com.google.gwt.user.server.rpc.EnumMap Maven / Gradle / Ivy
/*
* Copyright 2022 Google Inc.
*
* 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.google.gwt.user.server.rpc;
/**
* A serialization-compatible mock for {@link java.util.EnumMap} that uses an equal
* {@link #serialVersionUID} and a compatible set of fields. When de-serializing an
* {@link java.util.EnumMap} instance into an instance of this class, e.g., by overriding
* {@link ObjectInputStream}'s {@link ObjectInputStream#resolveClass} method such that it delivers
* this class instead of {@link java.util.EnumMap}, the fields are made accessible through getters;
* in particular, {@link #getKeyType()} reveals the original {@link java.util.EnumMap}'s key type,
* even if the map is empty.
*
*
* The {@link EnumMap#getEnumMapKeyType(java.util.EnumMap)} method can be used to determine the key
* type of any {@link java.util.EnumMap}, even if it's empty.
*/
class EnumMap, V> extends java.util.EnumMap {
private final Class keyType;
private transient K[] keyUniverse;
private transient Object[] vals;
private transient int size = 0;
private static final long serialVersionUID = 458661240069192865L;
EnumMap(Class c) {
super(c);
keyType = null;
}
public K[] getKeyUniverse() {
return keyUniverse;
}
public Object[] getVals() {
return vals;
}
public int getSize() {
return size;
}
public Class getKeyType() {
return keyType;
}
/**
* Reconstitute the EnumMap instance from a stream (i.e., deserialize it).
*/
private void readObject(java.io.ObjectInputStream s) throws java.io.IOException,
ClassNotFoundException {
// Read in the key type and any hidden stuff
s.defaultReadObject();
// Read in size (number of Mappings)
int numberOfMappings = s.readInt();
// Read the keys and values, and put the mappings in the HashMap
for (int i = 0; i < numberOfMappings; i++) {
s.readObject(); // key
s.readObject(); // value
}
}
}