JBR API

June 5, 2024 ยท View on GitHub

JetBrains incubator project

JBR API

JBR API is an interface for the functionality specific to JetBrains Runtime aka JBR. JBR API provides a standalone jar with classes and interfaces representing various APIs allowing the client code to be compiled against any JDK, while enjoying unique features provided by JBR at run time without worrying about compatibility and runtime errors.

Quickstart

Any feature exposed via JBR API begins with a service, which is a basic unit of JBR API. Each service has three related methods in the JBR class:

  • JBR.get<NAME>() - returns the service instance if it's supported or null.
  • JBR.get<NAME>(Extensions...) - returns the service instance with the set of optional extensions enabled (see below).
  • JBR.is<NAME>Supported() - a convenience method equivalent to JBR.get<NAME>() != null.
if (JBR.isSomeServiceSupported()) {
    JBR.getSomeService().doSomething();
}
// or
SomeService service = JBR.getSomeService();
if (service != null) {
    service.doSomething();
}
Tip

More details with a list of available services can be found in the javadoc.

Extensions

API methods marked with @Extension are optional, meaning that the service would still be considered supported even if some of its extension methods are not. Such extensions must be explicitly enabled when retrieving the service with JBR.get<NAME>(Extensions...). Extension methods may appear not only in services but in regular interfaces too. In that case the set of enabled extensions is implicitly propagated to objects retrieved from that service.

Example 
SomeService service;
Foo foo;

service = JBR.getSomeService();
foo = service.getFoo();
foo.bar(); // UnsupportedOperationException: Foo.bar - extension BAR is disabled

service = JBR.getSomeService(Extensions.BAR);
foo = service.getFoo();
foo.bar(); // OK

Versioning

JBR API releases follow semantic versioning. API and implementation versions can be retrieved from the JBR class:

  • JBR.getApiVersion() - the version of jbr-api.jar currently used.
  • JBR.getImplVersion() - the version of JBR API implemented by the current runtime.
Info

Versions should not be used for any purpose other than logging.

Neither the API nor implementation versions are used in compatibility checks or when determining the service availability.

However, you can assume that when impl.major == api.major && impl.minor >= api.minor, all services currently present in that JBR API are guaranteed to be supported by that implementation.

References