1 /* 2 * Copyright (C) 2014 The Dagger Authors. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package dagger.internal; 18 19 import static dagger.internal.Preconditions.checkNotNull; 20 21 import dagger.MembersInjector; 22 import javax.inject.Inject; 23 24 /** 25 * Basic {@link MembersInjector} implementations used by the framework. 26 */ 27 public final class MembersInjectors { 28 /** 29 * Returns a {@link MembersInjector} implementation that injects no members 30 * 31 * <p>Note that there is no verification that the type being injected does not have {@link Inject} 32 * members, so care should be taken to ensure appropriate use. 33 */ 34 @SuppressWarnings("unchecked") noOp()35 public static <T> MembersInjector<T> noOp() { 36 return (MembersInjector<T>) NoOpMembersInjector.INSTANCE; 37 } 38 39 private static enum NoOpMembersInjector implements MembersInjector<Object> { 40 INSTANCE; 41 injectMembers(Object instance)42 @Override public void injectMembers(Object instance) { 43 checkNotNull(instance, "Cannot inject members into a null reference"); 44 } 45 } 46 MembersInjectors()47 private MembersInjectors() {} 48 } 49