/*
 * Copyright (C) 2009 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.elasticsearch.common.inject;

/**
 * Injects dependencies into the fields and methods on instances of type {@code T}. Ignores the
 * presence or absence of an injectable constructor.
 *
 * @param <T> type to inject members of
 * @author crazybob@google.com (Bob Lee)
 * @author jessewilson@google.com (Jesse Wilson)
 * @since 2.0
 */
public interface MembersInjector<T> {

    /**
     * Injects dependencies into the fields and methods of {@code instance}. Ignores the presence or
     * absence of an injectable constructor.
     * <p>
     * Whenever Guice creates an instance, it performs this injection automatically (after first
     * performing constructor injection), so if you're able to let Guice create all your objects for
     * you, you'll never need to use this method.
     *
     * @param instance to inject members on. May be {@code null}.
     */
    void injectMembers(T instance);
}
