com.blazebit.persistence.impl.util.SetView Maven / Gradle / Ivy

/*
 * Copyright 2014 - 2020 Blazebit.
 *
 * 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.blazebit.persistence.impl.util;

import java.io.Serializable;
import java.util.Collection;
import java.util.Iterator;
import java.util.Set;

/**
 * A set implementation that allows to provide a set view of a collection.
 *
 * @author Christian Beikov
 * @since 1.2.0
 */
public class SetView implements Set, Serializable {

    final Collection c;

    public SetView(Collection c) {
        if (c == null) {
            throw new NullPointerException();
        }
        this.c = c;
    }

    public int size() {
        return c.size();
    }

    public boolean isEmpty() {
        return c.isEmpty();
    }

    public boolean contains(Object o) {
        return c.contains(o);
    }

    public Object[] toArray() {
        return c.toArray();
    }

    public  T[] toArray(T[] a) {
        return c.toArray(a);
    }

    public String toString() {
        return c.toString();
    }

    public Iterator iterator() {
        return new Iterator() {
            private final Iterator i = c.iterator();

            public boolean hasNext() {
                return i.hasNext();
            }

            public E next() {
                return i.next();
            }

            public void remove() {
                throw new UnsupportedOperationException();
            }
        };
    }

    public boolean add(E e) {
        throw new UnsupportedOperationException();
    }

    public boolean remove(Object o) {
        throw new UnsupportedOperationException();
    }

    public boolean containsAll(Collection coll) {
        return c.containsAll(coll);
    }

    public boolean addAll(Collection coll) {
        throw new UnsupportedOperationException();
    }

    public boolean removeAll(Collection coll) {
        throw new UnsupportedOperationException();
    }

    public boolean retainAll(Collection coll) {
        throw new UnsupportedOperationException();
    }

    public void clear() {
        throw new UnsupportedOperationException();
    }

}