Package sunlabs.brazil.handler

Class MultiProxyHandler

  • All Implemented Interfaces:
    Handler
    public class MultiProxyHandler
extends GenericProxyHandler
    Handler for permitting multiple cross connected virtual web sites. Each handler instance adds its prefix and destination to a static hashtable so the URL rewrite rules rewrite all of them correctly.

    The GenericProxyHandler rewrites all of the links in each wepage to point back to the local. machine. Using this handler, if multiple virtual websites are configured, then links in one site that point to other virtual web sites are rewritten to point locally as well.

    For example, suppose we have 2 MultiProxyhandlers A and B configured into the server as:


      A.prefix=/foo/
      A.host=www.foo.com
      B.prefix=/bar/
      B.host=www.bar.com.
    A local request for /foo/bar/test.html will fetch http://www.foo.com/bar/test.html. If the result is an html page, then any links in that page that resolve to www.foo.com/... will be rewritten to the local server as /foo/..., and any links that points to www.bar.com/... will be rewritten to /bar/....
    Version:
    2.3, 07/03/21
    Author:
    Stephen Uhler

    • Field Detail

      • proxies

        public static java.util.Hashtable proxies
        Holds all proxy -> prefix mappings for this server.

    • Constructor Detail

      • MultiProxyHandler

        public MultiProxyHandler()

    • Method Detail

      • init

        public boolean init​(Server server,
                    java.lang.String prefix)
        Initialize this handler. Add rewrite mapping into the global table. If any "virtual" web sites reference other "virtual" web sites, then rewrite the links accordingly.
        Specified by:
        init in interface Handler
        Overrides:
        init in class GenericProxyHandler
        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)
                throws java.io.IOException
        Description copied from class: GenericProxyHandler
        If this is one of "our" url's, fetch the document from the destination server, and return it as if it was local.
        Specified by:
        respond in interface Handler
        Overrides:
        respond in class GenericProxyHandler
        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.
        Throws:
        java.io.IOException - if there was an I/O error while sending the response to the client. Typically, in that case, the Server will (try to) send an error message to the client and then close the client's connection.

        The IOException should not be used to silently ignore problems such as being unable to access some server-side resource (for example getting a FileNotFoundException due to not being able to open a file). In that case, the Handler's duty is to turn that IOException into a HTTP response indicating, in this case, that a file could not be found.