com.liferay.portal.kernel.util.ListUtil Maven / Gradle / Ivy
/**
* 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.bean.BeanPropertiesUtil;
import com.liferay.portal.kernel.io.unsync.UnsyncBufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.Set;
import java.util.function.ToLongFunction;
/**
* @author Brian Wing Shun Chan
* @author Shuyang Zhou
*/
public class ListUtil {
public static List copy(List master) {
if (master == null) {
return null;
}
return new ArrayList<>(master);
}
public static void copy(
List master, List copy) {
if ((master == null) || (copy == null)) {
return;
}
copy.clear();
copy.addAll(master);
}
public static int count(
List list, PredicateFilter predicateFilter) {
if (isEmpty(list)) {
return 0;
}
int count = 0;
for (E element : list) {
if (predicateFilter.filter(element)) {
count++;
}
}
return count;
}
public static void distinct(
List list, Comparator comparator) {
if (isEmpty(list)) {
return;
}
Set set = new HashSet<>();
Iterator itr = list.iterator();
while (itr.hasNext()) {
E obj = itr.next();
if (!set.add(obj)) {
itr.remove();
}
}
if (comparator != null) {
Collections.sort(list, comparator);
}
}
public static void distinct(List list) {
distinct(list, null);
}
public static boolean exists(
List list, PredicateFilter predicateFilter) {
if (isEmpty(list)) {
return false;
}
for (E element : list) {
if (predicateFilter.filter(element)) {
return true;
}
}
return false;
}
public static List filter(
List inputList, List outputList,
PredicateFilter predicateFilter) {
for (T item : inputList) {
if (predicateFilter.filter(item)) {
outputList.add(item);
}
}
return outputList;
}
public static List filter(
List inputList, PredicateFilter predicateFilter) {
return filter(
inputList, new ArrayList(inputList.size()), predicateFilter);
}
public static List fromArray(E[] array) {
if (ArrayUtil.isEmpty(array)) {
return new ArrayList<>();
}
return new ArrayList<>(Arrays.asList(array));
}
@SuppressWarnings("rawtypes")
public static List fromCollection(Collection c) {
if ((c != null) && (c instanceof List)) {
return (List)c;
}
if ((c == null) || c.isEmpty()) {
return new ArrayList<>();
}
List list = new ArrayList<>(c.size());
list.addAll(c);
return list;
}
public static List fromEnumeration(Enumeration enu) {
List list = new ArrayList<>();
while (enu.hasMoreElements()) {
E obj = enu.nextElement();
list.add(obj);
}
return list;
}
public static List fromFile(File file) throws IOException {
if (!file.exists()) {
return new ArrayList<>();
}
List list = new ArrayList<>();
try (UnsyncBufferedReader unsyncBufferedReader =
new UnsyncBufferedReader(new FileReader(file))) {
String s = StringPool.BLANK;
while ((s = unsyncBufferedReader.readLine()) != null) {
list.add(s);
}
}
return list;
}
public static List fromFile(String fileName) throws IOException {
return fromFile(new File(fileName));
}
public static List fromMapKeys(Map map) {
if (MapUtil.isEmpty(map)) {
return new ArrayList<>();
}
return new ArrayList<>(map.keySet());
}
public static List fromMapValues(Map map) {
if (MapUtil.isEmpty(map)) {
return new ArrayList<>();
}
return new ArrayList<>(map.values());
}
public static List fromString(String s) {
return fromArray(StringUtil.splitLines(s));
}
public static List fromString(String s, String delimiter) {
return fromArray(StringUtil.split(s, delimiter));
}
public static boolean isEmpty(List list) {
if ((list == null) || list.isEmpty()) {
return true;
}
return false;
}
public static boolean isNotEmpty(List list) {
return !isEmpty(list);
}
public static boolean isNotNull(List list) {
return !isNull(list);
}
public static boolean isNull(List list) {
if ((list == null) || list.isEmpty()) {
return true;
}
for (Object bean : list) {
if (Validator.isNotNull(bean)) {
return false;
}
}
return true;
}
public static boolean isUnmodifiableList(List list) {
return _UNMODIFIABLE_LIST_CLASS.isInstance(list);
}
public static List remove(List list, List remove) {
if (isEmpty(list) || isEmpty(remove)) {
return list;
}
list = copy(list);
for (E element : remove) {
list.remove(element);
}
return list;
}
public static Iterator reverseIterator(List list) {
final ListIterator listIterator = list.listIterator(list.size());
return new Iterator() {
@Override
public boolean hasNext() {
return listIterator.hasPrevious();
}
@Override
public E next() {
return listIterator.previous();
}
@Override
public void remove() {
listIterator.remove();
}
};
}
public static List sort(List list) {
return sort(list, null);
}
public static List sort(
List list, Comparator comparator) {
if (isUnmodifiableList(list)) {
list = copy(list);
}
Collections.sort(list, comparator);
return list;
}
public static List subList(List list, int start, int end) {
if (start < 0) {
start = 0;
}
if ((end < 0) || (end > list.size())) {
end = list.size();
}
if (start < end) {
return list.subList(start, end);
}
return Collections.emptyList();
}
public static A[] toArray(
List list, Accessor accessor) {
if (isEmpty(list)) {
return (A[])Array.newInstance(accessor.getAttributeClass(), 0);
}
A[] array = (A[])Array.newInstance(
accessor.getAttributeClass(), list.size());
for (int i = 0; i < list.size(); i++) {
T bean = list.get(i);
A attribute = accessor.get(bean);
array[i] = attribute;
}
return array;
}
public static List toList(boolean[] array) {
if (ArrayUtil.isEmpty(array)) {
return new ArrayList<>();
}
List list = new ArrayList<>(array.length);
for (boolean value : array) {
list.add(value);
}
return list;
}
public static List toList(char[] array) {
if (ArrayUtil.isEmpty(array)) {
return new ArrayList<>();
}
List list = new ArrayList<>(array.length);
for (char value : array) {
list.add(value);
}
return list;
}
public static List toList(double[] array) {
if (ArrayUtil.isEmpty(array)) {
return new ArrayList<>();
}
List list = new ArrayList<>(array.length);
for (double value : array) {
list.add(value);
}
return list;
}
public static List toList(E[] array) {
if (ArrayUtil.isEmpty(array)) {
return new ArrayList<>();
}
return new ArrayList<>(Arrays.asList(array));
}
public static List toList(float[] array) {
if (ArrayUtil.isEmpty(array)) {
return new ArrayList<>();
}
List list = new ArrayList<>(array.length);
for (float value : array) {
list.add(value);
}
return list;
}
public static List toList(int[] array) {
if (ArrayUtil.isEmpty(array)) {
return new ArrayList<>();
}
List list = new ArrayList<>(array.length);
for (int value : array) {
list.add(value);
}
return list;
}
public static List toList(List list, Accessor accessor) {
List aList = new ArrayList<>(list.size());
for (T t : list) {
aList.add(accessor.get(t));
}
return aList;
}
public static List toList(List list, Function function) {
final List result = new ArrayList<>(list.size());
for (T t : list) {
result.add(function.apply(t));
}
return result;
}
public static List toList(List vlist) {
return new ArrayList(vlist);
}
public static List toList(long[] array) {
if (ArrayUtil.isEmpty(array)) {
return new ArrayList<>();
}
List list = new ArrayList<>(array.length);
for (long value : array) {
list.add(value);
}
return list;
}
public static List toList(short[] array) {
if (ArrayUtil.isEmpty(array)) {
return new ArrayList<>();
}
List list = new ArrayList<>(array.length);
for (short value : array) {
list.add(value);
}
return list;
}
public static long[] toLongArray(
List list, Accessor accessor) {
if (isEmpty(list)) {
return _EMPTY_LONG_ARRAY;
}
long[] array = new long[list.size()];
for (int i = 0; i < list.size(); i++) {
T bean = list.get(i);
Long attribute = accessor.get(bean);
array[i] = attribute;
}
return array;
}
public static long[] toLongArray(
List list, ToLongFunction toLongFunction) {
if (isEmpty(list)) {
return _EMPTY_LONG_ARRAY;
}
long[] array = new long[list.size()];
for (int i = 0; i < list.size(); i++) {
array[i] = toLongFunction.applyAsLong(list.get(i));
}
return array;
}
/**
* @see ArrayUtil#toString(Object[], Accessor)
*/
public static String toString(
List list, Accessor accessor) {
return toString(list, accessor, StringPool.COMMA);
}
/**
* @see ArrayUtil#toString(Object[], Accessor, String)
*/
public static String toString(
List list, Accessor accessor, String delimiter) {
if (isEmpty(list)) {
return StringPool.BLANK;
}
StringBundler sb = new StringBundler(2 * list.size() - 1);
for (int i = 0; i < list.size(); i++) {
T bean = list.get(i);
A attribute = accessor.get(bean);
if (attribute != null) {
sb.append(attribute);
}
if ((i + 1) != list.size()) {
sb.append(delimiter);
}
}
return sb.toString();
}
/**
* @see ArrayUtil#toString(Object[], String)
*/
public static String toString(List list, String param) {
return toString(list, param, StringPool.COMMA);
}
/**
* @see ArrayUtil#toString(Object[], String, String)
*/
public static String toString(
List list, String param, String delimiter) {
if (isEmpty(list)) {
return StringPool.BLANK;
}
StringBundler sb = new StringBundler(2 * list.size() - 1);
for (int i = 0; i < list.size(); i++) {
Object bean = list.get(i);
Object value = null;
if (Validator.isNull(param)) {
value = String.valueOf(bean);
}
else {
value = BeanPropertiesUtil.getObject(bean, param);
}
if (value != null) {
sb.append(value);
}
if ((i + 1) != list.size()) {
sb.append(delimiter);
}
}
return sb.toString();
}
public static List unique(List list) {
Set set = new LinkedHashSet<>();
set.addAll(list);
if (list.size() == set.size()) {
return list;
}
return new ArrayList<>(set);
}
private static final long[] _EMPTY_LONG_ARRAY = {};
private static final Class> _UNMODIFIABLE_LIST_CLASS;
static {
List