/*
* Copyright 2002-2016 the original author or authors.
*
* 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 org.springframework.cache.annotation;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.util.concurrent.Callable;
import org.springframework.core.annotation.AliasFor;
Annotation indicating that the result of invoking a method (or all methods
in a class) can be cached.
Each time an advised method is invoked, caching behavior will be applied, checking whether the method has been already invoked for the given arguments. A sensible default simply uses the method parameters to compute the key, but a SpEL expression can be provided via the key attribute, or a custom KeyGenerator implementation can replace the default one (see keyGenerator).
If no value is found in the cache for the computed key, the target method will be invoked and the returned value stored in the associated cache. Note that Java8's Optional return types are automatically handled and its content is stored in the cache if present.
This annotation may be used as a meta-annotation to create custom
composed annotations with attribute overrides.
Author: Costin Leau, Phillip Webb, Stephane Nicoll, Sam Brannen See Also: Since: 3.1
/**
* Annotation indicating that the result of invoking a method (or all methods
* in a class) can be cached.
*
* <p>Each time an advised method is invoked, caching behavior will be applied,
* checking whether the method has been already invoked for the given arguments.
* A sensible default simply uses the method parameters to compute the key, but
* a SpEL expression can be provided via the {@link #key} attribute, or a custom
* {@link org.springframework.cache.interceptor.KeyGenerator} implementation can
* replace the default one (see {@link #keyGenerator}).
*
* <p>If no value is found in the cache for the computed key, the target method
* will be invoked and the returned value stored in the associated cache. Note
* that Java8's {@code Optional} return types are automatically handled and its
* content is stored in the cache if present.
*
* <p>This annotation may be used as a <em>meta-annotation</em> to create custom
* <em>composed annotations</em> with attribute overrides.
*
* @author Costin Leau
* @author Phillip Webb
* @author Stephane Nicoll
* @author Sam Brannen
* @since 3.1
* @see CacheConfig
*/
@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
public @interface Cacheable {
Alias for cacheNames. /**
* Alias for {@link #cacheNames}.
*/
@AliasFor("cacheNames")
String[] value() default {};
Names of the caches in which method invocation results are stored.
Names may be used to determine the target cache (or caches), matching
the qualifier value or bean name of a specific bean definition.
See Also: Since: 4.2
/**
* Names of the caches in which method invocation results are stored.
* <p>Names may be used to determine the target cache (or caches), matching
* the qualifier value or bean name of a specific bean definition.
* @since 4.2
* @see #value
* @see CacheConfig#cacheNames
*/
@AliasFor("value")
String[] cacheNames() default {};
Spring Expression Language (SpEL) expression for computing the key dynamically.
Default is "", meaning all method parameters are considered as a key, unless a custom keyGenerator has been configured.
The SpEL expression evaluates against a dedicated context that provides the
following meta-data:
#root.method, #root.target, and #root.caches for references to the method, target object, and affected cache(s) respectively.- Shortcuts for the method name (
#root.methodName) and target class (#root.targetClass) are also available. - Method arguments can be accessed by index. For instance the second argument can be accessed via
#root.args[1], #p1 or #a1. Arguments can also be accessed by name if that information is available.
/**
* Spring Expression Language (SpEL) expression for computing the key dynamically.
* <p>Default is {@code ""}, meaning all method parameters are considered as a key,
* unless a custom {@link #keyGenerator} has been configured.
* <p>The SpEL expression evaluates against a dedicated context that provides the
* following meta-data:
* <ul>
* <li>{@code #root.method}, {@code #root.target}, and {@code #root.caches} for
* references to the {@link java.lang.reflect.Method method}, target object, and
* affected cache(s) respectively.</li>
* <li>Shortcuts for the method name ({@code #root.methodName}) and target class
* ({@code #root.targetClass}) are also available.
* <li>Method arguments can be accessed by index. For instance the second argument
* can be accessed via {@code #root.args[1]}, {@code #p1} or {@code #a1}. Arguments
* can also be accessed by name if that information is available.</li>
* </ul>
*/
String key() default "";
The bean name of the custom KeyGenerator to use. Mutually exclusive with the key attribute.
See Also:
/**
* The bean name of the custom {@link org.springframework.cache.interceptor.KeyGenerator}
* to use.
* <p>Mutually exclusive with the {@link #key} attribute.
* @see CacheConfig#keyGenerator
*/
String keyGenerator() default "";
The bean name of the custom CacheManager to use to create a default CacheResolver if none is set already. Mutually exclusive with the cacheResolver attribute.
See Also:
/**
* The bean name of the custom {@link org.springframework.cache.CacheManager} to use to
* create a default {@link org.springframework.cache.interceptor.CacheResolver} if none
* is set already.
* <p>Mutually exclusive with the {@link #cacheResolver} attribute.
* @see org.springframework.cache.interceptor.SimpleCacheResolver
* @see CacheConfig#cacheManager
*/
String cacheManager() default "";
The bean name of the custom CacheResolver to use. See Also:
/**
* The bean name of the custom {@link org.springframework.cache.interceptor.CacheResolver}
* to use.
* @see CacheConfig#cacheResolver
*/
String cacheResolver() default "";
Spring Expression Language (SpEL) expression used for making the method
caching conditional.
Default is "", meaning the method result is always cached.
The SpEL expression evaluates against a dedicated context that provides the
following meta-data:
#root.method, #root.target, and #root.caches for references to the method, target object, and affected cache(s) respectively.- Shortcuts for the method name (
#root.methodName) and target class (#root.targetClass) are also available. - Method arguments can be accessed by index. For instance the second argument can be accessed via
#root.args[1], #p1 or #a1. Arguments can also be accessed by name if that information is available.
/**
* Spring Expression Language (SpEL) expression used for making the method
* caching conditional.
* <p>Default is {@code ""}, meaning the method result is always cached.
* <p>The SpEL expression evaluates against a dedicated context that provides the
* following meta-data:
* <ul>
* <li>{@code #root.method}, {@code #root.target}, and {@code #root.caches} for
* references to the {@link java.lang.reflect.Method method}, target object, and
* affected cache(s) respectively.</li>
* <li>Shortcuts for the method name ({@code #root.methodName}) and target class
* ({@code #root.targetClass}) are also available.
* <li>Method arguments can be accessed by index. For instance the second argument
* can be accessed via {@code #root.args[1]}, {@code #p1} or {@code #a1}. Arguments
* can also be accessed by name if that information is available.</li>
* </ul>
*/
String condition() default "";
Spring Expression Language (SpEL) expression used to veto method caching.
Unlike condition, this expression is evaluated after the method has been called and can therefore refer to the result.
Default is "", meaning that caching is never vetoed.
The SpEL expression evaluates against a dedicated context that provides the
following meta-data:
#result for a reference to the result of the method invocation. For supported wrappers such as Optional, #result refers to the actual object, not the wrapper#root.method, #root.target, and #root.caches for references to the method, target object, and affected cache(s) respectively.- Shortcuts for the method name (
#root.methodName) and target class (#root.targetClass) are also available. - Method arguments can be accessed by index. For instance the second argument can be accessed via
#root.args[1], #p1 or #a1. Arguments can also be accessed by name if that information is available.
Since: 3.2
/**
* Spring Expression Language (SpEL) expression used to veto method caching.
* <p>Unlike {@link #condition}, this expression is evaluated after the method
* has been called and can therefore refer to the {@code result}.
* <p>Default is {@code ""}, meaning that caching is never vetoed.
* <p>The SpEL expression evaluates against a dedicated context that provides the
* following meta-data:
* <ul>
* <li>{@code #result} for a reference to the result of the method invocation. For
* supported wrappers such as {@code Optional}, {@code #result} refers to the actual
* object, not the wrapper</li>
* <li>{@code #root.method}, {@code #root.target}, and {@code #root.caches} for
* references to the {@link java.lang.reflect.Method method}, target object, and
* affected cache(s) respectively.</li>
* <li>Shortcuts for the method name ({@code #root.methodName}) and target class
* ({@code #root.targetClass}) are also available.
* <li>Method arguments can be accessed by index. For instance the second argument
* can be accessed via {@code #root.args[1]}, {@code #p1} or {@code #a1}. Arguments
* can also be accessed by name if that information is available.</li>
* </ul>
* @since 3.2
*/
String unless() default "";
Synchronize the invocation of the underlying method if several threads are
attempting to load a value for the same key. The synchronization leads to
a couple of limitations:
unless() is not supported- Only one cache may be specified
- No other cache-related operation can be combined
This is effectively a hint and the actual cache provider that you are
using may not support it in a synchronized fashion. Check your provider
documentation for more details on the actual semantics.
See Also: Since: 4.3
/**
* Synchronize the invocation of the underlying method if several threads are
* attempting to load a value for the same key. The synchronization leads to
* a couple of limitations:
* <ol>
* <li>{@link #unless()} is not supported</li>
* <li>Only one cache may be specified</li>
* <li>No other cache-related operation can be combined</li>
* </ol>
* This is effectively a hint and the actual cache provider that you are
* using may not support it in a synchronized fashion. Check your provider
* documentation for more details on the actual semantics.
* @since 4.3
* @see org.springframework.cache.Cache#get(Object, Callable)
*/
boolean sync() default false;
}