Class ReplaceFilter

  • All Implemented Interfaces:
    Filter, Handler

    public class ReplaceFilter
    extends java.lang.Object
    implements Filter
    Filter to replace current content with a static form, or template. This should be called the TemplateFilter, but that name's already taken. The content is replaced by the template lock-stock-and-barrel. Typically, an upstream filter has extracted the relevent parts of the content, and a down-stream filter will combine it with the template. The filename to use for the template is computed at each request, so it may be modified dynamically. The following server properties are used:
    type
    Text subtype of content to filter. Defaults to "html"
    debug
    If set, the template is re-read each time. Otherwise a cached copy is used.
    fileName
    Name of the file to use as the form or template. The file is searched for as a Resource if not found in the filesystem.
    root
    The document root used to find the template file. If not found, "root" with no prefix is used instead.
    Version:
    2.2
    Author:
    Stephen Uhler
    • Constructor Summary

      Constructors 
      Constructor Description
      ReplaceFilter()  
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      byte[] filter​(Request request, MimeHeaders headers, byte[] content)
      Grab the template file name, Read in the file, and deliver it as content.
      boolean init​(Server server, java.lang.String prefix)
      Initializes the handler.
      boolean respond​(Request request)
      This is the request object before the content was fetched
      boolean shouldFilter​(Request request, MimeHeaders headers)
      Only replace text documents
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • ReplaceFilter

        public ReplaceFilter()
    • Method Detail

      • init

        public boolean init​(Server server,
                            java.lang.String prefix)
        Description copied from interface: Handler
        Initializes the handler.
        Specified by:
        init in interface Handler
        Parameters:
        server - The HTTP server that created this Handler. Typical Handlers will use Server.props to obtain run-time configuration information.
        prefix - The handlers name. The string this Handler may prepend to all of the keys that it uses to extract configuration information from Server.props. This is set (by the Server and ChainHandler) to help avoid configuration parameter namespace collisions.
        Returns:
        true if this Handler initialized successfully, false otherwise. If false is returned, this Handler should not be used.
      • respond

        public boolean respond​(Request request)
        This is the request object before the content was fetched
        Specified by:
        respond in interface Handler
        Parameters:
        request - The Request object that represents the HTTP request.
        Returns:
        true if the request was handled. A request was handled if a response was supplied to the client, typically by calling Request.sendResponse() or Request.sendError.
      • shouldFilter

        public boolean shouldFilter​(Request request,
                                    MimeHeaders headers)
        Only replace text documents
        Specified by:
        shouldFilter in interface Filter
        Parameters:
        request - The in-progress HTTP request.
        headers - The MIME headers generated by the wrapped Handler.
        Returns:
        true if this filter would like to examine and possibly rewrite the content, false otherwise.
      • filter

        public byte[] filter​(Request request,
                             MimeHeaders headers,
                             byte[] content)
        Grab the template file name, Read in the file, and deliver it as content.
        Specified by:
        filter in interface Filter
        Parameters:
        request - The finished HTTP request.
        headers - The MIME headers generated by the Handler.
        content - The output from the Handler that this Filter may rewrite.
        Returns:
        The rewritten content. The Filter may return the original content unchanged. The Filter may return null to indicate that the FilterHandler should stop processing the request and should not return any content to the client.