JPA in VaadinCSCI 3130 Winter 2016

What is JPA?

Java Persistence API Allows for “easy” storage of Java Objects Is a type of Object Relational Mapping (ORM)

framework Book of Vaadin: https://vaadin.com/docs/-/

part/framework/jpacontainer/jpacontainer-overview.html

How does it work?

Your Objects Your UI

JPA

Database

How do I use it?

Carefully!

1. Update ivy.xml2. Change Project Facet3. Edit persistence.xml4. Define Data Model5. Connect JPA to UI

1. Update ivy.xml

Update ivy.xml

Add these lines to ivy.xml:<dependency org="com.vaadin.addon" name="jpacontainer" rev="3.2.0" />

<dependency org="org.eclipse.persistence" name="org.eclipse.persistence.jpa" rev="2.6.2" />

<dependency org="com.h2database" name="h2" rev="1.4.191" />

Save and wait for the new libraries to download

2. Add Project Facet

Add Project Facet

Add Project Facet

Add Project Facet

Add Project Facet

Add Project Facet

Add Project Facet

Add Project Facet

Add Project Facet

Add Project Facet

Edit Persistence.xml

Edit persistence.xml

persistence.xml tells JPA how to connect to the database

By default it is in src/META-INF/persistence.xml

Edit persistence.xml

Edit persistence.xml

Edit persistence.xml

Edit persistence.xml

Edit persistence.xml

Edit persistence.xml

4. Define Data Model

Define Data Model

Create the classes to hold your data Annotate data classes with @Entity Annotate id field with @Id Annotate relationships with @OneToMany, @ManyToOne, @ManyToMany, etc…

For reciprocal relationships, make sure to use mappedBy

5. Connect JPA to UI

Connect JPA to UI

Create a new JPAContainer. Connect it to a Table, Form, etc. Perform operations on the container (add,

delete, update, etc)