Class 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

      Fields 
      Modifier and Type Field Description
      protected javax.servlet.FilterConfig _config  
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected GenericFilter()  
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method 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, 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)
      • 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 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