com.opensymphony.xwork2.util.KeyProperty Maven / Gradle / Ivy

/*
 * 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 com.opensymphony.xwork2.util;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 
 * Sets the KeyProperty for type conversion.
 * 
 *
 * Annotation usage:
 *
 * 
 * The KeyProperty annotation must be applied at field or method level.
 * This annotation should be used with Generic types, if the key property of the key element needs to be specified.
 * 
 * Annotation parameters:
 *
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * 
 * Parameter Required Default Description
value no id The key property value.
 * 
 *
 * Example code:
 *  * 
 * // The key property for User objects within the users collection is the userName attribute.
 * @KeyProperty( value = "userName" )
 * protected List<User> users = null;
 * 
 * 
 *
 * @author Patrick Lightbody
 * @author Rainer Hermanns
 */
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD, ElementType.METHOD})
public @interface KeyProperty {

    /**
     * @return The KeyProperty value. Defaults to the id attribute.
     */
    String value() default "id";
}