1 /* 2 * Copyright (C) 2007 The Guava 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 com.google.common.collect.testing; 18 19 import java.util.AbstractCollection; 20 import java.util.Arrays; 21 import java.util.Collection; 22 import java.util.Iterator; 23 24 /** 25 * A simplistic collection which implements only the bare minimum allowed by the 26 * spec, and throws exceptions whenever it can. 27 * 28 * @author Kevin Bourrillion 29 */ 30 public class MinimalCollection<E> extends AbstractCollection<E> { 31 // TODO: expose allow nulls parameter? 32 33 public static <E> MinimalCollection<E> of(E... contents) { 34 return new MinimalCollection<E>(Object.class, true, contents); 35 } 36 37 // TODO: use this 38 public static <E> MinimalCollection<E> ofClassAndContents( 39 Class<? super E> type, E... contents) { 40 return new MinimalCollection<E>(type, true, contents); 41 } 42 43 private final E[] contents; 44 private final Class<? super E> type; 45 private final boolean allowNulls; 46 47 // Package-private so that it can be extended. 48 MinimalCollection(Class<? super E> type, boolean allowNulls, E... contents) { 49 // TODO: consider making it shuffle the contents to test iteration order. 50 this.contents = Platform.clone(contents); 51 this.type = type; 52 this.allowNulls = allowNulls; 53 54 if (!allowNulls) { 55 for (Object element : contents) { 56 if (element == null) { 57 throw new NullPointerException(); 58 } 59 } 60 } 61 } 62 63 @Override public int size() { 64 return contents.length; 65 } 66 67 @Override public boolean contains(Object object) { 68 if (!allowNulls) { 69 // behave badly 70 if (object == null) { 71 throw new NullPointerException(); 72 } 73 } 74 Platform.checkCast(type, object); // behave badly 75 return Arrays.asList(contents).contains(object); 76 } 77 78 @Override public boolean containsAll(Collection<?> collection) { 79 if (!allowNulls) { 80 for (Object object : collection) { 81 // behave badly 82 if (object == null) { 83 throw new NullPointerException(); 84 } 85 } 86 } 87 return super.containsAll(collection); 88 } 89 90 @Override public Iterator<E> iterator() { 91 return Arrays.asList(contents).iterator(); 92 } 93 94 @Override public Object[] toArray() { 95 Object[] result = new Object[contents.length]; 96 Platform.unsafeArrayCopy(contents, 0, result, 0, contents.length); 97 return result; 98 } 99 100 /* 101 * a "type A" unmodifiable collection freaks out proactively, even if there 102 * wasn't going to be any actual work to do anyway 103 */ 104 105 @Override public boolean addAll(Collection<? extends E> elementsToAdd) { 106 throw up(); 107 } 108 @Override public boolean removeAll(Collection<?> elementsToRemove) { 109 throw up(); 110 } 111 @Override public boolean retainAll(Collection<?> elementsToRetain) { 112 throw up(); 113 } 114 @Override public void clear() { 115 throw up(); 116 } 117 private static UnsupportedOperationException up() { 118 throw new UnsupportedOperationException(); 119 } 120 } 121
