Package org.springframework.web.servlet

Class FrameworkServlet

java.lang.Object

jakarta.servlet.GenericServlet

jakarta.servlet.http.HttpServlet

org.springframework.web.servlet.HttpServletBean

org.springframework.web.servlet.FrameworkServlet

All Implemented Interfaces:

Servlet, ServletConfig, Serializable, Aware, ApplicationContextAware, EnvironmentAware, EnvironmentCapable

Direct Known Subclasses:

DispatcherServlet

public abstract class FrameworkServlet
extends HttpServletBean
implements ApplicationContextAware

Base servlet for Spring's web framework. Provides integration with a Spring application context, in a JavaBean-based overall solution.

This class offers the following functionality:

• Manages a WebApplicationContext instance per servlet. The servlet's configuration is determined by beans in the servlet's namespace.
• Publishes events on request processing, whether or not a request is successfully handled.

Subclasses must implement doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse) to handle requests. Because this extends HttpServletBean rather than HttpServlet directly, bean properties are automatically mapped onto it. Subclasses can override initFrameworkServlet() for custom initialization.

Detects a "contextClass" parameter at the servlet init-param level, falling back to the default context class, XmlWebApplicationContext, if not found. Note that, with the default FrameworkServlet, a custom context class needs to implement the ConfigurableWebApplicationContext SPI.

Accepts an optional "contextInitializerClasses" servlet init-param that specifies one or more ApplicationContextInitializer classes. The managed web application context will be delegated to these initializers, allowing for additional programmatic configuration, e.g. adding property sources or activating profiles against the context's environment. See also ContextLoader which supports a "contextInitializerClasses" context-param with identical semantics for the "root" web application context.

Passes a "contextConfigLocation" servlet init-param to the context instance, parsing it into potentially multiple file paths which can be separated by any number of commas and spaces, like "test-servlet.xml, myServlet.xml". If not explicitly specified, the context implementation is supposed to build a default location from the namespace of the servlet.

Note: In case of multiple config locations, later bean definitions will override ones defined in earlier loaded files, at least when using Spring's default ApplicationContext implementation. This can be leveraged to deliberately override certain bean definitions via an extra XML file.

The default namespace is "'servlet-name'-servlet", e.g. "test-servlet" for a servlet-name "test" (leading to a "/WEB-INF/test-servlet.xml" default location with XmlWebApplicationContext). The namespace can also be set explicitly via the "namespace" servlet init-param.

FrameworkServlet may be injected with a web application context, rather than creating its own internally. This is useful in Servlet 3.0+ environments, which support programmatic registration of servlet instances. See FrameworkServlet(WebApplicationContext) Javadoc for details.

Author:

Rod Johnson, Juergen Hoeller, Sam Brannen, Chris Beams, Rossen Stoyanchev, Phillip Webb

See Also:

• doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)
• setContextClass(java.lang.Class<?>)
• setContextConfigLocation(java.lang.String)
• setContextInitializerClasses(java.lang.String)
• setNamespace(java.lang.String)
• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final Class<?>	DEFAULT_CONTEXT_CLASS	Default context class for FrameworkServlet.
static final String	DEFAULT_NAMESPACE_SUFFIX	Suffix for WebApplicationContext namespaces.
static final String	SERVLET_CONTEXT_PREFIX	Prefix for the ServletContext attribute for the WebApplicationContext.

Fields inherited from class org.springframework.web.servlet.HttpServletBean

logger

Fields inherited from class jakarta.servlet.http.HttpServlet

LEGACY_DO_HEAD

Constructor Summary

Constructors

Constructor	Description
FrameworkServlet()	Create a new FrameworkServlet that will create its own internal web application context based on defaults and values provided through servlet init-params.
FrameworkServlet(WebApplicationContext webApplicationContext)	Create a new FrameworkServlet with the given web application context.

Method Summary

Modifier and Type	Method	Description
protected void	applyInitializers(ConfigurableApplicationContext wac)	Delegate the WebApplicationContext before it is refreshed to any ApplicationContextInitializer instances specified by the "contextInitializerClasses" servlet init-param.
protected LocaleContext	buildLocaleContext(HttpServletRequest request)	Build a LocaleContext for the given request, exposing the request's primary locale as current locale.
protected ServletRequestAttributes	buildRequestAttributes(HttpServletRequest request, HttpServletResponse response, RequestAttributes previousAttributes)	Build ServletRequestAttributes for the given request (potentially also holding a reference to the response), taking pre-bound attributes (and their type) into consideration.
protected void	configureAndRefreshWebApplicationContext(ConfigurableWebApplicationContext wac)
protected WebApplicationContext	createWebApplicationContext(ApplicationContext parent)	Instantiate the WebApplicationContext for this servlet, either a default XmlWebApplicationContext or a custom context class, if set.
protected WebApplicationContext	createWebApplicationContext(WebApplicationContext parent)	Instantiate the WebApplicationContext for this servlet, either a default XmlWebApplicationContext or a custom context class, if set.
void	destroy()	Close the WebApplicationContext of this servlet.
protected final void	doDelete(HttpServletRequest request, HttpServletResponse response)	Delegate DELETE requests to processRequest(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse).
protected final void	doGet(HttpServletRequest request, HttpServletResponse response)	Delegate GET requests to processRequest/doService.
protected void	doOptions(HttpServletRequest request, HttpServletResponse response)	Delegate OPTIONS requests to processRequest(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse), if desired.
protected final void	doPost(HttpServletRequest request, HttpServletResponse response)	Delegate POST requests to processRequest(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse).
protected final void	doPut(HttpServletRequest request, HttpServletResponse response)	Delegate PUT requests to processRequest(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse).
protected abstract void	doService(HttpServletRequest request, HttpServletResponse response)	Subclasses must implement this method to do the work of request handling, receiving a centralized callback for GET, POST, PUT and DELETE.
protected void	doTrace(HttpServletRequest request, HttpServletResponse response)	Delegate TRACE requests to processRequest(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse), if desired.
protected WebApplicationContext	findWebApplicationContext()	Retrieve a WebApplicationContext from the ServletContext attribute with the configured name.
String	getContextAttribute()	Return the name of the ServletContext attribute which should be used to retrieve the WebApplicationContext that this servlet is supposed to use.
Class<?>	getContextClass()	Return the custom context class.
String	getContextConfigLocation()	Return the explicit context config location, if any.
String	getContextId()	Return the custom WebApplicationContext id, if any.
String	getNamespace()	Return the namespace for this servlet, falling back to default scheme if no custom namespace was set: e.g.
String	getServletContextAttributeName()	Return the ServletContext attribute name for this servlet's WebApplicationContext.
protected String	getUsernameForRequest(HttpServletRequest request)	Determine the username for the given request.
final WebApplicationContext	getWebApplicationContext()	Return this servlet's WebApplicationContext.
protected void	initFrameworkServlet()	This method will be invoked after any bean properties have been set and the WebApplicationContext has been loaded.
protected final void	initServletBean()	Overridden method of HttpServletBean, invoked after any bean properties have been set.
protected WebApplicationContext	initWebApplicationContext()	Initialize and publish the WebApplicationContext for this servlet.
boolean	isEnableLoggingRequestDetails()	Whether logging of potentially sensitive, request details at DEBUG and TRACE level is allowed.
void	onApplicationEvent(ContextRefreshedEvent event)	Callback that receives refresh events from this servlet's WebApplicationContext.
protected void	onRefresh(ApplicationContext context)	Template method which can be overridden to add servlet-specific refresh work.
protected void	postProcessWebApplicationContext(ConfigurableWebApplicationContext wac)	Post-process the given WebApplicationContext before it is refreshed and activated as context for this servlet.
protected final void	processRequest(HttpServletRequest request, HttpServletResponse response)	Process this request, publishing an event regardless of the outcome.
void	refresh()	Refresh this servlet's application context, as well as the dependent state of the servlet.
protected void	service(HttpServletRequest request, HttpServletResponse response)	Override the parent class implementation in order to intercept requests using PATCH or non-standard HTTP methods (WebDAV).
void	setApplicationContext(ApplicationContext applicationContext)	Called by Spring via ApplicationContextAware to inject the current application context.
void	setContextAttribute(String contextAttribute)	Set the name of the ServletContext attribute which should be used to retrieve the WebApplicationContext that this servlet is supposed to use.
void	setContextClass(Class<?> contextClass)	Set a custom context class.
void	setContextConfigLocation(String contextConfigLocation)	Set the context config location explicitly, instead of relying on the default location built from the namespace.
void	setContextId(String contextId)	Specify a custom WebApplicationContext id, to be used as serialization id for the underlying BeanFactory.
void	setContextInitializerClasses(String contextInitializerClasses)	Specify the set of fully-qualified ApplicationContextInitializer class names, per the optional "contextInitializerClasses" servlet init-param.
void	setContextInitializers(ApplicationContextInitializer<?>... initializers)	Specify which ApplicationContextInitializer instances should be used to initialize the application context used by this FrameworkServlet.
void	setDispatchOptionsRequest(boolean dispatchOptionsRequest)	Set whether this servlet should dispatch an HTTP OPTIONS request to the doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse) method.
void	setDispatchTraceRequest(boolean dispatchTraceRequest)	Set whether this servlet should dispatch an HTTP TRACE request to the doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse) method.
void	setEnableLoggingRequestDetails(boolean enable)	Whether to log request params at DEBUG level, and headers at TRACE level.
void	setNamespace(String namespace)	Set a custom namespace for this servlet, to be used for building a default context config location.
void	setPublishContext(boolean publishContext)	Set whether to publish this servlet's context as a ServletContext attribute, available to all objects in the web container.
void	setPublishEvents(boolean publishEvents)	Set whether this servlet should publish a ServletRequestHandledEvent at the end of each request.
void	setThreadContextInheritable(boolean threadContextInheritable)	Set whether to expose the LocaleContext and RequestAttributes as inheritable for child threads (using an InheritableThreadLocal).

Methods inherited from class org.springframework.web.servlet.HttpServletBean

addRequiredProperty, createEnvironment, getEnvironment, getServletName, init, initBeanWrapper, setEnvironment

Methods inherited from class jakarta.servlet.http.HttpServlet

doHead, getLastModified, init, service

Methods inherited from class jakarta.servlet.GenericServlet

getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_NAMESPACE_SUFFIX

public static final String DEFAULT_NAMESPACE_SUFFIX

Suffix for WebApplicationContext namespaces. If a servlet of this class is given the name "test" in a context, the namespace used by the servlet will resolve to "test-servlet".

See Also:

• Constant Field Values

DEFAULT_CONTEXT_CLASS

public static final Class<?> DEFAULT_CONTEXT_CLASS

Default context class for FrameworkServlet.

See Also:

• XmlWebApplicationContext

SERVLET_CONTEXT_PREFIX

public static final String SERVLET_CONTEXT_PREFIX

Prefix for the ServletContext attribute for the WebApplicationContext. The completion is the servlet name.

Constructor Details

FrameworkServlet

public FrameworkServlet()

Create a new FrameworkServlet that will create its own internal web application context based on defaults and values provided through servlet init-params. Typically used in Servlet 2.5 or earlier environments, where the only option for servlet registration is through web.xml which requires the use of a no-arg constructor.

Calling setContextConfigLocation(java.lang.String) (init-param 'contextConfigLocation') will dictate which XML files will be loaded by the default XmlWebApplicationContext

Calling setContextClass(java.lang.Class<?>) (init-param 'contextClass') overrides the default XmlWebApplicationContext and allows for specifying an alternative class, such as AnnotationConfigWebApplicationContext.

Calling setContextInitializerClasses(java.lang.String) (init-param 'contextInitializerClasses') indicates which ApplicationContextInitializer classes should be used to further configure the internal application context prior to refresh().

See Also:

• FrameworkServlet(WebApplicationContext)

FrameworkServlet

public FrameworkServlet(WebApplicationContext webApplicationContext)

Create a new FrameworkServlet with the given web application context. This constructor is useful in Servlet environments where instance-based registration of servlets is possible through the ServletContext.addServlet(java.lang.String, java.lang.String) API.

Using this constructor indicates that the following properties / init-params will be ignored:

• setContextClass(Class) / 'contextClass'
• setContextConfigLocation(String) / 'contextConfigLocation'
• setContextAttribute(String) / 'contextAttribute'
• setNamespace(String) / 'namespace'

The given web application context may or may not yet be refreshed. If it (a) is an implementation of ConfigurableWebApplicationContext and (b) has not already been refreshed (the recommended approach), then the following will occur:

• If the given context does not already have a parent, the root application context will be set as the parent.
• If the given context has not already been assigned an id, one will be assigned to it
• ServletContext and ServletConfig objects will be delegated to the application context
• postProcessWebApplicationContext(org.springframework.web.context.ConfigurableWebApplicationContext) will be called
• Any ApplicationContextInitializers specified through the "contextInitializerClasses" init-param or through the setContextInitializers(org.springframework.context.ApplicationContextInitializer<?>...) property will be applied.
• refresh() will be called

If the context has already been refreshed or does not implement ConfigurableWebApplicationContext, none of the above will occur under the assumption that the user has performed these actions (or not) per his or her specific needs.

See WebApplicationInitializer for usage examples.

Parameters:

webApplicationContext - the context to use

See Also:

• initWebApplicationContext()
• configureAndRefreshWebApplicationContext(org.springframework.web.context.ConfigurableWebApplicationContext)
• WebApplicationInitializer

Method Details

setContextAttribute

public void setContextAttribute(@Nullable
 String contextAttribute)

Set the name of the ServletContext attribute which should be used to retrieve the WebApplicationContext that this servlet is supposed to use.

getContextAttribute

@Nullable
public String getContextAttribute()

Return the name of the ServletContext attribute which should be used to retrieve the WebApplicationContext that this servlet is supposed to use.

setContextClass

public void setContextClass(Class<?> contextClass)

Set a custom context class. This class must be of type WebApplicationContext.

When using the default FrameworkServlet implementation, the context class must also implement the ConfigurableWebApplicationContext interface.

See Also:

• createWebApplicationContext(org.springframework.context.ApplicationContext)

getContextClass

public Class<?> getContextClass()

Return the custom context class.

setContextId

public void setContextId(@Nullable
 String contextId)

Specify a custom WebApplicationContext id, to be used as serialization id for the underlying BeanFactory.

getContextId

@Nullable
public String getContextId()

Return the custom WebApplicationContext id, if any.

setNamespace

public void setNamespace(String namespace)

Set a custom namespace for this servlet, to be used for building a default context config location.

getNamespace

public String getNamespace()

Return the namespace for this servlet, falling back to default scheme if no custom namespace was set: e.g. "test-servlet" for a servlet named "test".

setContextConfigLocation

public void setContextConfigLocation(@Nullable
 String contextConfigLocation)

Set the context config location explicitly, instead of relying on the default location built from the namespace. This location string can consist of multiple locations separated by any number of commas and spaces.

getContextConfigLocation

@Nullable
public String getContextConfigLocation()

Return the explicit context config location, if any.

setContextInitializers

public void setContextInitializers(@Nullable
 ApplicationContextInitializer<?>... initializers)

Specify which ApplicationContextInitializer instances should be used to initialize the application context used by this FrameworkServlet.

See Also:

• configureAndRefreshWebApplicationContext(org.springframework.web.context.ConfigurableWebApplicationContext)
• applyInitializers(org.springframework.context.ConfigurableApplicationContext)

setContextInitializerClasses

public void setContextInitializerClasses(String contextInitializerClasses)

Specify the set of fully-qualified ApplicationContextInitializer class names, per the optional "contextInitializerClasses" servlet init-param.

See Also:

• configureAndRefreshWebApplicationContext(ConfigurableWebApplicationContext)
• applyInitializers(ConfigurableApplicationContext)

setPublishContext

public void setPublishContext(boolean publishContext)

Set whether to publish this servlet's context as a ServletContext attribute, available to all objects in the web container. Default is "true".

This is especially handy during testing, although it is debatable whether it's good practice to let other application objects access the context this way.

setPublishEvents

public void setPublishEvents(boolean publishEvents)

Set whether this servlet should publish a ServletRequestHandledEvent at the end of each request. Default is "true"; can be turned off for a slight performance improvement, provided that no ApplicationListeners rely on such events.

See Also:

• ServletRequestHandledEvent

setThreadContextInheritable

public void setThreadContextInheritable(boolean threadContextInheritable)

Set whether to expose the LocaleContext and RequestAttributes as inheritable for child threads (using an InheritableThreadLocal).

Default is "false", to avoid side effects on spawned background threads. Switch this to "true" to enable inheritance for custom child threads which are spawned during request processing and only used for this request (that is, ending after their initial task, without reuse of the thread).

WARNING: Do not use inheritance for child threads if you are accessing a thread pool which is configured to potentially add new threads on demand (e.g. a JDK ThreadPoolExecutor), since this will expose the inherited context to such a pooled thread.

setDispatchOptionsRequest

public void setDispatchOptionsRequest(boolean dispatchOptionsRequest)

Set whether this servlet should dispatch an HTTP OPTIONS request to the doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse) method.

Default in the FrameworkServlet is "false", applying HttpServlet's default behavior (i.e.enumerating all standard HTTP request methods as a response to the OPTIONS request). Note however that as of 4.3 the DispatcherServlet sets this property to "true" by default due to its built-in support for OPTIONS.

Turn this flag on if you prefer OPTIONS requests to go through the regular dispatching chain, just like other HTTP requests. This usually means that your controllers will receive those requests; make sure that those endpoints are actually able to handle an OPTIONS request.

Note that HttpServlet's default OPTIONS processing will be applied in any case if your controllers happen to not set the 'Allow' header (as required for an OPTIONS response).

setDispatchTraceRequest

public void setDispatchTraceRequest(boolean dispatchTraceRequest)

Set whether this servlet should dispatch an HTTP TRACE request to the doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse) method.

Default is "false", applying HttpServlet's default behavior (i.e. reflecting the message received back to the client).

Turn this flag on if you prefer TRACE requests to go through the regular dispatching chain, just like other HTTP requests. This usually means that your controllers will receive those requests; make sure that those endpoints are actually able to handle a TRACE request.

Note that HttpServlet's default TRACE processing will be applied in any case if your controllers happen to not generate a response of content type 'message/http' (as required for a TRACE response).

setEnableLoggingRequestDetails

public void setEnableLoggingRequestDetails(boolean enable)

Whether to log request params at DEBUG level, and headers at TRACE level. Both may contain sensitive information.

By default set to false so that request details are not shown.

Parameters:

enable - whether to enable or not

Since:

5.1

isEnableLoggingRequestDetails

public boolean isEnableLoggingRequestDetails()

Whether logging of potentially sensitive, request details at DEBUG and TRACE level is allowed.

Since:

5.1

setApplicationContext

public void setApplicationContext(ApplicationContext applicationContext)

Called by Spring via ApplicationContextAware to inject the current application context. This method allows FrameworkServlets to be registered as Spring beans inside an existing WebApplicationContext rather than finding a bootstrapped context.

Primarily added to support use in embedded servlet containers.

Specified by:

setApplicationContext in interface ApplicationContextAware

Parameters:

applicationContext - the ApplicationContext object to be used by this object

Since:

4.0

See Also:

• BeanInitializationException

initServletBean

protected final void initServletBean()
                              throws ServletException

Overridden method of HttpServletBean, invoked after any bean properties have been set. Creates this servlet's WebApplicationContext.

Overrides:

initServletBean in class HttpServletBean

Throws:

ServletException - if subclass initialization fails

initWebApplicationContext

protected WebApplicationContext initWebApplicationContext()

Initialize and publish the WebApplicationContext for this servlet.

Delegates to createWebApplicationContext(org.springframework.context.ApplicationContext) for actual creation of the context. Can be overridden in subclasses.

Returns:

the WebApplicationContext instance

See Also:

• FrameworkServlet(WebApplicationContext)
• setContextClass(java.lang.Class<?>)
• setContextConfigLocation(java.lang.String)

findWebApplicationContext

@Nullable
protected WebApplicationContext findWebApplicationContext()

Retrieve a WebApplicationContext from the ServletContext attribute with the configured name. The WebApplicationContext must have already been loaded and stored in the ServletContext before this servlet gets initialized (or invoked).

Subclasses may override this method to provide a different WebApplicationContext retrieval strategy.

Returns:

the WebApplicationContext for this servlet, or null if not found

See Also:

• getContextAttribute()

createWebApplicationContext

protected WebApplicationContext createWebApplicationContext(@Nullable
 ApplicationContext parent)

Instantiate the WebApplicationContext for this servlet, either a default XmlWebApplicationContext or a custom context class, if set.

This implementation expects custom contexts to implement the ConfigurableWebApplicationContext interface. Can be overridden in subclasses.

Do not forget to register this servlet instance as application listener on the created context (for triggering its callback), and to call ConfigurableApplicationContext.refresh() before returning the context instance.

Parameters:

parent - the parent ApplicationContext to use, or null if none

Returns:

the WebApplicationContext for this servlet

See Also:

• XmlWebApplicationContext

configureAndRefreshWebApplicationContext

protected void configureAndRefreshWebApplicationContext(ConfigurableWebApplicationContext wac)

createWebApplicationContext

protected WebApplicationContext createWebApplicationContext(@Nullable
 WebApplicationContext parent)

Instantiate the WebApplicationContext for this servlet, either a default XmlWebApplicationContext or a custom context class, if set. Delegates to #createWebApplicationContext(ApplicationContext).

Parameters:

parent - the parent WebApplicationContext to use, or null if none

Returns:

the WebApplicationContext for this servlet

See Also:

• XmlWebApplicationContext
• createWebApplicationContext(ApplicationContext)

postProcessWebApplicationContext

protected void postProcessWebApplicationContext(ConfigurableWebApplicationContext wac)

Post-process the given WebApplicationContext before it is refreshed and activated as context for this servlet.

The default implementation is empty. refresh() will be called automatically after this method returns.

Note that this method is designed to allow subclasses to modify the application context, while initWebApplicationContext() is designed to allow end-users to modify the context through the use of ApplicationContextInitializers.

Parameters:

wac - the configured WebApplicationContext (not refreshed yet)

See Also:

• createWebApplicationContext(org.springframework.context.ApplicationContext)
• initWebApplicationContext()
• ConfigurableApplicationContext.refresh()

applyInitializers

protected void applyInitializers(ConfigurableApplicationContext wac)

Delegate the WebApplicationContext before it is refreshed to any ApplicationContextInitializer instances specified by the "contextInitializerClasses" servlet init-param.

See also postProcessWebApplicationContext(org.springframework.web.context.ConfigurableWebApplicationContext), which is designed to allow subclasses (as opposed to end-users) to modify the application context, and is called immediately before this method.

Parameters:

wac - the configured WebApplicationContext (not refreshed yet)

See Also:

• createWebApplicationContext(org.springframework.context.ApplicationContext)
• postProcessWebApplicationContext(org.springframework.web.context.ConfigurableWebApplicationContext)
• ConfigurableApplicationContext.refresh()

getServletContextAttributeName

public String getServletContextAttributeName()

Return the ServletContext attribute name for this servlet's WebApplicationContext.

The default implementation returns SERVLET_CONTEXT_PREFIX + servlet name.

See Also:

• SERVLET_CONTEXT_PREFIX
• HttpServletBean.getServletName()

getWebApplicationContext

@Nullable
public final WebApplicationContext getWebApplicationContext()

Return this servlet's WebApplicationContext.

initFrameworkServlet

protected void initFrameworkServlet()
                             throws ServletException

This method will be invoked after any bean properties have been set and the WebApplicationContext has been loaded. The default implementation is empty; subclasses may override this method to perform any initialization they require.

Throws:

ServletException - in case of an initialization exception

refresh

public void refresh()

Refresh this servlet's application context, as well as the dependent state of the servlet.

See Also:

• getWebApplicationContext()
• ConfigurableApplicationContext.refresh()

onApplicationEvent

public void onApplicationEvent(ContextRefreshedEvent event)

Callback that receives refresh events from this servlet's WebApplicationContext.

The default implementation calls onRefresh(org.springframework.context.ApplicationContext), triggering a refresh of this servlet's context-dependent state.

Parameters:

event - the incoming ApplicationContext event

onRefresh

protected void onRefresh(ApplicationContext context)

Template method which can be overridden to add servlet-specific refresh work. Called after successful context refresh.

This implementation is empty.

Parameters:

context - the current WebApplicationContext

See Also:

• refresh()

destroy

public void destroy()

Close the WebApplicationContext of this servlet.

Specified by:

destroy in interface Servlet

Overrides:

destroy in class GenericServlet

See Also:

• ConfigurableApplicationContext.close()

service

protected void service(HttpServletRequest request,
 HttpServletResponse response)
                throws ServletException,
IOException

Override the parent class implementation in order to intercept requests using PATCH or non-standard HTTP methods (WebDAV).

Overrides:

service in class HttpServlet

Throws:

ServletException

IOException

doGet

protected final void doGet(HttpServletRequest request,
 HttpServletResponse response)
                    throws ServletException,
IOException

Delegate GET requests to processRequest/doService.

Will also be invoked by HttpServlet's default implementation of doHead, with a NoBodyResponse that just captures the content length.

Overrides:

doGet in class HttpServlet

Throws:

ServletException

IOException

See Also:

• doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)
• HttpServlet.doHead(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)

doPost

protected final void doPost(HttpServletRequest request,
 HttpServletResponse response)
                     throws ServletException,
IOException

Delegate POST requests to processRequest(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse).

Overrides:

doPost in class HttpServlet

Throws:

ServletException

IOException

See Also:

• doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)

doPut

protected final void doPut(HttpServletRequest request,
 HttpServletResponse response)
                    throws ServletException,
IOException

Delegate PUT requests to processRequest(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse).

Overrides:

doPut in class HttpServlet

Throws:

ServletException

IOException

See Also:

• doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)

doDelete

protected final void doDelete(HttpServletRequest request,
 HttpServletResponse response)
                       throws ServletException,
IOException

Delegate DELETE requests to processRequest(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse).

Overrides:

doDelete in class HttpServlet

Throws:

ServletException

IOException

See Also:

• doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)

doOptions

protected void doOptions(HttpServletRequest request,
 HttpServletResponse response)
                  throws ServletException,
IOException

Delegate OPTIONS requests to processRequest(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse), if desired.

Applies HttpServlet's standard OPTIONS processing otherwise, and also if there is still no 'Allow' header set after dispatching.

Overrides:

doOptions in class HttpServlet

Throws:

ServletException

IOException

See Also:

• doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)

doTrace

protected void doTrace(HttpServletRequest request,
 HttpServletResponse response)
                throws ServletException,
IOException

Delegate TRACE requests to processRequest(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse), if desired.

Applies HttpServlet's standard TRACE processing otherwise.

Overrides:

doTrace in class HttpServlet

Throws:

ServletException

IOException

See Also:

• doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)

processRequest

protected final void processRequest(HttpServletRequest request,
 HttpServletResponse response)
                             throws ServletException,
IOException

Process this request, publishing an event regardless of the outcome.

The actual event handling is performed by the abstract doService(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse) template method.

Throws:

ServletException

IOException

buildLocaleContext

@Nullable
protected LocaleContext buildLocaleContext(HttpServletRequest request)

Build a LocaleContext for the given request, exposing the request's primary locale as current locale.

Parameters:

request - current HTTP request

Returns:

the corresponding LocaleContext, or null if none to bind

See Also:

• LocaleContextHolder.setLocaleContext(org.springframework.context.i18n.LocaleContext)

buildRequestAttributes

@Nullable
protected ServletRequestAttributes buildRequestAttributes(HttpServletRequest request,
 @Nullable
 HttpServletResponse response,
 @Nullable
 RequestAttributes previousAttributes)

Build ServletRequestAttributes for the given request (potentially also holding a reference to the response), taking pre-bound attributes (and their type) into consideration.

Parameters:

request - current HTTP request

response - current HTTP response

previousAttributes - pre-bound RequestAttributes instance, if any

Returns:

the ServletRequestAttributes to bind, or null to preserve the previously bound instance (or not binding any, if none bound before)

See Also:

• RequestContextHolder.setRequestAttributes(org.springframework.web.context.request.RequestAttributes)

getUsernameForRequest

@Nullable
protected String getUsernameForRequest(HttpServletRequest request)

Determine the username for the given request.

The default implementation takes the name of the UserPrincipal, if any. Can be overridden in subclasses.

Parameters:

request - current HTTP request

Returns:

the username, or null if none found

See Also:

• HttpServletRequest.getUserPrincipal()

doService

protected abstract void doService(HttpServletRequest request,
 HttpServletResponse response)
                           throws Exception

Subclasses must implement this method to do the work of request handling, receiving a centralized callback for GET, POST, PUT and DELETE.

The contract is essentially the same as that for the commonly overridden doGet or doPost methods of HttpServlet.

This class intercepts calls to ensure that exception handling and event publication takes place.

Parameters:

request - current HTTP request

response - current HTTP response

Throws:

Exception - in case of any kind of processing failure

See Also:

• HttpServlet.doGet(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)
• HttpServlet.doPost(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)