/**
* Copyright 2015 Netflix, Inc.
*
* 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.netflix.hystrix.contrib.javanica.cache.annotation;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Marks a method argument as part of the cache key.
* If no arguments are marked all arguments are used.
* If {@link CacheResult} or {@link CacheRemove} annotation has specified <code>cacheKeyMethod</code> then
* a method arguments will not be used to build cache key even if they annotated with {@link CacheKey}.
*
* @author dmgcodevil
*/
@Target({ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface CacheKey {
/**
* Allows specify name of a certain argument property.
* for example: <code>@CacheKey("id") User user</code>,
* or in case composite property: <code>@CacheKey("profile.name") User user</code>.
* <code>null</code> properties are ignored, i.e. if <code>profile</code> is <code>null</code>
* then result of <code>@CacheKey("profile.name") User user</code> will be empty string.
*
* @return name of an argument property
*/
String value() default "";
}