dubbo-common/src/main/java/org/apache/dubbo/common/utils/CollectionUtils.java - dubbo - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You 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 org.apache.dubbo.common.utils;

 import java.util.AbstractSet;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 import static java.util.Collections.emptySet;
 import static java.util.Collections.unmodifiableSet;

 /**
  * Miscellaneous collection utility methods.
  * Mainly for internal use within the framework.
  *
  * @author william.liangf
  * @since 2.0.7
  */
 public class CollectionUtils {

     private static final Comparator<String> SIMPLE_NAME_COMPARATOR = new Comparator<String>() {
         @Override
         public int compare(String s1, String s2) {
             if (s1 == null && s2 == null) {
                 return 0;
             }
             if (s1 == null) {
                 return -1;
             }
             if (s2 == null) {
                 return 1;
             }
             int i1 = s1.lastIndexOf('.');
             if (i1 >= 0) {
                 s1 = s1.substring(i1 + 1);
             }
             int i2 = s2.lastIndexOf('.');
             if (i2 >= 0) {
                 s2 = s2.substring(i2 + 1);
             }
             return s1.compareToIgnoreCase(s2);
         }
     };

     private CollectionUtils() {
     }

     @SuppressWarnings({"unchecked", "rawtypes"})
     public static <T> List<T> sort(List<T> list) {
         if (isNotEmpty(list)) {
             Collections.sort((List) list);
         }
         return list;
     }

     public static List<String> sortSimpleName(List<String> list) {
         if (list != null && list.size() > 0) {
             Collections.sort(list, SIMPLE_NAME_COMPARATOR);
         }
         return list;
     }

     public static Map<String, Map<String, String>> splitAll(Map<String, List<String>> list, String separator) {
         if (list == null) {
             return null;
         }
         Map<String, Map<String, String>> result = new HashMap<>();
         for (Map.Entry<String, List<String>> entry : list.entrySet()) {
             result.put(entry.getKey(), split(entry.getValue(), separator));
         }
         return result;
     }

     public static Map<String, List<String>> joinAll(Map<String, Map<String, String>> map, String separator) {
         if (map == null) {
             return null;
         }
         Map<String, List<String>> result = new HashMap<>();
         for (Map.Entry<String, Map<String, String>> entry : map.entrySet()) {
             result.put(entry.getKey(), join(entry.getValue(), separator));
         }
         return result;
     }

     public static Map<String, String> split(List<String> list, String separator) {
         if (list == null) {
             return null;
         }
         Map<String, String> map = new HashMap<>();
         if (list.isEmpty()) {
             return map;
         }
         for (String item : list) {
             int index = item.indexOf(separator);
             if (index == -1) {
                 map.put(item, "");
             } else {
                 map.put(item.substring(0, index), item.substring(index + 1));
             }
         }
         return map;
     }

     public static List<String> join(Map<String, String> map, String separator) {
         if (map == null) {
             return null;
         }
         List<String> list = new ArrayList<>();
         if (map.size() == 0) {
             return list;
         }
         for (Map.Entry<String, String> entry : map.entrySet()) {
             String key = entry.getKey();
             String value = entry.getValue();
             if (StringUtils.isEmpty(value)) {
                 list.add(key);
             } else {
                 list.add(key + separator + value);
             }
         }
         return list;
     }

     public static String join(List<String> list, String separator) {
         StringBuilder sb = new StringBuilder();
         for (String ele : list) {
             if (sb.length() > 0) {
                 sb.append(separator);
             }
             sb.append(ele);
         }
         return sb.toString();
     }

     public static boolean mapEquals(Map<?, ?> map1, Map<?, ?> map2) {
         if (map1 == null && map2 == null) {
             return true;
         }
         if (map1 == null || map2 == null) {
             return false;
         }
         if (map1.size() != map2.size()) {
             return false;
         }
         for (Map.Entry<?, ?> entry : map1.entrySet()) {
             Object key = entry.getKey();
             Object value1 = entry.getValue();
             Object value2 = map2.get(key);
             if (!objectEquals(value1, value2)) {
                 return false;
             }
         }
         return true;
     }

     private static boolean objectEquals(Object obj1, Object obj2) {
         if (obj1 == null && obj2 == null) {
             return true;
         }
         if (obj1 == null || obj2 == null) {
             return false;
         }
         return obj1.equals(obj2);
     }

     public static Map<String, String> toStringMap(String... pairs) {
         Map<String, String> parameters = new HashMap<>();
         if (ArrayUtils.isEmpty(pairs)) {
             return parameters;
         }

         if (pairs.length > 0) {
             if (pairs.length % 2 != 0) {
                 throw new IllegalArgumentException("pairs must be even.");
             }
             for (int i = 0; i < pairs.length; i = i + 2) {
                 parameters.put(pairs[i], pairs[i + 1]);
             }
         }
         return parameters;
     }

     @SuppressWarnings("unchecked")
     public static <K, V> Map<K, V> toMap(Object... pairs) {
         Map<K, V> ret = new HashMap<>();
         if (pairs == null || pairs.length == 0) {
             return ret;
         }

         if (pairs.length % 2 != 0) {
             throw new IllegalArgumentException("Map pairs can not be odd number.");
         }
         int len = pairs.length / 2;
         for (int i = 0; i < len; i++) {
             ret.put((K) pairs[2 * i], (V) pairs[2 * i + 1]);
         }
         return ret;
     }

     /**
      * Return {@code true} if the supplied Collection is {@code null} or empty.
      * Otherwise, return {@code false}.
      *
      * @param collection the Collection to check
      * @return whether the given Collection is empty
      */
     public static boolean isEmpty(Collection<?> collection) {
         return collection == null || collection.isEmpty();
     }

     /**
      * Return {@code true} if the supplied Collection is {@code not null} or not empty.
      * Otherwise, return {@code false}.
      *
      * @param collection the Collection to check
      * @return whether the given Collection is not empty
      */
     public static boolean isNotEmpty(Collection<?> collection) {
         return !isEmpty(collection);
     }

     /**
      * Return {@code true} if the supplied Map is {@code null} or empty.
      * Otherwise, return {@code false}.
      *
      * @param map the Map to check
      * @return whether the given Map is empty
      */
     public static boolean isEmptyMap(Map map) {
         return map == null || map.size() == 0;
     }

     /**
      * Return {@code true} if the supplied Map is {@code not null} or not empty.
      * Otherwise, return {@code false}.
      *
      * @param map the Map to check
      * @return whether the given Map is not empty
      */
     public static boolean isNotEmptyMap(Map map) {
         return !isEmptyMap(map);
     }

     /**
      * Convert to multiple values to be {@link LinkedHashSet}
      *
      * @param values one or more values
      * @param <T>    the type of <code>values</code>
      * @return read-only {@link Set}
      */
     public static <T> Set<T> ofSet(T... values) {
         int size = values == null ? 0 : values.length;
         if (size < 1) {
             return emptySet();
         }

         float loadFactor = 1f / ((size + 1) * 1.0f);

         if (loadFactor > 0.75f) {
             loadFactor = 0.75f;
         }

         Set<T> elements = new LinkedHashSet<>(size, loadFactor);
         for (int i = 0; i < size; i++) {
             elements.add(values[i]);
         }
         return unmodifiableSet(elements);
     }

     /**
      * Get the size of the specified {@link Collection}
      *
      * @param collection the specified {@link Collection}
      * @return must be positive number
      * @since 2.7.6
      */
     public static int size(Collection<?> collection) {
         return collection == null ? 0 : collection.size();
     }

     /**
      * Compares the specified collection with another, the main implementation references
      * {@link AbstractSet}
      *
      * @param one     {@link Collection}
      * @param another {@link Collection}
      * @return if equals, return <code>true</code>, or <code>false</code>
      * @since 2.7.6
      */
     public static boolean equals(Collection<?> one, Collection<?> another) {

         if (one == another) {
             return true;
         }

         if (isEmpty(one) && isEmpty(another)) {
             return true;
         }

         if (size(one) != size(another)) {
             return false;
         }

         try {
             return one.containsAll(another);
         } catch (ClassCastException | NullPointerException unused) {
             return false;
         }
     }

     /**
      * Add the multiple values into {@link Collection the specified collection}
      *
      * @param collection {@link Collection the specified collection}
      * @param values     the multiple values
      * @param <T>        the type of values
      * @return the effected count after added
      * @since 2.7.6
      */
     public static <T> int addAll(Collection<T> collection, T... values) {

         int size = values == null ? 0 : values.length;

         if (collection == null || size < 1) {
             return 0;
         }

         int effectedCount = 0;
         for (int i = 0; i < size; i++) {
             if (collection.add(values[i])) {
                 effectedCount++;
             }
         }

         return effectedCount;
     }

     /**
      * Take the first element from the specified collection
      *
      * @param values the collection object
      * @param <T>    the type of element of collection
      * @return if found, return the first one, or <code>null</code>
      * @since 2.7.6
      */
     public static <T> T first(Collection<T> values) {
         if (isEmpty(values)) {
             return null;
         }
         if (values instanceof List) {
             List<T> list = (List<T>) values;
             return list.get(0);
         } else {
             return values.iterator().next();
         }
     }

 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You 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 org.apache.dubbo.common.utils;

	import java.util.AbstractSet;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.Comparator;
	import java.util.HashMap;
	import java.util.LinkedHashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	import static java.util.Collections.emptySet;
	import static java.util.Collections.unmodifiableSet;

	/**
	* Miscellaneous collection utility methods.
	* Mainly for internal use within the framework.
	*
	* @author william.liangf
	* @since 2.0.7
	*/
	public class CollectionUtils {

	private static final Comparator<String> SIMPLE_NAME_COMPARATOR = new Comparator<String>() {
	@Override
	public int compare(String s1, String s2) {
	if (s1 == null && s2 == null) {
	return 0;
	}
	if (s1 == null) {
	return -1;
	}
	if (s2 == null) {
	return 1;
	}
	int i1 = s1.lastIndexOf('.');
	if (i1 >= 0) {
	s1 = s1.substring(i1 + 1);
	}
	int i2 = s2.lastIndexOf('.');
	if (i2 >= 0) {
	s2 = s2.substring(i2 + 1);
	}
	return s1.compareToIgnoreCase(s2);
	}
	};

	private CollectionUtils() {
	}

	@SuppressWarnings({"unchecked", "rawtypes"})
	public static <T> List<T> sort(List<T> list) {
	if (isNotEmpty(list)) {
	Collections.sort((List) list);
	}
	return list;
	}

	public static List<String> sortSimpleName(List<String> list) {
	if (list != null && list.size() > 0) {
	Collections.sort(list, SIMPLE_NAME_COMPARATOR);
	}
	return list;
	}

	public static Map<String, Map<String, String>> splitAll(Map<String, List<String>> list, String separator) {
	if (list == null) {
	return null;
	}
	Map<String, Map<String, String>> result = new HashMap<>();
	for (Map.Entry<String, List<String>> entry : list.entrySet()) {
	result.put(entry.getKey(), split(entry.getValue(), separator));
	}
	return result;
	}

	public static Map<String, List<String>> joinAll(Map<String, Map<String, String>> map, String separator) {
	if (map == null) {
	return null;
	}
	Map<String, List<String>> result = new HashMap<>();
	for (Map.Entry<String, Map<String, String>> entry : map.entrySet()) {
	result.put(entry.getKey(), join(entry.getValue(), separator));
	}
	return result;
	}

	public static Map<String, String> split(List<String> list, String separator) {
	if (list == null) {
	return null;
	}
	Map<String, String> map = new HashMap<>();
	if (list.isEmpty()) {
	return map;
	}
	for (String item : list) {
	int index = item.indexOf(separator);
	if (index == -1) {
	map.put(item, "");
	} else {
	map.put(item.substring(0, index), item.substring(index + 1));
	}
	}
	return map;
	}

	public static List<String> join(Map<String, String> map, String separator) {
	if (map == null) {
	return null;
	}
	List<String> list = new ArrayList<>();
	if (map.size() == 0) {
	return list;
	}
	for (Map.Entry<String, String> entry : map.entrySet()) {
	String key = entry.getKey();
	String value = entry.getValue();
	if (StringUtils.isEmpty(value)) {
	list.add(key);
	} else {
	list.add(key + separator + value);
	}
	}
	return list;
	}

	public static String join(List<String> list, String separator) {
	StringBuilder sb = new StringBuilder();
	for (String ele : list) {
	if (sb.length() > 0) {
	sb.append(separator);
	}
	sb.append(ele);
	}
	return sb.toString();
	}

	public static boolean mapEquals(Map<?, ?> map1, Map<?, ?> map2) {
	if (map1 == null && map2 == null) {
	return true;
	}
	if (map1 == null \|\| map2 == null) {
	return false;
	}
	if (map1.size() != map2.size()) {
	return false;
	}
	for (Map.Entry<?, ?> entry : map1.entrySet()) {
	Object key = entry.getKey();
	Object value1 = entry.getValue();
	Object value2 = map2.get(key);
	if (!objectEquals(value1, value2)) {
	return false;
	}
	}
	return true;
	}

	private static boolean objectEquals(Object obj1, Object obj2) {
	if (obj1 == null && obj2 == null) {
	return true;
	}
	if (obj1 == null \|\| obj2 == null) {
	return false;
	}
	return obj1.equals(obj2);
	}

	public static Map<String, String> toStringMap(String... pairs) {
	Map<String, String> parameters = new HashMap<>();
	if (ArrayUtils.isEmpty(pairs)) {
	return parameters;
	}

	if (pairs.length > 0) {
	if (pairs.length % 2 != 0) {
	throw new IllegalArgumentException("pairs must be even.");
	}
	for (int i = 0; i < pairs.length; i = i + 2) {
	parameters.put(pairs[i], pairs[i + 1]);
	}
	}
	return parameters;
	}

	@SuppressWarnings("unchecked")
	public static <K, V> Map<K, V> toMap(Object... pairs) {
	Map<K, V> ret = new HashMap<>();
	if (pairs == null \|\| pairs.length == 0) {
	return ret;
	}

	if (pairs.length % 2 != 0) {
	throw new IllegalArgumentException("Map pairs can not be odd number.");
	}
	int len = pairs.length / 2;
	for (int i = 0; i < len; i++) {
	ret.put((K) pairs[2 * i], (V) pairs[2 * i + 1]);
	}
	return ret;
	}

	/**
	* Return {@code true} if the supplied Collection is {@code null} or empty.
	* Otherwise, return {@code false}.
	*
	* @param collection the Collection to check
	* @return whether the given Collection is empty
	*/
	public static boolean isEmpty(Collection<?> collection) {
	return collection == null \|\| collection.isEmpty();
	}

	/**
	* Return {@code true} if the supplied Collection is {@code not null} or not empty.
	* Otherwise, return {@code false}.
	*
	* @param collection the Collection to check
	* @return whether the given Collection is not empty
	*/
	public static boolean isNotEmpty(Collection<?> collection) {
	return !isEmpty(collection);
	}

	/**
	* Return {@code true} if the supplied Map is {@code null} or empty.
	* Otherwise, return {@code false}.
	*
	* @param map the Map to check
	* @return whether the given Map is empty
	*/
	public static boolean isEmptyMap(Map map) {
	return map == null \|\| map.size() == 0;
	}

	/**
	* Return {@code true} if the supplied Map is {@code not null} or not empty.
	* Otherwise, return {@code false}.
	*
	* @param map the Map to check
	* @return whether the given Map is not empty
	*/
	public static boolean isNotEmptyMap(Map map) {
	return !isEmptyMap(map);
	}

	/**
	* Convert to multiple values to be {@link LinkedHashSet}
	*
	* @param values one or more values
	* @param <T> the type of <code>values</code>
	* @return read-only {@link Set}
	*/
	public static <T> Set<T> ofSet(T... values) {
	int size = values == null ? 0 : values.length;
	if (size < 1) {
	return emptySet();
	}

	float loadFactor = 1f / ((size + 1) * 1.0f);

	if (loadFactor > 0.75f) {
	loadFactor = 0.75f;
	}

	Set<T> elements = new LinkedHashSet<>(size, loadFactor);
	for (int i = 0; i < size; i++) {
	elements.add(values[i]);
	}
	return unmodifiableSet(elements);
	}

	/**
	* Get the size of the specified {@link Collection}
	*
	* @param collection the specified {@link Collection}
	* @return must be positive number
	* @since 2.7.6
	*/
	public static int size(Collection<?> collection) {
	return collection == null ? 0 : collection.size();
	}

	/**
	* Compares the specified collection with another, the main implementation references
	* {@link AbstractSet}
	*
	* @param one {@link Collection}
	* @param another {@link Collection}
	* @return if equals, return <code>true</code>, or <code>false</code>
	* @since 2.7.6
	*/
	public static boolean equals(Collection<?> one, Collection<?> another) {

	if (one == another) {
	return true;
	}

	if (isEmpty(one) && isEmpty(another)) {
	return true;
	}

	if (size(one) != size(another)) {
	return false;
	}

	try {
	return one.containsAll(another);
	} catch (ClassCastException \| NullPointerException unused) {
	return false;
	}
	}

	/**
	* Add the multiple values into {@link Collection the specified collection}
	*
	* @param collection {@link Collection the specified collection}
	* @param values the multiple values
	* @param <T> the type of values
	* @return the effected count after added
	* @since 2.7.6
	*/
	public static <T> int addAll(Collection<T> collection, T... values) {

	int size = values == null ? 0 : values.length;

	if (collection == null \|\| size < 1) {
	return 0;
	}

	int effectedCount = 0;
	for (int i = 0; i < size; i++) {
	if (collection.add(values[i])) {
	effectedCount++;
	}
	}

	return effectedCount;
	}

	/**
	* Take the first element from the specified collection
	*
	* @param values the collection object
	* @param <T> the type of element of collection
	* @return if found, return the first one, or <code>null</code>
	* @since 2.7.6
	*/
	public static <T> T first(Collection<T> values) {
	if (isEmpty(values)) {
	return null;
	}
	if (values instanceof List) {
	List<T> list = (List<T>) values;
	return list.get(0);
	} else {
	return values.iterator().next();
	}
	}

	}