com.netflix.servo.util.UnmodifiableSet Maven / Gradle / Ivy

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/*
 * Copyright 2014 Netflix, Inc.
 *
 * 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.netflix.servo.util;

import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

/**
 * Utility class to create unmodifiable sets.
 */
public final class UnmodifiableSet {
    private UnmodifiableSet() {
    }

    /**
     * Returns an unmodifiable view of the set created from the given elements.
     * @param elements Array of elements
     * @param  type of the elements
     * @return an unmodifiable view of the set created from the given elements.
     */
    public static  Set of(E... elements) {
        Set result = new HashSet();
        Collections.addAll(result, elements);
        return Collections.unmodifiableSet(result);
    }

    /**
     * Returns an unmodifiable view of the set created from the given elements.
     * @param elementsIterator iterator to get the elements of the set.
     * @param  type of the elements
     * @return an unmodifiable view of the set created from the given elements.
     */
    public static  Set copyOf(Iterator elementsIterator) {
        Set result = new HashSet();
        while (elementsIterator.hasNext()) {
            result.add(elementsIterator.next());
        }
        return Collections.unmodifiableSet(result);
    }
}