01: // Copyright 2007 The Apache Software Foundation
02: //
03: // Licensed under the Apache License, Version 2.0 (the "License");
04: // you may not use this file except in compliance with the License.
05: // You may obtain a copy of the License at
06: //
07: // http://www.apache.org/licenses/LICENSE-2.0
08: //
09: // Unless required by applicable law or agreed to in writing, software
10: // distributed under the License is distributed on an "AS IS" BASIS,
11: // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12: // See the License for the specific language governing permissions and
13: // limitations under the License.
14:
15: package org.apache.tapestry.util;
16:
17: import static org.apache.tapestry.ioc.internal.util.Defense.notNull;
18:
19: import org.apache.tapestry.ValueEncoder;
20:
21: /**
22: * A value encoder that can be used for aribrary Enum types. The enum name is stored as the client
23: * side value (the "primary key").
24: */
25: public class EnumValueEncoder<E extends Enum<E>> implements
26: ValueEncoder<E> {
27: private final Class<E> _enumType;
28:
29: public EnumValueEncoder(final Class<E> enumType) {
30: notNull(enumType, "enumType");
31:
32: _enumType = enumType;
33: }
34:
35: public String toClient(E value) {
36: return value.name();
37: }
38:
39: @SuppressWarnings("unchecked")
40: public E toValue(String clientValue) {
41: if (clientValue == null)
42: return null;
43:
44: return Enum.valueOf(_enumType, clientValue);
45: }
46:
47: }
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