Package org.springframework.webflow.mvc.servlet

Interface FlowHandler

All Known Implementing Classes:
AbstractFlowHandler
public interface FlowHandler
A controller helper used for customizing access to a single flow definition in a Servlet enviroment. This helper is used to:
  1. Launch executions of that flow with data in the execution input map
  2. Handle outcomes reached by that flow in a custom manner
  3. Handle unhandled exceptions dealing with that flow in a custom manner.
Such a handler can be visually thought of as a "flow reference" on a Garrett IA diagram. It holds a reference to the flow id to launch, how to provision its input, how to process its outcomes, and how to handle uncaught exceptions.
Author:
Keith Donald

  • Method Summary

    Modifier and Type
    Method
    Description
    MutableAttributeMap<Object>
    createExecutionInputMap(jakarta.servlet.http.HttpServletRequest request)
    Creates the flow execution input map to pass to a new instance of the flow being started.
    String
    getFlowId()
    Returns the id of the flow handled by this handler.
    String
    handleException(FlowException e, jakarta.servlet.http.HttpServletRequest request, jakarta.servlet.http.HttpServletResponse response)
    Handles a flow exception that was not handled by the Web Flow system.
    String
    handleExecutionOutcome(FlowExecutionOutcome outcome, jakarta.servlet.http.HttpServletRequest request, jakarta.servlet.http.HttpServletResponse response)
    Handles a specific flow execution outcome.

  • Method Details

    • getFlowId

      String getFlowId()
      Returns the id of the flow handled by this handler. Used by a Controller to load the flow definition. Optional.
      Returns:
      the flow id, or null if the flow id should be determined by the caller

    • createExecutionInputMap

      MutableAttributeMap<Object> createExecutionInputMap(jakarta.servlet.http.HttpServletRequest request)
      Creates the flow execution input map to pass to a new instance of the flow being started. Used by a Controller to launch the flow execution with the correct input.
      Parameters:
      request - the current request
      Returns:
      the input map, or null if the contents of the input map should be determined by the caller

    • handleExecutionOutcome

      String handleExecutionOutcome(FlowExecutionOutcome outcome, jakarta.servlet.http.HttpServletRequest request, jakarta.servlet.http.HttpServletResponse response)
      Handles a specific flow execution outcome. Used by a Controller to get the location of the resource to redirect to after the outcome is handled.

      The following prefixes are supported for qualifying the returned location string:

      • servletRelative: - the location is relative to the current servlet
      • contextRelative: - the location is relative to the current web application
      • serverRelative: - the location is relative to the server root
      If the returned location is a path with no prefix, for example "/hotels/index", it is treated as relative to the current servlet by default. Fully qualified URLs beginning with http:// or https:// may also be returned.

      For servlet-relative, context-relative, and server-relative URLs, a leading slash is optional.

      Parameters:
      outcome - the outcome that was reached
      request - the current request
      response - the current response
      Returns:
      the location of the new resource to redirect to, or null if the execution outcome was not handled and should be handled by the caller

    • handleException

      String handleException(FlowException e, jakarta.servlet.http.HttpServletRequest request, jakarta.servlet.http.HttpServletResponse response)
      Handles a flow exception that was not handled by the Web Flow system. Used by a Controller to handle a specific type of exception dealing with this flow in a custom manner.
      Parameters:
      e - the unhandled exception originating from Spring Web Flow. May be thrown by the flow execution itself or the flow executor system if no execution could be restored.
      request - the current request
      response - the current response
      Returns:
      the location of the error resource to redirect to, or null if the execution outcome was not handled and should be handled by the caller