handleRequestInternal should be
* synchronized around the HttpSession, to serialize invocations
* from the same client. No effect if there is no HttpSession.
* </td>
* </tr>
* </table>
*
* @author Rod Johnson
* @author Juergen Hoeller
* @see WebContentInterceptor
*/
public abstract class AbstractController extends WebContentGenerator implements Controller {
private boolean synchronizeOnSession = false;
/**
* Set if controller execution should be synchronized on the session,
* to serialize parallel invocations from the same client.
* <p>More specifically, the execution of the handleRequestInternal
* method will get synchronized if this flag is "true". The best available
* session mutex will be used for the synchronization; ideally, this will
* be a mutex exposed by HttpSessionMutexListener.
* <p>The session mutex is guaranteed to be the same object during
* the entire lifetime of the session, available under the key defined
* by the <code>SESSION_MUTEX_ATTRIBUTE constant. It serves as a
* safe reference to synchronize on for locking on the current session.
* <p>In many cases, the HttpSession reference itself is a safe mutex
* as well, since it will always be the same object reference for the
* same active logical session. However, this is not guaranteed across
* different servlet containers; the only 100% safe way is a session mutex.
* @see org.springframework.web.servlet.mvc.AbstractController#handleRequestInternal
* @see org.springframework.web.util.HttpSessionMutexListener
* @see org.springframework.web.util.WebUtils#getSessionMutex(javax.servlet.http.HttpSession)
*/
public final void setSynchronizeOnSession(boolean synchronizeOnSession) {
this.synchronizeOnSession = synchronizeOnSession;
}
/**
* Return whether controller execution should be synchronized on the session.
*/
public final boolean isSynchronizeOnSession() {
return this.synchronizeOnSession;
}
public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response)
throws Exception {
// Delegate to WebContentGenerator for checking and preparing.
checkAndPrepare(request, response, this instanceof LastModified);
// Execute handleRequestInternal in synchronized block if required.
if (this.synchronizeOnSession) {
HttpSession session = request.getSession(false);
if (session != null) {
Object mutex = WebUtils.getSessionMutex(session);
synchronized (mutex) {
return handleRequestInternal(request, response);
}
}
}
return handleRequestInternal(request, response);
}
/**
* Template method. Subclasses must implement this.
* The contract is the same as for <code>handleRequest.
* @see #handleRequest
*/
protected abstract ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response)
throws Exception;
}
Other Spring Framework examples (source code examples)
Here is a short list of links related to this Spring Framework AbstractController.java source code file:
The search page
Other Spring Framework source code examples at this package level
Click here to learn more about this project
Spring Framework example source code file (AbstractController.java)
The Spring Framework AbstractController.java source code/*
* Copyright 2002-2007 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.mvc;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.support.WebContentGenerator;
import org.springframework.web.util.WebUtils;
/**
* <p>Convenient superclass for controller implementations, using the Template
* Method design pattern.</p>
*
* <p>As stated in the {@link org.springframework.web.servlet.mvc.Controller Controller}
* interface, a lot of functionality is already provided by certain abstract
* base controllers. The AbstractController is one of the most important
* abstract base controller providing basic features such as the generation
* of caching headers and the enabling or disabling of
* supported methods (GET/POST).</p>
*
* <p>Workflow
* (<a href="Controller.html#workflow">and that defined by interface): |
