Try out some of the MicroProfile 1.3 technologies, including MicroProfile Rest Client 1.0, MicroProfile Config 1.2, and MicroProfile OpenAPI 1.0, in the February 2018 beta of WebSphere Liberty.

Thanks to your support for our regular beta programme, we are able to release new Liberty features every few months. Check out the release of WebSphere Liberty which is built on the release of Open Liberty. Look out for more betas over the coming months. If you just can’t wait, take a look at the daily builds of Open Liberty.

Follow Open Liberty happenings on @OpenLibertyIO.

What’s new in this beta?

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MicroProfile Rest Client 1.0

The MicroProfile Rest Client builds on the JAX-RS 2.0 Client APIs to provide a type-safe approach for invoking RESTful services over HTTP. This means writing client applications with more model-centric code and less “plumbing”. You can create a Java interface that represents a remote RESTful service. Decorate the methods with appropriate @Path, @GET, @POST, etc. annotations, and then invoke those methods like a POJO and get the response from the remote service.

To enable the MicroProfile Rest Client in the server.xml:


To find out more about the MicroProfile Rest Client in Liberty, see Andy McCright’s blog post on the website.

MicroProfile Config 1.2

Building on version 1.1, MicroProfile Config 1.2 adds a number of new built-in converters, including Class, List, Set and automatic conversion for classes which have a suitable String constructor or static valueOf method. You can use this feature with either the cdi-1.2 feature or the cdi-2.0 feature.

You can find a full list of changes since version 1.1 on the MicroProfile Config 1.2 Milestone.

API/SPI changes

The ConfigBuilder SPI has been extended with a method that allows for a converter with the specified class type to be registered (#205). This change removes the limitation in previous releases of being unable to add a lambda converter.

Functional changes

  • Implementations must now support the array converter (#259). For the array converter, the programmatic lookup of a property (e.g. config.getValue(myProp, String[].class)) must support the return type of the array. For the injection lookup, an Array, List, or Set must be supported as well (e.g. @Inject @ConfigProperty(name="myProp") private List<MyObject> propValue;).
  • Implementations must also support the common sense converters (#269) where there is no corresponding type of converters provided for a given class. The implementation must use the class’s constructor with a single string parameter, then try valueOf(String) followed by parse(CharSequence).
  • Implementations must also support Class converter (#267).

Specification Changes

Specification changes: (#205), (#259), (#269), and (#267).

Other changes

The API bundle can work with either CDI 1.2 or CDI 2.0 in the OSGi environment (#249).

To enable the MicroProfile Config 1.2 feature just add the following feature definition to your server.xml:


For more information about MicroProfile Config 1.2, see the website.

MicroProfile OpenAPI 1.0

The MicroProfile OpenAPI 1.0 feature (mpOpenAPI-1.0) is a preview implementation of the MicroProfile OpenAPI 1.0 specification. In this beta, we’ve added support for more mechanisms from the MicroProfile OpenAPI 1.0 specification. MicroProfile OpenAPI 1.0 now handles all configurable items, fully supports filter, and handles more annotations.

To try it out, add this feature to your server.xml list of features:


Then use one of the documentation methods. You can view the generated OpenAPI document in the endpoint /openapi, or view the rendered user interface at the endpoint api/explorer.

CDI 2.0

CDI 2.0 is shining new and implements the latest CDI spec. It contains quite a few nice capabilities, especially the very useful and powerful Configurator SPIs. The new feature cdi-2.0 pulls in the Weld bundle 3.0.2. The following features of CDI 2.0 are available for use:

  • Asynchronous events
  • Configurators for major SPI elements
  • Configure or veto observer methods
  • Add built-in annotation literals
  • Apply interceptor on producers

To enable the CDI 2.0 feature just add the following feature definition to your server.xml:


For more information about CDI 2.0, see the CDI spec.

What’s already in there?

The January Liberty beta included MicroProfile OpenAPI 1.0 and JSON format logging.

For supported features, take a look at, which was released in December.

Looking for the latest?

If you’re visiting this post from the future and you’re looking for the latest releases of Liberty, here are the links you’re looking for:

Latest beta release
Latest stable release

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