1 /* 2 * Copyright (C) 2013 DroidDriver committers 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 io.appium.droiddriver.util; 18 19 /** 20 * Simple static methods to be called at the start of your own methods to verify 21 * correct arguments and state. 22 */ 23 public final class Preconditions { 24 private Preconditions() {} 25 26 /** 27 * Ensures that an object reference passed as a parameter to the calling 28 * method is not null. 29 * 30 * @param reference an object reference 31 * @return the non-null reference that was validated 32 * @throws NullPointerException if {@code reference} is null 33 */ 34 public static <T> T checkNotNull(T reference) { 35 if (reference == null) { 36 throw new NullPointerException(); 37 } 38 return reference; 39 } 40 } 41
