About JSP's application variables

Hi,
I want to use some XML files in my project for which i have got some URLs. Now there are two ways to use the files. The first is that i get these XML files from their particular URLs and store them into application variable, while the second way is, i save them into my disk and use it from disk only. Now i want to know, which one is the best solution.......storing in application variable or storing on disk?

Thanx for your suggestion...
I have around 10-15 MBs of XML files. I just want to
know the access time of getting it from Disk or
getting it from application variable. Which one is
best in regards of access time?Well it depends on how you are trying to access it and what you are accessing. You could use the DOM parser which stores it in memory anyway or the SAX parser , or you could process it with XSLT.
Either ways, you can test the speed yourself. Just use a Java Probing tool to measure performance.

Similar Messages

How to Create and Use Application Variables in Java

I Have this need to have a common variable (Counter) for all the users(Sessions) accessing my Site witch is in JSP.
I think An Application Variable is the solution for my problem...
But I don't know how to use this. Even though I search the web for any tutorials or Examples could not fing any.
Could any one Please tell me or direct me to a site which has good information about this
Thanks In Advance!!!
Badsy.

// get the application object
public class myServlet extends HttpServlet
public void doGet(HttpServletRequest req,
HttpServletResponse res)
ServletContext application = getServletContext();
}

Storage capacity of a Application variable?

Hi All,
I want to display a common information to all the user.
The size of the text information(may consists of html content for formatting) may vary each time.
1) Is storing the information in application variable a better way?
2) What is the storage capacity of a Application variable?
3) Cookies storage capacity is 4k and restricts certain characters.Do Application/ Session variable have storage capacity or it restricts any character.
Regards,
Maha

Hello Friend,
If U are refering about the mem size of implicit Application varible in JSP.
Then i think U are refering to an Instance related to ServletContext.
If that is the case it enitrely depens on the webserver you are using.There would few option by which one can fix the cache size but again how to manage that cache space specified between ServletContext,HttpSession,HttpServletRequest and PageContext is entirely dependent upon webserver you are using.....
U can try referring the link below which is related to SUN-ONE Application server
http://docs.sun.com/source/816-7150-10/dwdeploy.html
and as far as restriction is concerned i don't think u would have restriction of storing any unicode charecters..... But i'm not completely sure abt it through.

Problem with application-variables - CFLOCK?

Hi,
i have a problem with my application. It is a multi-user
application with 100 parallel-users and CFMX 7.
The problem wich occures is with application variables. These
are mainly structs wich get filled onApplicationStart(). The
problem is, that the variables suddenly disappear, they are empty.
I have read about CFLock and found out, that it is necesseary
to use cflock. And i found out, that onApplicationStart does
correct locking automatically. That is where i do not understand
the problem. The variables get intialized correctly and in further
they only get read-access. Why can they be corrupted?
My other question about that is, wheather i need cflock for
all Read-Access to Application and Session-Variables, even if there
happens no writing to the variables?
Best Regards,
Andreas

> ?The element of position 2, of dimension 2, of an array
object used as part of
> an expression, cannot be found.?
> The array is in this case the struct.
Well, OK, that could be a problem. Arrays are not structs:
they are two
different things, are not interchangeable, and have
completely different
sets of functions to utilise them. You cannot treat a struct
as an array.
If CF is claiming your "struct" is an array, then it actually
*is* an
array, not a struct.
What's the line of code which is generating that error?
I suppose one could get this error if you have an array of
structs thus:
myArray
.key1
myArray.key2
(etc)
and you're trying to reference it with a numeric key rather
than by key
name, eg:
myArray
[n]
When n is an integer value, rather than a string (which
corresponds to the
name of the key).
> > Have you trapped the error, done a <cfdump>
of the application scope and
> > checked to see if it's the whole lot going awry, or
just some values?
> I have not used cfdump for it, because the server had to
be immediately
> restarted for our customers. But i think, that it is
not completely empty,
> because the index runs to pos2 of dimenstion2.
So does this not happen in your dev / testing environment?
> Will
> onApplicationStart() be called before? Or only if
onRequestStart() returns true?
I would ***-u-me that the application one would be called
before the
request one. It's pretty easy for you to test this though, I
should think?
(Sorry: for reasons beyond the scope of this conversation,
we're still
forced to use Application.cfm in our software, so I've only a
passing
knowledge of how Application.cfc works).
> Here is the code from onRequestStart()
> <cffunction name="onRequestStart"
returntype="boolean">
> <cfargument name="Requestedpage" required="yes" />
> <cfscript>
> var lFile = "/cargorent/Login.cfm";
> var iPosn = ListFindNoCase( lFile,
Arguments.Requestedpage );
> if( iPosn gt 0 )
> return true;
>
> if( NOT IsDefined( "session.user.Loginname" ) or
session.user.Loginname eq
> "" )
> {
> WriteOutput( "<p><p> The current user is no
longer valid, please log in
> again.</p></p>" & chr(10) & chr(13)
> WriteOutput( "<script
language=""javascript"">parent.location = ""
http://"
> & CGI.HTTP_HOST &
"/Login/Login.cfm"";</script>" );
> return false;
> }
>
> return true;
> </cfscript>
> </cffunction>
One thing I will say here is that I really think you should
be separating
your processing from your display. A function should do
processing. it
should pass that processing back to a CFM template which
should handle
whatever needs to be displayed on the browser. Although
that's nowt to do
with your current issue.
Adam

JSP and Instance Variables

I have some questions about JSP presentation (Interactive Component Call in Screenflow):
- Only BPM Objects are possible to be mapped in JSP?
- Is possible to map two or more BPM Objects to the JSP?
- What is the difference of mapping using the variable "attributes" in argument mapping and the option "Select BPM object variable" in main task of Interactive Component Call activity?

I seem to be having a similar problem.
If I include this fragment, for an instance variable called "contacts" which is a BPMObject of type "ITSSContactRequest".
<%
Object r = request.getAttribute("contacts");
Class cl = r.getClass();
out.println(cl.getName());
%>
I get the following output:
xobject.ITSSContactManagement.ITSSContactRequest
and I can access the object via reflection:
<%
Object r = request.getAttribute("contacts");
Class cl = r.getClass();
out.println(cl.getName());
Method getGeneralContacts = cl.getMethod("getGeneralContacts", null);
Object rv = getGeneralContacts.invoke(r);
%>
and access the rv variable accordingly.
However, if I try and cast the variable directly:
<%
Object r = request.getAttribute("contacts");
Class cl = r.getClass();
out.println(cl.getName());
xobject.ITSSContactManagement.ITSSContactRequest rq = (xobject.ITSSContactManagement.ITSSContactRequest)r;
%>
I get the following error message:
"The task could not be successfully executed. Reason: 'fuego.web.execution.exception.InternalForwardException: UnExpected error during internal forward process.'.
See log file for more information [Error code: workspace-1258985548580] "
The same error occurs if I try and import the object via
<%@ page import="xobject.ITSSContactManagement.ITSSContactRequest" %>
Thanks for any help.

Questions About JSP?

hi;
I am php devloper and I am learning Java now.
I am using NB6.1 , Tomcat 6.0 , J2ee 5.
I have some questions about devleoping web application with jsp.
1.What are
/WEB-INF/web.xml
/META-INF/context.xml
/META-INF/MANIFEST.MF
files that generated with NB.are important or optional.are auto generated or may I edit.
2.can I distribute my web application in non text format.How?
3.if I want to add some files to my application that its running in tomcat.how can i do that with out rebuild all.
thank you
Add to mtz1406's Reputation

thank you all for helping.
I will write more information about my questions may this help others:
*{ /WEB-INF/web.xml* - The +Web Application Deployment
Descriptor+ for your application. This is an XML file describing
the servlets and other components that make up your application,
along with any initialization parameters and container-managed
security constraints that you want the server to enforce for you.
This file is discussed in more detail in the following subsection.
As mentioned above, the <code>/WEB-INF/web.xml</code> file contains the
Web Application Deployment Descriptor for your application. As the filename
extension implies, this file is an XML document, and defines everything about
your application that a server needs to know (except the context path,
which is assigned by the system administrator when the application is
deployed).
The complete syntax and semantics for the deployment descriptor is defined
in Chapter 13 of the Servlet API Specification, version 2.3. Over time, it
is expected that development tools will be provided that create and edit the
deployment descriptor for you. In the meantime, to provide a starting point,
a [basic web.xml file|http://localhost:8080/docs/appdev/web.xml.txt]
is provided. This file includes comments that describe the purpose of each
included element.
NOTE - The Servlet Specification includes a Document
Type Descriptor (DTD) for the web application deployment descriptor, and
Tomcat 6 enforces the rules defined here when processing your application's
<code>/WEB-INF/web.xml</code> file. In particular, you must
enter your descriptor elements (such as <code><filter></code>,
<code><servlet></code>, and <code><servlet-mapping></code> in
the order defined by the DTD (see Section 13.3).
h4. } from tomcat documentation
Tomcat Context Descriptor
bq. A /META-INF/context.xml file can be used to define Tomcat specific \\ configuration options, such as loggers, data sources, session manager \\ configuration and more. This XML file must contain one Context element, which \\ will be considered as if it was the child of the Host element corresponding \\ to the Host to which the The Tomcat configuration documentation contains \\ information on the Context element.
}from tomcat documentation
but I still want more information about this question:
Q3: I want to distribute (sell to another organaization) without give sorce code in jsp files.So I want to precompile it to be just class files or jar files.
I want to use ant that become with netbeans 6.1.can anyone give me information about how to do that.
thank you again

About jsp tags..............

Pls help
I am studing about JSP
if we write code in scriptlet tag i.e. < % %>
code goes into service() method of servlet ,which is automatically created by jsp Engine
if we write code in declaration tag i.e. <%! %>
code goes outside service() method of servlet ,which is automatically
created by jsp Engine means at class level.
is their any tag so that jsp code goes into init() method of servlet ,which is automatically created by jsp Engine for that jsp

simple and straight u need to code init() method using <%! %> tags.. but in case JSP it has to be jspInit() method.
The jspInit method is called by the container once and only once for a servlet instance. As you might guess from its name it is used to do initial once only setup such as getting resources and initialising variables that are used in the JSP page. The jspInit method can be overridden within a JSP page with code like the following.
<%!
public void jspInit(){
/*getServletConfig is inherited */
ServletConfig config= getServletConfig();
%>REF : http://www.examulator.com/moodle/mod/resource/view.php?id=380
REGARDS,
RaHuL

Are application variables 'user specific'?

hi - i've got a feeling i may have done something stupid.
we have several domains all pointing to one application.
in application we look at the cgi.http_host to work out which
site the domain the user is expecting and then serve up customised
content accordingly.
only this is i've set put the customised content in
application scoped vars - is that a bad move?
eg. in application.cfm i have:
<cfif cgi.http_host eq 'www.redredred.com' >
<cfset application.message= "welcome - we love the colour
red" >
<cfelseif cgi.http_host eq 'www.blueblueblue.com' >
<cfset application.message= "welcome - to our site where
we love blue" >
<cfelse>
<cfset application.message= "welcome to our site (we love
all colours)" >
</cfif>
then in the index.cfm:
<cfoutput>#application.message#</cfouput>
is there a chance that by doing this someone who has visited
www.redredred.com will get a message about blue?

happysailingdude wrote:
>
> is there a chance that by doing this someone who has
visited www.redredred.com
> will get a message about blue?
>
Not only a chance, but there is something wrong if the person
does not
get this message, once the next user has set the variable to
blue.
Application variables are global to the application and will
be shared
by all users of that application. That is the designed and
desired
purpose of application variables.
In ColdFusion an application is defined by any template that
shares the
same 'name' as defined in either the name parameter of a
<cfapplication...> tag or the this.name property of an
Application.cfc file.
If all these web sites are using the same string for the
application
name then they share the same application scope and they will
all have
the same value for application.message. And this value will
be the
value set by the last visitor to any of the sites.
<cflock...> is not relevant to this issue. It will
prevent the variable
from being set at the exact same moment by multiple users on
multiple
sites, but it will not stop the value from changing
sequentially as
first one, then another user visits any of these sites and
changing the
value.
The solution to your problem is to set different application
scopes by
dynamically setting the application name. Thus each website
will be
separate and distinct applications with their own application
scope
variables and your system should behave the way desired.

Global Application variable

How do I set a global application variable in a Swing application?
Namely
MDI display opens a new window
new window sets a variable
close the new window and return to the MDI window
MDI window needs to use the variable.
Note: the new window is is its own class object.

What are you talking about?
Static variables are "global".
In some class (it does not really matter which) define
a static variable. O.K. now you have a "global"
variable.
Some people may say that this is "bad" programming
practice, but it is what you asked for.public static variables of public classes are 'global' in the sense you can refer to them if anywhere in an application. Public classes are also 'global' in this sense.
However, we don't call them global variables, they are class variables. A global variable is generally defined to be one that is associated with the running application. It has no context other than that. It can be used anywhere at any time without any qualifications. In other words, the are terrible.
I had to maintain an application that had 50 or so global variables. Some of these variables represented the exact same piece of information so it was cruicial during modifications to make sure that they were kept in sync. Don't use this type of design.

JSP Sample Application

We installed the SQLTAGLIB application from JSP sample application publish on TECHNET.
Compiled and Run it successfully.
Now we are trying to develop some Page using
sqltaglib.tld but while compiling,
on this line
<%@taglib uri="sqltaglib.tld" prefix="sql" %>
get this error message
[ Start of root element ]
pl. give the solution.
Thanks
null

Here is some info from the docs:
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Note the following requirements for using SQL tags:
Install the file ojsputil.jar and include it in your classpath. This file is provided with the OracleJSP installation.
Make sure the tag library description file, sqltaglib.tld, is deployed with the application and is in the location specified in the taglib directives of your JSP pages, such as in the following example:
<%@ taglib uri="/WEB-INF/sqltaglib.tld" prefix="sql" %>
For general information about JSP 1.1 tag library usage, including tag library description files and taglib directives, see "Standard Tag Library Framework".<HR></BLOCKQUOTE>
Please post follow-ups in the OTN Sample Code forum.
Thanks,
-rh
null

Same Application Variables name in different websites on the same server.

Hi,
I have two websites in the same server that use both their own Application.cfm file.
In each Application.cfm file is defined the application variable Application.DB
In website1 the Application.DB = DB1
In website2 the Application.DB = DB2
Since I'm studying Application.CFC solution, and I did read that application variables with same name have as scope the entire server ... I'm a bit worried. This happen also with Application.CFM ?

Since I'm studying Application.CFC solution, and I did read that application variables with same name have as scope the entire server ... I'm a bit worried. This happen also with Application.CFM ?
That's not quite how it works. Each application has its own name, and application.foo on one application (name) is a different variable from application.foo within a different application (name).
Reading these sections of the docs might help:
Configuring and using application variables:
http://help.adobe.com/en_US/ColdFusion/9.0/Developing/WSc3ff6d0ea77859461172e0811cbec0c35c -7fec.html
cfapplication:
http://help.adobe.com/en_US/ColdFusion/9.0/CFMLRef/WSc3ff6d0ea77859461172e0811cbec22c24-7d 69.html
About applications:
http://help.adobe.com/en_US/ColdFusion/9.0/Developing/WSc3ff6d0ea77859461172e0811cbec0b63c -7fda.html
Defining the application and its event handlers in Application.cfc:
http://help.adobe.com/en_US/ColdFusion/9.0/Developing/WSc3ff6d0ea77859461172e0811cbec22c24 -7d39.html
You should definitely be using Application.cfc, not Application.cfm, btw.
Adam
Adam

Monitor my jsp-servlet application through the jmx

heloo,
i am new in JMX. and i want to manage(or monitor) my jsp-servlet application. there lots of
servlets and jsp files. its is running in tomcat. i made simple demo application which
is given by oracle tutorial. but it is just for one interface and its implementations so how
can i monitor my whole jsp-servlet application by JMX.
i want to Monitor three things
Memory
JVM
Thread
Thanks...

Hi,
I fixed my problem by setting the system wide variable (WindowsXP)
CLASSPATH to r:\\dealershop\\WEB-INF\\classes.
Thanks,
Andrea
andrea costantinis wrote:
Hi,
I developed a JSP/servlet test application that makes
use of kodo 2.2.3 STANDARD EDITION for its persitence.
I successfully compile and annotate the application.
I am also able to successfully generate the db
schema with schematool.
Unfortunately, when I run the application using
Resin 2.0.2, Kodo is unable to initialize properly.
Initially it was not able to find \"system.prefs\" file.
I fixed that by putting \"system.prefs\" in WEB-INF\\classes.
Unfortunately, Kodo is still unable to initialize and
gives the following message:
The system could not initialize; the following registered
persistent types are missing metadata
or have not been enhanced:
[class com.dpov.purchaseorder.PurchaseOrder,
class com.dpov.catalog.Product,
class com.dpov.uidgen.counter.Counter,
class com.dpov.catalog.dao.jdo.CategoryHierarchyEntry,
class com.dpov.catalog.dao.jdo.CategoryHierarchyDAO,
class com.dpov.pricelist.PriceInfo,
class com.dpov.pricelist.PriceList,
class com.dpov.catalog.Category,
class com.dpov.lineitem.LineItem,
class com.dpov.dealer.Dealer,
class com.dpov.user.User,
class com.dpov.customer.Customer].
I use \"system.jdo\" to describe metadata for the enhancer.
I tried to put it both in WEB-INF\\lib and WEB-INF\\classes but
it still fails.
Please note that:
1) my classpath variable is not set
2) my application\'s class file are in WEB-INF\\classes
3) kodo jars are in WEB-INF\\lib
4) mysql jdbc driver is in WEB-INF\\lib
5) system.prefs is in WEB-INF\\classes
6) system.jdo is in WEB-INF\\classes
Thanks in advance,
Andrea

Application variable limits?

I want to use an application variable as a list,but the length of the list could be very long and it's a variable number of entries in the list.
The docs say strings can be as large as server memory will allow. Is there any limit beyond server memory for application variables?
Thanks!

I agree with Dan whole-heartedly, Application variables should be pretty static. but of greater concern: If you are worried about server memory being a problem, would it be better/possible to store your variable in a database?
On the flipside - "test it" create a big couple gig application variable and see what happens
-sean

How long is the live time of the Application variable???

Tell me if anyone knows the default live time of the application variable in JSP. Can i set this time?
Thanks in advance!

I believe that the answer is application server dependent, but most application servers will keep the values around until the application server is restarted (or crashes).
Some of the better (and more expensive) application servers can persist application state across server restarts but I haven't witnessed this firsthand. (I've seen it in action with session state, however).
Hope this helps ...

How to run JSP/Servlet applications on Apache?

As we all know that tomcat is an JSP/Servlet engine. Apache is a web server not a JSP/Servlet enabled web server. Then in order to run JSP/Servlet applications on Apache web server on unix, what should I do?
Thanks.
James Liu

Can you give me some detailed information about how to combine Apache and Tomcat? Note, the application is going to run on Sun Solaris Operating System.
By the way, where do you put your final version of application? on windows or on Unix? on tomcat or on apache?
I am building the application using tomcat on windows, but now I almost finished the application, so I decide to move it to Unix which uses apache as the web server. But I got problems, the Servlet engine (JServ) can not understand "RequestDispatcher" (an object used to redirect jsp pages).
Help please.
James

About JSP's application variables

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