Re: How to clean objects in user's session
Older versions of tomcat have their Enumeration from
session.getAttributeNames() backed by an Iterator. So if a change is made you
get the ConcurrentModificationException. I know tomcat 5 does not have this
problem but I don't know about tomcat4. Since your using 4.1.24 - I am
guessing the change was not backported.
The easiest solution is to call invalidate - but this also usually logs the
user out too so it may not be acceptable. Once a session is invalidated - it
can't be used anymore for getting and setting stuff.
The alternative is clone/copy the Enumeration (probably the hard way by an
extra iteration) - then iterate through the copied version. The copied
version has no relation to the list so you can clear its atributes without
the exception.
-Tim
Imran Balkhi wrote:
Hello,
Our application is divided into multiple vertical views (ie, multiple
company). User can work in only one vertical slice at a time (ie, abc
company). Currently users have to logout and login again to change the
vertical. There is a business requirement to provide ability to switch
verticals without the need to logout and relogin. Here are my options.
1) invalidate the session object and create a new session. I am not sure
if this is possible with logout and relogin routine. We are using our own
authentication.
2) remove vertical specific objects from user's session. This option
seems to be less intrusive on users. However, I am not able to remove
objects Here is the test code
if((userPreference.getCurrentCompanyId() 0)
userPreference.getCurrentCompanyId() != companyId){
Enumeration sessionAttributes = session.getAttributeNames();
while(sessionAttributes.hasMoreElements()) {
String name = (String) sessionAttributes.nextElement();
if ((name.compareTo(userSession) != 0) //exclude vertical
independent objects
(name.compareTo(style) != 0)
(name.compareTo(moduleID) != 0)
(name.compareTo(listNavigatorMap) != 0))
logger.debug (Name : + name);
session.removeAttribute(name);
}
}
}
I am getting ConcurrentModificationException, detials are in attached file.
Can any one point out what am I doing wrong or let me know if there are
better ways to get to goal.
Thanks,
Imran
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RE: How to clean objects in user's session
Thanks Tim, your suggestion works. Here is the changed code
Enumeration sessionAttributes = session.getAttributeNames();
ArrayList list = new ArrayList();
while(sessionAttributes.hasMoreElements()) {
String name = (String) sessionAttributes.nextElement();
if ((name.compareTo(userSession) != 0)
(name.compareTo(style) != 0)
(name.compareTo(moduleID) != 0)
(name.compareTo(listNavigatorMap) != 0))
list.add(name);
}
}
Iterator iList = list.iterator();
while(iList.hasNext()) {
session.removeAttribute((String) iList.next());
}
Imran
-Original Message-
From: Tim Funk [mailto:[EMAIL PROTECTED]
Sent: Saturday, July 19, 2003 5:48 AM
To: Tomcat Users List
Subject: Re: How to clean objects in user's session
Older versions of tomcat have their Enumeration from
session.getAttributeNames() backed by an Iterator. So if a change is made
you
get the ConcurrentModificationException. I know tomcat 5 does not have this
problem but I don't know about tomcat4. Since your using 4.1.24 - I am
guessing the change was not backported.
The easiest solution is to call invalidate - but this also usually logs the
user out too so it may not be acceptable. Once a session is invalidated - it
can't be used anymore for getting and setting stuff.
The alternative is clone/copy the Enumeration (probably the hard way by an
extra iteration) - then iterate through the copied version. The copied
version has no relation to the list so you can clear its atributes without
the exception.
-Tim
Imran Balkhi wrote:
Hello,
Our application is divided into multiple vertical views (ie, multiple
company). User can work in only one vertical slice at a time (ie, abc
company). Currently users have to logout and login again to change the
vertical. There is a business requirement to provide ability to switch
verticals without the need to logout and relogin. Here are my options.
1) invalidate the session object and create a new session. I am not sure
if this is possible with logout and relogin routine. We are using our own
authentication.
2) remove vertical specific objects from user's session. This option
seems to be less intrusive on users. However, I am not able to remove
objects Here is the test code
if((userPreference.getCurrentCompanyId() 0)
userPreference.getCurrentCompanyId() != companyId){
Enumeration sessionAttributes = session.getAttributeNames();
while(sessionAttributes.hasMoreElements()) {
String name = (String) sessionAttributes.nextElement();
if ((name.compareTo(userSession) != 0) //exclude vertical
independent objects
(name.compareTo(style) != 0)
(name.compareTo(moduleID) != 0)
(name.compareTo(listNavigatorMap) != 0))
logger.debug (Name : + name);
session.removeAttribute(name);
}
}
}
I am getting ConcurrentModificationException, detials are in attached
file.
Can any one point out what am I doing wrong or let me know if there are
better ways to get to goal.
Thanks,
Imran
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
How to clean objects in user's session
Hello,
Our application is divided into multiple vertical views (ie, multiple
company). User can work in only one vertical slice at a time (ie, abc
company). Currently users have to logout and login again to change the
vertical. There is a business requirement to provide ability to switch
verticals without the need to logout and relogin. Here are my options.
1) invalidate the session object and create a new session. I am not sure
if this is possible with logout and relogin routine. We are using our own
authentication.
2) remove vertical specific objects from user's session. This option
seems to be less intrusive on users. However, I am not able to remove
objects Here is the test code
if((userPreference.getCurrentCompanyId() 0)
userPreference.getCurrentCompanyId() != companyId){
Enumeration sessionAttributes = session.getAttributeNames();
while(sessionAttributes.hasMoreElements()) {
String name = (String) sessionAttributes.nextElement();
if ((name.compareTo(userSession) != 0) //exclude vertical
independent objects
(name.compareTo(style) != 0)
(name.compareTo(moduleID) != 0)
(name.compareTo(listNavigatorMap) != 0))
logger.debug (Name : + name);
session.removeAttribute(name);
}
}
}
I am getting ConcurrentModificationException, detials are in attached file.
Can any one point out what am I doing wrong or let me know if there are
better ways to get to goal.
Thanks,
Imran
htmlheadtitleApache Tomcat/4.1.24 - Error
report/titleSTYLE!--H1{font-family : sans-serif,Arial,Tahoma;color :
white;background-color : #0086b2;} H3{font-family : sans-serif,Arial,Tahoma;color :
white;background-color : #0086b2;} BODY{font-family : sans-serif,Arial,Tahoma;color :
black;background-color : white;} B{color : white;background-color : #0086b2;} HR{color
: #0086b2;} --/STYLE /headbodyh1HTTP Status 500 - /h1HR size=1
noshadepbtype/b Exception report/ppbmessage/b
u/u/ppbdescription/b uThe server encountered an internal error () that
prevented it from fulfilling this request./u/ppbexception/b
preorg.apache.jasper.JasperException
at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:254)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2415)
at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at
org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:223)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:594)
