org.springframework.web.context.request.async.WebAsyncUtils Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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
*
* https://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.request.async;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.WebRequest;
/**
* Utility methods related to processing asynchronous web requests.
*
* @author Rossen Stoyanchev
* @author Juergen Hoeller
* @since 3.2
*/
public abstract class WebAsyncUtils {
/**
* The name attribute containing the {@link WebAsyncManager}.
*/
public static final String WEB_ASYNC_MANAGER_ATTRIBUTE =
WebAsyncManager.class.getName() + ".WEB_ASYNC_MANAGER";
/**
* Obtain the {@link WebAsyncManager} for the current request, or if not
* found, create and associate it with the request.
*/
public static WebAsyncManager getAsyncManager(ServletRequest servletRequest) {
WebAsyncManager asyncManager = null;
Object asyncManagerAttr = servletRequest.getAttribute(WEB_ASYNC_MANAGER_ATTRIBUTE);
if (asyncManagerAttr instanceof WebAsyncManager) {
asyncManager = (WebAsyncManager) asyncManagerAttr;
}
if (asyncManager == null) {
asyncManager = new WebAsyncManager();
servletRequest.setAttribute(WEB_ASYNC_MANAGER_ATTRIBUTE, asyncManager);
}
return asyncManager;
}
/**
* Obtain the {@link WebAsyncManager} for the current request, or if not
* found, create and associate it with the request.
*/
public static WebAsyncManager getAsyncManager(WebRequest webRequest) {
int scope = RequestAttributes.SCOPE_REQUEST;
WebAsyncManager asyncManager = null;
Object asyncManagerAttr = webRequest.getAttribute(WEB_ASYNC_MANAGER_ATTRIBUTE, scope);
if (asyncManagerAttr instanceof WebAsyncManager) {
asyncManager = (WebAsyncManager) asyncManagerAttr;
}
if (asyncManager == null) {
asyncManager = new WebAsyncManager();
webRequest.setAttribute(WEB_ASYNC_MANAGER_ATTRIBUTE, asyncManager, scope);
}
return asyncManager;
}
/**
* Create an AsyncWebRequest instance. By default, an instance of
* {@link StandardServletAsyncWebRequest} gets created.
* @param request the current request
* @param response the current response
* @return an AsyncWebRequest instance (never {@code null})
*/
public static AsyncWebRequest createAsyncWebRequest(HttpServletRequest request, HttpServletResponse response) {
return new StandardServletAsyncWebRequest(request, response);
}
}