org.springframework.web.bind.annotation.SessionAttribute Maven / Gradle / Ivy
/*
* 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.web.bind.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;
import org.springframework.core.annotation.AliasFor;
/**
* Annotation to bind a method parameter to a session attribute.
*
* The main motivation is to provide convenient access to existing, permanent
* session attributes (e.g. user authentication object) with an optional/required
* check and a cast to the target method parameter type.
*
*
For use cases that require adding or removing session attributes consider
* injecting {@code org.springframework.web.context.request.WebRequest} or
* {@code javax.servlet.http.HttpSession} into the controller method.
*
*
For temporary storage of model attributes in the session as part of the
* workflow for a controller, consider using {@link SessionAttributes} instead.
*
* @author Rossen Stoyanchev
* @since 4.3
* @see RequestMapping
* @see SessionAttributes
* @see RequestAttribute
*/
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface SessionAttribute {
/**
* Alias for {@link #name}.
*/
@AliasFor("name")
String value() default "";
/**
* The name of the session attribute to bind to.
*
The default name is inferred from the method parameter name.
*/
@AliasFor("value")
String name() default "";
/**
* Whether the session attribute is required.
*
Defaults to {@code true}, leading to an exception being thrown
* if the attribute is missing in the session or there is no session.
* Switch this to {@code false} if you prefer a {@code null} or Java 8
* {@code java.util.Optional} if the attribute doesn't exist.
*/
boolean required() default true;
}