JPA Support

JPA Support with Hammock

JPA is supported out of the box with Hammock, allowing you to leverage the built in functions as well as some custom grown features.

Creating DataSources

Before we get into JPA, its important to understand how configuration of DataSources works. There are a few ways to create DataSources using Hammock. Hammock does provide support for @DataSourceDefinition and @DataSourceDefinitions found on any CDI managed bean. However, a producer method is probably the cleaner way since it allows the configuration to be externalized. Such a bean may look like this:

@Inject
@ConfigProperty(name="test2.url")
private String url;

@Inject
@ConfigProperty(name="test2.username")
private String username;

@Inject
@ConfigProperty(name = "test2.password")
private String password;

@Produces
@ApplicationScoped
@Named("test2")
public DataSource createDataSource(DataSourceDefinitionBuilder builder) {
   return builder.url(url)
      .user(username)
      .password(password)
      .name("test2")
      .build();
}

Default Persistence unit

Hammock by default creates a default persistence unit for your app, and unless you need something special its probably the right way to go. The unit is named __default and it works by finding all entities defined within your application, pointing to the datasource defined by the name in hammock.jpa.__default.datasource. All custom properties that are prefixed by hammock.jpa.__default will get added to the EntityManagerFactory on creation, allowing you to override additional configuration via properties.