(24F) CST8277 Enterprise Application Programming

Assignment 2:  DataBank-JSF-JPA-EJB-BootStrap-Physician

Please read this document carefully.  If your submission does not meet the requirements as stated here, you may lose marks even though your program runs.  Additionally, this assignment is also a teaching opportunity, that is materials presented in this document may be on the midterm and/or the final exam!

Overview

For Assignment 2, ACME Medical has tasked you to improve the Physician Directory web application you developed back in Assignment 1.  Specifically, the company wants you to:

1.   Use Java Persistence API (JPA) to access the database and provide the required CRUD capabilities (instead of directly using JDBC)

2.   Use Bootstrap CSS framework to layout and style. the Physician Directory web application as a Single Page Application (SPA)

The main page of the improved web application is shown below.   The main page shows the list of physicians already on the database.

Clicking the “Add New Physician” button on the main page would show the Add New Physician form. while staying on the same page:

Clicking the “Submit” button (after entering all the necessary information) or “Cancel” button will just hide the Add New Physician form. and add the new physician to the table (if applicable).

Note that if the user didn’t provide all the necessary information in the correct format, validation error messages will be displayed as shown below:

Clicking the “Edit” button on the main page should enable the fields on the corresponding row for editing as shown below:

Similar to the add scenario, if the user didn’t provide all the necessary information in the correct format, validation error message will be displayed as shown below:

Clicking the “Cancel” button while editing will cancel the update operation and will just make the fields on the corresponding row back to being read-only with their original values.

Clicking the “Delete” button on the main page should trigger a pop-up to confirm if the user wants to proceed with deleting the selected physician.  Clicking OK on the pop-up should remove the selected physician from the database as well as from the list of physicians shown on the main page.   Clicking the “Cancel” button should simply cancel the delete operation.

Finally, if the user is trying to update a physician that has already been updated by another user (e.g. from a different browser accessing the same web application) OR if the user is trying to update a physician that has already been deleted by another user (e.g. from a different browser accessing the same web application), user- friendly error messages should be displayed as can be seen on the 2 screen shots below:

User is trying to update a physician that has already been updated by another user

User is trying to update a physician that has already been deleted by another user

Theme for Assignment 2

After completing this assignment, you will have achieved the following:

1.   Use JSF in conjunction with new EE components:  EJBs and JPA

2.   Create a model class for JPA with all appropriate mappings/annotations

3.   Use a JSF @ViewScoped managed bean

4.  Add validation to JSF views

5.   Use Bootstrap CSS framework to layout and style. the Physician Directory application as a SPA

Importing Assignment 2

ACME Medical has provided you with a starter code DataBank-JSF-JPA-Physician-Skeleton.zip to complete. You must use the file DataBank-JSF-JPA-Physician-Skeleton.zip from Brightspace to start your solution. You need to extract its contents to some work folder on your hard drive.  Failure to use the provided starter code DataBank-JSF-JPA-Physician-Skeleton.zip may lead to a grade of 0 for this assignment.

The starter code/skeleton project is an Eclipse Maven project and you need to import the project as an existing Maven project:

Import

1.   In Eclipse, go to File/Import…/Existing Maven Projects

2.   Navigate to your project folder

3.  When importing, make sure the pom.xml file is checked/selected

Please note that you might need to do the following important steps only if needed:

Important Steps

1.  After opening the project in Eclipse

2.   Right-click your project and go to Properties

3.   Go to Deployment Assembly

4.   Click Add and choose Java Build Path Entries

5.   Click Next and choose Maven Dependencies

6.   Click Finish

Remember, if you right-click Maven->Update Project, you have to do the above steps again.

Starting Assignment 2

You must use the skeleton project provided for this assignment to start your solution.

Your Information

In the folder src/main/resource, there is a file called Bundle.properties which contains constants used in the UI.  Please change the default values for:

Note:   Your  name should be as it appears in ACSIS.   Failure to  do this  may lead to a grade of 0 for the assignment.

Update the DB

Attached to this assignment on Brightspace, there is a DB script. file (as2-databank.sql) which you must run on your DB first.

Skeleton Project

Project starts with many errors.  That is fine. You need to find and fix the issues.  There are hints such as TODO markers in the code which can help you.

Updating the Application – Additional EE Components:  Entity Manager and JPA EntityManager

To   connect   the   DAO   to   the   DB,   we   need   to   inject   a   reference   (into   the   DAOImpl)   using   the @PersistenceContext annotation:

•    Q1:  What is the folder/name of the standard JPA descriptor document (config)?

•    Q2:  What is the name of the Persistence Unit?  (Hint:  Look in the ‘non-Java’ Maven ‘resources’ folder)

Java Persistence API (JPA)

The PhysicianPojo model needs additional JPA annotations in order to work.   It also needs new member fields to handle the CREATED/UPDATED/VERSION DB columns. The type for the CREATED/UPDATED member fields should be java.time.LocalDateTime.

•    Q3:  What should the @Entity name be?  What would it be if the name is not set?

•    Q4:  What should the @Table name be?  What would it be if the name is not set?

•    Q5:    What  is  the  JPQL  query  string  for  the  @NamedQuery ‘Physician.findAll’  that  retrieves  all physicians from the database?

•    Q6:   What are the column names for firstName, lastName?  What would JPA ‘think’ the DB column names are if the annotations were not set?

•    Q7:  If annotations are placed on the fields, what should @Access(AcessType.SOME_TYPE) be?

•    Q8:  What type should the member field version be?

Audit Columns

The purpose of the CREATED/UPDATED columns is to answer the following questions:

•    When was the record created?

•    When was the record last updated?

These columns are referred to as ‘audit’ columns, they allow you to know when a given row changed.  This has obvious benefits in production systems where fraud or security breaches are a concern.  Often, DBAs like to solve this problem with database triggers or logic that causes a table row to be updated whenever a particular action or event takes place:

The above PLSQL code (Procedural Language for SQL) works only on Oracle databases.  Accomplishing the same task across multiple databases can greatly increase the complexity of an application when support of multiple database vendors is required.

We can implement a solution using JPA that works across all databases.  In the previous section, we discussed adding two new member fields to handle the CREATED/UPDATED columns.  To populate the audit member fields automatically, we use a JPA ‘listener’ that is invoked whenever a particular event occurs.   There are seven events (Note:  This is a good quizzes/final exam material.):

1.  @PrePersist – executed before the EntityManager persist operation is actually executed

2.  @PreRemove – executed before the EntityManager remove is actually executed

3.  @PostPersist – executed after the EntityManager persist operation (INSERT SQL already committed)

4.  @PostRemove – executed after the EntityManager remove operation (DELET SQL already committed)

5.  @PreUpdate – executed before the UPDATE SQL is executed

6.  @PostUpdate – executed after the UPDATE SQL is committed

7.  @PostLoad – executed after an entity has been loaded into the current @PersistenceContext or when entity has been refreshed (EntityManager refresh operation)

The PhysicianPojo class is missing the @EntityListeners annotation, it needs to be added.  Please refer to the JSF-EJB-JPA-Regional-Inventory sample project discussed during the lecture.

•    Q9:  What is the argument to setCreatedOnDate/setUpdatedDate?

Updating the Application – JSF, EJB, and JPA

The JSF controller is un-aware that some new EE components and APIs (EntityManager and JPA) are now associated with the PhysicianDao managed bean, and its API has changed only slightly.  The PhysicianDaoImpl is also simplified with no direct manipulation for the DB using SQL, since all DB operations are delegated to the EntityManager.

Our new application uses JPA which needs to be configured and initialized.  Luckily, when running inside an EE application server (such as Payara), this is simple:

•    In payara-resources.xml, specify the  Payara JDBC connection pool and its mapping to a  JNDI name (already done in Assignment 1, no need to change for Assignment 2).

•    In the JPA standard persistence deployment descriptor file (that is, persistence.xml) (what was the answer to above Q1 and Q2?), ensure that the entry <jta-data-source>jndi-name</jta-data- source> is properly setup.

Updating the Application – JSF Navigation and SPA

In Assignment 1, the Physician Directory application provided CRUD capabilities across three (3) JSF views:

1.   list-physicians.xhtml

2.   add-physician.xhtml

3.   edit-physician.xhtml

Even though the application is a simple CRUD list-view application, navigating between views can become quite difficult.   Amongst the various controller methods are hard-coded strings such as "add-physician?faces- redirect=true" and   "list-physicians?faces-redirect=true".       What   if,  for  example,  a  ‘Sign   In’ functionality needs to be added to the application?

Figure   1.      Credit   to   Russell   Bateman    'A   short   treatise   on   JSF'

(https://bit.ly/2RToMnQ)

JSF supports separating controller code from navigation decisions by allowing the developer to specifynavigation rules in the faces-config.xml file:

Even with this separation, it is easy to see that the navigation rules for a fully featured application would become very hard to maintain.  This is one of the motivating factors in the move to single-page applications (SPA), where the web app stays on a single page instead of loading new pages from the server, rewriting its content either via direct DOM manipulation or asynchronously using AJAX calls.

In JSF, the primary way to manage this is to ensure that ‘outcomes’ of actions invoked on various components (i.e. <h:commandButton action="#{physicianController.someOutcome()}"/>) is to return a null String, or the method signature is changed to return void.  Over on the ‘View’ side of things, the primary mechanism to help the user interact with the application is to toggle (i.e. hide/show) various on-screen artifacts via their rendered attribute (which is present on almost all JSF components), delegating control of the toggle-state to the controller, or in the case of editing an individual row of <h:dataTable>, to the model object itself.

•    Q10:   What must be added to PhysicianController in order to toggle (i.e. hide/show) the ‘Add New Physician’ view?

•    Q11:   What  must be added to PhysicianPojo in order to toggle (i.e. hide/show) editing?   If a  new member field is added to PhysicianPojo, what about the JPA mapping? Should the state of this member field be stored in the DB?  If not, how does one prevent that from happening?

Updating the Application – JSF @ViewScoped Helper Class

In Assignment  1, to hold the “to-be-created”/”to-be-updated”  physician data, we either use ‘spare’ fields in PhysicianController or used the (@Inject’d) sessionMap to hold them.   In Assignment 2, we introduce a new class NewPhysicianView to specifically handle this responsibility.

•    Q12:  What annotation(s) should we add to NewPhysicianView?

•    Q13:  What field(s) should we add to NewPhysicianView?

•    Q14:  How is NewPhysicianView used in index.xhtml?

Submitting Assignment 2

To submit your Assignment 2, first you must export your completed project as a zip file.   Eclipse has an export function to create an external archive, i.e. a zip file, of your project. Make sure to not include the “target” subfolder when  generating  the  zip  file  (see  screenshots  below).    You  should  name  your  zip  file  as  <lastname>- <firstname>-Assignment2.zip, for example, Smith-John-Assignment2.zip. You must then upload the correct generated zip file to Brightspace under Assignment 2 (Brightspace/Activities/Assignments/Assignment 2).

Please make sure that your completed project compiles and builds successfully, has good indentation and coding style, not overly complicated, and is efficient.  The completed code must demonstrate your understanding of how a JSF and JPA work.

Note:  Do not forget to upload the correct generated zip file to Brightspace under Assignment 2.

Demoing Assignment 2

For Assignment 2, please note that demo is mandatory.  If you think you have completed your project early (before the due date), you can demo your Assignment 2 to your lab professor during your respective lab session before the due date.  The advantage of demoing for your Assignment 2 before the due date, you will have a chance  to  fix  issues/bugs  found  during  the  demo  session  before  you  submit  your  completed  project  on Brightspace.    Please  note  that  you  are  allowed  to  keep  submitting  updated  versions  of  your  project  on Brightspace (before the due date) though only the latest version will be considered your official submission and it will be the one to be graded by your lab professor.   Note:   Failure to demo your Assignment 2 will result in a grade of 0 for Assignment 2.  The last week to demo your Assignment 2 is Week 10.