001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.juneau.marshall.internal;
018
019import static org.apache.juneau.commons.utils.Shorts.*;
020
021import java.util.*;
022
023import org.apache.juneau.commons.bean.*;
024import org.apache.juneau.marshall.*;
025import org.apache.juneau.marshall.collections.*;
026
027/**
028 * Represents a wrapped {@link Map} where entries in the map can be removed without affecting the underlying map.
029 *
030 *
031 * @param <T> The class type of the wrapped bean.
032 * @serial exclude
033 */
034@SuppressWarnings({
035   "java:S110", // Inheritance depth inherited from JsonMap -> MarshalledMap -> LinkedHashMap chain; intentional
036   "rawtypes" // Raw types necessary for generic Map delegation
037})
038public class DelegateMap<T extends Map> extends JsonMap implements Delegate<T> {
039   private static final long serialVersionUID = 1L;
040
041   private final transient ClassMeta<T> classMeta;
042
043   /**
044    * Constructor.
045    *
046    * @param m The metadata object that created this delegate object.
047    * @param session The current bean session.
048    */
049   @SuppressWarnings({
050      "javabugs:S2259", // The map must not be null, per the constructor contract.
051      "unchecked" // Type erasure requires cast for Map operations
052   })
053   public DelegateMap(T m, MarshallingSession session) {
054      this.classMeta = session.getClassMetaForObject(m);
055      m.forEach((k, v) -> put(s(k), v));
056   }
057
058   /**
059    * Remove all but the specified keys from this map.
060    *
061    * <p>
062    * This does not affect the underlying map.
063    *
064    * @param keys The remaining keys in the map (in the specified order).
065    * @return This object.
066    */
067   public DelegateMap<T> filterKeys(List<String> keys) {
068      var m = new JsonMap();
069      keys.forEach(k -> {
070         if (containsKey(k))
071            m.put(k, get(k));
072      });
073      this.clear();
074      this.putAll(m);
075      return this;
076   }
077
078   @Override
079   public boolean equals(Object o) {
080      return o instanceof Map<?,?> o2 && eq(this, o2, (x, y) -> x.entrySet().equals(y.entrySet()));
081   }
082
083   @Override
084   public int hashCode() {
085      return entrySet().hashCode();
086   }
087
088   @Override /* Overridden from Delegate */
089   public ClassMeta<T> getBeanInfo() { return classMeta; }
090}