Multiple JSP's accessing the same thread

I have multiple users calling multiple JSP's. I also now want to add in a connection pool, which is implemented as a Runnable (It's a thread). However, how do I set it up so that all of the JSP's get a reference to the same connection pool?
I have done this in a Servlet, where I could have the connection pool constructed in the init() function, and then the Servlet kept a static reference to the pool. Then for each request, I pass the reference to the pool into the service() function of my supporting classes.
How can I do this in JSP?

There are few things.......
I do not know which application server you are using , but almost all competitive application server provide the concept of connection pooling. You do not have to implement connection pooling yourself. And to get a handle to the connection from the pool is through JNDI namespace(as you do for EJB.)
Now if you still want to do that yourself then, i can propose one way.
1) Put a instance of the Java class which holds the connection pooling in the application scope.
ie useBean= Yourclass scope="application"
2) Now all the JSP's will be able to get to the same object.
So Look for documentation for putting objects in different scope ie session, application etc.
Srinivasan Ranganathan

Similar Messages

The Windows SMB feature has file locking if multiple users are accessing the same file. Does Snow Leopard Server File Sharing (AFP) provide similar features?

The Windows SMB feature has file locking if multiple users are accessing the same file. Does File Sharing (AFP) on Snow Leopard Server provide similar services?

Were you ever able to solve this problem. I'm having similar issues since upgrading to snow leopard. Four macs connect to a Windows Server 2003 for shared files. Each user has full permissions & when we "get info" it shows read & write permissions. Two of the computers were running 10.4, two were running 10.5. Everything worked properly until upgrading to snow leopard. Some files let me copy, move, delete. Others either just hang up or we get a "no permission" error. Also getting a "pdf is in use" error, even when the file/folder doesn't contain a pdf. We had our IT rep check the server who said everything is in working order. They don't represent macs any longer but feel that it's a mac problem. I would have to agree since this problem only started after the upgrade, and the one machine that was not upgraded (still running 10.5.8) is not dealing with these problems.
Lastly, I would install 10.5 back on all of the computers if I could, but the leopard disk that came with one of the computers wouldn't work with the 2 machines running 10.4 and I didn't see it available at the apple store. I'll buy it if it's still available, but why wouldn't the disks that I have work?
Thanks for any help

How do I use multiple classes to access the same object?

This should be staightforward. I have and object and I have multiple GUIs which operate on the same object. Do all the classes creating the GUIs need to be inner classes of the data class? I hope this question makes sense.
Thanks,
Mike

public final class SingletonClass {
private static SingletonClass instance;
private int lastIndex = 10;
public final static SingletonClass getInstance()
if (instance == null) instance = new SingletoClass();
return instance;
public int getLastIndex() {
return lastIndex;
}1) This won't work since one could create a new SingletonClass. You need to add a private constructor. Also, because the constructor is private the class doesn't have to be final.
2) Your design isn't thread-safe. You need to synchronize the access to the shared variable instance.
public class SingletonClass {
    private static SingletonClass instance;
    private static Object mutex = new Object( );
    private int lastIndex = 10;
    private SingletonClass() { }
    public static SingletonClass getInstance() {
        synchronized (mutex) {
            if (instance == null) {
                instance = new SingletonClass();
        return instance;
    public int getLastIndex() {
        return lastIndex;
}if you are going to create an instance of SingletonClass anyway then I suggest you do it when the class is loaded. This way you don't need synchronization.
public class SingletonClass {
    private static SingletonClass instance=new SingletonClass();
    private int lastIndex = 10;
    private SingletonClass() { }
    public static SingletonClass getInstance() {
        return instance;
    public int getLastIndex() {
        return lastIndex;
}If you don't really need an object, then you could just make getLastIndex() and lastIndex static and not use the singleton pattern at all.
public class SingletonClass {
    private static int lastIndex = 10;
    private SingletonClass() { }
    public static int getLastIndex() {
        return lastIndex;
}- Marcus

How to permit multiple workspaces to access the same schema?

Hello,
When creating a new workspace (version 3.2), I am getting the following warnings:
"Warning: The requested schema already exists. Warning: The requested schema is already assigned to one or more workspaces. Please ensure that giving multiple workspaces access to the same schema is permitted by the security policies at your site before approving this request."
How do I "ensure that giving multiple workspaces access to the same schema is permitted"?
What are the advantages/disadvantages of doing so?
Thanks,
Gabor

The correct answer to it would have been: I use manual provisioning.I didn't ask a detailed enough question. What I am wondering is how you are set up to to workspace provisioning at your site. In apex_admin, if you navigate to Home>Manage Service>Instance Settings there is a radio group like:
Provisioning Status:
0 Manual - An administrator manually creates each workspace
0 Request - Link displayed on login page enabling users to request workspaces
0 Email Verification - Workspace created after email address is verified by the user
The help text for this is:
Provisioning Status:
Determines how the process of provisioning (or creating) a workspace works for your development instance. Options include:
    * Manual - An Application Express administrator manually creates new workspaces and notifies the Workspace administrator of the login information.
    * Request - Users request workspaces directly in a self-service fashion. Selecting this option displays a link on the Login page enabling users to request a workspace. When a user requests a workspace, each request is submitted to a queue for approval.
    * Email Verification - Works similar to Request except each user receives an initial email containing a link. Clicking this link validates the user's email address before the request is processed.
Note: To enable users to request a workspace using a link on the Login page, you must choose Request or Email Verification. If you select Manual, no link appears on the login page.How is yours set up?
As to the first original question (How do I "ensure that giving multiple workspaces access to the same schema is permitted"?), I still do not know.Whether it is permitted or not is a decision made by the apex site administrator who approves/declines workspace requests. Whether it ought to be permitted is a different question and is really same as your second question which involves issues you said you are now starting to understand better. So I think we've covered your original questions. If not, please elaborate.
As to the last subject (How did the hidden workspace get created and how do I get rid of id? What happens if I don't?), this happened at work, so I can only tell you more on Monday (luckily...). Until then, here is what I remember. The work space was created, which is proven by the fact that when I want to create a new workspace with the same name, I am getting an error, which says that a workspace with that name already exists. However, I cannot delete the workspace, since it show up nowhere.No hidden workspace got created. I'm pretty sure the request is just in the queue waiting to be approved/declined. In the meantime a workspace with the same name cannot be requested.
By the way, how do you quote some text here? I just put a '>' in the first character position before the text to quote. You can also use the " rich text icon above the text pane.
Scott

Can multiple XP users access the same iTunes library?

Because I'm having a REALLY hard time getting that to work at all. I've moved my entire iTunes folder into 'Shared Documents' so that all users should be able to access it and changed the option in iTunes Preferences to the correct 'all users' path, but iTunes still tries to find the info in 'my' (sal's) documents instead of 'all.'
Anyone figure this out, or does it somehow break the EULA and isn't supported? The wife and I just want to use the same library since we're on one computer. Seems silly to not allow a user with admin rights to allow other users access.
Thanks,
Sal
Windows XP

Sal,
As this article in the Apple Knowledge Base explains the trick is to move the iTunes Music folder, not the entire iTunes folder, to "a publicly accessible location" and I believe they mean to suggest C:\Documents and Settings\All Users\Documents\My Music as a good place.
It is important that the iTunes Library files remain in Sal's Documents and Sal's Wife's Documents.

Having multiple environments open in the same thread.

Dear Sir,
I have a question about the concurrency model inside the bdbje. I read the documents and faqs and wrote some simple
programs using it.
Here is my question, from my understanding, one can open an environment in multiple processes assuming that only
one of the environments is opened for writing. I would like to know how can I open one read environment
and one write environment in the same process. Since in my application, reads and writes can be initiated from
multiple processes [assuming that always having at most one writer]. In my tests when a process receives
a read requests it creates an environment for reading, and if during the reading process the process receives
a write request, it create a new environment to handle the write request. This simple thing throws the following exception:
je.env.isReadOnly is set to false in the config parameter which is incompatible with the value of true in the underlying environment
It seems like I can't have multiple environments with different configurations open at the same time in the same process, i would like
to know if this is really the case, are there any option that I can tweak to fix this.
Thanks,
AliS

hello,
An immutable property of an Environment can not be changed
at runtime. The ReadOnly property for an environment is one of
the few immutable environment properties. Hence, the IllegalArgumentException
was thrown when your application tried to open an environment handle as
ReadWrite when a handle had already been opened ReadOnly. All environment
handles opened by a single process must have the same value for immutable
properties.
You can find some additional information is at:
http://www.oracle.com/technology/documentation/berkeley-db/je/java/index.html
under: EnvironmentConfig
thanks,
Sandra

How do I enable multiple profiles to access the same itunes library?

Family of 4; with 4 different user profiles/log ins. One family iTunes library; how can I allow all profiles to access the one master iTunes library?

annafromsalt lake city wrote:
how can I allow all profiles to access the one master iTunes library?
move the entire iTunes folder to <MacintoshHD>/users/shared. on each user account, launch iTunes while holding the option(⌥) key, click on choose library when prompted, and select the iTunes folder you moved to the share folder.
be aware only one iTunes at a time can access the library !

Accessing the same stateful session bean from multiple clients in a clustered environment

I am trying to access the same stateful session bean from multiple
          clients. I also want this bean to have failover support so we want to
          deploy it in a cluster. The following description is how we have tried
          to solve this problem, but it does not seem to be working. Any
          insight would be greatly appreciated!
          I have set up a cluster of three servers. I deployed a stateful
          session bean with in memory replication across the cluster. A client
          obtains a reference to an instance of one of these beans to handle a
          request. Subsequent requests will have to use the same bean and could
          come from various clients. So after using the bean the first client
          stores the handle to the bean (actually the replica aware stub) to be
          used by other clients to be able to obtain the bean. When another
          client retrieves the handle gets the replica aware stub and makes a
          call to the bean the request seems to unpredictably go to any of the
          three servers rather than the primary server hosting that bean. If the
          call goes to the primary server everything seems to work fine the
          session data is available and it gets backed up on the secondary
          server. If it happens to go to the secondary server a bean that has
          the correct session data services the request but gives the error
          <Failed to update the secondary copy of a stateful session bean from
          home:ejb20-statefulSession-TraderHome>. Then any subsequent requests
          to the primary server will not reflect changes made on the secondary
          and vice versa. If the request happens to go to the third server that
          is not hosting an instance of that bean then the client receives an
          error that the bean was not available. From my understanding I thought
          the replica aware stub would know which server is the primary host for
          that bean and send the request there.
          Thanks in advance,
          Justin


          If 'allow-concurrent-call' does exactly what you need, then you don't have a problem,
          do you?
          Except of course if you switch ejb containers. Oh well.
          Mike
          "FBenvadi" <[email protected]> wrote:
          >I've got the same problem.
          >I understand from you that concurrent access to a stateful session bean
          >is
          >not allowed but there is a
          >token is weblogic-ejb-jar.xml that is called 'allow-concurrent-call'
          >that
          >does exactly what I need.
          >What you mean 'you'll get a surprise when you go to production' ?
          >I need to understand becouse I can still change the design.
          >Thanks Francesco
          >[email protected]
          >
          >"Mike Reiche" <[email protected]> wrote in message
          >news:[email protected]...
          >>
          >> Get the fix immediately from BEA and test it. It would be a shame to
          >wait
          >until
          >> December only to get a fix - that doesn't work.
          >>
          >> As for stateful session bean use - just remember that concurrent access
          >to
          >a stateful
          >> session bean is not allowed. Things will work fine until you go to
          >production
          >> and encounter some real load - then you will get a surprise.
          >>
          >> Mike
          >>
          >> [email protected] (Justin Meyer) wrote:
          >> >I just heard back from WebLogic Tech Support and they have confirmed
          >> >that this is a bug. Here is their reply:
          >> >
          >> >There is some problem in failover of stateful session beans when its
          >> >run from a java client.However, it is fixed now.
          >> >
          >> >The fix will be in SP2 which will be out by december.
          >> >
          >> >
          >> >Mike,
          >> >Thanks for your reply. I do infact believe we are correctly using
          >a
          >> >stateful session bean however it may have been misleading from my
          >> >description of the problem. We are not accessing the bean
          >> >concurrently from 2 different clients. The second client will only
          >> >come into play if the first client fails. In this case we want to
          >be
          >> >able to reacquire the handle to our stateful session bean and call
          >it
          >> >from the secondary client.
          >> >
          >> >
          >> >Justin
          >> >
          >> >"Mike Reiche" <[email protected]> wrote in message
          >news:<[email protected]>...
          >> >> You should be using an entity bean, not a stateful session bean
          >for
          >> >this application.
          >> >>
          >> >> A stateful session bean is intended to be keep state (stateful)
          >for
          >> >the duration
          >> >> of a client's session (session).
          >> >>
          >> >> It is not meant to be shared by different clients - in fact, if
          >you
          >> >attempt to
          >> >> access the same stateful session bean concurrently - it will throw
          >> >an exception.
          >> >>
          >> >> We did your little trick (storing/retrieving handle) with a stateful
          >> >session bean
          >> >> on WLS 5.1 - and it did work properly - not as you describe. Our
          >sfsb's
          >> >were not
          >> >> replicated as yours are.
          >> >>
          >> >> Mike
          >> >>
          >> >> [email protected] (Justin Meyer) wrote:
          >> >> >I am trying to access the same stateful session bean from multiple
          >> >> >clients. I also want this bean to have failover support so we want
          >> >to
          >> >> >deploy it in a cluster. The following description is how we have
          >tried
          >> >> >to solve this problem, but it does not seem to be working. Any
          >> >> >insight would be greatly appreciated!
          >> >> >
          >> >> >I have set up a cluster of three servers. I deployed a stateful
          >> >> >session bean with in memory replication across the cluster. A client
          >> >> >obtains a reference to an instance of one of these beans to handle
          >> >a
          >> >> >request. Subsequent requests will have to use the same bean and
          >could
          >> >> >come from various clients. So after using the bean the first client
          >> >> >stores the handle to the bean (actually the replica aware stub)
          >to
          >> >be
          >> >> >used by other clients to be able to obtain the bean. When another
          >> >> >client retrieves the handle gets the replica aware stub and makes
          >> >a
          >> >> >call to the bean the request seems to unpredictably go to any of
          >the
          >> >> >three servers rather than the primary server hosting that bean.
          >If
          >> >the
          >> >> >call goes to the primary server everything seems to work fine the
          >> >> >session data is available and it gets backed up on the secondary
          >> >> >server. If it happens to go to the secondary server a bean that
          >has
          >> >> >the correct session data services the request but gives the error
          >> >> ><Failed to update the secondary copy of a stateful session bean
          >from
          >> >> >home:ejb20-statefulSession-TraderHome>. Then any subsequent requests
          >> >> >to the primary server will not reflect changes made on the secondary
          >> >> >and vice versa. If the request happens to go to the third server
          >that
          >> >> >is not hosting an instance of that bean then the client receives
          >an
          >> >> >error that the bean was not available. From my understanding I
          >thought
          >> >> >the replica aware stub would know which server is the primary host
          >> >for
          >> >> >that bean and send the request there.
          >> >> >
          >> >> >Thanks in advance,
          >> >> >Justin
          >>
          >
          >

Can multiple LabVIEW programs simultaneously access the same NI-DAQmx hardware?

I am developing a test station system that, in essence, runs several
seperate LabVIEW programs simultaneously on the same computer, each
controlling a different set of I/O channels on one shared set of NI
DAQ hardware (analog and digital I/O PCI boards with external signal
conditioning).
I have already gotten a system like this running almost flawlessly
using LabVIEW 6.1, NI-DAQmx 7.1 with traditional channels, and older
E-series DAQ hardware. So long as two programs do not try to write to
the same output channel simultaneously, everything works exactly as
expected--I can even read from the same (named) channel simultaneously
from more than one program. The only issue I have had is that if
one
of the compiled applications is closed (not just stopped, but closed)
while others are still running, Windows XP (SP1) will bluescreen on a
driver error. This is undesireable, but acceptable (though if there's
a fix/workaround, I'd love to hear it).
I am now building a similar system using mostly the same software
(with an upgrade to LabVIEW 7.1), and I've noticed that the new
M-series DAQ hardware seems to offer much more bang for the buck than
old E-series hardware and its kin.
My question is this: It appears that I/O on M-series hardware must be
performed with new mx channels, with traditional channels not being an
option. I am therefore wondering if I will be able to do this kind of
multiple simultaneous access with mx channels, or if I must purchase
the classic hardware and use traditional channels for this somewhat
unorthodox application.
(Incidentally, the multiple simultaneous program thing is a
requirement for this system, as it is the only clean way to run
multiple
identical copies of the same complete program that only
operate on different I/O channels, and re-doing the program from
scratch is not an option.)

Dear Anonymous,
Thank you for contacting National Instruments.
To address your question, I don't know if multiple simultaneous access with mx channels is possible, but I do not see why it wouldn't be. The best way to find out would be to test it. I don't have your program or hardware, so I'm pointing you to some Compatibility VIs. These are VIs that look exactly like Traditional DAQ VIs except that underneath they call the DAQmx driver instead of the Traditional DAQ driver. If your device works when you substitute these Compatibility VIs in for the Traditional DAQ VIs, then you'll know the M Series boards will work for you.
Here is the link for information about the Compatibility VIs:
http://digital.ni.com/softlib.nsf/954feaeea92d90918625674b00658b
83/9d67f671bcc6850586256e630059308b?OpenDocument
Let me know if you have any further questions or if this does not resolve your issue.
Thanks again and have a great day!
Chad AE
Applications Engineer - National Instruments

Multiple User Accessing the same record issue

I am planning to design an app where we have the following use case requirement.
If a user who is logged into the system is accessing a record(plan in this case) anyone else who is logged into the system at the same time should be locked out of that same plan but should still be able to access other plans in the system. A plan has many things associated with it so the 2nd user should be locked out of everything associated to the plan being accessed by the first user.
What is the best way to implement this at the application or the database level?
Here are some options we have been bouncing around.
1. When the first user logs in and accesses the first plan we lock the plan at the app level using a singleton class which has one and only one instance on the app server. The plan_id can be put as an entry into a hashtable which can be in the session and is created if one does not exist. When the 2nd user tries to access the same plan, since the plan_id is still in the hashtable he would be locked out. However we somehow need to timeout the first user after 30 mts of inactivity or so so that others can access the plan and are not locked out for ever if the first user walks away from his PC or does not close his browser, thus keeping his session alive indefinitely.
2. In the database in the plan table we add a column for 'locked'. When the first entry is created in the plan table locked column is marked as 'yes' or 1 and when the user closes the browser we use some javascript to trigger an event which changes that 'yes' or 1 to 'no' or 0 thus unlocking the plan. However the big issue we see in this concept is that we will have to put a javascript onUnload method in all jsp pages in the app because the user could be anywhere in the app after starting his plan access after login.
Conceptually the 2 options are the same but one is done at the app whereas the other is at the database level.
Is there a better way to handle this scenario using transactions or some other technological option.
Thanks

Another solution involving no modification of the database structure:
As soon as a user want to access a plan, try to UPDATE the plan record... if it fails, the record was locked
by another user before. When the user has finished with the plan, you can COMMIT or ROLLBACK the changes, which will free the lock for other users.
An advantage of this solution is that if program crashes unexpectedly, there will automatically be a ROLLBACK.
Of course, you need a transaction for this... and perhaps more if you want to separate the 'locking transaction' (virtual update just for restricting access) from the 'operating transaction' (in which you will
do the DB stuff: inserts, updates, deletes, etc.)
Hope this helped,
Regards.

Can i access the same Itunes account and playlist on multiple computers

I would like to access the same I Tunes (library, play lists, etc.) on multiple computers...is this possible?

Hello sdfarmer99,
This can be done by setting up Home Sharing on the system with the library that you want to share.
iTunes: Setting up Home Sharing on your computer
http://support.apple.com/kb/HT4620
Cheers,
Allen

Keychain Access: Adding multiple Certificates, signed by the same CA

Hello, Community.
I have recently posted my request for help in this thread:
http://discussions.apple.com/thread.jspa?messageID=10448884
Now, I am facing a new problem: I wish to add a new Certificate to the Keychain, but whenever I try, it tells me the item exists, and does not add it to the Keychain. It adds the keys perfectly fine, both public and private, but not the Certificate.
What can I do to have multiple Certificates, signed by the same CA.
I cannot add them to my Keychain, so that will be of no help. And I have tried to create every Certificate anew in the same Keychain, but this will not work, either. I created they Certificates and exported them before I went on to the next and they are now on my desktop. This is very inconvenient, as the keychain is distributed over a network as a shared Keychain and resides in a Snow Leopard Server (Domestic version, not Snow Leopard Server). Our business is one day behind, but since it is now weekend, I hope to get this issue resolved by Monday morning, send out the e-mails we should have and update our register with sales.
Could I please have some advice?
Also, if this topic is handled in full in another thread, please post the links, so I can read up on this topic and try to find a solution.
Thank you for your time.
Kashidom Nenakh
Mantha Designs incorporated
http://www.manthadesigns.net
[email protected]

http://www.isi.edu/~brian/security/kerberos.html

Prevent multiple users accessing the same form

hi,
i am working in forms
i have a requirement like this
if more than one user are using the same form and try to access the same record then the second user should not be able to do transaction
he should be popped up with a msg saying that other user is working on it
can any one suggest how to do this in my form
thanks in advance
selvaraj s

That is pretty much exactly the way Forms works automatically.
Two users can use the same form, and can even display the same data record. One of the users can make changes to the record -- Forms locks the row upon the FIRST keystroke in the first field the user begins to change.
Once the row is locked, the second user is free to look at the record, and won't even know if another user has begun making changes. However, if second user tries to change even one field in the record, Forms pops up the message, "Could not reserve record (2 tries). Keep trying? Yes / No"
There are also protections so if the first user actually changes the row and commits, then the second user tries to make a change. Forms will automatically detect whether changes were made, and if so, will undo the change and issue the message, "FRM-40654: Record has been updated by another user. Re-query to see change."
The above automatic processing works very nicely. If it will not work for you, then what is it you need?

Multiple users accessing the same server.

Ok here is my issue, about 2 months ago I started having issues with Filesharing on my 2012 Mac Mini running Lion server (current update). We have 3 users that VPN into our conpany network and usually access the same folder, 2 months ago they started conflicting with each other. When one VPNs into the network and connects to the server they are fine, if the second one connects to the network they are fine but if the second one tries to access the fileshare they knock the second one off the server. The first one's connection eventually hangs and they have to completely disconnect from the VPN. I am wondering if this was caused by a patch or if there is something else going on. I have tried to reboot the server and checked the logs for anything but I am not seeing what may be causing this. I have restarted the Filesharing in the Server app and still get the same problem, the users are connecting via local credentials to the server. I don't think it is a password issue since either user can log in and access as long as another user doesn't so I am not sure what the issue could be.
any help appriciated,
josh

By 'standard record locking system' do you mean there is nothing I need to do programatically? No block level properties to change?
So you are saying this is just the way it always works. So as soon as one of our call center agents opens a record all I have to do is create a pending update to any field?
But won't another user be able to open the form and just query that record not knowing another user has it open?

Installing multiple instances accessing the same database

Hi,
I want to install two different instances of Oracle 10g in two different machines which will access the same database which will be stored in the shared storage.
Is it possible to install them without installing RAC? The instances will be one active and the other passive, so the services will be up in one server and down in the other and the switching (shutting down one server and starting up the other) will be manual.
Two servers will be running Linux and clustered in Linux level.
Does Oracle offers this solution without installing Clusterware software?
Thank you

> The instances will be one active and the other passive, so the services will be up in one server and down in
the other and the switching (shutting down one server and starting up the other) will be manual
Missed this part as I was thinking proper cluster and RAC.
This is neither. Yes, this can be done using two servers and shared storage.
Is it a good idea? Not really. As this configuration does not provide redundancy at physical database level. You loose that storage.. bye-bye database. Does not matter whether you have a 100 backup servers that can be used.
Thus the business reasons that you are trying to meet with this config have to be clarified and expectations determined.
Separate servers using Data Guard will be a far more superior solution in many respects.

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