/* * Copyright (C) 2009 The Guava Authors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.google.common.collect.testing; import com.google.common.annotations.GwtCompatible; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.List; import java.util.Set; /** * A simplistic set which implements the bare minimum so that it can be used in tests without * relying on any specific Set implementations. Slow. Explicitly allows null elements so that they * can be used in the testers. * * @author Regina O'Dell */ @GwtCompatible public class MinimalSet extends MinimalCollection implements Set { @SuppressWarnings("unchecked") // empty Object[] as E[] public static MinimalSet of(E... contents) { return ofClassAndContents(Object.class, (E[]) new Object[0], Arrays.asList(contents)); } @SuppressWarnings("unchecked") // empty Object[] as E[] public static MinimalSet from(Collection contents) { return ofClassAndContents(Object.class, (E[]) new Object[0], contents); } public static MinimalSet ofClassAndContents( Class type, E[] emptyArrayForContents, Iterable contents) { List setContents = new ArrayList(); for (E e : contents) { if (!setContents.contains(e)) { setContents.add(e); } } return new MinimalSet(type, setContents.toArray(emptyArrayForContents)); } private MinimalSet(Class type, E... contents) { super(type, true, contents); } /* * equals() and hashCode() are more specific in the Set contract. */ @Override public boolean equals(Object object) { if (object instanceof Set) { Set that = (Set) object; return (this.size() == that.size()) && this.containsAll(that); } return false; } @Override public int hashCode() { int hashCodeSum = 0; for (Object o : this) { hashCodeSum += (o == null) ? 0 : o.hashCode(); } return hashCodeSum; } }