com.groiss.servlet
Class Dispatcher

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          com.groiss.servlet.Dispatcher

All Implemented Interfaces:

Public, Serializable, Servlet, ServletConfig

public class Dispatcher
extends HttpServlet
implements Public

This servlet calls methods via reflection.

See Also:

Serialized Form

Field Summary

static com.groiss.servlet.impl.OldRequestHandler

oldHandler

Constructor Summary

Dispatcher()

Method Summary

static void	addModificationInfo(HttpServletRequest req, HttpServletResponse resp, long lastModified, Locale locale) adds some header fields to the response so we can determine modification on the next request adds an ETag and a Last-Modified-Header
static Locale	getBrowserLocale(HttpServletRequest req) Read the locale from the browser.
static String	getContextPath() Returns the context path of this application.
static Method	getMethod(String m) Return the method from a string containing the class and method name, syntax: classname "." methodname
static long	getRequestCount() Get the request count for statistics.
void	init()
static boolean	isModifiedSince(HttpServletRequest req, HttpServletResponse resp, long lastModified, Locale l) returns true if the requested resource has been modified since the last request the following methods are used: check the ETag-header check the if-modified-since - header
static void	reloadClasses() Reload the method cache the Dispatcher holds.
void	service(HttpServletRequest req, HttpServletResponse res)
static void	setExpiresImmediatelyForGuest(HttpServletRequest req, HttpServletResponse res) if no user is currently logged in, it's required, that some resources are not cached, so the user gets the new files as soon he loggs in
static Locale	setLocale(HttpServletRequest req) Set the locale to the ThreadContext.
void	setPathInfo(String pi) This method is useful if you call the dispatcher servlet from a method already called by the dispatcher.
static void	writeToResp(HttpServletResponse res, String pageStr)

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

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

Field Detail

oldHandler

public static com.groiss.servlet.impl.OldRequestHandler oldHandler

Constructor Detail

Dispatcher

public Dispatcher()

Method Detail

init

public void init()

Overrides:

init in class GenericServlet

setPathInfo

public void setPathInfo(String pi)

This method is useful if you call the dispatcher servlet from a method already called by the dispatcher.

Parameters:

pi - s string defining the method to call in form classname "." methodname

service

public void service(HttpServletRequest req,
                    HttpServletResponse res)
             throws IOException,
                    UnsupportedEncodingException

Overrides:

service in class HttpServlet

Throws:

IOException

UnsupportedEncodingException

writeToResp

public static void writeToResp(HttpServletResponse res,
                               String pageStr)
                        throws Exception

Throws:

Exception

getRequestCount

public static long getRequestCount()

Get the request count for statistics.

Returns:

the counter, starting with 0 on startup.

getMethod

public static Method getMethod(String m)
                        throws Exception

Return the method from a string containing the class and method name, syntax: classname "." methodname

Parameters:

m -

Returns:

the method object

Throws:

Exception - an exception is thrown if the string describes not a method with the signature necessary for the dispatcher.

reloadClasses

public static void reloadClasses()

Reload the method cache the Dispatcher holds.

setLocale

public static Locale setLocale(HttpServletRequest req)

Set the locale to the ThreadContext.

getBrowserLocale

public static Locale getBrowserLocale(HttpServletRequest req)

Read the locale from the browser.

getContextPath

public static String getContextPath()

Returns the context path of this application.

addModificationInfo

public static void addModificationInfo(HttpServletRequest req,
                                       HttpServletResponse resp,
                                       long lastModified,
                                       Locale locale)

adds some header fields to the response so we can determine modification on the next request
adds an ETag and a Last-Modified-Header

Parameters:

req - request

resp - response

lastModified - last modification timestamp

locale - the current locale

isModifiedSince

public static boolean isModifiedSince(HttpServletRequest req,
                                      HttpServletResponse resp,
                                      long lastModified,
                                      Locale l)

returns true if the requested resource has been modified since the last request
the following methods are used:

1. check the ETag-header
2. check the if-modified-since - header

Parameters:

req - request

resp - response

lastModified - last modification timestamp

l - the current locale

Returns:

true if the resource has been modified since the the last request, false otherwise

setExpiresImmediatelyForGuest

public static void setExpiresImmediatelyForGuest(HttpServletRequest req,
                                                 HttpServletResponse res)

if no user is currently logged in, it's required, that some resources are not cached, so the user gets the new files as soon he loggs in

Parameters:

req -

res -