/*
* Copyright 2002-2006,2009 The Apache Software Foundation.
*
* 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.opensymphony.xwork2.util;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* <!-- START SNIPPET: description -->
* <p/>Sets the Key for type conversion.
* <!-- END SNIPPET: description -->
*
* <p/> <u>Annotation usage:</u>
*
* <!-- START SNIPPET: usage -->
* <p/>The Key annotation must be applied at field or method level.
* <!-- END SNIPPET: usage -->
* <p/> <u>Annotation parameters:</u>
*
* <!-- START SNIPPET: parameters -->
* <table>
* <thead>
* <tr>
* <th>Parameter</th>
* <th>Required</th>
* <th>Default</th>
* <th>Description</th>
* </tr>
* </thead>
* <tbody>
* <tr>
* <td>value</td>
* <td>no</td>
* <td>java.lang.Object.class</td>
* <td>The key property value.</td>
* </tr>
* </tbody>
* </table>
* <!-- END SNIPPET: parameters -->
*
* <p/> <u>Example code:</u>
* <pre>
* <!-- START SNIPPET: example -->
* // The key property for User objects within the users collection is the <code>userName</code> attribute.
* @Key( value = java.lang.Long.class )
* private Map<Long, User> userMap;
* <!-- END SNIPPET: example -->
* </pre>
*
* @author Rainer Hermanns
* @version $Id$
*/
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD, ElementType.METHOD})
public @interface Key {
/**
* The Key value.
* Defaults to <tt>java.lang.Object.class</tt>.
*/
Class value() default java.lang.Object.class;
}