1 /* 2 * Copyright (C) 2016 The Android Open Source Project 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 com.android.packageinstaller.permission.utils; 18 19 import android.text.TextUtils; 20 21 import androidx.annotation.Nullable; 22 23 import java.util.Objects; 24 25 public final class ArrayUtils { ArrayUtils()26 private ArrayUtils() { /* cannot be instantiated */ } 27 28 /** 29 * Checks if an array is null or has no elements. 30 * 31 * @param array the array to check for 32 * 33 * @return whether the array is null or has no elements. 34 */ isEmpty(@ullable T[] array)35 public static <T> boolean isEmpty(@Nullable T[] array) { 36 return array == null || array.length == 0; 37 } 38 39 /** 40 * Checks that value is present as at least one of the elements of the array. 41 * @param array the array to check in 42 * @param value the value to check for 43 * @return true if the value is present in the array 44 */ contains(T[] array, T value)45 public static <T> boolean contains(T[] array, T value) { 46 return indexOf(array, value) != -1; 47 } 48 49 /** 50 * Return first index of {@code value} in {@code array}, or {@code -1} if 51 * not found. 52 */ indexOf(T[] array, T value)53 public static <T> int indexOf(T[] array, T value) { 54 if (array == null) return -1; 55 for (int i = 0; i < array.length; i++) { 56 if (Objects.equals(array[i], value)) return i; 57 } 58 return -1; 59 } 60 appendString(String[] cur, String val)61 public static String[] appendString(String[] cur, String val) { 62 if (cur == null) { 63 return new String[] { val }; 64 } 65 final int N = cur.length; 66 for (int i = 0; i < N; i++) { 67 if (TextUtils.equals(cur[i], val)) { 68 return cur; 69 } 70 } 71 String[] ret = new String[N + 1]; 72 System.arraycopy(cur, 0, ret, 0, N); 73 ret[N] = val; 74 return ret; 75 } 76 } 77