= Persistence Fragment
:index-group: JPA
:jbake-type: page
:jbake-status: published

The JPA provides Java developers with an object/relational mapping facility for managing relational data in Java applications.

@Entity define the entity class that you want to convert into a table in a database.
@Id define the main key of the table.
@GeneratedValue provides for the specification of generation strategies for the values of primary keys.

== Movie

....
package org.superbiz.injection.jpa;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
public class Movie {
    @Id
    @GeneratedValue
    private long id;
    private String director;
    private String title;
    private int year;

    public Movie() {
        // no-op
    }

    public Movie(String director, String title, int year) {
        this.director = director;
        this.title = title;
        this.year = year;
    }

    public long getId() {
        return id;
    }

    public String getDirector() {
        return director;
    }

    public void setDirector(String director) {
        this.director = director;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public int getYear() {
        return year;
    }

    public void setYear(int year) {
        this.year = year;
    }
}
....

== persistence-fragment.xml

 <persistence-fragment version="2.0">
   <persistence-unit-fragment name="movie-unit">
     <class>org.superbiz.injection.jpa.Movie</class>
     <exclude-unlisted-classes>true</exclude-unlisted-classes>
   </persistence-unit-fragment>
 </persistence-fragment>

== MoviesTest

....
package org.superbiz.injection.jpa;

import org.apache.openejb.assembler.classic.ReloadableEntityManagerFactory;
import org.junit.Test;

import javax.ejb.embeddable.EJBContainer;
import javax.naming.Context;
import javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceUnit;
import java.util.Properties;

import static org.junit.Assert.assertTrue;

public class MoviesTest {
    @PersistenceUnit
    private EntityManagerFactory emf;

    @Test
    public void test() throws Exception {
        final Properties p = new Properties();
        p.put("movieDatabase", "new://Resource?type=DataSource");
        p.put("movieDatabase.JdbcDriver", "org.hsqldb.jdbcDriver");
        p.put("movieDatabase.JdbcUrl", "jdbc:hsqldb:mem:moviedb");

        final EJBContainer container = EJBContainer.createEJBContainer(p);
        final Context context = container.getContext();
        context.bind("inject", this);

        assertTrue(((ReloadableEntityManagerFactory) emf).getManagedClasses().contains(Movie.class.getName()));

        container.close();
    }
}
....

== persistence.xml

 <persistence version="2.0"
              xmlns="http://java.sun.com/xml/ns/persistence"
              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
                        http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
   <persistence-unit name="movie-unit">
     <jta-data-source>movieDatabase</jta-data-source>
     <non-jta-data-source>movieDatabaseUnmanaged</non-jta-data-source>
     <properties>
       <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema(ForeignKeys=true)"/>
     </properties>
   </persistence-unit>
 </persistence>