org.xmlBlaster.protocol.http.ajax
Class AjaxServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.xmlBlaster.protocol.http.ajax.AjaxServlet

All Implemented Interfaces:

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

public class AjaxServlet

extends javax.servlet.http.HttpServlet

This servlet supports requests from a browser, it queries the topic given by "gpsTopicId" configuration which needs to contain GPS coordinates (published for example by a PDA).

Use xmlBlaster/demo/http/gps.html to display the coordinates in a map.

Callback messages are send as xml to the browser:

 <xmlBlasterResponse>
  <update>
    <qos>...</qos>
    <key>...</key>
    <content>...</content>
  </update>
 </xmlBlasterResponse>
 

Author:

Marcel Ruff xmlBlaster@marcelruff.info 2007

See Also:

Serialized Form

Field Summary

private java.util.Map	blasterInstanceMap key is the browser sessionId
private static java.util.logging.Logger	log
private int	maxInactiveInterval
private java.util.Properties	props
private static long	serialVersionUID

Fields inherited from class javax.servlet.http.HttpServlet

Fields inherited from class javax.servlet.GenericServlet

Constructor Summary

AjaxServlet()

Method Summary

void	destroy()
void	doGet(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse res) ServletSessionTimeout according to specification: The default timeout period for sessions is defined by the servlet container and can be obtained via the getMaxInactiveInterval method of the HttpSession interface.
void	doPost(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse res)
boolean	get(javax.servlet.http.HttpServletRequest req, java.lang.String key, boolean defaultVal)
int	get(javax.servlet.http.HttpServletRequest req, java.lang.String key, int defaultVal)
long	get(javax.servlet.http.HttpServletRequest req, java.lang.String key, long defaultVal)
private BlasterInstance	getBlasterInstance(javax.servlet.http.HttpServletRequest req)
BlasterInstance[]	getBlasterInstances()
java.lang.String	getInfo(javax.servlet.http.HttpServletRequest req)
java.lang.String	getInfo(javax.servlet.http.HttpServletRequest req, boolean more, boolean all)
java.lang.String	getServletInfo()
void	init(javax.servlet.ServletConfig conf)
void	log(java.lang.String text)

Methods inherited from class javax.servlet.http.HttpServlet

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

Methods inherited from class javax.servlet.GenericServlet

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

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

log

private static java.util.logging.Logger log

props

private java.util.Properties props

maxInactiveInterval

private int maxInactiveInterval

blasterInstanceMap

private java.util.Map blasterInstanceMap

key is the browser sessionId

Constructor Detail

AjaxServlet

public AjaxServlet()

Method Detail

init

public void init(javax.servlet.ServletConfig conf)
          throws javax.servlet.ServletException

Throws:

javax.servlet.ServletException

doPost

public void doPost(javax.servlet.http.HttpServletRequest req,
                   javax.servlet.http.HttpServletResponse res)
            throws javax.servlet.ServletException,
                   java.io.IOException

Throws:

javax.servlet.ServletException

java.io.IOException

getInfo

public java.lang.String getInfo(javax.servlet.http.HttpServletRequest req)

getInfo

public java.lang.String getInfo(javax.servlet.http.HttpServletRequest req,
                                boolean more,
                                boolean all)

doGet

public void doGet(javax.servlet.http.HttpServletRequest req,
                  javax.servlet.http.HttpServletResponse res)
           throws javax.servlet.ServletException,
                  java.io.IOException

 ServletSessionTimeout according to specification:
 The default timeout period for sessions is defined by the servlet container and
	can be obtained via the getMaxInactiveInterval method of the HttpSession
	interface. This timeout can be changed by the Developer using the
	setMaxInactiveInterval method of the HttpSession interface. The timeout
	periods used by these methods are defined in seconds. By definition, if the timeout
	period for a session is set to -1, the session will never expire.
 

We have set the maxInactiveInterval to 1800 sec in web.xml (30 min):

If no Ajax call arrives after the given timeout the servlet-session dies, as a browser user may choose to halt NMEA updates we must set this to a high enough value.

The web.xml setting <session-config> 30 </session-config> is overwritten by our maxInactiveInterval

Test: http://localhost:8080/watchee/ajax?ActionType=request&task=getRawPhoto&locationPictureId=5823&random=0.6236216717670112

Throws:

javax.servlet.ServletException

java.io.IOException

get

public boolean get(javax.servlet.http.HttpServletRequest req,
                   java.lang.String key,
                   boolean defaultVal)

get

public long get(javax.servlet.http.HttpServletRequest req,
                java.lang.String key,
                long defaultVal)

get

public int get(javax.servlet.http.HttpServletRequest req,
               java.lang.String key,
               int defaultVal)

getBlasterInstance

private BlasterInstance getBlasterInstance(javax.servlet.http.HttpServletRequest req)
                                    throws XmlBlasterException

Throws:

XmlBlasterException

getServletInfo

public java.lang.String getServletInfo()

getBlasterInstances

public BlasterInstance[] getBlasterInstances()

destroy

public void destroy()

log

public void log(java.lang.String text)