How do keep updates on the users online?

right now i am developing a chat program that uses applets, users login in and out. i am putting the list of users on a database and my problem is that i am using a list to know the online users, and i am asking for suggestions how, since i have to update the list of the users in each applet that runs on chat...

You could have the client list use a "stay-alive update" system. This system is pretty basic in design. The client will contact the server every few minutes to determine weather or not a user is still online, if they are then the user stays in the list, if not, then the user is removed. Between the time a user logs off and the list is updated, if a user tries to connect to another client the communication at least on the server side (better if it is on the client side) is to force a check on the status of the user prior to contacting.
Think of the TCP/IP protocol and that should help you.

Similar Messages

  • How to keep track of the users who are all currently logged in

    Hi All,
    I have basic knowledge of Session and Servlets. I am wondering how to keep track of the users who are all currently logged in. There should be some way of achieving it.
    I thought of it and come up with having an Application variable that hold it when ever a user successfully logged in.
    Thanks in advance for any reply.

    You can do this by keeping data in a static veriable in a some class of yours. The variable will need to be a collection.
    Whenever a user loogs in to the site a servlet/jsp should put the users information in to the collection and when logs off or when the session expires the entry should be take off.
    You can achive this by storing the velues in a some sort of a week collection where the entries are automaticaly removed when all the other refferences to the entry goes out of scope.
    You might need to read bit about java.lang.ref package and WeekReference
    Or you can make the entry in the collection contain the last time that the user visited any of the pages and a thread can run time to time and clean up the older entries which have timed out

  • How pricing condition be auto updated if the user changes price in PO ?

    Hi
    Is there any configuration setting on how pricing condition can be automatically updated if the user changes price in the purchase order ?
    Thanks
    Maruthi

    Hi Maruthi,
    As far as I know, POs (like many other documents in SAP) are "snapshots" of data as it was at the time of the document creation.  This snapshot has no direct link to master data, so it will not change unless you go to the document and manually change/refresh whatever data you need updated. 
    Even if there were a way to link your PO to master data to auto-update I don't see how any change on a PO could go backwards and change master data.  Pricing works the other way around - the PO takes the price from the condition records, not the records from the PO.
    Hope this helps,
    J

  • My new nano keeps going into sleep mode every copy of minutes while music is playing.  I can't figure out how to stop this.  The user guide isn't too helpful.  Any ideas?

    My new nano keeps going into sleep mode every copy of minutes while music is playing.  I can't figure out how to stop this.  The user guide isn't too helpful.  Any ideas?

    This is usually a sign that your iPod's headphones are not plugged in all the way.  Make sure that you cannot see any of the silver still showing from the headphone's plug.  You should hear a sort of popping/clicking noise when inserting the headphones letting you know that they have been fully seated.
    B-rock

  • I still have ilife '09. How can i update to the new ilife? Do i have to pay for each app seperately in order to update?

    I still have ilife '09. How can i update to the new ilife? Do i have to pay for each app seperately in order to update?
    I am an Aperture user and I am tired of managing my old iphoto library seperately. In order to use the new combined aperture/iphoto abilities i need a newer version of iphoto. Apple says that the new iphoto is free, however my iphoto (version 8.1.2) did not update. How do i update iphoto so that i can use the library with Aperture?

    iPhoto, iMovie and Garageband are free. However, you must be running Mavericks in order to download and use them. Mavericks is free also.  Therefore your Mac must be capable of running Mavericks:
    The following is from: Apple - Upgrade your Mac to OS X Mavericks.
    iMac (Mid 2007 or newer)
    MacBook (Late 2008 Aluminum, or Early 2009 or newer)
    MacBook Pro (Mid/Late 2007 or newer)
    MacBook Air (Late 2008 or newer)
    Mac mini (Early 2009 or newer)
    Mac Pro (Early 2008 or newer)
    Xserve (Early 2009)
    iWork is not as it's an upgrade and not an update. Upgrades for iWork have always had to be purchased. However, the previous iWork apps will work fine with Mavericks.
    OT

  • How do I update just the day of a date value?

    Example:
    Table: FC_GQ_SOURCE_ANALYSIS
    Sample_type = C
    Effective_date = null
    Sample_date = 20/13/07/14 09:00:00
    What needs to happen is for any sample analysis that has a sample_type of "C" we need the effective date to be the first of the month for whatever month the sample date is and keep the time as it is…
    so in the example data the effective date should be 2013/07/01 09:00:00.
    How would I update just the day part of that date string?

    Hi,
    You don't need to convert to a string and back again to do that.  Use TRUNC to get the right day, and date arithmetic to get the right time, like this:
    UPDATE  fc_gq_source_analysis
    SET     effective_date = TRUNC (sample_date, 'MONTH')
                                 + (sample_date - TRUNC (sample_date))
    WHERE   sample_type  = 'C'
    TRUNC (sample_date, 'MONTH')        is midnight on the 1st of the month that you want.
    sample_date - TRUNC (sample_date)   is the time that you want, expressed as a number of days (e.g., 9/24 of a day).

  • How do i update my original ipad online

    how do i update my origianl ipad online
    i need to update it because i am trying to manually secure my wifi through my ipad

    iOS versions before 5.0 require that you start iTunes on your computer and connect your iPad. Select your iPad in the left column of itunes on your computer and select Summary in the right column. Then click Check for Updates and follow the prompts to update your iOS on the iPad.
    If your iPad has iOS version 5.0 or later you can update the iOS without connecting to your computer. Go to
    Settings > General > Software Update and follow the prompts.

  • HT1338 I have a macbook OS X Version 10.4.11 how do I update to the new version

    I have a macbook OS X Version 10.4.11 how do I update to the new version

    Choose About this Mac from the Apple menu and check the processor.
    If it's a Core Duo Mac, click here, install the DVD, and run Software Update.
    If it's a Core 2 Duo or better Mac, follow the Core Duo instructions, open the Mac App Store, and try purchasing Mountain Lion. If you get told it's incompatible, phone the online Apple Store and order a download code for Lion; a regular MacBook(not MacBook Pro) which shipped with 10.4.11 or earlier is incapable of running 10.8.
    (83778)

  • How can i get all the users from weblogic server?

    how can i get all the users from weblogic server?
    i have configurated a LDAP server using iPlanet and
    in weblogic server console i see those users from LDAP
    server. but how can i get all the users in my program
    from weblogic server instead of LDAP server?
    BTW,how to configure a RDBMSAuthenticator and what should i do
    in Oracle? which tables should i create? and how are their architectures?
    Thanks
    Daniel

    BTW, i use weblogic platform 8.1
    "Daniel" <[email protected]> дÈëÓʼþ
    news:[email protected]..
    how can i get all the users from weblogic server?
    i have configurated a LDAP server using iPlanet and
    in weblogic server console i see those users from LDAP
    server. but how can i get all the users in my program
    from weblogic server instead of LDAP server?
    BTW,how to configure a RDBMSAuthenticator and what should i do
    in Oracle? which tables should i create? and how are their architectures?
    Thanks
    Daniel

  • HT2188 How can I update to the latest ios version on my ipod touch?

    How can I update to the latest ios version on my ipod touch?

    Check to see what model of iPod you have:
    http://support.apple.com/kb/HT1353
    If you have a second-generation iPod, the last version of iOS it can run is iOS 4.2.1. If you have a 3rd or 4th generation iPod touch, see:
    http://support.apple.com/kb/HT4972
    Regards.

  • How do I update to the latest version on InDesign?

    How do I update to the latest version on InDesign?

    If you mean how do you update the version you have you can try going thru the Help option in the main toolbar or you can try direct updates.
    Direct Updates
    https://www.adobe.com/downloads/updates/
    cc updates:  http://prodesigntools.com/adobe-cc-updates-direct-links-windows.html
    cc 2104 updates:  http://prodesigntools.com/adobe-cc-2014-updates-links-windows.html
    If you mean how do you upgrade to the latest version then you purchase a Cloud subscription for InDesign or for the Complete plan.
    Creative Cloud Plans
    https://creative.adobe.com/plans

  • How do I update to the most recent version of itunes?

    How do I update to the most recent version of Itunes?

    just hit the  logo in the menu bar (the menu bar is the bar wich is in the top of ur screen) then click "Software Update..." and check the where it says iTunes, then click Update. ur mac will restart and then iTunes will have the latest version (10.5.1)    
    George Karakadas, hope this will help u
    <Edited by Host>

  • HT4623 how do I update to the latest ios? i have a ipad 1.

    How do I update to the lastest ios?I have a ipad 1

    Did you read the instructions in the article?
    Update your device using iTunes
    Ensure that you're using the latest version of iTunes.
    Connect your device to your computer using the included USB cable.
    After iTunes opens, select your device when it appears in iTunes under Devices.
    Click "Check for Update" in the Summary pane to check for available updates.

  • How will I block/restrict the user to change the payment term in FBL5N?

    Hi All,
    How will I block/restrict the user to change the payment term in FBL5N????
    I have tried on following objects:
    F_BKPF_BLA
    F_BKPF_BUK
    F_BKPF_GSB
    F_BKPF_KOA
    F_IT_ALV
    F_KNA1_BED
    F_KNA1_BUK
    F_LFA1_BUK
    S_ALV_LAYO
    But, not succeeded.
    =>Actually user runs FBL5N, double click on a record then click on Change icon.
    =>Change Payment Term.
    Please reply ASAP. Point will be awarded.
    With Best Regards
    Dharmendra

    Hi Dharmendra,
    Please set an authorization trace in ST01 and then ask the user to execute the transaction and the steps on the same application server as the o ne on which the trace has been set (valid in case we are talking about mutiple application servers for same <SID>). After this is done switch off the trace,list it and fill all the authorization objects. That might give you the perfect idea.
    Regards.
    Ruchit.

  • How to keep track of the changes done in ALV GRID Report

    Hi Experts,
    how to keep track of the changed record in ALV GRID Report. how to set the field to be editable even for the entire row also. Can anybody guide along with code also?...
    Valuable answers will be rewarded.
    Thanks,
    Satish.

    Hi,
    Access the table through SM30. It comes blank as standard. Click "New Entries" and make entries for changes to be tracked. For example, whenever an org. unit changes 002 and 003 relationship, you will make entries like:
    01 O 1001 B002 Activate box checked
    01 O 1001 B003 Activate box checked
    Here, 01 is your active plan version, O is org. unit, 1001 is infotype and B002 and B003 are the subtypes. You can also use * for infotype and subtype which means every change will be logged.
    If you then run the report RHCDOC_DISPLAY through SA38, it will pick up all the changes pertaining to B002 and B003 relationship for org. units (in the above example).
    Similarly, you can set up this table for other object types.
    For more information, follow SPRO>Personnel Management>OM>Basic Settings>Activate change documents and go through the documentation for that node. Also, read up the documentation for the report.
    Hope this helps.
    Donnie

Maybe you are looking for