/*******************************************************************************
 * Copyright (c) 2010-2014 Alexander Kerner. All rights reserved.
 * 
 * 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 net.sf.kerner.utils.collections.set.impl;

import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Set;

public class UtilSet {

    public static <T> T getFirstElement(final Set<T> set) {
        return set.iterator().next();
    }

    public static <T> T getLastElement(final Set<T> set) {
        return new ArrayList<T>(set).get(set.size() - 1);
    }

    public static boolean isNullSet(final Set<?> set) {
        if (set == null) {
            return true;
        }
        for (final Object o : set) {
            if (o != null) {
                return false;
            }
        }
        return true;
    }

    public static <T> Set<T> newSet() {
        return new LinkedHashSet<T>();
    }

    public static <T> Set<T> newSet(final Collection<? extends T> col) {
        return new LinkedHashSet<T>(col);
    }

}

/*******************************************************************************
 * Copyright (c) 2010-2014 Alexander Kerner. All rights reserved.
 *
 * 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 net.sf.kerner.utils.collections.set.impl;

import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Set;

public class UtilSet {

    public static <T> T getFirstElement(final Set<T> set) {
        return set.iterator().next();
    }

    public static <T> T getLastElement(final Set<T> set) {
        return new ArrayList<T>(set).get(set.size() - 1);
    }

    public static <T> Set<T> newSet() {
        return new LinkedHashSet<T>();
    }

    public static <T> Set<T> newSet(final Collection<? extends T> col) {
        return new LinkedHashSet<T>(col);
    }

}

Remove UtilSet#isNullSet().