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/*
* 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.
*
* This class is GWT compatible.
*
* @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;
}
}