jsp question
Hi,
Im devlopping a website.
I have all the countries stored in my DB,
When a user wants to subscribe to the website, ha has to select his country.
I loaded the countries from my DB in memory in a "load-on-start" servlet.
I'm making a JSP file that gets the countries and display them in a combobox.
My question :
For every request,
the jsp file needs to get the countries and display them from a java class.
But I want the countries to be loaded in this combobox just once (not for every new request).
Thank you for any help.
Im devlopping a website.
I have all the countries stored in my DB,
When a user wants to subscribe to the website, ha has to select his country.
I loaded the countries from my DB in memory in a "load-on-start" servlet.
I'm making a JSP file that gets the countries and display them in a combobox.
My question :
For every request,
the jsp file needs to get the countries and display them from a java class.
But I want the countries to be loaded in this combobox just once (not for every new request).
Thank you for any help.
SOLUTION
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SOLUTION
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Hi!
Store the country-names in an EJB Session Bean and let the server handle the load and cache of the data.
In that way country-names are stored in memory at startup and can be accessed quickly.
Regards,
Tomas Helgi
Store the country-names in an EJB Session Bean and let the server handle the load and cache of the data.
In that way country-names are stored in memory at startup and can be accessed quickly.
Regards,
Tomas Helgi
I think an EJB Session Bean for this task is like using a rocket launcher to kill a fly.
SOLUTION
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ASKER
If I store them in a session, the countries need to be loaded for each user no?
I want to load them just for once.
So actually I could load them in a static class and then access this class with a loop in the select.
Well actually I already did that and I tought it was a problem for performance and that
I could find a better solution.
>Perhaps build the select in an include
why?
I want to load them just for once.
So actually I could load them in a static class and then access this class with a loop in the select.
Well actually I already did that and I tought it was a problem for performance and that
I could find a better solution.
>Perhaps build the select in an include
why?
> I want to load them just for once.
thought u said you'd already loaded them?
> So actually I could load them in a static class and then access this class with a loop in the select.
should load them into a static class.
you should load them once and store them in the application context
>>Perhaps build the select in an include
>why?
In case you want to add the select to >1 pages
thought u said you'd already loaded them?
> So actually I could load them in a static class and then access this class with a loop in the select.
should load them into a static class.
you should load them once and store them in the application context
>>Perhaps build the select in an include
>why?
In case you want to add the select to >1 pages
ASKER
> I want to load them just for once.
>thought u said you'd already loaded them?
Actually I meant load them once from the application into my jsp page ...
I don't know if this affects performance because
at every request a big loop in the select is executed, and laod them from the class.
Then I have a loop to select language, and other loop.
U know what I mean ?
>thought u said you'd already loaded them?
Actually I meant load them once from the application into my jsp page ...
I don't know if this affects performance because
at every request a big loop in the select is executed, and laod them from the class.
Then I have a loop to select language, and other loop.
U know what I mean ?
ASKER CERTIFIED SOLUTION
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ASKER
Thank u very much
As I said before.
Create a HttpSessionListener class and put a static java-class/object in that class which then can be accessed from all JSP pages. Doing this you load the data ONCE when the web-app is first loaded and destroyed when no users are browsing the web by counting active users.
Do it something like this :
import javax.servlet.http.HttpSes
import javax.servlet.http.HttpSes
public class SessionCounter implements HttpSessionListener {
private static int activeSessions = 0;
private static myCountry countries; // this class holds the countries ;)
private static boolean countries_loaded = false
public void sessionCreated(HttpSession
activeSessions++;
if(activeSessions > 0 and !countries_loaded){
countries_loaded = true;
countries = new myCountry();
......
}
}
public void sessionDestroyed(HttpSessi
if(activeSessions > 0)
activeSessions--;
}
public static int getActiveSessions() {
return activeSessions;
}
}
Regards,
Tomas Helgi
Create a HttpSessionListener class and put a static java-class/object in that class which then can be accessed from all JSP pages. Doing this you load the data ONCE when the web-app is first loaded and destroyed when no users are browsing the web by counting active users.
Do it something like this :
import javax.servlet.http.HttpSes
import javax.servlet.http.HttpSes
public class SessionCounter implements HttpSessionListener {
private static int activeSessions = 0;
private static myCountry countries; // this class holds the countries ;)
private static boolean countries_loaded = false
public void sessionCreated(HttpSession
activeSessions++;
if(activeSessions > 0 and !countries_loaded){
countries_loaded = true;
countries = new myCountry();
......
}
}
public void sessionDestroyed(HttpSessi
if(activeSessions > 0)
activeSessions--;
}
public static int getActiveSessions() {
return activeSessions;
}
}
Regards,
Tomas Helgi
Hmmm forgot one thing. ;)
import javax.servlet.http.HttpSes
import javax.servlet.http.HttpSes
public class SessionCounter implements HttpSessionListener {
private static int activeSessions = 0;
private static myCountry countries; // this class holds the countries ;)
private static boolean countries_loaded = false
public void sessionCreated(HttpSession
activeSessions++;
if(activeSessions > 0 and !countries_loaded){
countries_loaded = true;
countries = new myCountry();
......
}
}
public void sessionDestroyed(HttpSessi
if(activeSessions > 0)
activeSessions--;
}
public static int getActiveSessions() {
return activeSessions;
}
public static myCountry getCountryClass(){
return countries;
}
}
Regards,
Tomas Helgi
import javax.servlet.http.HttpSes
import javax.servlet.http.HttpSes
public class SessionCounter implements HttpSessionListener {
private static int activeSessions = 0;
private static myCountry countries; // this class holds the countries ;)
private static boolean countries_loaded = false
public void sessionCreated(HttpSession
activeSessions++;
if(activeSessions > 0 and !countries_loaded){
countries_loaded = true;
countries = new myCountry();
......
}
}
public void sessionDestroyed(HttpSessi
if(activeSessions > 0)
activeSessions--;
}
public static int getActiveSessions() {
return activeSessions;
}
public static myCountry getCountryClass(){
return countries;
}
}
Regards,
Tomas Helgi
ASKER
Thank u Tomas but I can't see why I should destroy the data when no sessions are active,
also I can't see any code that "destroys" the data like u say.
also I can't see any code that "destroys" the data like u say.
Perhaps build the select in an include