Interface View

All Known Subinterfaces:
All Known Implementing Classes:
AbstractAtomFeedView, AbstractFeedView, AbstractJackson2View, AbstractPdfStamperView, AbstractPdfView, AbstractRssFeedView, AbstractTemplateView, AbstractUrlBasedView, AbstractView, AbstractXlsView, AbstractXlsxStreamingView, AbstractXlsxView, FreeMarkerView, GroovyMarkupView, InternalResourceView, JstlView, MappingJackson2JsonView, MappingJackson2XmlView, MarshallingView, RedirectView, ScriptTemplateView, XsltView

public interface View
MVC View for a web interaction. Implementations are responsible for rendering content, and exposing the model. A single view exposes multiple model attributes.

This class and the MVC approach associated with it is discussed in Chapter 12 of Expert One-On-One J2EE Design and Development by Rod Johnson (Wrox, 2002).

View implementations may differ widely. An obvious implementation would be JSP-based. Other implementations might be XSLT-based, or use an HTML generation library. This interface is designed to avoid restricting the range of possible implementations.

Views should be beans. They are likely to be instantiated as beans by a ViewResolver. As this interface is stateless, view implementations should be thread-safe.

Rod Johnson, Arjen Poutsma, Rossen Stoyanchev
See Also:
  • Field Details


      static final String RESPONSE_STATUS_ATTRIBUTE
      Name of the HttpServletRequest attribute that contains the response status code.

      Note: This attribute is not required to be supported by all View implementations.


      static final String PATH_VARIABLES
      Name of the HttpServletRequest attribute that contains a Map with path variables. The map consists of String-based URI template variable names as keys and their corresponding Object-based values -- extracted from segments of the URL and type converted.

      Note: This attribute is not required to be supported by all View implementations.


      static final String SELECTED_CONTENT_TYPE
      The MediaType selected during content negotiation, which may be more specific than the one the View is configured with. For example: "application/vnd.example-v1+xml" vs "application/*+xml".
  • Method Details

    • getContentType

      @Nullable default String getContentType()
      Return the content type of the view, if predetermined.

      Can be used to check the view's content type upfront, i.e. before an actual rendering attempt.

      the content type String (optionally including a character set), or null if not predetermined
    • render

      void render(@Nullable Map<String,?> model, HttpServletRequest request, HttpServletResponse response) throws Exception
      Render the view given the specified model.

      The first step will be preparing the request: In the JSP case, this would mean setting model objects as request attributes. The second step will be the actual rendering of the view, for example including the JSP via a RequestDispatcher.

      model - a Map with name Strings as keys and corresponding model objects as values (Map can also be null in case of empty model)
      request - current HTTP request
      response - he HTTP response we are building
      Exception - if rendering failed