com.liferay.portal.kernel.util.SetUtil.java Source code

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Here is the source code for com.liferay.portal.kernel.util.SetUtil.java

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/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

package com.liferay.portal.kernel.util;

import com.liferay.petra.string.StringPool;
import com.liferay.portal.kernel.io.unsync.UnsyncBufferedReader;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;

import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

/**
 * @author Brian Wing Shun Chan
 */
public class SetUtil {

    public static Set<Boolean> fromArray(boolean[] array) {
        if (ArrayUtil.isEmpty(array)) {
            return new HashSet<>();
        }

        Set<Boolean> set = new HashSet<>();

        for (boolean b : array) {
            set.add(b);
        }

        return set;
    }

    public static Set<Byte> fromArray(byte[] array) {
        if (ArrayUtil.isEmpty(array)) {
            return new HashSet<>();
        }

        Set<Byte> set = new HashSet<>();

        for (byte b : array) {
            set.add(b);
        }

        return set;
    }

    public static Set<Character> fromArray(char[] array) {
        if (ArrayUtil.isEmpty(array)) {
            return new HashSet<>();
        }

        Set<Character> set = new HashSet<>();

        for (char c : array) {
            set.add(c);
        }

        return set;
    }

    public static Set<Double> fromArray(double[] array) {
        if (ArrayUtil.isEmpty(array)) {
            return new HashSet<>();
        }

        Set<Double> set = new HashSet<>();

        for (double d : array) {
            set.add(d);
        }

        return set;
    }

    public static <E> Set<E> fromArray(E[] array) {
        if (ArrayUtil.isEmpty(array)) {
            return new HashSet<>();
        }

        Set<E> set = new HashSet<>();

        for (E obj : array) {
            set.add(obj);
        }

        return set;
    }

    public static Set<Float> fromArray(float[] array) {
        if (ArrayUtil.isEmpty(array)) {
            return new HashSet<>();
        }

        Set<Float> set = new HashSet<>();

        for (float f : array) {
            set.add(f);
        }

        return set;
    }

    public static Set<Integer> fromArray(int[] array) {
        if (ArrayUtil.isEmpty(array)) {
            return new HashSet<>();
        }

        Set<Integer> set = new HashSet<>();

        for (int i : array) {
            set.add(i);
        }

        return set;
    }

    public static Set<Long> fromArray(long[] array) {
        if (ArrayUtil.isEmpty(array)) {
            return new HashSet<>();
        }

        Set<Long> set = new HashSet<>();

        for (long l : array) {
            set.add(l);
        }

        return set;
    }

    public static Set<Short> fromArray(short[] array) {
        if (ArrayUtil.isEmpty(array)) {
            return new HashSet<>();
        }

        Set<Short> set = new HashSet<>();

        for (short s : array) {
            set.add(s);
        }

        return set;
    }

    public static <E> Set<E> fromCollection(Collection<? extends E> c) {
        if ((c != null) && (c instanceof Set)) {
            return (Set<E>) c;
        }

        if ((c == null) || c.isEmpty()) {
            return new HashSet<>();
        }

        return new HashSet<>(c);
    }

    public static <E> Set<E> fromEnumeration(Enumeration<? extends E> enu) {
        Set<E> set = new HashSet<>();

        while (enu.hasMoreElements()) {
            set.add(enu.nextElement());
        }

        return set;
    }

    public static Set<String> fromFile(File file) throws IOException {
        Set<String> set = new HashSet<>();

        try (UnsyncBufferedReader unsyncBufferedReader = new UnsyncBufferedReader(new FileReader(file))) {

            String s = StringPool.BLANK;

            while ((s = unsyncBufferedReader.readLine()) != null) {
                set.add(s);
            }
        }

        return set;
    }

    public static Set<String> fromFile(String fileName) throws IOException {
        return fromFile(new File(fileName));
    }

    public static <E> Set<E> fromIterator(Iterator<E> itr) {
        Set<E> set = new HashSet<>();

        while (itr.hasNext()) {
            set.add(itr.next());
        }

        return set;
    }

    public static <E> Set<E> fromList(List<? extends E> array) {
        if (ListUtil.isEmpty(array)) {
            return new HashSet<>();
        }

        return new HashSet<>(array);
    }

    public static Set<String> fromString(String s) {
        return fromArray(StringUtil.splitLines(s));
    }

    public static <T> Set<T> intersect(Collection<T> collection1, Collection<T> collection2) {

        if (collection1.isEmpty() || collection2.isEmpty()) {
            return Collections.emptySet();
        }

        Set<T> set1 = _toSet(collection1);
        Set<T> set2 = _toSet(collection2);

        if (set1.size() > set2.size()) {
            set2.retainAll(set1);

            return set2;
        }

        set1.retainAll(set2);

        return set1;
    }

    public static Set<Long> intersect(long[] array1, long[] array2) {
        return intersect(fromArray(array1), fromArray(array2));
    }

    public static boolean isEmpty(Set<?> set) {
        if ((set == null) || set.isEmpty()) {
            return true;
        }

        return false;
    }

    public static boolean isNotEmpty(Set<?> set) {
        return !isEmpty(set);
    }

    public static <T> Set<T> symmetricDifference(Collection<T> collection1, Collection<T> collection2) {

        if (collection1.isEmpty()) {
            return _toSet(collection2);
        }

        if (collection2.isEmpty()) {
            return _toSet(collection1);
        }

        Set<T> set1 = _toSet(collection1);
        Set<T> set2 = _toSet(collection2);

        Set<T> intersection = intersect(set1, set2);

        if (set1.size() > set2.size()) {
            set1.addAll(set2);
        } else {
            set2.addAll(set1);

            set1 = set2;
        }

        set1.removeAll(intersection);

        return set1;
    }

    public static Set<Long> symmetricDifference(long[] array1, long[] array2) {
        return symmetricDifference(fromArray(array1), fromArray(array2));
    }

    private static <T> Set<T> _toSet(Collection<T> collection) {
        if (collection instanceof Set) {
            return (Set<T>) collection;
        }

        return new HashSet<>(collection);
    }

}