1 /* 2 * Copyright 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.mediaframeworktest.helpers; 18 19 import java.util.Collection; 20 import java.util.Objects; 21 22 /** 23 * Helper set of methods to perform precondition checks before starting method execution. 24 * 25 * <p>Typically used to sanity check arguments or the current object state.</p> 26 */ 27 /** 28 * (non-Javadoc) 29 * @see android.hardware.camera2.cts.helpers.Preconditions 30 */ 31 public final class Preconditions { 32 33 /** 34 * Checks that the value has the expected bitwise flags set. 35 * 36 * @param argName Name of the argument 37 * @param arg Argument to check 38 * @param flagsName Name of the bitwise flags 39 * @param flags Bit flags to check. 40 * @return arg 41 * 42 * @throws IllegalArgumentException if the bitwise flags weren't set 43 */ 44 public static int checkBitFlags(String argName, int arg, String flagsName, int flags) { 45 if ((arg & flags) == 0) { 46 throw new IllegalArgumentException( 47 String.format("Argument '%s' must have flags '%s' set", argName, flagsName)); 48 } 49 50 return arg; 51 } 52 53 /** 54 * Checks that the value is {@link Object#equals equal} to the expected value. 55 * 56 * @param argName Name of the argument 57 * @param arg Argument to check 58 * @param expectedName Name of the expected value 59 * @param expectedValue Expected value 60 * @return arg 61 * 62 * @throws IllegalArgumentException if the values were not equal 63 */ 64 public static <T> T checkEquals(String argName, T arg, 65 String expectedName, T expectedValue) { 66 if (!Objects.equals(arg, expectedValue)) { 67 throw new IllegalArgumentException( 68 String.format( 69 "Argument '%s' must be equal to '%s' (was '%s', but expected '%s')", 70 argName, expectedName, arg, expectedValue)); 71 } 72 73 return arg; 74 } 75 76 /** 77 * Checks that the value is not {@code null}. 78 * 79 * <p> 80 * Returns the value directly, so you can use {@code checkNotNull("value", value)} inline. 81 * </p> 82 * 83 * @param argName Name of the argument 84 * @param arg Argument to check 85 * @return arg 86 * 87 * @throws NullPointerException if arg was {@code null} 88 */ 89 public static <T> T checkNotNull(String argName, T arg) { 90 if (arg == null) { 91 throw new NullPointerException("Argument '" + argName + "' must not be null"); 92 } 93 94 return arg; 95 } 96 97 /** 98 * Checks that the value is not {@code null}. 99 * 100 * <p> 101 * Returns the value directly, so you can use {@code checkNotNull("value", value)} inline. 102 * </p> 103 * 104 * @param arg Argument to check 105 * @return arg 106 * 107 * @throws NullPointerException if arg was {@code null} 108 */ 109 public static <T> T checkNotNull(T arg) { 110 return checkNotNull("", arg); 111 } 112 113 /** 114 * Checks that the state is currently {@link true}. 115 * 116 * @param message Message to raise an exception with if the state checking fails. 117 * @param state State to check 118 * 119 * @throws IllegalStateException if state was {@code false} 120 * 121 * @return The state value (always {@code true}). 122 */ 123 public static boolean checkState(String message, boolean state) { 124 if (!state) { 125 throw new IllegalStateException(message); 126 } 127 128 return state; 129 } 130 131 /** 132 * Ensures that the {@link Collection} is not {@code null}, and none of its elements are 133 * {@code null}. 134 * 135 * @param value a {@link Collection} of boxed objects 136 * @param valueName the name of the argument to use if the check fails 137 * 138 * @return the validated {@link Collection} 139 * 140 * @throws NullPointerException if the {@code value} or any of its elements were {@code null} 141 */ 142 public static <T> Collection<T> checkCollectionElementsNotNull(final Collection<T> value, 143 final String valueName) { 144 if (value == null) { 145 throw new NullPointerException(valueName + " must not be null"); 146 } 147 148 long ctr = 0; 149 for (T elem : value) { 150 if (elem == null) { 151 throw new NullPointerException( 152 String.format("%s[%d] must not be null", valueName, ctr)); 153 } 154 ++ctr; 155 } 156 157 return value; 158 } 159 160 /** 161 * Ensures that the {@link Collection} is not {@code null}, and contains at least one element. 162 * 163 * @param value a {@link Collection} of boxed elements. 164 * @param valueName the name of the argument to use if the check fails. 165 166 * @return the validated {@link Collection} 167 * 168 * @throws NullPointerException if the {@code value} was {@code null} 169 * @throws IllegalArgumentException if the {@code value} was empty 170 */ 171 public static <T> Collection<T> checkCollectionNotEmpty(final Collection<T> value, 172 final String valueName) { 173 if (value == null) { 174 throw new NullPointerException(valueName + " must not be null"); 175 } 176 if (value.isEmpty()) { 177 throw new IllegalArgumentException(valueName + " is empty"); 178 } 179 return value; 180 } 181 182 // Suppress default constructor for noninstantiability 183 private Preconditions() { throw new AssertionError(); } 184 } 185
