/*
* 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.wicket.util.lang;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.wicket.util.string.StringValue;
/**
* A base class for defining enumerated types. Since this class extends StringValue, every
* enumerated type subclass is a StringValue that can be manipulated, converted and displayed in
* useful ways. In addition to constructing a type with the given name, lists are kept of all
* enumeration values by subclass. The list of available values in the enumeration represented by a
* given subclass can be retrieved by calling getValues(Class).
*
* @author Jonathan Locke
*/
public abstract class EnumeratedType extends StringValue
{
/**
*
*/
private static final long serialVersionUID = 1L;
/** Map of type values by class */
private static final Map<String, List<EnumeratedType>> valueListByClass = Generics.newConcurrentHashMap();
/**
* Constructor.
*
* @param name
* Name of this enumerated type value
*/
public EnumeratedType(final String name)
{
super(name);
// Add this object to the list of values for our subclass
getValues(getClass()).add(this);
}
/**
* Gets the enumerated type values for a given subclass of EnumeratedType.
*
* @param c
* The enumerated type subclass to get values for
* @return List of all values of the given subclass
*/
public static List<EnumeratedType> getValues(final Class<? extends EnumeratedType> c)
{
// Get values for class
List<EnumeratedType> valueList = valueListByClass.get(c.getName());
// If no list exists
if (valueList == null)
{
// create lazily
valueList = new ArrayList<>();
valueListByClass.put(c.getName(), valueList);
}
return valueList;
}
/**
* Method to ensure that == works after deserialization
*
* @return object instance
* @throws java.io.ObjectStreamException
*/
public Object readResolve() throws java.io.ObjectStreamException
{
EnumeratedType result = this;
List<EnumeratedType> values = getValues(getClass());
for (EnumeratedType value : values)
{
if ((value.toString() != null) && value.toString().equals(this.toString()))
{
result = value;
break;
}
}
return result;
}
}