Package org.restlet.routing

Class Redirector

java.lang.Object
org.restlet.Restlet
org.restlet.routing.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:

  • Field Details

    • MODE_CLIENT_FOUND

      public static final int MODE_CLIENT_FOUND
      In this mode, the client is simply redirected to the URI generated from the target URI pattern using the Status.REDIRECTION_FOUND status. Note: this is a client-side redirection.
      See Also:

    • MODE_CLIENT_PERMANENT

      public static final int MODE_CLIENT_PERMANENT
      In this mode, the client is permanently redirected to the URI generated from the target URI pattern, using the Status.REDIRECTION_PERMANENT status. Note: this is a client-side redirection.
      See Also:

    • MODE_CLIENT_SEE_OTHER

      public static final int MODE_CLIENT_SEE_OTHER
      In this mode, the client is simply redirected to the URI generated from the target URI pattern using the Status.REDIRECTION_SEE_OTHER status. Note: this is a client-side redirection.
      See Also:

    • MODE_CLIENT_TEMPORARY

      public static final int MODE_CLIENT_TEMPORARY
      In this mode, the client is temporarily redirected to the URI generated from the target URI pattern using the Status.REDIRECTION_TEMPORARY status. Note: this is a client-side redirection.
      See Also:

    • 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:

    • MODE_SERVER_OUTBOUND

      public static final int MODE_SERVER_OUTBOUND
      In this mode, the call is sent to Application.getOutboundRoot() or if null to Context.getClientDispatcher(). 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 server-side proxy. 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:

    • 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 String targetTemplate
      The target URI pattern.

  • Constructor Details

    • Redirector

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

    • Redirector

      public Redirector(Context context, 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 Details

    • 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 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(String targetTemplate)
      Sets the target URI pattern.
      Parameters:
      targetTemplate - The target URI pattern.