Spring Framework 6.1.4 · org.springframework.web.servlet.mvc.AbstractController

Convenient superclass for controller implementations, using the Template Method design pattern.

Workflow (and that defined by interface):

handleRequest() will be called by the DispatcherServlet
Inspection of supported methods (ServletException if request method is not support)
If session is required, try to get it (ServletException if not found)
Set caching headers if needed according to the cacheSeconds property
Call abstract method handleRequestInternal() (optionally synchronizing around the call on the HttpSession), which should be implemented by extending classes to provide actual functionality to return ModelAndView objects.

Exposed configuration properties (and those defined by interface):

name	default	description
supportedMethods	GET,POST	comma-separated (CSV) list of methods supported by this controller, such as GET, POST and PUT
requireSession	false	whether a session should be required for requests to be able to be handled by this controller. This ensures that derived controller can - without fear of null pointers - call request.getSession() to retrieve a session. If no session can be found while processing the request, a ServletException will be thrown
cacheSeconds	-1	indicates the amount of seconds to include in the cache header for the response following on this request. 0 (zero) will include headers for no caching at all, -1 (the default) will not generate any headers and any positive number will generate headers that state the amount indicated as seconds to cache the content
synchronizeOnSession	false	whether the call to `handleRequestInternal` should be synchronized around the HttpSession, to serialize invocations from the same client. No effect if there is no HttpSession.

Field Summary

Modifier and Type	Field and Description
private boolean	synchronizeOnSession

Inherited from org.springframework.web.servlet.support.WebContentGenerator:: HEADER_CACHE_CONTROL METHOD_GET METHOD_HEAD METHOD_POST

Constructor Summary

Access	Constructor and Description
public	AbstractController() Create a new AbstractController which supports HTTP methods GET, HEAD and POST by default.
public	AbstractController(boolean `true` if this controller should support HTTP methods GET, HEAD and POST by default, or `false` if it should be unrestricted restrictDefaultSupportedMethods) Create a new AbstractController.

Method Summary

Modifier and Type	Method and Description
public ModelAndView	handleRequest(HttpServletRequest current HTTP request request, HttpServletResponse current HTTP response response) Implements org.springframework.web.servlet.mvc.Controller.handleRequest. Process the request and return a ModelAndView object which the DispatcherServlet will render.
protected abstract ModelAndView	handleRequestInternal(HttpServletRequest request, HttpServletResponse response) Template method.
public final boolean	isSynchronizeOnSession() Return whether controller execution should be synchronized on the session.
public final void	setSynchronizeOnSession(boolean synchronizeOnSession) Set if controller execution should be synchronized on the session, to serialize parallel invocations from the same client.

Field Detail

synchronizeOnSession	back to summary
private boolean synchronizeOnSession

Constructor Detail

AbstractController	back to summary
public AbstractController() Create a new AbstractController which supports HTTP methods GET, HEAD and POST by default.

AbstractController back to summary

AbstractController	back to summary
public AbstractController(boolean restrictDefaultSupportedMethods) Create a new AbstractController. Parameters restrictDefaultSupportedMethods:boolean `true` if this controller should support HTTP methods GET, HEAD and POST by default, or `false` if it should be unrestricted Since 4.3

public AbstractController(boolean restrictDefaultSupportedMethods)

Create a new AbstractController.

Parameters

restrictDefaultSupportedMethods:boolean: true if this controller should support HTTP methods GET, HEAD and POST by default, or false if it should be unrestricted

Since

4.3

Method Detail

handleRequest back to summary

handleRequest	back to summary
public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception Implements org.springframework.web.servlet.mvc.Controller.handleRequest. Doc from org.springframework.web.servlet.mvc.Controller.handleRequest. Process the request and return a ModelAndView object which the DispatcherServlet will render. A `null` return value is not an error: it indicates that this object completed request processing itself and that there is therefore no ModelAndView to render. Parameters request:HttpServletRequest current HTTP request response:HttpServletResponse current HTTP response Returns:ModelAndView a ModelAndView to render, or `null` if handled directly Annotations @Override @Nullable Exceptions Exception: in case of errors

public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception

Implements org.springframework.web.servlet.mvc.Controller.handleRequest.

Doc from org.springframework.web.servlet.mvc.Controller.handleRequest.

Process the request and return a ModelAndView object which the DispatcherServlet will render. A null return value is not an error: it indicates that this object completed request processing itself and that there is therefore no ModelAndView to render.

Parameters

request:HttpServletRequest: current HTTP request
response:HttpServletResponse: current HTTP response

Returns:ModelAndView

a ModelAndView to render, or null if handled directly

Annotations

@Override
@Nullable

Exceptions

Exception:: in case of errors

handleRequestInternal back to summary

handleRequestInternal	back to summary
protected abstract ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response) throws Exception Template method. Subclasses must implement this. The contract is the same as for `handleRequest`. Annotations @Nullable See Also `handleRequest`

protected abstract ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response) throws Exception

Template method. Subclasses must implement this. The contract is the same as for handleRequest.

Annotations

@Nullable

See Also

handleRequest

isSynchronizeOnSession	back to summary
public final boolean isSynchronizeOnSession() Return whether controller execution should be synchronized on the session.

setSynchronizeOnSession back to summary

setSynchronizeOnSession	back to summary
public final void setSynchronizeOnSession(boolean synchronizeOnSession) Set if controller execution should be synchronized on the session, to serialize parallel invocations from the same client. 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. The session mutex is guaranteed to be the same object during the entire lifetime of the session, available under the key defined by the `SESSION_MUTEX_ATTRIBUTE` constant. It serves as a safe reference to synchronize on for locking on the current session. 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 Also `AbstractController#handleRequestInternal`, `org.springframework.web.util.HttpSessionMutexListener`, `org.springframework.web.util.WebUtils#getSessionMutex(jakarta.servlet.http.HttpSession)`

public final void setSynchronizeOnSession(boolean synchronizeOnSession)

Set if controller execution should be synchronized on the session, to serialize parallel invocations from the same client.

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.

The session mutex is guaranteed to be the same object during the entire lifetime of the session, available under the key defined by the SESSION_MUTEX_ATTRIBUTE constant. It serves as a safe reference to synchronize on for locking on the current session.

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 Also: AbstractController#handleRequestInternal, org.springframework.web.util.HttpSessionMutexListener, org.springframework.web.util.WebUtils#getSessionMutex(jakarta.servlet.http.HttpSession)