com.helger.xservlet.handler.simple

Interface IXServletSimpleHandler

All Superinterfaces:

IXServletBasicHandler, Serializable

All Known Implementing Classes:

RedirectAbsoluteXServletHandler, RedirectToServletXServletHandler

public interface IXServletSimpleHandler
extends IXServletBasicHandler

Special interface for a simple servlet handler.

Author:

Philip Helger

Method Summary

Modifier and Type	Method and Description
default com.helger.servlet.response.UnifiedResponse	createUnifiedResponse(com.helger.http.EHttpVersion eHttpVersion, com.helger.commons.http.EHttpMethod eHttpMethod, javax.servlet.http.HttpServletRequest aHttpRequest, com.helger.web.scope.IRequestWebScope aRequestScope) Create a unified response object.
default LocalDateTime	getLastModificationDateTime(com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope) Get the last modification date time for the current request.
default String	getSupportedETag(com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope) Get the ETag supported for this request.
void	handleRequest(com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope, com.helger.servlet.response.UnifiedResponse aUnifiedResponse) This is the main request handling method.
default com.helger.commons.state.EContinue	initRequestState(com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope, com.helger.servlet.response.UnifiedResponse aUnifiedResponse) This callback method is unconditionally called before the last-modification checks are performed.
default com.helger.commons.state.EContinue	onException(com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope, com.helger.servlet.response.UnifiedResponse aUnifiedResponse, Throwable t) Called when an exception occurred in handleRequest(IRequestWebScopeWithoutResponse, UnifiedResponse).
default void	onRequestBegin(com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope) Called before a valid request is handled.
default void	onRequestEnd(Throwable aCaughtException) Called after a valid request was processed.

Methods inherited from interface com.helger.xservlet.handler.IXServletBasicHandler

onServletDestroy, onServletInit

Method Detail

createUnifiedResponse

@Nonnull
default com.helger.servlet.response.UnifiedResponse createUnifiedResponse(@Nonnull
                                                                                    com.helger.http.EHttpVersion eHttpVersion,
                                                                                    @Nonnull
                                                                                    com.helger.commons.http.EHttpMethod eHttpMethod,
                                                                                    @Nonnull
                                                                                    javax.servlet.http.HttpServletRequest aHttpRequest,
                                                                                    @Nonnull
                                                                                    com.helger.web.scope.IRequestWebScope aRequestScope)

Create a unified response object.

Parameters:

eHttpVersion - HTTP version of the current request.

eHttpMethod - HTTP method of the current request.

aHttpRequest - Current HTTP request

aRequestScope - Current HTTP request scope

Returns:

The new unified response. Never null.

initRequestState

@OverrideOnDemand
default com.helger.commons.state.EContinue initRequestState(@Nonnull
                                                                               com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope,
                                                                               @Nonnull
                                                                               com.helger.servlet.response.UnifiedResponse aUnifiedResponse)

This callback method is unconditionally called before the last-modification checks are performed. So this method can be used to determine the requested object from the request. This method is not called if HTTP version or HTTP method are not supported.

Parameters:

aRequestScope - The request scope that will be used for processing the request. Never null.

aUnifiedResponse - The response object to be filled. Never null.

Returns:

EContinue.BREAK to stop processing (e.g. because a resource does not exist), EContinue.CONTINUE to continue processing as usual.

getLastModificationDateTime

@Nullable
default LocalDateTime getLastModificationDateTime(@Nonnull
                                                             com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope)

Get the last modification date time for the current request. If it was not modified since the last request time, a 304 (not modified) response code is returned. This method is always called for GET and HEAD requests. This method is called after initRequestState(IRequestWebScopeWithoutResponse, UnifiedResponse) .

Parameters:

aRequestScope - The request scope that will be used for processing the request. Never null.

Returns:

null if no last modification date time can be determined

getSupportedETag

@Nullable
default String getSupportedETag(@Nonnull
                                           com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope)

Get the ETag supported for this request. If an ETag matches, a 304 (not modified) response code is returned. This method is always called for GET and HEAD requests.

Parameters:

aRequestScope - The request scope that will be used for processing the request. Never null.

Returns:

null if this servlet does not support ETags

onRequestBegin

@OverrideOnDemand
 @Nonnull
default void onRequestBegin(@Nonnull
                                                          com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope)

Called before a valid request is handled. This method is only called if HTTP version matches, HTTP method is supported and sending a cached HTTP response is not an option.

Parameters:

aRequestScope - The request scope that will be used for processing the request. Never null.

handleRequest

void handleRequest(@Nonnull
                   com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope,
                   @Nonnull
                   com.helger.servlet.response.UnifiedResponse aUnifiedResponse)
            throws Exception

This is the main request handling method. Overwrite this method to fill your HTTP response.

Parameters:

aRequestScope - The request scope to use. There is no direct access to the HttpServletResponse. Everything must be handled with the unified response! Never null.

aUnifiedResponse - The response object to be filled. Never null.

Throws:

Exception - In case of an error

onException

@OverrideOnDemand
 @Nonnull
default com.helger.commons.state.EContinue onException(@Nonnull
                                                                                     com.helger.web.scope.IRequestWebScopeWithoutResponse aRequestScope,
                                                                                     @Nonnull
                                                                                     com.helger.servlet.response.UnifiedResponse aUnifiedResponse,
                                                                                     @Nonnull
                                                                                     Throwable t)

Called when an exception occurred in handleRequest(IRequestWebScopeWithoutResponse, UnifiedResponse). This method is only called for non-request-cancel operations.

Parameters:

aRequestScope - The source request scope. Never null.

aUnifiedResponse - The response to the current request. Never null.

t - The Throwable that occurred. Never null.

Returns:

EContinue.CONTINUE to propagate the Exception, EContinue.BREAK to swallow it. May not be null.

onRequestEnd

@OverrideOnDemand
default void onRequestEnd(@Nullable
                                             Throwable aCaughtException)

Called after a valid request was processed. This method is only called if the handleRequest method was invoked. If an exception occurred this method is called after onException(IRequestWebScopeWithoutResponse, UnifiedResponse, Throwable)

Parameters:

aCaughtException - null if no exception occurred, non-null in case of exception.