Rewriting https://github.com/malkusch/localized project for my own needs. Now support Hibernate 5.2.2.Final. Other versions weren't tested.

@Localized

Internationalization (i18n) is so boring. There is no one single best practice. And they are all just a pain in the ass when your String is no more a String but something like a Map<Locale, String>. Bye JSR-303 validation annotations. So let's try to find a solution which keeps i18n simple, without polluting your domain model and keep the type of the properties:

@Entity
class Book {

    @Id
    private int id;

    private Author author;

    @Localized
    private String title;

}

@Localized annotates the property Book.title as a translatable String. This looks promising. But how does Hibernate know which Locale is relevant?

LocaleResolver

That's the job of a LocaleResolver implementation. Implement or choose one from the package io.github.deathman.localized.locale_resolver. There are several ways of registering the LocaleResolver:

Specify the fully qualified class name in the hibernate property hibernate.listeners.localized.locale_resolver:

<property name="hibernate.listeners.localized.locale_resolver">com.github.deathman92.localized.locale_resolver.SpringLocaleResolver</property>

Register it programmatically:

LocalizedIntegrator.setLocaleResolver(new SpringLocaleResolver());

Gradle

repositories {
 jcenter()
}

dependencies {
 compile("com.github.deathman92.localized:localized:1.0.0")
}

Maven

<dependency>
  <groupId>com.github.deathman92.localized</groupId>
  <artifactId>localized</artifactId>
  <version>1.0.0</version>
</dependency>

Concept

The mechanism is straight forward: A @Localized field is backed by many LocalizedProperty entities (each locale one entity). Hibernate's event system provides infrastructure for replacing and storing transparently the @Localized fields.This concept increases the Session communication. Do not use @Localized when performance is a concern.

Some concepts of original realisation have been remade.

• Type of field 'value' is String now instead of @Lob.
• Reference by type is replaced with refenrence by table name to simplify inserting by SQL.
• If no translation found for locale default value of field is used.

Limitations

I18n happens around Hibernate's POST_LOAD, POST_UPDATE, POST_INSERT and POST_DELETE events. In between nothing happens. I.e. you have to fix the locale at Session begin (before the first POST_LOAD event on a localized entity). If you change the locale during a session you have to synchronize the entities with Session.flush() and Session.refresh(Object).

Dependencies

• org.hibernate:hibernate-core:5.2.2.Final
• org.springframework:spring-context:4.3.2.RELEASE

Other versions weren't tested.

Disclaimer

There is no practical knowledge about stability, scalability or performance. Use it at your own risk!

Licence

MIT