Step 7. Connecting Entities to a User Interface

Time to complete this step: 30 minutes

In this step, you will import a Web application that incorporates the database connection, entities, and Spring classes you have created in this tutorial. This application includes JPA entities, Spring service beans, DAO classes, JSPs, and servlets. After importing the application, you will create a new server and run the application.

The tasks you will complete in this step are:

• Import the Web application
• Review the application components
• Create a new server
• Run the JPA Web application
• Troubleshooting

Import the Web application

1. Import web.zip into the Web application oepe-jpa-tutorial.
2. Right click on the project oepe-jpa-tutorial. Select Import > General > Archive File and click Next. Browse to the location where you decided to download web.zip and click Finish. Overwrite any and all files as you import.

Review the application components

The imported application includes a JSP page and a managed bean. The project also contains a faces-config.xml file, which manages the navigation of the application and the JSPs that comprise the user interface.

Now, let's review the MVC connection strategy, which is to use Spring DAO through a JSF Managed Bean.

The web/WEB-INF/config folder contains the faces-config.xml file that configures the Managed Bean configurations and Navigation Rules for the Web application.

1. Double click the faces-config.xml file to open the Faces Config Editor. Note that Customer and customerManagedBean are defined as managed beans in the request scope.



2. Navigation Rules are defined for addCustomer.jsp and viewAllCustomers.jsp. The navigation case for addCustomer.jsp specifies /pages/viewAllCustomers.jsp as the destination page while the outcome is success.

   

3. Similarly, the navigation case for viewAllCustomers.jsp describes /pages/viewOrders.jsp as the destination page while the outcome is orderList.

   

Create a new server

Now you will create a server to use to run your completed sample application. If one exists already in the Servers tab, delete it.

1. In the Java EE perspective, the following views should be visible as tabs at the bottom (by default) of Oracle Enterprise Pack for Eclipse: Problems, Tasks, Properties, Servers, Database Explorer, Snippets.
2. Click the Servers view tab, right-click in its window, and then click New > Server.

   

3. In the New Server dialog, under Select the server type, confirm that Oracle > Oracle WebLogic Server v11gR1 PatchSet 1 is selected, and then click Next.
4. In the Domain Directory box, ensure that the dropdown shows the domain directory as the following:

   C:\<middleware home>\wlserver_10.3\samples\domains\wl_server
   

5. Click Finish.

   Undeploy previous tutorial code

   Oracle WebLogic Server does not support the deployment of projects with the same name from two different locations on disk.

   For this reason, any time you deploy a sample or run through a tutorial, you should check your server for previous deployments of the same code. If your server already has a deployment of the sample or tutorial code, you should undeploy any previous code.

Run the JPA Web application

1. After the server starts successfully, open a browser. Enter the address http://localhost:7001/oepe-jpa-tutorial/pages/addCustomer.jsf in the address line of the browser pane to view the addCustomer.jsf page in the browser (if necessary).
   
   
2. Enter the name Bob and click Submit to add a new customer named Bob.

The application calls addCustomer( ) action method of the CustomerManagedBean and forwards the request to viewAllCustomers.jsp, if the customer is added successfully. The viewAllCustomers.jsp gets the customers list using the <h:dataTable> component and displays it as shown below.



3. Click View Orders for the customer name JOHN to get the list of order(s) placed by JOHN.
   
   
4. Click Back to browse to the previous page and view orders placed by other customers.
5. Once you are done, stop the server.

Troubleshooting

1. Not able to commit the changes. Oracle WebLogic Server throws exception:

   Caused by: javax.persistence.RollbackException: Transaction rolled back because transaction was set to RollbackOnly.
   	at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commitInternal(EntityTransactionImpl.java:92)
   	at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commit(EntityTransactionImpl.java:63)
   	at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:456)
   

   Please make sure the database connection properties in persistence.xml are correct.
2. Oracle WebLogic Server complains "No Persistence provider for EntityManager"

   javax.persistence.PersistenceException: No Persistence provider for EntityManager named unitK:  The following providers:
   org.eclipse.persistence.jpa.PersistenceProvider
   kodo.persistence.PersistenceProviderImpl
   org.apache.openjpa.persistence.PersistenceProviderImpl
   Returned null to createEntityManagerFactory.
   

   Please make sure the persistence unit name referenced in Spring applicationContext.xml is same as the one defined in JPA persistence.xml, e.g. "oepe-jpa-tutorial."

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