org.zkoss.web.servlet

Class GenericFilter

java.lang.Object

org.zkoss.web.servlet.GenericFilter

All Implemented Interfaces:

javax.servlet.Filter

public abstract class GenericFilter
extends Object
implements javax.servlet.Filter

A generic class to help implementing servlet filter. Its role is like javax.servlet.GenericServlet to javax.servlet.Servlet.

Author:

tomyeh

Field Summary

Fields

Modifier and Type	Field and Description
protected javax.servlet.FilterConfig	_config

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	GenericFilter()

Method Summary

Methods

Modifier and Type	Method and Description
void	destroy() Called by the web container to indicate to a filter that it is being taken out of service.
protected void	forward(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, String uri) Forward to the specified page.
protected void	forward(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, String uri, Map params, int mode) Forward to the specified page with parameters.
String	getFilterName() Returns the filter's name.
String	getInitParameter(String name) Returns a String containing the value of the named initialization parameter, or null if the parameter does not exist.
Enumeration	getInitParameterNames() Returns a String containing the value of the named initialization parameter, or null if the parameter does not exist.
javax.servlet.ServletContext	getServletContext() Returns the servlet context in which this filter is running.
protected void	include(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, String uri) Includes the specified page.
protected void	include(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, String uri, Map params, int mode) Includes the specified page with parameters.
protected void	init() A convenience method which can be overridden so that there's no need to call super.init(config).
void	init(javax.servlet.FilterConfig config) Called by the web container to indicate to a filter that it is being placed into service.
protected void	sendRedirect(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, String page, Map params, int mode) Redirects to another page.

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.servlet.Filter

doFilter

Field Detail

_config

protected javax.servlet.FilterConfig _config

Constructor Detail

GenericFilter

protected GenericFilter()

Method Detail

init

protected void init()
             throws javax.servlet.ServletException

A convenience method which can be overridden so that there's no need to call super.init(config).

Throws:

javax.servlet.ServletException

See Also:

init(FilterConfig)

init

public final void init(javax.servlet.FilterConfig config)
                throws javax.servlet.ServletException

Called by the web container to indicate to a filter that it is being placed into service. However, deriving class usually doesn't override this method but overriding init().

Specified by:

init in interface javax.servlet.Filter

Throws:

javax.servlet.ServletException

getInitParameter

public final String getInitParameter(String name)

Returns a String containing the value of the named initialization parameter, or null if the parameter does not exist.

getInitParameterNames

public final Enumeration getInitParameterNames()

Returns a String containing the value of the named initialization parameter, or null if the parameter does not exist.

getFilterName

public final String getFilterName()

Returns the filter's name.

getServletContext

public final javax.servlet.ServletContext getServletContext()

Returns the servlet context in which this filter is running.

sendRedirect

protected void sendRedirect(javax.servlet.http.HttpServletRequest request,
                javax.servlet.http.HttpServletResponse response,
                String page,
                Map params,
                int mode)
                     throws javax.servlet.ServletException,
                            IOException

Redirects to another page. Note: it supports only HTTP.

It resolves "*" contained in URI, if any, to the proper Locale, and the browser code. Refer to Servlets.locate(ServletContext, ServletRequest, String, Locator) for details.

Parameters:

page - the page's uri; null to denote the same request

mode - one of Servlets.OVERWRITE_URI, Servlets.IGNORE_PARAM, and Servlets.APPEND_PARAM. It defines how to handle if both uri and params contains the same parameter. mode is used only if both uri contains query string and params is not empty.

Throws:

javax.servlet.ServletException

IOException

forward

protected final void forward(javax.servlet.ServletRequest request,
           javax.servlet.ServletResponse response,
           String uri)
                      throws javax.servlet.ServletException,
                             IOException

Forward to the specified page.

It resolves "*" contained in URI, if any, to the proper Locale, and the browser code. Refer to Servlets.locate(ServletContext, ServletRequest, String, Locator) for details.

Throws:

javax.servlet.ServletException

IOException

Since:

3.6.3

forward

protected final void forward(javax.servlet.ServletRequest request,
           javax.servlet.ServletResponse response,
           String uri,
           Map params,
           int mode)
                      throws javax.servlet.ServletException,
                             IOException

Forward to the specified page with parameters.

It resolves "*" contained in URI, if any, to the proper Locale, and the browser code. Refer to Servlets.locate(ServletContext, ServletRequest, String, Locator) for details.

Throws:

javax.servlet.ServletException

IOException

Since:

3.6.3

include

protected final void include(javax.servlet.ServletRequest request,
           javax.servlet.ServletResponse response,
           String uri)
                      throws javax.servlet.ServletException,
                             IOException

Includes the specified page.

It resolves "*" contained in URI, if any, to the proper Locale, and the browser code. Refer to Servlets.locate(ServletContext, ServletRequest, String, Locator) for details.

Throws:

javax.servlet.ServletException

IOException

Since:

3.6.3

include

protected final void include(javax.servlet.ServletRequest request,
           javax.servlet.ServletResponse response,
           String uri,
           Map params,
           int mode)
                      throws javax.servlet.ServletException,
                             IOException

Includes the specified page with parameters.

It resolves "*" contained in URI, if any, to the proper Locale, and the browser code. Refer to Servlets.locate(ServletContext, ServletRequest, String, Locator) for details.

Throws:

javax.servlet.ServletException

IOException

Since:

3.6.3

destroy

public void destroy()

Called by the web container to indicate to a filter that it is being taken out of service.

This implementation does nothing.

Specified by:

destroy in interface javax.servlet.Filter