play framework 2.0 - internationalization - how to translate a message

Question

First question: how can I retrieve the translation of a text in a controller?

Second question: how can I retrieve the translation of a text in a template?

The api says that there is a .get method that translates a message:

http://www.playframework.org/documentation/api/2.0/java/play/i18n/Messages.html

However my application does not recognize this method. Opening in eclipse the Message.class shows that there is an .apply method in it, written in Scala and Java!?

object Messages {

  /**
   * Translates a message.
   *
   * Uses `java.text.MessageFormat` internally to format the message.
   *
   * @param key the message key
   * @param args the message arguments
   * @return the formatted message or a default rendering if the key wasn’t defined
   */
  def apply(key: String, args: Any*)(implicit lang: Lang): String = {
    Play.maybeApplication.flatMap { app =>
      app.plugin[MessagesPlugin].map(_.api.translate(key, args)).getOrElse(throw new Exception("this plugin was not registered or disabled"))
    }.getOrElse(noMatch(key, args))
  }

Now eclipse tells me that I can invoke this method like this:

> String play.api.i18n.Messages.apply(String arg0, Seq<Object> arg1,
> Lang arg2)

But what should I enter as the "Seq" argument?

--The solution--

The problem was that I imported play.api.i18n.Messages instead of play.i18n.Messages ...

Having defined two message files (messages.de-DE and messages.en-UK) and using the following code everything works fine:

Controller:

    import play.i18n.Messages;
    import play.api.i18n.Lang;

    Lang en = new Lang("en","GB");
    play.i18n.Lang en_lang = new play.i18n.Lang(en);

    Lang de = new Lang("de", "DE");
    play.i18n.Lang de_lang = new play.i18n.Lang(de);

    Logger.info(Messages.get("home.title"));
    Logger.info(Messages.get(en_lang, "home.title"));
    Logger.info(Messages.get(de_lang, "home.title"));

application.conf

    application.langs="en-GB,de-DE"

Answer 1

Getting the translation inside the controller:

// in messages file
msg.key=Hello Translation

// in you controller
Messages.get("msg.key");

You can even pass parameters:

// in messages file
msg.key=Hello {0}, here is your translation

//in controller
Messages.get("msg.key", User.firstName);

From the view you can use: Messages("msg.key")

You can even apply HTML formatting (only applicable for views of course):

// in messages file
msg.key=Hello <strong>{0}</strong>, here is your translation

// in controller
Messages.get("msg.key", User.firstName);

//in view
@Html(objectInView)

Please note the following: Currently it is not possible to define the language explicitly, see bug report: https://play.lighthouseapp.com/projects/82401/tickets/174-20-i18n-add-ability-to-define-implicit-lang-for-java-api

Similar question was asked before: Access translated i18n messages from Scala templates (Play! Internationalization)

i18n error: controller and templates uses different implicit languages