Package org.restlet.routing

Class Redirector

  • All Implemented Interfaces:
    Uniform
    public class Redirector
extends Restlet
    Rewrites URIs then redirects the call or the client to a new destination. There are various redirection modes that you can choose from: client-side redirections (MODE_CLIENT_FOUND, MODE_CLIENT_PERMANENT, MODE_CLIENT_SEE_OTHER, MODE_CLIENT_TEMPORARY) or server-side redirections, similar to a reverse proxy ( MODE_SERVER_OUTBOUND and MODE_SERVER_INBOUND).

    When setting the redirection URIs, you can also used special URI variables to reuse most properties from the original request as well as URI template variables. For a complete list of properties, please see the Resolver class. For example "/target?referer={fi}" would redirect to the relative URI, inserting the referrer URI as a query parameter.

    To create a reverse proxy, a typically configuration will use the MODE_SERVER_OUTBOUND constant and a target URI like "http://targetHost/targetRootPath/{rr}" to ensure that all child URIs are properly redirected as well, "rr" appending the remaining part of the current request URI that hasn't been routed yet.

    Concurrency note: instances of this class or its subclasses can be invoked by several threads at the same time and therefore must be thread-safe. You should be especially careful when storing state in member variables.
    Author:
    Jerome Louvel
    See Also:
    Template, User Guide - URI rewriting and redirection

    • Field Detail

      • MODE_SERVER_INBOUND

        public static final int MODE_SERVER_INBOUND
        In this mode, the call is sent to Context.getServerDispatcher(). Once the selected client connector has completed the request handling, the response is normally returned to the client. In this case, you can view the Redirector as acting as a transparent proxy Restlet. Note: this is a server-side redirection.

        Warning: remember to add the required connectors to the parent Component and to declare them in the list of required connectors on the Application.getConnectorService() property.

        Note that in this mode, the headers of HTTP requests, stored in the request's attributes, are removed before dispatching. Also, when a HTTP response comes back the headers are also removed. You can control this behavior by setting the headersCleaning attribute or by overriding the rewrite(Request) or rewrite(Response).
        See Also:
        Context.getServerDispatcher(), Constant Field Values

      • headersCleaning

        protected volatile boolean headersCleaning
        Indicates if all headers of HTTP requests stored in the request's attributes, must be removed before the redirection. If set to true, it removes all headers, otherwise it keeps only the extension (or non HTTP standard) headers

      • mode

        protected volatile int mode
        The redirection mode.

      • targetTemplate

        protected volatile java.lang.String targetTemplate
        The target URI pattern.

    • Constructor Detail

      • Redirector

        public Redirector​(Context context,
                  java.lang.String targetTemplate)
        Constructor for the client dispatcher mode.
        Parameters:
        context - The context.
        targetTemplate - The template to build the target URI.
        See Also:
        Template

      • Redirector

        public Redirector​(Context context,
                  java.lang.String targetPattern,
                  int mode)
        Constructor.
        Parameters:
        context - The context.
        targetPattern - The pattern to build the target URI (using StringTemplate syntax and the CallModel for variables).
        mode - The redirection mode.

    • Method Detail

      • getMode

        public int getMode()
        Returns the redirection mode.
        Returns:
        The redirection mode.

      • getTargetRef

        protected Reference getTargetRef​(Request request,
                                 Response response)
        Returns the target reference to redirect to by automatically resolving URI template variables found using the Template class using the request and response as data models.
        Parameters:
        request - The request to handle.
        response - The response to update.
        Returns:
        The target reference to redirect to.

      • getTargetTemplate

        public java.lang.String getTargetTemplate()
        Returns the target URI pattern.
        Returns:
        The target URI pattern.

      • handle

        public void handle​(Request request,
                   Response response)
        Handles a call by redirecting using the selected redirection mode.
        Specified by:
        handle in interface Uniform
        Overrides:
        handle in class Restlet
        Parameters:
        request - The request to handle.
        response - The response to update.

      • inboundServerRedirect

        protected void inboundServerRedirect​(Reference targetRef,
                                     Request request,
                                     Response response)
        Redirects a given call to a target reference. In the default implementation, the request HTTP headers, stored in the request's attributes, are removed before dispatching. After dispatching, the response HTTP headers are also removed to prevent conflicts with the main call.
        Parameters:
        targetRef - The target reference with URI variables resolved.
        request - The request to handle.
        response - The response to update.

      • isHeadersCleaning

        public boolean isHeadersCleaning()
        Indicates if the headers must be cleaned.
        Returns:
        True if the headers must be cleaned.

      • outboundServerRedirect

        protected void outboundServerRedirect​(Reference targetRef,
                                      Request request,
                                      Response response)
        Redirects a given call to a target reference. In the default implementation, the request HTTP headers, stored in the request's attributes, are removed before dispatching. After dispatching, the response HTTP headers are also removed to prevent conflicts with the main call.
        Parameters:
        targetRef - The target reference with URI variables resolved.
        request - The request to handle.
        response - The response to update.

      • rewrite

        protected Representation rewrite​(Representation initialEntity)
        Optionally rewrites the response entity returned in the MODE_SERVER_INBOUND and MODE_SERVER_OUTBOUND modes. By default, it just returns the initial entity without any modification.
        Parameters:
        initialEntity - The initial entity returned.
        Returns:
        The rewritten entity.

      • rewrite

        protected void rewrite​(Request initialRequest)
        Optionally updates the request sent in the MODE_SERVER_INBOUND and MODE_SERVER_OUTBOUND modes. By default, it leverages the headersCleaning attribute in order to clean the headers: if set to true, it removes all headers, otherwise it keeps only the extension (or non HTTP standard) headers
        Parameters:
        initialRequest - The initial request returned.

      • rewrite

        protected void rewrite​(Response initialResponse)
        Optionally updates the response sent in the MODE_SERVER_INBOUND and MODE_SERVER_OUTBOUND modes. By default, it leverages the headersCleaning attribute in order to clean the headers: if set to true, it removes all headers, otherwise it keeps only the extension (or non HTTP standard) headers
        Parameters:
        initialResponse - The initial response returned.

      • rewriteLocation

        public void rewriteLocation​(Request request,
                            Response response)
        Rewrite the location of the response, and the Location of the entity, if any.
        Parameters:
        request - The request to handle.
        response - The response to update.

      • serverRedirect

        protected void serverRedirect​(Restlet next,
                              Reference targetRef,
                              Request request,
                              Response response)
        Redirects a given call on the server-side to a next Restlet with a given target reference. In the default implementation, the request HTTP headers, stored in the request's attributes, are removed before dispatching. After dispatching, the response HTTP headers are also removed to prevent conflicts with the main call.
        Parameters:
        next - The next Restlet to forward the call to.
        targetRef - The target reference with URI variables resolved.
        request - The request to handle.
        response - The response to update.

      • setHeadersCleaning

        public void setHeadersCleaning​(boolean headersCleaning)
        Indicates if the headers must be cleaned.
        Parameters:
        headersCleaning - True if the headers must be cleaned.

      • setMode

        public void setMode​(int mode)
        Sets the redirection mode.
        Parameters:
        mode - The redirection mode.

      • setTargetTemplate

        public void setTargetTemplate​(java.lang.String targetTemplate)
        Sets the target URI pattern.
        Parameters:
        targetTemplate - The target URI pattern.