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java.lang.Objectjavax.servlet.GenericServlet
javax.servlet.http.HttpServlet
org.springframework.web.servlet.HttpServletBean
org.springframework.web.servlet.FrameworkServlet
public abstract class FrameworkServlet
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:
WebApplicationContext instance per servlet. The servlet's configuration is determined
by beans in the servlet's namespace.
Subclasses must implement doService(javax.servlet.http.HttpServletRequest, javax.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.
As of Spring 3.1, FrameworkServlet may now 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.
doService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse),
setContextClass(java.lang.Class>),
setContextConfigLocation(java.lang.String),
setContextInitializerClasses(java.lang.String),
setNamespace(java.lang.String),
Serialized Form| Field Summary | |
|---|---|
static Class<?> |
DEFAULT_CONTEXT_CLASS
Default context class for FrameworkServlet. |
static String |
DEFAULT_NAMESPACE_SUFFIX
Suffix for WebApplicationContext namespaces. |
static String |
SERVLET_CONTEXT_PREFIX
Prefix for the ServletContext attribute for the WebApplicationContext. |
| Fields inherited from class org.springframework.web.servlet.HttpServletBean |
|---|
logger |
| Constructor Summary | |
|---|---|
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 | |
|---|---|
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 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 void |
doDelete(HttpServletRequest request,
HttpServletResponse response)
Delegate DELETE requests to processRequest(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse). |
protected void |
doGet(HttpServletRequest request,
HttpServletResponse response)
Delegate GET requests to processRequest/doService. |
protected void |
doOptions(HttpServletRequest request,
HttpServletResponse response)
Delegate OPTIONS requests to processRequest(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse), if desired. |
protected void |
doPost(HttpServletRequest request,
HttpServletResponse response)
Delegate POST requests to processRequest(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse). |
protected void |
doPut(HttpServletRequest request,
HttpServletResponse response)
Delegate PUT requests to processRequest(javax.servlet.http.HttpServletRequest, javax.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(javax.servlet.http.HttpServletRequest, javax.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. |
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 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. |
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 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. |
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<ConfigurableApplicationContext>... contextInitializers)
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(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) method. |
void |
setDispatchTraceRequest(boolean dispatchTraceRequest)
Set whether this servlet should dispatch an HTTP TRACE request to the doService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) method. |
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, getServletContext, getServletName, init, initBeanWrapper, setEnvironment |
| Methods inherited from class javax.servlet.http.HttpServlet |
|---|
doHead, getLastModified, service, service |
| Methods inherited from class javax.servlet.GenericServlet |
|---|
getInitParameter, getInitParameterNames, getServletConfig, getServletInfo, init, log, log |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Field Detail |
|---|
public static final String DEFAULT_NAMESPACE_SUFFIX
public static final Class<?> DEFAULT_CONTEXT_CLASS
XmlWebApplicationContextpublic static final String SERVLET_CONTEXT_PREFIX
| Constructor Detail |
|---|
public FrameworkServlet()
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().
FrameworkServlet(WebApplicationContext)public FrameworkServlet(WebApplicationContext webApplicationContext)
FrameworkServlet with the given web application context. This
constructor is useful in Servlet 3.0+ environments where instance-based registration
of servlets is possible through the ServletContext#addServlet 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:
ServletContext and ServletConfig objects will be delegated to
the application contextpostProcessWebApplicationContext(org.springframework.web.context.ConfigurableWebApplicationContext) will be calledApplicationContextInitializers specified through the
"contextInitializerClasses" init-param or through the setContextInitializers(org.springframework.context.ApplicationContextInitializer...) property will be applied.refresh() will be calledConfigurableWebApplicationContext, 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.
webApplicationContext - the context to useinitWebApplicationContext(),
configureAndRefreshWebApplicationContext(org.springframework.web.context.ConfigurableWebApplicationContext),
WebApplicationInitializer| Method Detail |
|---|
public void setContextAttribute(String contextAttribute)
WebApplicationContext that this servlet is supposed to use.
public String getContextAttribute()
WebApplicationContext that this servlet is supposed to use.
public void setContextClass(Class<?> contextClass)
WebApplicationContext.
When using the default FrameworkServlet implementation,
the context class must also implement the
ConfigurableWebApplicationContext
interface.
createWebApplicationContext(org.springframework.context.ApplicationContext)public Class<?> getContextClass()
public void setContextId(String contextId)
public String getContextId()
public void setNamespace(String namespace)
public String getNamespace()
public void setContextInitializerClasses(String contextInitializerClasses)
ApplicationContextInitializer class
names, per the optional "contextInitializerClasses" servlet init-param.
configureAndRefreshWebApplicationContext(ConfigurableWebApplicationContext),
#applyInitializers(ConfigurableWebApplicationContext)public void setContextInitializers(ApplicationContextInitializer<ConfigurableApplicationContext>... contextInitializers)
ApplicationContextInitializer instances should be used
to initialize the application context used by this FrameworkServlet.
configureAndRefreshWebApplicationContext(ConfigurableWebApplicationContext),
#applyInitializers(ConfigurableWebApplicationContext)public void setContextConfigLocation(String contextConfigLocation)
public String getContextConfigLocation()
public void setPublishContext(boolean publishContext)
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.
public void setPublishEvents(boolean publishEvents)
ServletRequestHandledEventpublic void setThreadContextInheritable(boolean threadContextInheritable)
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.
public void setDispatchOptionsRequest(boolean dispatchOptionsRequest)
doService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) method.
Default is "false", applying HttpServlet's
default behavior (i.e. enumerating all standard HTTP request methods
as a response to the OPTIONS request).
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).
public void setDispatchTraceRequest(boolean dispatchTraceRequest)
doService(javax.servlet.http.HttpServletRequest, javax.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).
protected final void initServletBean()
throws ServletException
HttpServletBean, invoked after any bean properties
have been set. Creates this servlet's WebApplicationContext.
initServletBean in class HttpServletBeanServletException - if subclass initialization failsprotected WebApplicationContext initWebApplicationContext()
Delegates to createWebApplicationContext(org.springframework.context.ApplicationContext) for actual creation
of the context. Can be overridden in subclasses.
FrameworkServlet(WebApplicationContext),
setContextClass(java.lang.Class>),
setContextConfigLocation(java.lang.String)protected WebApplicationContext findWebApplicationContext()
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.
null if not foundgetContextAttribute()protected WebApplicationContext createWebApplicationContext(ApplicationContext parent)
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.
parent - the parent ApplicationContext to use, or null if none
XmlWebApplicationContextprotected void configureAndRefreshWebApplicationContext(ConfigurableWebApplicationContext wac)
protected WebApplicationContext createWebApplicationContext(WebApplicationContext parent)
XmlWebApplicationContext
or a custom context class, if set.
Delegates to #createWebApplicationContext(ApplicationContext).
parent - the parent WebApplicationContext to use, or null if none
XmlWebApplicationContext,
createWebApplicationContext(ApplicationContext)protected void applyInitializers(ConfigurableApplicationContext wac)
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 after this method.
wac - the configured WebApplicationContext (not refreshed yet)createWebApplicationContext(org.springframework.context.ApplicationContext),
postProcessWebApplicationContext(org.springframework.web.context.ConfigurableWebApplicationContext),
ConfigurableApplicationContext.refresh()protected void postProcessWebApplicationContext(ConfigurableWebApplicationContext wac)
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 #initializeWebApplicationContext is designed to allow
end-users to modify the context through the use of
ApplicationContextInitializers.
wac - the configured WebApplicationContext (not refreshed yet)createWebApplicationContext(org.springframework.context.ApplicationContext),
#initializeWebApplicationContext,
ConfigurableApplicationContext.refresh()public String getServletContextAttributeName()
The default implementation returns
SERVLET_CONTEXT_PREFIX + servlet name.
SERVLET_CONTEXT_PREFIX,
HttpServletBean.getServletName()public final WebApplicationContext getWebApplicationContext()
protected void initFrameworkServlet()
throws ServletException
ServletException - in case of an initialization exceptionpublic void refresh()
getWebApplicationContext(),
ConfigurableApplicationContext.refresh()public void onApplicationEvent(ContextRefreshedEvent event)
The default implementation calls onRefresh(org.springframework.context.ApplicationContext),
triggering a refresh of this servlet's context-dependent state.
event - the incoming ApplicationContext eventprotected void onRefresh(ApplicationContext context)
This implementation is empty.
context - the current WebApplicationContextrefresh()
protected final void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,
IOException
Will also be invoked by HttpServlet's default implementation of doHead,
with a NoBodyResponse that just captures the content length.
doGet in class HttpServletServletException
IOExceptiondoService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse),
HttpServlet.doHead(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
protected final void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,
IOException
processRequest(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse).
doPost in class HttpServletServletException
IOExceptiondoService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
protected final void doPut(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,
IOException
processRequest(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse).
doPut in class HttpServletServletException
IOExceptiondoService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
protected final void doDelete(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,
IOException
processRequest(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse).
doDelete in class HttpServletServletException
IOExceptiondoService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
protected void doOptions(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,
IOException
processRequest(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse), if desired.
Applies HttpServlet's standard OPTIONS processing otherwise, and also if there is still no 'Allow' header set after dispatching.
doOptions in class HttpServletServletException
IOExceptiondoService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
protected void doTrace(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,
IOException
processRequest(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse), if desired.
Applies HttpServlet's standard TRACE processing otherwise.
doTrace in class HttpServletServletException
IOExceptiondoService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
protected final void processRequest(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,
IOException
The actual event handling is performed by the abstract
doService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) template method.
ServletException
IOExceptionprotected LocaleContext buildLocaleContext(HttpServletRequest request)
request - current HTTP request
protected String getUsernameForRequest(HttpServletRequest request)
The default implementation takes the name of the UserPrincipal, if any. Can be overridden in subclasses.
request - current HTTP request
null if none foundHttpServletRequest.getUserPrincipal()
protected abstract void doService(HttpServletRequest request,
HttpServletResponse response)
throws Exception
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.
request - current HTTP requestresponse - current HTTP response
Exception - in case of any kind of processing failureHttpServlet.doGet(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse),
HttpServlet.doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)public void destroy()
destroy in interface Servletdestroy in class GenericServletConfigurableApplicationContext.close()
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