org.zkoss.zk.au.http
Class DHtmlUpdateServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.zkoss.zk.au.http.DHtmlUpdateServlet

All Implemented Interfaces:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public class DHtmlUpdateServlet
extends javax.servlet.http.HttpServlet

Used to receive command from the server and send result back to client. Though it is called DHtmlUpdateServlet, it is used to serve all kind of HTTP-based clients, including ajax (HTML+Ajax), mil (Mobile Interactive Language), and others (see Desktop.getDeviceType().

Init parameters:

compress

It specifies whether to compress the output if the browser supports the compression (Accept-Encoding).

extension0, extension1...

It specifies an AU extension (AuExtension). The extension0 parameter specifies the first AU extension, the extension1 parameter the second AU extension, and so on.
The syntax of the value is
/prefix=class

By default: there are three extensions are associated with "/upload", "/view" and "/dropupload" (see addAuExtension(org.zkoss.zk.ui.WebApp, java.lang.String, org.zkoss.zk.au.http.AuExtension). Also, "/web" is reserved. Don't associate to any AU extension.

Author:

tomyeh

See Also:

Serialized Form

Constructor Summary

DHtmlUpdateServlet()

Method Summary

AuExtension	addAuExtension(java.lang.String prefix, AuExtension extension) Adds an AU extension and associates it with the specified prefix.
static AuExtension	addAuExtension(WebApp wapp, java.lang.String prefix, AuExtension extension) Adds an AU extension and associates it with the specified prefix, even before DHtmlUpdateServlet is started.
void	denoteSessionTimeout(WebApp wapp, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, boolean compress) Denote HTTP 410 Session timeout response
void	destroy()
protected void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
protected void	doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
AuExtension	getAuExtension(java.lang.String prefix) Returns the AU extension associated with the specified prefix, or null if no AU extension associated.
static AuExtension	getAuExtension(WebApp wapp, java.lang.String prefix) Returns the AU extension that is associated the specified prefix.
protected Desktop	getDesktop(Session sess, java.lang.String dtid) Returns the desktop of the specified ID, or null if not found.
protected long	getLastModified(javax.servlet.http.HttpServletRequest request)
static DHtmlUpdateServlet	getUpdateServlet(WebApp wapp) Returns the update servlet of the specified application, or null if not loaded yet.
void	init()
boolean	isCompress()
void	process(Session sess, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, boolean compress) Process asynchronous update requests from the client.
protected Desktop	recoverDesktop(Session sess, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, WebAppCtrl wappc, java.lang.String dtid) Recovers the desktop if possible.
void	setCompress(boolean compress)

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPut, doTrace, service, service

Methods inherited from class javax.servlet.GenericServlet

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

Constructor Detail

DHtmlUpdateServlet

public DHtmlUpdateServlet()

Method Detail

getUpdateServlet

public static DHtmlUpdateServlet getUpdateServlet(WebApp wapp)

Returns the update servlet of the specified application, or null if not loaded yet. Note: if the update servlet is not loaded, it returns null.

Since:

3.0.2

init

public void init()
          throws javax.servlet.ServletException

Overrides:

init in class javax.servlet.GenericServlet

Throws:

javax.servlet.ServletException

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Servlet

Overrides:

destroy in class javax.servlet.GenericServlet

isCompress

public boolean isCompress()

setCompress

public void setCompress(boolean compress)

getAuExtension

public static final AuExtension getAuExtension(WebApp wapp,
                                               java.lang.String prefix)

Returns the AU extension that is associated the specified prefix.

Since:

5.0.0

addAuExtension

public static final AuExtension addAuExtension(WebApp wapp,
                                               java.lang.String prefix,
                                               AuExtension extension)
                                        throws javax.servlet.ServletException

Adds an AU extension and associates it with the specified prefix, even before DHtmlUpdateServlet is started.

Unlike addAuExtension(String, AuExtension), it can be called even if the update servlet is not loaded yet (getUpdateServlet(org.zkoss.zk.ui.WebApp) returns null).

If there was an AU extension associated with the same name, the the old AU extension will be replaced.

Throws:

javax.servlet.ServletException

Since:

5.0.0

addAuExtension

public AuExtension addAuExtension(java.lang.String prefix,
                                  AuExtension extension)
                           throws javax.servlet.ServletException

Adds an AU extension and associates it with the specified prefix.

If there was an AU extension associated with the same name, the the old AU extension will be replaced.

If you want to add an Au extension, even before DHtmlUpdateServlet is started, use addAuExtension(WebApp, String, AuExtension) instead.

Parameters:

prefix - the prefix. It must start with "/", but it cannot be "/" nor "/web" (which are reserved).

extension - the AU extension (never null).

Returns:

the previous AU extension associated with the specified prefix, or null if the prefix was not associated before.

Throws:

javax.servlet.ServletException

Since:

5.0.0

See Also:

addAuExtension(WebApp,String,AuExtension)

getAuExtension

public AuExtension getAuExtension(java.lang.String prefix)

Returns the AU extension associated with the specified prefix, or null if no AU extension associated.

Since:

5.0.0

getLastModified

protected long getLastModified(javax.servlet.http.HttpServletRequest request)

Overrides:

getLastModified in class javax.servlet.http.HttpServlet

doGet

protected void doGet(javax.servlet.http.HttpServletRequest request,
                     javax.servlet.http.HttpServletResponse response)
              throws javax.servlet.ServletException,
                     java.io.IOException

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

java.io.IOException

doPost

protected void doPost(javax.servlet.http.HttpServletRequest request,
                      javax.servlet.http.HttpServletResponse response)
               throws javax.servlet.ServletException,
                      java.io.IOException

Overrides:

doPost in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

java.io.IOException

denoteSessionTimeout

public void denoteSessionTimeout(WebApp wapp,
                                 javax.servlet.http.HttpServletRequest request,
                                 javax.servlet.http.HttpServletResponse response,
                                 boolean compress)
                          throws javax.servlet.ServletException,
                                 java.io.IOException

Denote HTTP 410 Session timeout response

Throws:

javax.servlet.ServletException

java.io.IOException

Since:

6.5.2

process

public void process(Session sess,
                    javax.servlet.http.HttpServletRequest request,
                    javax.servlet.http.HttpServletResponse response,
                    boolean compress)
             throws javax.servlet.ServletException,
                    java.io.IOException

Process asynchronous update requests from the client.

Throws:

javax.servlet.ServletException

java.io.IOException

Since:

3.0.0

getDesktop

protected Desktop getDesktop(Session sess,
                             java.lang.String dtid)

Returns the desktop of the specified ID, or null if not found. If null is returned, recoverDesktop(org.zkoss.zk.ui.Session, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, org.zkoss.zk.ui.sys.WebAppCtrl, java.lang.String) will be invoked.

Parameters:

sess - the session (never null)

dtid - the desktop ID to look for

Since:

5.0.3

recoverDesktop

protected Desktop recoverDesktop(Session sess,
                                 javax.servlet.http.HttpServletRequest request,
                                 javax.servlet.http.HttpServletResponse response,
                                 WebAppCtrl wappc,
                                 java.lang.String dtid)

Recovers the desktop if possible. It is called if getDesktop(org.zkoss.zk.ui.Session, java.lang.String) returns null.

The default implementation will look for any failover manager (FailoverManager) is registered, and forward the invocation to it if found.

Returns:

the recovered desktop, or null if failed to recover

Since:

5.0.3