: Customer 1
[java] customer sss no: 2323232
[java] customer loan amount: 0.0
[java] customer annual salary: 0.0
[java] customer birthdate: Thu Oct 27 00:00:00 EDT 2005
[java] updating ejb...
[java] done.findBySssNoTest... 2323232
[java] customer name: Customer 2
[java] customer sss no: 2323232
[java] customer loan amount: 0.0
[java] customer annual salary: 0.0
[java] customer birthdate: Thu Oct 27 00:00:00 EDT 2005
BUILD SUCCESSFUL
Total time: 4 seconds
Finished at: Thu Oct 27 18:59:44 EDT 2005
E:\loan-bmp>
Test the applications the same way you tested on JBoss.
Summary
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This article covered how to migrate a sample application, from JBoss to the Apache Geronimo application server. You followed step-by-step instructions to build the application, deploy and run it, and then migrate it to the Geronimo environment.
The following list summarizes the major differences found during this sample application migration.
- In the Geronimo specific deployment plan, the ejbreference name is mapped to the gbean name of the ejb unlike in the JBoss specific deployment descriptor where the resource name is mapped to the JNDI name of the ejb.
- In order to deploy a datasource in JBoss you need to just copy the configuration file to the deploy directory but in Geronimo you need to use the deployer tool or the Web console.
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