public final class CommandResolver extends Object
Resolves special pages, JSPs and Commands on behalf of a WikiEngine. CommandResolver will automatically resolve page names with singular/plural variants. It can also detect the correct Command based on parameters supplied in an HTTP request, or due to the JSP being accessed.
CommandResolver's static findCommand(String) method is
the simplest method; it looks up and returns the Command matching
a supplied wiki context. For example, looking up the request context
view returns PageCommand.VIEW. Use this method
to obtain static Command instances that aren't targeted at a particular
page or group.
For more complex lookups in which the caller supplies an HTTP
request, findCommand(HttpServletRequest, String) will
look up and return the correct Command. The String parameter
defaultContext supplies the request context to use
if it cannot be detected. However, note that the default wiki
context may be over-ridden if the request was for a "special page."
For example, suppose the WikiEngine's properties specify a
special page called UserPrefs
that redirects to UserPreferences.jsp. The ordinary
lookup method findCommand(String) using a supplied
context view would return PageCommand.VIEW. But
the findCommand(HttpServletRequest, String) method,
when passed the same context (view) and an HTTP request
containing the page parameter value UserPrefs,
will instead return WikiCommand.PREFS.
| Constructor and Description |
|---|
CommandResolver(WikiEngine engine,
Properties properties)
Constructs a CommandResolver for a given WikiEngine.
|
| Modifier and Type | Method and Description |
|---|---|
protected Command |
extractCommandFromPath(javax.servlet.http.HttpServletRequest request)
Extracts a Command based on the JSP path of an HTTP request.
|
protected String |
extractPageFromParameter(String requestContext,
javax.servlet.http.HttpServletRequest request)
Determines the correct wiki page based on a supplied request context and
HTTP request.
|
Command |
findCommand(javax.servlet.http.HttpServletRequest request,
String defaultContext)
Attempts to locate a Command for a supplied wiki context and HTTP
request, incorporating the correct WikiPage into the command if reqiured.
|
static Command |
findCommand(String context)
Attempts to locate a wiki command for a supplied request context.
|
String |
getFinalPageName(String page)
Returns the correct page name, or
null, if no such page can be found. |
String |
getSpecialPageReference(String page)
If the page is a special page, this method returns a direct URL to that
page; otherwise, it returns
null. |
protected WikiPage |
resolvePage(javax.servlet.http.HttpServletRequest request,
String page)
Looks up and returns the correct, versioned WikiPage based on a supplied
page name and optional
version parameter passed in an HTTP
request. |
protected boolean |
simplePageExists(String page)
Determines whether a "page" exists by examining the list of special pages
and querying the page manager.
|
public CommandResolver(WikiEngine engine, Properties properties)
engine - the wiki engineproperties - the properties used to initialize the wikipublic static Command findCommand(String context)
AbstractCommand.allCommands() and
return the one whose requestContext matches the
supplied context. If the supplied context does not resolve to a known
Command, this method throws an IllegalArgumentException.context - the request contextpublic Command findCommand(javax.servlet.http.HttpServletRequest request, String defaultContext)
Attempts to locate a Command for a supplied wiki context and HTTP
request, incorporating the correct WikiPage into the command if reqiured.
This method will first determine what page the user requested by
delegating to extractPageFromParameter(String, HttpServletRequest). If
this page equates to a special page, we return the Command
corresponding to that page. Otherwise, this method simply returns the
Command for the supplied request context.
The reason this method attempts to resolve against special pages is because some of them resolve to contexts that may be different from the one supplied. For example, a VIEW request context for the special page "UserPreferences" should return a PREFS context instead.
When the caller supplies a request context and HTTP request that
specifies an actual wiki page (rather than a special page), this method
will return a "targeted" Command that includes the resolved WikiPage
as the target. (See resolvePage(HttpServletRequest, String)
for the resolution algorithm). Specifically, the Command will
return a non-null value for its AbstractCommand.getTarget() method.
Note: if this method determines that the Command is the VIEW PageCommand, then the Command returned will always be targeted to the front page.
request - the HTTP request; if null, delegates
to findCommand(String)defaultContext - the request context to use by defaultpublic String getFinalPageName(String page) throws ProviderException
Returns the correct page name, or null, if no such page can be found.
Aliases are considered.
In some cases, page names can refer to other pages. For example, when you have matchEnglishPlurals set, then a page name "Foobars" will be transformed into "Foobar", should a page "Foobars" not exist, but the page "Foobar" would. This method gives you the correct page name to refer to.
This facility can also be used to rewrite any page name, for example, by using aliases. It can also be used to check the existence of any page.
page - the page name.null, if the page does not exist.ProviderException - if the underlyng page provider that locates pages
throws an exceptionpublic String getSpecialPageReference(String page)
If the page is a special page, this method returns a direct URL to that
page; otherwise, it returns null.
Special pages are non-existant references to other pages. For example, you could define a special page reference "RecentChanges" which would always be redirected to "RecentChanges.jsp" instead of trying to find a Wiki page called "RecentChanges".
page - the page name ro search fornullprotected Command extractCommandFromPath(javax.servlet.http.HttpServletRequest request)
getJSP()
value, that Command is returned.request - the HTTP requestnull if not foundprotected String extractPageFromParameter(String requestContext, javax.servlet.http.HttpServletRequest request)
URLConstructor. If a page name was
passed in the request, return the correct name after taking into account
potential plural matches.null, attempt to see
if a "special page" was intended by examining the servlet path. For
example, the request path "/UserPreferences.jsp" will resolve to
"UserPreferences."nullrequestContext - the request contextrequest - the HTTP requestprotected WikiPage resolvePage(javax.servlet.http.HttpServletRequest request, String page)
version parameter passed in an HTTP
request. If the version parameter does not exist in the
request, the latest version is returned.request - the HTTP requestpage - the name of the page to look up; this page must existprotected boolean simplePageExists(String page) throws ProviderException
page - the page to seektrue if the page exists, false
otherwiseProviderException - if the underlyng page provider that locates pages
throws an exceptionCopyright © 2001-2019 The Apache Software Foundation. All rights reserved.