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, AjaxServletMBean

public class AjaxServlet
extends javax.servlet.http.HttpServlet
implements AjaxServletMBean

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 java.util.Set	blockedIPs
private ContextNode	contextNode
private int	maxInactiveInterval
private int	maxUserSessions We support additional admin sessions
private JmxMBeanHandle	mbeanHandle My JMX registration
private java.util.Properties	props
private static long	serialVersionUID

Constructor Summary

AjaxServlet()

Method Summary

void	add(java.lang.String sessionId, BlasterInstance blasterInstance)
void	addBlockedIP(java.lang.String ip)
java.lang.String	cleanupOldSessionsKeepGivenAmount(int maxSessions, java.lang.String notificationText, boolean creationTimestamp)
private void	cleanupSession(javax.servlet.http.HttpServletRequest req)
void	clearBlockedIPs()
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[]	getBlockedIPs()
private int	getConfProp(java.lang.String key, int def)
ContextNode	getContextNode()
java.lang.String	getInfo(javax.servlet.http.HttpServletRequest req)
java.lang.String	getInfo(javax.servlet.http.HttpServletRequest req, boolean more, boolean all)
private java.util.Locale	getLocale(javax.servlet.http.HttpServletRequest request)
int	getMaxUserSessions()
int	getNumBlasterInstances()
boolean	getReqProp(javax.servlet.http.HttpServletRequest req, java.lang.String key, boolean def) Access a boolean parameter.
java.lang.String	getServletInfo()
private java.lang.String	getText(javax.servlet.http.HttpServletRequest request, java.lang.String key, java.lang.String defaultVal, java.lang.String arg1, java.lang.String arg2) Support for internationalization of exceptions.
private BlasterInstance	hasBlasterInstance(javax.servlet.http.HttpServletRequest req)
void	init(javax.servlet.ServletConfig conf)
boolean	isBlockedIP(java.lang.String ip)
void	log(java.lang.String text)
boolean	maxUserSessionsReached(javax.servlet.http.HttpServletRequest req)
void	removeBlasterInstance(java.lang.String sessionId)
void	setMaxUserSessions(int maxUserSessions)

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

props

private java.util.Properties props

maxInactiveInterval

private int maxInactiveInterval

contextNode

private ContextNode contextNode

mbeanHandle

private JmxMBeanHandle mbeanHandle

My JMX registration

blockedIPs

private java.util.Set blockedIPs

blasterInstanceMap

private java.util.Map blasterInstanceMap

key is the browser sessionId

maxUserSessions

private int maxUserSessions

We support additional admin sessions

Constructor Detail

AjaxServlet

public AjaxServlet()

Method Detail

getConfProp

private int getConfProp(java.lang.String key,
                        int def)

init

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

Specified by:

init in interface javax.servlet.Servlet

Overrides:

init in class javax.servlet.GenericServlet

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

Overrides:

doPost in class javax.servlet.http.HttpServlet

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)

getLocale

private java.util.Locale getLocale(javax.servlet.http.HttpServletRequest request)

getText

private java.lang.String getText(javax.servlet.http.HttpServletRequest request,
                                 java.lang.String key,
                                 java.lang.String defaultVal,
                                 java.lang.String arg1,
                                 java.lang.String arg2)

Support for internationalization of exceptions. Throw e.g. ajaxServlet_de.properties into the war CLASSPATH

Parameters:

request -

key - The key to lookup the text

defaultVal - The text to take if not found

arg1 - Can be null

arg2 - Can be null

Returns:

The localized text depending on the browser language

cleanupSession

private void cleanupSession(javax.servlet.http.HttpServletRequest req)

getReqProp

public boolean getReqProp(javax.servlet.http.HttpServletRequest req,
                          java.lang.String key,
                          boolean def)

Access a boolean parameter.

Parameters:

req -

key - The URL key

def - The default if not found

Returns:

boolean support without value: "&admin&name=xy" will return true for admin

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

Overrides:

doGet in class javax.servlet.http.HttpServlet

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)

add

public void add(java.lang.String sessionId,
                BlasterInstance blasterInstance)

removeBlasterInstance

public void removeBlasterInstance(java.lang.String sessionId)

hasBlasterInstance

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

Parameters:

req -

Returns:

null if not known

Throws:

XmlBlasterException

getBlasterInstance

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

Throws:

XmlBlasterException

getServletInfo

public java.lang.String getServletInfo()

Specified by:

getServletInfo in interface javax.servlet.Servlet

Overrides:

getServletInfo in class javax.servlet.GenericServlet

getNumBlasterInstances

public int getNumBlasterInstances()

Specified by:

getNumBlasterInstances in interface AjaxServletMBean

getBlasterInstances

public BlasterInstance[] getBlasterInstances()

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Servlet

Overrides:

destroy in class javax.servlet.GenericServlet

log

public void log(java.lang.String text)

Overrides:

log in class javax.servlet.GenericServlet

getContextNode

public ContextNode getContextNode()

cleanupOldSessionsKeepGivenAmount

public java.lang.String cleanupOldSessionsKeepGivenAmount(int maxSessions,
                                                          java.lang.String notificationText,
                                                          boolean creationTimestamp)

Specified by:

cleanupOldSessionsKeepGivenAmount in interface AjaxServletMBean

isBlockedIP

public boolean isBlockedIP(java.lang.String ip)

addBlockedIP

public void addBlockedIP(java.lang.String ip)

clearBlockedIPs

public void clearBlockedIPs()

Specified by:

clearBlockedIPs in interface AjaxServletMBean

getBlockedIPs

public java.lang.String[] getBlockedIPs()

Specified by:

getBlockedIPs in interface AjaxServletMBean

getMaxUserSessions

public int getMaxUserSessions()

Specified by:

getMaxUserSessions in interface AjaxServletMBean

setMaxUserSessions

public void setMaxUserSessions(int maxUserSessions)

Specified by:

setMaxUserSessions in interface AjaxServletMBean

maxUserSessionsReached

public boolean maxUserSessionsReached(javax.servlet.http.HttpServletRequest req)