org.springframework.web.context.support.ServletContextAttributeFactoryBean Maven / Gradle / Ivy
/*
* Copyright 2002-2017 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.context.support;
import javax.servlet.ServletContext;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.lang.Nullable;
import org.springframework.web.context.ServletContextAware;
/**
* {@link FactoryBean} that fetches a specific, existing ServletContext attribute.
* Exposes that ServletContext attribute when used as bean reference,
* effectively making it available as named Spring bean instance.
*
* Intended to link in ServletContext attributes that exist before
* the startup of the Spring application context. Typically, such
* attributes will have been put there by third-party web frameworks.
* In a purely Spring-based web application, no such linking in of
* ServletContext attributes will be necessary.
*
*
NOTE: As of Spring 3.0, you may also use the "contextAttributes" default
* bean which is of type Map, and dereference it using an "#{contextAttributes.myKey}"
* expression to access a specific attribute by name.
*
* @author Juergen Hoeller
* @since 1.1.4
* @see org.springframework.web.context.WebApplicationContext#CONTEXT_ATTRIBUTES_BEAN_NAME
* @see ServletContextParameterFactoryBean
*/
public class ServletContextAttributeFactoryBean implements FactoryBean