Package edu.uiuc.ncsa.security.servlet

Interface Presentable

public interface Presentable

Created by Jeff Gaynor
on 10/20/11 at 2:02 PM

A filter for servlets that display something.

Servlets that present something to a user (e.g. those serving up JSP) implement this interface. The contract is then that in the main doGet or doPost methods, prepare is invoked before the start of every call and present at the very end. Generally servlets should not touch the response output stream before handing it off, though be sure to consult any documentation.

Method Summary

Modifier and Type	Method	Description
void	handleError(PresentableState state, Throwable t)	Handle and error.
void	prepare(PresentableState state)	This is invoked before the main processing for this servlet.
void	present(PresentableState state)	This is invoked after the main processing for the servlet.

Method Detail

prepare

void prepare(PresentableState state)
      throws Throwable

This is invoked before the main processing for this servlet. The aim is that all presentation-specific processing will be done here, e.g. setting form values before displaying them.

Parameters:

state -

Throws:

Throwable

present

void present(PresentableState state)
      throws Throwable

This is invoked after the main processing for the servlet. This contains the code that actually displays the results of processing to the user.

Parameters:

state -

Throws:

Throwable

handleError

void handleError(PresentableState state,
                 Throwable t)
          throws IOException,
                 javax.servlet.ServletException

Handle and error. Generally this means show an error page to be displayed when there is a problem. If this is due to an exception, the exception handler will pass along the exception as an attribute named exception in the request.

Throws:

IOException

javax.servlet.ServletException