THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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The following article provides concept-rich documentation on how to use JNDI to access connection pools for data sources, Java Messaging Services (JMS), mail sessions, and URL connections: Apache Geronimo JNDI naming and Java resource connection pools, Part 1: Data source connections. URL: http://www-128.ibm.com/developerworks/opensource/library/os-ag-jndi1
However, the mentioned article is written for Geronimo 1.x. This sample tutorial will demonstrate something similar but using EJB 3.0.
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persistence.xml references certain Entity Beans and maps them to use certain database pools. In this case, the entity bean Customer is using the database pool CustomerServicePool.
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<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.0"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
<persistence-unit name="CustomerPU">
<description>Entity Beans for Customer</description>
<provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
<class>com.service.customer.ejb.Customer</class>
<properties>
<property name="openjpa.jdbc.SynchronizeMappings" value="false"/>
</properties>
<jta-data-source>CustomerServicePool</jta-data-source>
<non-jta-data-source>CustomerServicePool</non-jta-data-source>
</persistence-unit>
</persistence>
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openejb-jar.xml is here because we are using OpenEJB. Nothing special is really defined in this file because we do not have any defined MDBs.
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<?xml version="1.0" encoding="UTF-8"?>
<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:dep="http://geronimo.apache.org/xml/ns/deployment-1.2">
<dep:environment>
<dep:moduleId>
<dep:groupId>${pom.groupId}</dep:groupId>
<dep:artifactId>${pom.artifactId}</dep:artifactId>
<dep:version>${version}</dep:version>
<dep:type>jar</dep:type>
</dep:moduleId>
<dep:dependencies>
</dep:dependencies>
<dep:hidden-classes/>
<dep:non-overridable-classes/>
</dep:environment>
</openejb-jar>
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web.xml references the EJB that was created in ProcessCustomerSessionBean.java. By doing this we are allowing the contents inside the WAR to use this EJB.
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<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
version="2.4">
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
<ejb-local-ref>
<ejb-ref-name>ejb/ProcessCustomerSessionBean</ejb-ref-name>
<ejb-ref-type>Session</ejb-ref-type>
<local>com.service.customer.ejb.ProcessCustomerSessionLocal</local>
</ejb-local-ref>
</web-app>
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geronimo-application.xml specifies the module's information and the context-root in which this web application resides. Additionally, it specifies the database pool plan that we want to create while deploying along with the connector that is needed to deploy this plan into Geronimo.
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<application xmlns="http://geronimo.apache.org/xml/ns/j2ee/application-1.1">
<dep:environment xmlns:dep="http://geronimo.apache.org/xml/ns/deployment-1.1">
<dep:moduleId>
<dep:groupId>${pom.groupId}</dep:groupId>
<dep:artifactId>${pom.artifactId}</dep:artifactId>
<dep:version>${version}</dep:version>
<dep:type>ear</dep:type>
</dep:moduleId>
<dep:dependencies/>
<dep:hidden-classes/>
<dep:non-overridable-classes/>
</dep:environment>
<module>
<connector>tranql-connector-ra-1.3.rar</connector>
<alt-dd>CustomerServicePool.xml</alt-dd>
</module>
</application>
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application.xml specifies a connector in which the EAR will use when trying to deploy the embedded database pool (CustomerServicePool.xml).
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<?xml version="1.0" encoding="UTF-8"?>
<application xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/application_5.xsd" version="5">
<description>Geronimo Sample EAR for CustomerService</description>
<display-name>Geronimo Sample EAR for CustomerService</display-name>
<module>
<ejb>CustomerService-ejb-2.0-SNAPSHOT.jar</ejb>
</module>
<module>
<web>
<web-uri>CustomerService-war-2.0-SNAPSHOT.war</web-uri>
<context-root>/service</context-root>
</web>
</module>
<module>
<connector>tranql-connector-ra-1.3.rar</connector>
</module>
</application>
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CustomerServiceJavaBean.java uses JNDI to look up the ProcessCustomerSessionBean EJB.
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package com.service.customer.web;
import com.service.customer.ejb.Customer;
import com.service.customer.ejb.ProcessCustomerSessionLocal;
import java.util.Locale;
import java.util.ResourceBundle;
import java.util.List;
import javax.naming.InitialContext;
public class CustomerServiceJavaBean
{
private ProcessCustomerSessionLocal process = null;
private ResourceBundle bundle = null;
public CustomerServiceJavaBean()
{
InitialContext initial = null;
bundle = ResourceBundle.getBundle("customer", Locale.getDefault(), CustomerServiceJavaBean.class.getClassLoader());
String jndiName = bundle.getString("jndi.process.ejb");
try
{
initial = new InitialContext();
process = (ProcessCustomerSessionLocal) initial.lookup(jndiName.trim());
System.out.println("Successful looking up: '" + jndiName.trim() + "'");
} // end try
catch (Exception e)
{
e.printStackTrace();
} // end catch
} // end CustomerServiceJavaBean
public List<Customer> getAllCustomers()
{
List<Customer> customerList = null;
try
{
customerList = process.findAllCustomers();
} // end try
catch (Exception e)
{
e.printStackTrace();
} // end catch
return customerList;
} // end getAllCustomerss
} // end CustomerServiceJavaBean
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ProcessCustomerSessionBean.java implements ProcessCustomerSessionLocal by grabbing an EntityManagerFactory by making use of the persistence.xml. It grabs it by using the @PersistenceUnit annotation. Since there is only one persistence unit defined in persistence.xml, we do not need to specify any additional parameters in the annotation.
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package com.service.customer.ejb;
import java.rmi.RemoteException;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import javax.persistence.PersistenceUnit;
import javax.ejb.EJBException;
import javax.ejb.Stateless;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
@Stateless
public class ProcessCustomerSessionBean implements ProcessCustomerSessionLocal {
@PersistenceUnit
protected EntityManagerFactory emf;
public ProcessCustomerSessionBean() {
}
public List<Customer> findAllCustomers() {
EntityManager em = emf.createEntityManager();
String query = "SELECT * FROM customer";
List<Customer> customerList =
(List<Customer>)em.createNativeQuery(query, Customer.class).getResultList();
em.close();
return customerList;
}
public Customer findCustomer(String key) {
EntityManager em = emf.createEntityManager();
String query = "SELECT * FROM customer WHERE id='"+key+"'";
List<Customer> customerList =
(List<Customer>)em.createNativeQuery(query, Customer.class).getResultList();
if(customerList.size() == 1) {
return (Customer)customerList.get(0);
} else {
return null;
}
}
}
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ProcessCustomerSessionLocal.java defines the business methods that is associated with this bean.
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package com.service.customer.ejb;
import com.service.customer.ejb.Customer;
public interface ProcessCustomerSessionLocal {
public java.util.List<Customer> findAllCustomers();
public Customer findCustomer(String key);
}
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Customer.java is the entity bean that represents the Customer table in the database. By using @Entity, @Table(name = "customer"), and @Id it tells OpenEJB that this is an entity bean, which is representative of the table "customer" and has "customerId" as the primary key. By using these annotations no other configuration is needed inside openejb-jar.xml (no ejb-jar.xml is needed at all).
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package com.service.customer.ejb;
import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "customer")
public class Customer implements Serializable {
private String customerId;
private String fullName;
private String emailAddress;
private String interests;
public Customer() {
}
public Customer(String customerId, String fullName, String emailAddress,
String interests) {
this.customerId = customerId;
this.fullName = fullName;
this.emailAddress = emailAddress;
this.interests = interests;
}
@Id
public String getCustomerId() {
return customerId;
}
public String getFullName() {
return fullName;
}
public String getEmailAddress() {
return emailAddress;
}
public String getInterests() {
return interests;
}
public void setCustomerId(String customerId) {
this.customerId = customerId;
}
public void setFullName(String fullName) {
this.fullName = fullName;
}
public void setEmailAddress(String emailAddress) {
this.emailAddress = emailAddress;
}
public void setInterests(String interests) {
this.interests = interests;
}
} // end Customer
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You can checkout the source code of this sample from SVN:
svn checkout http://svn.apache.org/repos/asf/geronimo/samples/trunk/samples/CustomerService
Configuring
Configuration of the application consists of creating the database and defining the connection pool to access it.
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To test the sample web application open and browse and type http://localhost:8080/service. It will forward you to the index page of the application which has a direct link to view the Customers.
