org.springframework.web.servlet.FlashMapManager Maven / Gradle / Ivy
/*
* Copyright 2002-2011 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.servlet;
import javax.servlet.http.HttpServletRequest;
/**
* A strategy interface for storing, retrieving, and managing {@code FlashMap}
* instances. See {@link FlashMap} for a general overview of flash attributes.
*
* A FlashMapManager is invoked at the beginning and at the end of requests.
* For each request it retrieves an "input" FlashMap with attributes passed
* from a previous request (if any) and creates an "output" FlashMap with
* attributes to pass to a subsequent request. "Input" and "output" FlashMap
* instances are exposed as request attributes and are accessible via methods
* in {@code org.springframework.web.servlet.support.RequestContextUtils}.
*
*
Annotated controllers will usually not use this FlashMap directly.
* See {@code org.springframework.web.servlet.mvc.support.RedirectAttributes}.
*
* @author Rossen Stoyanchev
* @since 3.1
*
* @see FlashMap
*/
public interface FlashMapManager {
/**
* Name of request attribute that holds a read-only
* {@code Map} with "input" flash attributes if any.
* @see org.springframework.web.servlet.support.RequestContextUtils#getInputFlashMap(HttpServletRequest)
*/
String INPUT_FLASH_MAP_ATTRIBUTE = FlashMapManager.class.getName() + ".INPUT_FLASH_MAP";
/**
* Name of request attribute that holds the "output" {@link FlashMap} with
* attributes to save for a subsequent request.
* @see org.springframework.web.servlet.support.RequestContextUtils#getOutputFlashMap(HttpServletRequest)
*/
String OUTPUT_FLASH_MAP_ATTRIBUTE = FlashMapManager.class.getName() + ".OUTPUT_FLASH_MAP";
/**
* Perform the following tasks unless the {@link #OUTPUT_FLASH_MAP_ATTRIBUTE}
* request attribute exists:
*
* - Find the "input" FlashMap, expose it under the request attribute
* {@link #INPUT_FLASH_MAP_ATTRIBUTE}, and remove it from underlying storage.
*
- Create the "output" FlashMap and expose it under the request
* attribute {@link #OUTPUT_FLASH_MAP_ATTRIBUTE}.
*
- Clean expired FlashMap instances.
*
* @param request the current request
*/
void requestStarted(HttpServletRequest request);
/**
* Start the expiration period of the "output" FlashMap save it in the
* underlying storage.
* The "output" FlashMap should not be saved if it is empty or if it was
* not created by the current FlashMapManager instance.
* @param request the current request
*/
void requestCompleted(HttpServletRequest request);
}