com.zentense.step2.util
Class Location

java.lang.Object
  com.zentense.step2.util.Location

public class Location
extends java.lang.Object

This class manipulates URL locations: you can forward to a new location, or just go back, save a URL and restore it afterwards, or cypher URLs. The global variable url is initialized when a new session begins with a new instance of Location.

This class also stores a stack of visited URL locations in this session. Each request is saved except if the request parameter 'forward' is present.

Version:

$Revision: 1.11 $

Author:

Jose R. Cabanes

Nested Class Summary

class

Location.URL

Constructor Summary

Location()
Empty constructor

Location(RequestRuntime vm)
Constructs the location and saves current page

Method Summary

void	back() Goes to previous URL (goes back!)
void	back(int seq) Goes to previous URL (goes back!)
java.lang.String	cypher(RequestRuntime vm, java.lang.String url) Cyphers a URL
java.lang.String	decypher(java.lang.String url) Decyphers a URL
static void	forward(java.lang.String url) Forwards to another page in this session
static void	forwardExternal(RequestRuntime vm, java.lang.String url) Forwards to a URL outside this session.
java.lang.String	getBackURL() Gets previous URL (the one you would go if you would click on back button).
java.lang.String	getCheckpointURL() Gets checkpoint URL (URL that was saved with save method)
java.lang.String	getCurrentURL() Gets the 'current' URL.
java.lang.String	getHREF(java.lang.String name)
int	getSequence() Gets current sequence number
Location.URL	getURL(HttpServletRequest req)
void	initCypher(HttpServletRequest req) Creates private key for cyphering URLs
java.lang.String	popRequest() Removes last request from the location stack
void	pushRequest(HttpServletRequest req) Used internayly by 2step: pushes a request into the location stack
void	refresh() Refreshes current URL
void	refresh(int seq) Reloads a URL
void	restore() Restores a previously saved location
void	save(HttpServletRequest req) Saves current url, so it could be restored with restore in the future
void	save(HttpServletRequest req, java.lang.String params) Saves current url, so it could be restored with restore.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Location

public Location()

Empty constructor

Location

public Location(RequestRuntime vm)

Constructs the location and saves current page

Parameters:

req - Servlet request whose parameters will be saved

Method Detail

getCurrentURL

public final java.lang.String getCurrentURL()

Gets the 'current' URL. In fact gets the previous URL. Suppose this case: there is a list of items and a link that change list order and then the same page must be rendered. In that case this method may be used for rendering the list again from the action that has changed list order.

Returns:

URL parameters

getBackURL

public final java.lang.String getBackURL()

Gets previous URL (the one you would go if you would click on back button). In fact it returns the URL two places ago in the locations stack. This is this way because it is supposed that the request that calls this method pushes the locations stack

Returns:

URL parameters

getCheckpointURL

public final java.lang.String getCheckpointURL()

Gets checkpoint URL (URL that was saved with save method)

Returns:

URL parameters

save

public final void save(HttpServletRequest req,
                       java.lang.String params)

Saves current url, so it could be restored with restore.

Parameters:

req - Servlet request whose parameters will be saved

params - Extra params to be appended to the URL

save

public final void save(HttpServletRequest req)

Saves current url, so it could be restored with restore in the future

Parameters:

req - Servlet request whose parameters will be saved

getURL

public final Location.URL getURL(HttpServletRequest req)

pushRequest

public final void pushRequest(HttpServletRequest req)

Used internayly by 2step: pushes a request into the location stack

Parameters:

req - Request to be pushed

popRequest

public final java.lang.String popRequest()

Removes last request from the location stack

restore

public final void restore()
                   throws java.lang.Exception

Restores a previously saved location

Parameters:

vm - A RequestRuntime instance

Throws:

java.lang.Exception - If forward fails

refresh

public final void refresh()
                   throws java.lang.Exception

Refreshes current URL

Parameters:

vm - A RequestRuntime instance

Throws:

java.lang.Exception - If forward fails

refresh

public final void refresh(int seq)
                   throws java.lang.Exception

Reloads a URL

Parameters:

vm - A RequestRuntime instance

seq - Sequence number of URL to be refreshed

Throws:

java.lang.Exception - If forward fails

back

public final void back()
                throws java.lang.Exception

Goes to previous URL (goes back!)

Parameters:

vm - A RequestRuntime instance

Throws:

java.lang.Exception - If forward fails

back

public final void back(int seq)
                throws java.lang.Exception

Goes to previous URL (goes back!)

Parameters:

vm - A RequestRuntime instance

seq - Sequence number of URL from where go back

Throws:

java.lang.Exception - If forward fails

forward

public static final void forward(java.lang.String url)
                          throws java.lang.Exception

Forwards to another page in this session

Parameters:

vm - A RequestRuntime instance

url - URL where to go to

Throws:

java.lang.Exception - If forward fails

forwardExternal

public static final void forwardExternal(RequestRuntime vm,
                                         java.lang.String url)
                                  throws java.lang.Exception

Forwards to a URL outside this session.

Parameters:

vm - A RequestRuntime instance

url - URL where to go to

Throws:

java.lang.Exception - If forward fails

getSequence

public final int getSequence()

Gets current sequence number

Returns:

Sequence number

initCypher

public final void initCypher(HttpServletRequest req)

Creates private key for cyphering URLs

Parameters:

req - servlet request

cypher

public final java.lang.String cypher(RequestRuntime vm,
                                     java.lang.String url)

Cyphers a URL

Parameters:

vm - A RequestRuntime instance

url - URL to cypher

Returns:

Cyphered URL

decypher

public final java.lang.String decypher(java.lang.String url)

Decyphers a URL

Parameters:

url - Cyphered URL

Returns:

Original URL

getHREF

public final java.lang.String getHREF(java.lang.String name)