MVC 1.0 Public Review Draft
posted by Christian Kaltepoth on 2017-12-18

We are very happy to announce that we submitted the required artifacts for the Public Review phase to the JCP. This is a huge step for the specification and the first release done by the new specification leads. Thanks everyone for your help with getting to this point.

You can get the API from Maven Central:


The specification document can be downloaded from the Specification section.

What's new?

There are many new features in MVC 1.0 since the Early Draft Review 2 version, which was released quite some time ago. The following sections summarize the most important aspects of the new release.

New license

As you may already know, the specification and reference implementation are now licensed under the Apache 2.0 License. We think that updating the license was a very important step for making MVC 1.0 a true community specification. The Apache license will allow you to use the specification and contributing to it without any legal issues.


MVC 1.0 now supports an API for dealing with I18N aspects. The specification defines the request locale as the locale to use for all locale-dependent operations. MVC will automatically use this locale for data type conversion (see below), for validation and binding error messages and more. The request locale can also be accessed by calling mvcContext.getLocale() on the injected MvcContext.

But there is more. MVC 1.0 provides an SPI for resolving the request locale. By default, the request locale is determined from the HTTP request headers. But if you need more control for the resolving, you can simply implement the LocaleResolver SPI to resolve the locale yourself. This allows you to store the active locale in the session, automatically infer it from the URL, etc.

Improved data binding

The MVC 1.0 specification relies on JAX-RS for data binding. Unfortunately the JAX-RS data binding isn't flexible enough for typical web application requirements. The main problems are that data binding in JAX-RS isn't locale-aware and that binding and validation errors are fatal and typically result in a 400 status code being sent to the client.

With MVC 1.0 you will be able to use the @MvcBinding annotation to enable MVC specific rules for data binding. The first difference to traditional JAX-RS data binding is that MVC bindings are locale-aware. This means that entering decimal values into web application forms and binding them to corresponding numerical types in the controller will work out of the box. MVC will automatically detect the correct number format depending on your request locale.

Another important feature of MVC data binding is that binding and validation errors don't result in exceptions being thrown anymore. Instead, such errors are available from the BindingResult class which can be injected into the controller. This allows the controller to check for errors and handle them in a very specific way. This usually means that the controller will store error details in the model and render the corresponding view again to show the errors to the user.

Much more

There are many more minor changes in this version of the spec, including:

  • New API for generating URLs from the view and from controllers.
  • CsrfOptions.EXPLICT is now the default for the CSRF protection.
  • The rules for allowed controller return types have been simplified.
  • Some clarifications regarding sub-resource handling.
  • And much more...

What's next?

As the name already suggests, the Public Review Phase is meant for the community to review the specification. Therefore, we encourage everyone who is interested in action-based web frameworks and Java EE / EE4J to have a look at the specification. Any kind of feedback is welcome. Our goal is to create an API that developers love to use. So if you see any problems with it, let us know.

Feel free to join our mailing list and let us know what you think. You can either post your thoughts on the list or file an issue on the issue tracker.

And don't forget: MVC 1.0 needs YOUR feedback!