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<h1>JPA and Enums via @Enumerated</h1>
</div>
</div>
</div>
<div class="row">
<div class="col-md-12">
<div id="preamble">
<div class="sectionbody">
<div class="paragraph">
<p>It can sometimes be desirable to have a Java <code>enum</code> type to represent a particular column in a database. JPA supports converting database data to and from Java <code>enum</code> types via the <code>@jakarta.persistence.Enumerated</code> annotation.</p>
</div>
<div class="paragraph">
<p>This example will show basic <code>@Enumerated</code> usage in a field of an <code>@Entity</code> as well as <code>enum</code>s as the parameter of a <code>Query</code>. We&#8217;ll also see that the actual database representation can be effectively <code>String</code> or <code>int</code>.</p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_enum">Enum</h2>
<div class="sectionbody">
<div class="paragraph">
<p>For our example we will leverage the familiar <code>Movie</code> entity and add a new field to represent the MPAA.org rating of the movie. This is defined via a simple <code>enum</code> that requires no JPA specific annotations.</p>
</div>
<div class="literalblock">
<div class="content">
<pre>public enum Rating {
UNRATED,
G,
PG,
PG13,
R,
NC17
}</pre>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="__enumerated">@Enumerated</h2>
<div class="sectionbody">
<div class="paragraph">
<p>In our <code>Movie</code> entity, we add a <code>rating</code> field of the enum type <code>Rating</code> and annotate it with <code>@Enumerated(EnumType.STRING)</code> to declare that its value should be converted from what is effectively a <code>String</code> in the database to the <code>Rating</code> type.</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlight"><code class="language-java" data-lang="java">@Entity
public class Movie {
@Id
@GeneratedValue
private int id;
private String director;
private String title;
private int year;
@Enumerated(EnumType.STRING)
private Rating rating;
public Movie() {
}
public Movie(String director, String title, int year, Rating rating) {
this.director = director;
this.title = title;
this.year = year;
this.rating = rating;
}
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;
}
public Rating getRating() {
return rating;
}
public void setRating(Rating rating) {
this.rating = rating;
}
}</code></pre>
</div>
</div>
<div class="paragraph">
<p>The above is enough and we are effectively done. For the sake of completeness we&#8217;ll show a sample <code>Query</code></p>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_enum_in_jpql_query">Enum in JPQL Query</h2>
<div class="sectionbody">
<div class="paragraph">
<p>Note the <code>findByRating</code> method which creates a <code>Query</code> with a <code>rating</code> named parameter. The key thing to notice is that the <code>rating</code> enum instance itself is passed into the
<code>query.setParameter</code> method, <strong>not</strong> <code>rating.name()</code> or <code>rating.ordinal()</code>.</p>
</div>
<div class="paragraph">
<p>Regardless if you use <code>EnumType.STRING</code> or <code>EnumType.ORDINAL</code>, you still always pass the enum itself in calls to <code>query.setParameter</code>.</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlight"><code class="language-java" data-lang="java">@Stateful
public class Movies {
@PersistenceContext(unitName = "movie-unit", type = PersistenceContextType.EXTENDED)
private EntityManager entityManager;
public void addMovie(Movie movie) {
entityManager.persist(movie);
}
public void deleteMovie(Movie movie) {
entityManager.remove(movie);
}
public List&lt;Movie&gt; findByRating(Rating rating) {
final Query query = entityManager.createQuery("SELECT m FROM Movie as m WHERE m.rating = :rating");
query.setParameter("rating", rating);
return query.getResultList();
}
public List&lt;Movie&gt; getMovies() throws Exception {
Query query = entityManager.createQuery("SELECT m from Movie as m");
return query.getResultList();
}
}</code></pre>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_enumtype_string_vs_enumtype_ordinal">EnumType.STRING vs EnumType.ORDINAL</h2>
<div class="sectionbody">
<div class="paragraph">
<p>It is a matter of style how you would like your <code>enum</code> data represented in the database. Either <code>name()</code> or <code>ordinal()</code> are supported:</p>
</div>
<div class="ulist">
<ul>
<li>
<p><code>@Enumerated(EnumType.STRING) Rating rating</code> the value of <code>rating.name()</code> is written and read from the corresponding database column; e.g. <code>G</code>, <code>PG</code>, <code>PG13</code></p>
</li>
<li>
<p><code>@Enumerated(EnumType.ORDINAL) Rating rating</code> the value of <code>rating.ordinal()</code> is written and read from the corresponding database column; e.g. <code>0</code>, <code>1</code>, <code>2</code></p>
</li>
</ul>
</div>
<div class="paragraph">
<p>The default is <code>EnumType.ORDINAL</code></p>
</div>
<div class="paragraph">
<p>There are advantages and disadvantages to each.</p>
</div>
<div class="sect2">
<h3 id="_disadvantage_of_enumtype_ordinal">Disadvantage of EnumType.ORDINAL</h3>
<div class="paragraph">
<p>A disadvantage of <code>EnumType.ORDINAL</code> is the effect of time and the desire to keep <code>enums</code> in a logical order. With <code>EnumType.ORDINAL</code> any new enum elements must be added to the
<strong>end</strong> of the list or you will accidentally change the meaning of all your records.</p>
</div>
<div class="paragraph">
<p>Let&#8217;s use our <code>Rating</code> enum and see how it would have had to evolve over time to keep up with changes in the MPAA.org ratings system.</p>
</div>
<div class="paragraph">
<p><strong>1980</strong></p>
</div>
<div class="literalblock">
<div class="content">
<pre>public enum Rating {
G,
PG,
R,
UNRATED
}</pre>
</div>
</div>
<div class="paragraph">
<p><strong>1984</strong> PG-13 is added</p>
</div>
<div class="literalblock">
<div class="content">
<pre>public enum Rating {
G,
PG,
R,
UNRATED,
PG13
}</pre>
</div>
</div>
<div class="paragraph">
<p><strong>1990</strong> NC-17 is added</p>
</div>
<div class="literalblock">
<div class="content">
<pre>public enum Rating {
G,
PG,
R,
UNRATED,
PG13,
NC17
}</pre>
</div>
</div>
<div class="paragraph">
<p>If <code>EnumType.STRING</code> was used, then the enum could be reordered at anytime and would instead look as we have defined it originally with ratings starting at <code>G</code> and increasing in severity to <code>NC17</code> and eventually <code>UNRATED</code>. With <code>EnumType.ORDINAL</code> the logical ordering would not have withstood the test of time as new values were added.</p>
</div>
<div class="paragraph">
<p>If the order of the enum values is significant to your code, avoid <code>EnumType.ORDINAL</code></p>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_unit_testing_the_jpa_enumerated">Unit Testing the JPA @Enumerated</h2>
<div class="sectionbody">
<div class="listingblock">
<div class="content">
<pre class="highlight"><code class="language-java" data-lang="java">public class MoviesTest extends TestCase {
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");
EJBContainer container = EJBContainer.createEJBContainer(p);
final Context context = container.getContext();
final Movies movies = (Movies) context.lookup("java:global/jpa-scratch/Movies");
movies.addMovie(new Movie("James Frawley", "The Muppet Movie", 1979, Rating.G));
movies.addMovie(new Movie("Jim Henson", "The Great Muppet Caper", 1981, Rating.G));
movies.addMovie(new Movie("Frank Oz", "The Muppets Take Manhattan", 1984, Rating.G));
movies.addMovie(new Movie("James Bobin", "The Muppets", 2011, Rating.PG));
assertEquals("List.size()", 4, movies.getMovies().size());
assertEquals("List.size()", 3, movies.findByRating(Rating.G).size());
assertEquals("List.size()", 1, movies.findByRating(Rating.PG).size());
assertEquals("List.size()", 0, movies.findByRating(Rating.R).size());
container.close();
}
}</code></pre>
</div>
</div>
</div>
</div>
<h1 id="_running" class="sect0">Running</h1>
<div class="paragraph">
<p>To run the example via maven:</p>
</div>
<div class="literalblock">
<div class="content">
<pre>cd jpa-enumerated
mvn clean install</pre>
</div>
</div>
<div class="paragraph">
<p>Which will generate output similar to the following:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlight"><code class="language-console" data-lang="console">-------------------------------------------------------
T E S T S
-------------------------------------------------------
Running org.superbiz.jpa.enums.MoviesTest
Apache OpenEJB 4.0.0-beta-2 build: 20120115-08:26
http://tomee.apache.org/
INFO - openejb.home = /Users/dblevins/openejb/examples/jpa-enumerated
INFO - openejb.base = /Users/dblevins/openejb/examples/jpa-enumerated
INFO - Using 'jakarta.ejb.embeddable.EJBContainer=true'
INFO - Configuring Service(id=Default Security Service, type=SecurityService, provider-id=Default Security Service)
INFO - Configuring Service(id=Default Transaction Manager, type=TransactionManager, provider-id=Default Transaction Manager)
INFO - Configuring Service(id=movieDatabase, type=Resource, provider-id=Default JDBC Database)
INFO - Found EjbModule in classpath: /Users/dblevins/openejb/examples/jpa-enumerated/target/classes
INFO - Beginning load: /Users/dblevins/openejb/examples/jpa-enumerated/target/classes
INFO - Configuring enterprise application: /Users/dblevins/openejb/examples/jpa-enumerated
INFO - Configuring Service(id=Default Stateful Container, type=Container, provider-id=Default Stateful Container)
INFO - Auto-creating a container for bean Movies: Container(type=STATEFUL, id=Default Stateful Container)
INFO - Configuring Service(id=Default Managed Container, type=Container, provider-id=Default Managed Container)
INFO - Auto-creating a container for bean org.superbiz.jpa.enums.MoviesTest: Container(type=MANAGED, id=Default Managed Container)
INFO - Configuring PersistenceUnit(name=movie-unit)
INFO - Auto-creating a Resource with id 'movieDatabaseNonJta' of type 'DataSource for 'movie-unit'.
INFO - Configuring Service(id=movieDatabaseNonJta, type=Resource, provider-id=movieDatabase)
INFO - Adjusting PersistenceUnit movie-unit &lt;non-jta-data-source&gt; to Resource ID 'movieDatabaseNonJta' from 'movieDatabaseUnmanaged'
INFO - Enterprise application "/Users/dblevins/openejb/examples/jpa-enumerated" loaded.
INFO - Assembling app: /Users/dblevins/openejb/examples/jpa-enumerated
INFO - PersistenceUnit(name=movie-unit, provider=org.apache.openjpa.persistence.PersistenceProviderImpl) - provider time 406ms
INFO - Jndi(name="java:global/jpa-enumerated/Movies!org.superbiz.jpa.enums.Movies")
INFO - Jndi(name="java:global/jpa-enumerated/Movies")
INFO - Created Ejb(deployment-id=Movies, ejb-name=Movies, container=Default Stateful Container)
INFO - Started Ejb(deployment-id=Movies, ejb-name=Movies, container=Default Stateful Container)
INFO - Deployed Application(path=/Users/dblevins/openejb/examples/jpa-enumerated)
INFO - Undeploying app: /Users/dblevins/openejb/examples/jpa-enumerated
INFO - Closing DataSource: movieDatabase
INFO - Closing DataSource: movieDatabaseNonJta
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 2.831 sec
Results :
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0</code></pre>
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