com.helger.xservlet

Class AbstractXServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

com.helger.xservlet.AbstractXServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

@NotThreadSafe
public abstract class AbstractXServlet
extends javax.servlet.http.HttpServlet

Abstract HTTP based servlet. Compared to the default HttpServlet this class uses a handler map with EHttpMethod as the key.
The following features are added compared to the default servlet implementation:

• It has counting statistics
• It has timing statistics
• It enforces a character set on the response
• It checks for known security attacks (like httpoxy)
• It has custom handler per HTTP method
• It has custom filter
• It has custom exception handler
• It handles Post-Redirect-Get centrally.

Note: it must be derived from HttpServlet to be usable with annotation based configuration in Jetty (was GenericServlet previously)

Since:

9.0.0

Author:

Philip Helger

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static String	REQUEST_ATTR_HANDLED_ASYNC Internal request attribute defining whether a request was handled asynchronously.
static String	REQUEST_ATTR_SCOPE_CREATED Internal request attribute defining whether a request scope was created or re-used

Constructor Summary

Constructors

Constructor and Description
AbstractXServlet() Constructor.

Method Summary

Modifier and Type	Method and Description
void	destroy()
protected com.helger.commons.callback.CallbackList<IXServletExceptionHandler>	exceptionHandler()
protected com.helger.commons.collection.impl.ICommonsList<IXServletHighLevelFilter>	filterHighLevelList()
protected com.helger.commons.collection.impl.ICommonsList<IXServletLowLevelFilter>	filterLowLevelList()
protected ServletStatusManager	getServletStatusMgr()
protected XServletHandlerRegistry	handlerRegistry()
void	init(javax.servlet.ServletConfig aSC) A final overload of "init".
void	log(String sMsg)
void	log(String sMsg, Throwable t)
protected void	logInvalidRequestSetup(String sMsg, javax.servlet.http.HttpServletRequest aHttpRequest) This method logs errors, in case a HttpServletRequest object is missing basic information or uses unsupported values for e.g.
protected void	service(javax.servlet.http.HttpServletRequest aHttpRequest, javax.servlet.http.HttpServletResponse aHttpResponse) Dispatches client requests to the protected service method.
void	service(javax.servlet.ServletRequest req, javax.servlet.ServletResponse res)
XServletSettings	settings()
String	toString()

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified

Methods inherited from class javax.servlet.GenericServlet

getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init

Methods inherited from class java.lang.Object

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

Field Detail

REQUEST_ATTR_HANDLED_ASYNC

public static final String REQUEST_ATTR_HANDLED_ASYNC

Internal request attribute defining whether a request was handled asynchronously. If this attribute is not present, it means synchronous

See Also:

Constant Field Values

REQUEST_ATTR_SCOPE_CREATED

public static final String REQUEST_ATTR_SCOPE_CREATED

Internal request attribute defining whether a request scope was created or re-used

See Also:

Constant Field Values

Constructor Detail

AbstractXServlet

public AbstractXServlet()

Constructor.

Method Detail

handlerRegistry

@Nonnull
 @ReturnsMutableObject
protected final XServletHandlerRegistry handlerRegistry()

Returns:

The handler registry for HTTP method to handler registration. Never null.

filterLowLevelList

@Nonnull
 @ReturnsMutableObject
protected final com.helger.commons.collection.impl.ICommonsList<IXServletLowLevelFilter> filterLowLevelList()

Returns:

The internal filter list where custom filters can be added. Never null.

filterHighLevelList

@Nonnull
 @ReturnsMutableObject
protected final com.helger.commons.collection.impl.ICommonsList<IXServletHighLevelFilter> filterHighLevelList()

Returns:

The internal filter list where custom filters can be added. Never null.

exceptionHandler

@Nonnull
 @ReturnsMutableObject
protected final com.helger.commons.callback.CallbackList<IXServletExceptionHandler> exceptionHandler()

Returns:

The internal exception handler list. Never null.

settings

public final XServletSettings settings()

Returns:

Settings for this servlet. May not be null.

getServletStatusMgr

@Nonnull
protected final ServletStatusManager getServletStatusMgr()

Returns:

The servlet status manager stored in the constructor. Never null.

log

public final void log(String sMsg)

Overrides:

log in class javax.servlet.GenericServlet

log

public final void log(String sMsg,
                      Throwable t)

Overrides:

log in class javax.servlet.GenericServlet

init

public final void init(@Nonnull
                       javax.servlet.ServletConfig aSC)
                throws javax.servlet.ServletException

A final overload of "init". Overload "init" instead.

Specified by:

init in interface javax.servlet.Servlet

Overrides:

init in class javax.servlet.GenericServlet

Throws:

javax.servlet.ServletException

destroy

@OverridingMethodsMustInvokeSuper
public final void destroy()

Specified by:

destroy in interface javax.servlet.Servlet

Overrides:

destroy in class javax.servlet.GenericServlet

logInvalidRequestSetup

@OverrideOnDemand
protected void logInvalidRequestSetup(@Nonnull
                                                         String sMsg,
                                                         @Nonnull
                                                         javax.servlet.http.HttpServletRequest aHttpRequest)

This method logs errors, in case a HttpServletRequest object is missing basic information or uses unsupported values for e.g. HTTP version and HTTP method.

Parameters:

sMsg - The concrete message to emit. May not be null.

aHttpRequest - The current HTTP request. May not be null.

service

protected final void service(@Nonnull
                             javax.servlet.http.HttpServletRequest aHttpRequest,
                             @Nonnull
                             javax.servlet.http.HttpServletResponse aHttpResponse)
                      throws javax.servlet.ServletException,
                             IOException

Dispatches client requests to the protected service method. There's no need to override this method.

Overrides:

service in class javax.servlet.http.HttpServlet

Parameters:

aHttpRequest - the HttpServletRequest object that contains the request the client made of the servlet

aHttpResponse - the HttpServletResponse object that contains the response the servlet returns to the client

Throws:

IOException - if an input or output error occurs while the servlet is handling the HTTP request

javax.servlet.ServletException - if the HTTP request cannot be handled

See Also:

Servlet.service(javax.servlet.ServletRequest, javax.servlet.ServletResponse)

service

public final void service(@Nonnull
                          javax.servlet.ServletRequest req,
                          @Nonnull
                          javax.servlet.ServletResponse res)
                   throws javax.servlet.ServletException,
                          IOException

Specified by:

service in interface javax.servlet.Servlet

Overrides:

service in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException

toString

public String toString()

Overrides:

toString in class Object