1 package org.apache.lucene.util;
4 * Licensed to the Apache Software Foundation (ASF) under one or more
5 * contributor license agreements. See the NOTICE file distributed with
6 * this work for additional information regarding copyright ownership.
7 * The ASF licenses this file to You under the Apache License, Version 2.0
8 * (the "License"); you may not use this file except in compliance with
9 * the License. You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
20 import java.io.ObjectStreamException;
21 import java.io.Serializable;
22 import java.io.StreamCorruptedException;
23 import java.util.HashMap;
27 * A serializable Enum class.
28 * @deprecated Use Java 5 enum, will be removed in a later Lucene 3.x release.
32 @SuppressWarnings("serial")
33 public abstract class Parameter implements Serializable {
34 static Map<String,Parameter> allParameters = new HashMap<String,Parameter>();
38 protected Parameter(String name) {
39 // typesafe enum pattern, no public constructor
41 String key = makeKey(name);
43 if(allParameters.containsKey(key))
44 throw new IllegalArgumentException("Parameter name " + key + " already used!");
46 allParameters.put(key, this);
49 private String makeKey(String name){
50 return getClass() + " " + name;
54 public String toString() {
59 * Resolves the deserialized instance to the local reference for accurate
60 * equals() and == comparisons.
62 * @return a reference to Parameter as resolved in the local VM
63 * @throws ObjectStreamException
65 protected Object readResolve() throws ObjectStreamException {
66 Object par = allParameters.get(makeKey(name));
69 throw new StreamCorruptedException("Unknown parameter value: " + name);