https://github.com/eclipse-ee4j/jaxrs-api: Jakarta RESTful Web Services (Eclipse Foundation) 
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 * Copyright (c) 2011, 2019 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package jakarta.ws.rs.core;


A feature extension contract.
Typically encapsulates a concept or facility that involves configuration of multiple providers (e.g. filters or
interceptors) and/or properties.

 A Feature is a special type of JAX-RS configuration meta-provider. Once a feature is registered, its configure(FeatureContext) method is invoked during JAX-RS runtime configuration and bootstrapping phase allowing the feature to further configure the runtime context in which it has been registered. From within the invoked configure(...) method a feature may provide additional runtime configuration for the facility or conceptual domain it represents, such as registering additional contract providers, including nested features and/or specifying domain-specific properties. 


 Features implementing this interface MAY be annotated with the @Provider annotation in order to be discovered by the JAX-RS runtime when scanning for resources and providers. Please note that this will only work for server side features. Features for the JAX-RS client must be registered programmatically. 


Author:Marek Potociar
Since:2.0
/**
 * A feature extension contract.
 *
 * Typically encapsulates a concept or facility that involves configuration of multiple providers (e.g. filters or
 * interceptors) and/or properties.
 * <p>
 * A {@code Feature} is a special type of JAX-RS configuration meta-provider. Once a feature is registered, its
 * {@link #configure(FeatureContext)} method is invoked during JAX-RS runtime configuration and bootstrapping phase
 * allowing the feature to further configure the runtime context in which it has been registered. From within the
 * invoked {@code configure(...)} method a feature may provide additional runtime configuration for the facility or
 * conceptual domain it represents, such as registering additional contract providers, including nested features and/or
 * specifying domain-specific properties.
 * </p>
 * <p>
 * Features implementing this interface MAY be annotated with the {@link jakarta.ws.rs.ext.Provider &#64;Provider}
 * annotation in order to be discovered by the JAX-RS runtime when scanning for resources and providers. Please note
 * that this will only work for server side features. Features for the JAX-RS client must be registered
 * programmatically.
 * </p>
 *
 * @author Marek Potociar
 * @since 2.0
 */
public interface Feature {

    
A call-back method called when the feature is to be enabled in a given runtime configuration scope. The responsibility of the feature is to properly update the supplied runtime configuration context and return true if the feature was successfully enabled or false otherwise. 
 Note that under some circumstances the feature may decide not to enable itself, which is indicated by returning false. In such case the configuration context does not add the feature to the collection of enabled features and a subsequent call to Configuration.isEnabled(Feature) or Configuration.isEnabled(Class<? extends Feature>) method would return false. 


Params:
  • context – configurable context in which the feature should be enabled.
Returns:true if the feature was successfully enabled, false otherwise.
/**
     * A call-back method called when the feature is to be enabled in a given runtime configuration scope.
     *
     * The responsibility of the feature is to properly update the supplied runtime configuration context and return
     * {@code true} if the feature was successfully enabled or {@code false} otherwise.
     * <p>
     * Note that under some circumstances the feature may decide not to enable itself, which is indicated by returning
     * {@code false}. In such case the configuration context does not add the feature to the collection of enabled features
     * and a subsequent call to {@link Configuration#isEnabled(Feature)} or {@link Configuration#isEnabled(Class)} method
     * would return {@code false}.
     * </p>
     *
     * @param context configurable context in which the feature should be enabled.
     * @return {@code true} if the feature was successfully enabled, {@code false} otherwise.
     */
    public boolean configure(FeatureContext context);
}