org.zkoss.web.servlet
Class GenericFilter

java.lang.Object
  extended by org.zkoss.web.servlet.GenericFilter
All Implemented Interfaces:
javax.servlet.Filter

public abstract class GenericFilter
extends java.lang.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
protected  javax.servlet.FilterConfig _config
           
 
Constructor Summary
protected GenericFilter()
           
 
Method Summary
 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, java.lang.String uri)
          Forward to the specified page.
protected  void forward(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, java.lang.String uri, java.util.Map params, int mode)
          Forward to the specified page with parameters.
 java.lang.String getFilterName()
          Returns the filter's name.
 java.lang.String getInitParameter(java.lang.String name)
          Returns a String containing the value of the named initialization parameter, or null if the parameter does not exist.
 java.util.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, java.lang.String uri)
          Includes the specified page.
protected  void include(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, java.lang.String uri, java.util.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, java.lang.String page, java.util.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)

getInitParameter

public final java.lang.String getInitParameter(java.lang.String name)
Returns a String containing the value of the named initialization parameter, or null if the parameter does not exist.


getInitParameterNames

public final java.util.Enumeration getInitParameterNames()
Returns a String containing the value of the named initialization parameter, or null if the parameter does not exist.


getFilterName

public final java.lang.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,
                            java.lang.String page,
                            java.util.Map params,
                            int mode)
                     throws javax.servlet.ServletException,
                            java.io.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
java.io.IOException

forward

protected final void forward(javax.servlet.ServletRequest request,
                             javax.servlet.ServletResponse response,
                             java.lang.String uri)
                      throws javax.servlet.ServletException,
                             java.io.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
java.io.IOException
Since:
3.6.3

forward

protected final void forward(javax.servlet.ServletRequest request,
                             javax.servlet.ServletResponse response,
                             java.lang.String uri,
                             java.util.Map params,
                             int mode)
                      throws javax.servlet.ServletException,
                             java.io.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
java.io.IOException
Since:
3.6.3

include

protected final void include(javax.servlet.ServletRequest request,
                             javax.servlet.ServletResponse response,
                             java.lang.String uri)
                      throws javax.servlet.ServletException,
                             java.io.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
java.io.IOException
Since:
3.6.3

include

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

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


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