content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * 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.alibaba.nacos.common.utils;
  
  import com.alibaba.nacos.common.NotThreadSafe;
  
  import java.util.Collection;
  import java.util.Dictionary;
  import java.util.Map;
  import java.util.Objects;
  import java.util.function.Predicate;
  import java.util.function.BiFunction;
  
  /**
   * Map utils.
   *
   * @author <a href="mailto:liaochuntao@live.com">liaochuntao</a>
   */
  public class MapUtil {
      
      private MapUtil() {
      }
      
      /**
       * Null-safe check if the specified Dictionary is empty.
       *
       * <p>Null returns true.
       *
       * @param map the collection to check, may be null
       * @return true if empty or null
       */
      public static boolean isEmpty(Map map) {
          return (map == null || map.isEmpty());
      }
      
      /**
       * Null-safe check if the specified Dictionary is empty.
       *
       * <p>Null returns true.
       *
       * @param coll the collection to check, may be null
       * @return true if empty or null
       */
      public static boolean isEmpty(Dictionary coll) {
          return (coll == null || coll.isEmpty());
      }
      
      /**
       * Null-safe check if the specified Dictionary is not empty.
       *
       * <p>Null returns false.
       *
       * @param map the collection to check, may be null
       * @return true if non-null and non-empty
       */
      public static boolean isNotEmpty(Map map) {
          return !isEmpty(map);
      }
      
      /**
       * Null-safe check if the specified Dictionary is not empty.
       *
       * <p>Null returns false.
       *
       * @param coll the collection to check, may be null
       * @return true if non-null and non-empty
       */
      public static boolean isNotEmpty(Dictionary coll) {
          return !isEmpty(coll);
      }
      
      /**
       * Put into map if value is not null.
       *
       * @param target target map
       * @param key    key
       * @param value  value
       */
      public static void putIfValNoNull(Map target, Object key, Object value) {
          Objects.requireNonNull(key, "key");
          if (value != null) {
              target.put(key, value);
          }
      }
      
      /**
       * Put into map if value is not empty.
       *
       * @param target target map
       * @param key    key
       * @param value  value
       */
      public static void putIfValNoEmpty(Map target, Object key, Object value) {
          Objects.requireNonNull(key, "key");
          if (value instanceof String) {
              if (StringUtils.isNotEmpty((String) value)) {
                  target.put(key, value);
              }
              return;
          }
          if (value instanceof Collection) {
              if (CollectionUtils.isNotEmpty((Collection) value)) {
                  target.put(key, value);
              }
              return;
          }
          if (value instanceof Map) {
              if (isNotEmpty((Map) value)) {
                  target.put(key, value);
              }
              return;
          }
          if (value instanceof Dictionary) {
              if (isNotEmpty((Dictionary) value)) {
                  target.put(key, value);
              }
          }
      }
      
      /**
       * ComputeIfAbsent lazy load.
       *
       * @param target          target Map data.
       * @param key             map key.
       * @param mappingFunction function which is need to be executed.
       * @param param1          function's parameter value1.
       * @param param2          function's parameter value1.
       * @return
       */
      @NotThreadSafe
      public static <K, C, V, T> V computeIfAbsent(Map<K, V> target, K key, BiFunction<C, T, V> mappingFunction, C param1,
              T param2) {
          
          Objects.requireNonNull(target, "target");
          Objects.requireNonNull(key, "key");
          Objects.requireNonNull(mappingFunction, "mappingFunction");
          Objects.requireNonNull(param1, "param1");
          Objects.requireNonNull(param2, "param2");
          
          return target.computeIfAbsent(key, (keyInner) -> mappingFunction.apply(param1, param2));
          
      }
      
      /**
       * remove value, Thread safety depends on whether the Map is a thread-safe Map.
       *
       * @param map         map
       * @param key         key
       * @param removeJudge judge this key can be remove
       * @param <K>         key type
       * @param <V>         value type
       * @return value
       */
      public static <K, V> V removeKey(Map<K, V> map, K key, Predicate<V> removeJudge) {
          return map.computeIfPresent(key, (k, v) -> removeJudge.test(v) ? null : v);
      }
  }
  