What is the better way to open and close connection in bean
Hello, may i ask about the best way to open and close the connection?
At the first, the connection code is store in Conn class bean. The JSP page will call a method in Process bean to process the query and update of database. the Process bean is using th Conn to connect to database.
In my process bean, it have a method for each type of sql like select, insert, update, and delete for each tables. Each method will call the Conn to open and close the connection. The jsp page can simply call a method retrieve or update records.
However, when calling the processUpdate method, it is a method that update a group of tables base on the query result of another group of tables and calculation. If I calling the query method in the same bean file, it will open and close the connection many times (more than 1000 times). After open and close the connection several times, the connection to mySQL will be fail.
Currently, i include 2 method in Process that is only calling the Conn to open the connection and close connection. When calling the openConnection method, it will also set the boolean connected in the class to true and call Conn to open connection. When calling the closeConnection method, it will also set the boolean connected in the class to false and call Conn to close connection.
After that, i add some change to the query method which is when the connected is false, it will open the connection by calling the Conn and close the connection themself. If the connected is true, it will not call the Conn to open and close the connection because it already connected to the database.
Now, i when i calling the query method in jsp, it can open the connection and close the connection individually. When i call the processUpdate in the jsp, this method will calling the openConnection before calling the query and calling closeConnection at the end. It not only faster the process(less open and close), it also no cause the connect to mySQL fail error again. However, it also make the coding in the bean file more longer and complex.
Is there have any better solution?
Use connection pooling. This will put the connection management in the hands of the webserver, not your code. Check out this post:
http://forum.java.sun.com/thread.jspa?threadID=741788&messageID=4252932#4252932
Similar Messages
-
What is the best way to open a HTTPS connection?
What is the best way to open a HTTPS connection and retrieve the content as XML? This is how most of the online API is done nowadays, how can this be done on the iphone SDK?
ThanksHave a look at the SeismicXML example that comes with the iPhone SDK. It uses http instead of https but it may work for you.
You can also look at the NSURLRequest and NSURLConnection classes.
Enjoy. -
What is the best way to open emails and attachments without using wifi?
For I-phone and I-pad, what is the best way to open emails and attachments without using wifi? I turned off wifi in my settings but my boss thinks there may be another way and a better way to use something else instead of wifi. Any help would be appreciated! Thank you!
Thanks! That is a very good question you post. My boss asked me that and I am assuming that he is having issues with using wifi wherever he is at. My boss is the kind of person that when he asks something you look into it and ask him no questions...he's the only one asking questions! But thank you for your response I will tell him the information you told me and hopefully that will help!
-
What's the quickest way to open Access Connections?
What's the quickest way to open Access Connections, apart from its Taskbar level meter?
I prefer to use the Power Manager battery meter instead, as it looks pretty ugly when both are used, and they take up too much space.
Fn+F5 no longer gives any access to Access Connections either. And it is not integrated into the standard Windows network system tray icon's right-click menu, like Power Manager is with the standard power system tray icon.
You cannot even type Access Connections in the Start Menu search box, as the shortcut is called something else, which I can never remember.
Ideally, I would at least like to be able to access it though the Fn+F5 box again (I'm pretty sure it was possible in versions).
jason404 - X220 (my sixth ThinkPad)If you are still interested in using a translator, I recommend the [https://addons.mozilla.org/en-US/firefox/addon/gtranslator/?src=userprofile gTranslator] add-on.<br>
This add-on is similar to the Google Chrome translation bar. -
What is the best way to store and search 2D data
Hi,
There is a set of data (~10k records ) in 2D dimension.
like this :
Col 1, Col 2, Col3....
What is the best way to store and search those records ?
Thanks in advance
WilsonHi,
Either userObjet[][] if you know how much data you have, and the data size is fixed, or use a list of lists. E.g. A Vector of Vectors (some will probably say that you should use an ArrayList instead, and that could be the case, but it sounds like you would want to display the data later on, and a DefaultTableModel (for JTables) uses a Vector as data holder).
Kaj -
What is the best way to scan and sort old photos in iPhoto
What is the best way to scan and sort old photos in iPhoto? They do not have digital dates.
Hey Chicago Sue,
Once you scan them and have them on your desktop. You should use Automator and assign the common IPTC tags to the images, so that when you do import them into iPhoto, they get recorded.
Here is an example of an action in Automator: -
I just bought a new PC and now have ample space on my C drive to house my music Library which is currenlty installed on a external drive. What is the best way to install and move the itunes library to my C Drive?
If the entire library is on the external drive then simply copy the iTunes folder into <User's Music> on the new computer, then install iTunes. If you've already installed iTunes you will want to remove the empty iTunes folder in <User's Music> first.
If it turns out you only have the media folder on the external drive then take a look at this post...
tt2 -
What is the best way to secure and harden a Macbook Pro against unwanted surveillance?
What is the best way to secure and harden a Macbook Pro against unwanted surveillance? Tor, VPN, Little Snitch, etc. This would be for that latest version of Mavericks.
djbabybokchoy wrote:
Nothing specific, just speaking in general. Ex-wives, governments, bad guys...anyone really. I'm just looking to make my Mac a bit more private and secure, especially when on public networks.
Governments and ex's will/may have recourse to the legal process (or in the case of the Gov they can choose to ignore the legal system if they feel like it) when they want to see something of yours, good luck hardening your Mac against that. The best way to avoid the possibility of snooping over public networks is to avoid them but if you can't then Kappy's suggestion will help.
Strong passwords (everywhere) and don't use the same password in multiple locations.
If you really want to secure your home wireless use Mac address connection authentication, do not allow unknown Mac addresses to connect. It's much stronger than a WPA password alone. -
What is the proper way to lift and move a 27" iMac?
What is the proper way to lift and move a 27" iMac? Can the stand get bent if supported under its thin edge while carrying it? thanks, Kevin
The stand isn't all that thin, but the best way is to pick it up with both arms around the screen holding the screen to your chest. Cradle the screen in your arms where your elbows are bent. The screen is then supported by your forearms and hands.
-
There are way too many photos on my internal hard drive. I have older libraries, and newer libraires in iPhoto and Aperture 2. What is the best way to find and reduce the number of duplicate photos/libraries before upgrading to Aperture 3?
Sharon-
Good idea.
Back up first.
I would probably wait for the merge function of the latest version before merging. Be sure to verify every merge.
Merge Libraries, then from within Aperture move images to referenced on external hard drives.
HTH
-Allen -
It's better or necessary open and close communication with instrument every loop?
I must communicate with my instrument, but I must change its value, for example temperature, every loop. See the Figure to understand:
I think that it is better if I open communication with my instrument out of while loop so I many operation: if I put Open VISA in While loop I open VISA session every loop, instead I think it is not intelligent. Can I open VISA SESSION out of the while loop or it is an error for EXCELLENT LABVIEW VI and I must open and close VISA SESSION every times I must talk (and set) with instrument? What is the better way?
Message Edited by Michelle1892773 on 02-22-2010 02:00 PMSomething like this?
I do have to say, i don't know what is happening in the false case of yours, but if nothing happens with the 100 that is wired to the shift register, once you enter the true case, the value in the shift register will always be great than "i". You might as well do what I have done then. However, if something does happen with that number in your false case, then keep it the way you have it.
That being said, why is the condition there to see if it has looped 100 times before doing the visa write??
Message Edited by for(imstuck) on 02-22-2010 04:45 PM
Message Edited by for(imstuck) on 02-22-2010 04:46 PM
CLA, LabVIEW Versions 2010-2013
Attachments:
visa.PNG 13 KB -
Since installing LTR 5.4, which I've now upgraded to 5.6, I've encountered repeated slowness and malfunctions in operations, especially when using the Compare View function and the Tab key to open and close the right and left side panels. Such problems never arose during two years of using LTR-4 and nothing else has changed on my computer. I have a pretty simple system with only a few plug-ins, which are usually not in operation. I have 12GB of RAM in my Windows 7 PC. I could illustrate these problems with screen shots if you would tell me how to submit screen shots. Otherwise I will try to describe the problems in words.
The problem is clearly cumulative, growing worse as usage time passes. Compare View feature gradually slows down and eventually seems to choke as my work session proceeds. If I Exit LTR and re-enter and start all over, things will work normally for maybe 30 minutes, but then the Compare View feature begins to become very slow to respond. In a recent example with my screen full of thumbnails in Library mode I highlighted two images to compare. LTR started to open the Compare View screen by first having the top row of thumbnails disappear to be replaced by the "SELECT" and "CANDIDATE" words in their spaces (but no images), but Compare View never succeeded in gaining control of the screen. After some seconds the top row of thumbnails reasserted its position and the Compare View windows disappeared. But LTR kept trying to bring them back. Again the top row of thumbnails would go away, Select and candidate would reappear, try again, and give up. This went on for at least 2-3 minutes before I tried to choose File and Exit, but even that did not initially want to respond. It doesn't like to accept other commands when it's trying to open Compare View. Finally it allowed me to exit.
To experiment I created a new catalog of 1100 images. After 30-40 minutes, the Compare View function began to operate very slowly. With left and right side panels visible and two thumbnails highlighted, hitting Compare View can take half a minute before the two mid-size images open in their respective SELECT and CANDIDATE windows. When the side panels are open and two images are in the Select/Candidate spaces, hitting the Tab button to close the side panels produces a very delayed response--25-30 seconds to close them, a few more seconds to enlarge the two images to full size. To reverse the process (i.e., to recall the two side panels), hitting Tab would make the two sides of the screen go black for up to a minute, with no words visible. Eventually the info fields in the panels would open up.
I also created a new user account and imported a folder of 160 images. After half an hour Compare View began mis-placing data. (I have a screen shot to show this.) CANDIDATE appears on the left side of SELECT, whereas it should be on the right. The accompanying camera exposure data appears almost entirely to the left of the mid-screen dividing line. Although the Candidate and Select headings were transposed, the image exposure data was not, but the data for the image on the right was almost entirely to the left of the line dividing the screen in two.
Gurus in The Lightroom Forum have examined Task Manager data showing Processes running and Performance indicators and they see nothing wrong. I could also send screen shots of this data.
At this point, the only way I can process my images is to work 30-40 minutes and then shut down everything, exit, and re-start LTR. This is not normal. I hope you can find the cause, and then the solution. If you would like to see my screen shots, tell me how to submit them.
Ollie
[email protected]Since installing LTR 5.4, which I've now upgraded to 5.6, I've encountered repeated slowness and malfunctions in operations, especially when using the Compare View function and the Tab key to open and close the right and left side panels. Such problems never arose during two years of using LTR-4 and nothing else has changed on my computer. I have a pretty simple system with only a few plug-ins, which are usually not in operation. I have 12GB of RAM in my Windows 7 PC. I could illustrate these problems with screen shots if you would tell me how to submit screen shots. Otherwise I will try to describe the problems in words.
The problem is clearly cumulative, growing worse as usage time passes. Compare View feature gradually slows down and eventually seems to choke as my work session proceeds. If I Exit LTR and re-enter and start all over, things will work normally for maybe 30 minutes, but then the Compare View feature begins to become very slow to respond. In a recent example with my screen full of thumbnails in Library mode I highlighted two images to compare. LTR started to open the Compare View screen by first having the top row of thumbnails disappear to be replaced by the "SELECT" and "CANDIDATE" words in their spaces (but no images), but Compare View never succeeded in gaining control of the screen. After some seconds the top row of thumbnails reasserted its position and the Compare View windows disappeared. But LTR kept trying to bring them back. Again the top row of thumbnails would go away, Select and candidate would reappear, try again, and give up. This went on for at least 2-3 minutes before I tried to choose File and Exit, but even that did not initially want to respond. It doesn't like to accept other commands when it's trying to open Compare View. Finally it allowed me to exit.
To experiment I created a new catalog of 1100 images. After 30-40 minutes, the Compare View function began to operate very slowly. With left and right side panels visible and two thumbnails highlighted, hitting Compare View can take half a minute before the two mid-size images open in their respective SELECT and CANDIDATE windows. When the side panels are open and two images are in the Select/Candidate spaces, hitting the Tab button to close the side panels produces a very delayed response--25-30 seconds to close them, a few more seconds to enlarge the two images to full size. To reverse the process (i.e., to recall the two side panels), hitting Tab would make the two sides of the screen go black for up to a minute, with no words visible. Eventually the info fields in the panels would open up.
I also created a new user account and imported a folder of 160 images. After half an hour Compare View began mis-placing data. (I have a screen shot to show this.) CANDIDATE appears on the left side of SELECT, whereas it should be on the right. The accompanying camera exposure data appears almost entirely to the left of the mid-screen dividing line. Although the Candidate and Select headings were transposed, the image exposure data was not, but the data for the image on the right was almost entirely to the left of the line dividing the screen in two.
Gurus in The Lightroom Forum have examined Task Manager data showing Processes running and Performance indicators and they see nothing wrong. I could also send screen shots of this data.
At this point, the only way I can process my images is to work 30-40 minutes and then shut down everything, exit, and re-start LTR. This is not normal. I hope you can find the cause, and then the solution. If you would like to see my screen shots, tell me how to submit them.
Ollie
[email protected] -
I recently migrated my MacBook from 10.5.8 to 10.6.8, using the Snow Leopard CD I purchased from Apple. Since then I have noticed a strange ozone smell coming from the MacBook in the area where the hinges are to open and close the unit. I was told by Apple that it probably is not serious and is coming from the fans in the MacBook. It is true that the smell/odor is more intense when the fans are working. Apple said I should take the MacBook to an Apple Store to have the hardware checked out. Everything seems to be working correctly. I am backing up automatically wirelessly to a Time Capsule, which I had not done until recently, although I had purchased the Time Capsule in 2009. I have not noticed this odor before. Does anyone suspect something more serious that may be going on?
You may be smelling it because with the new OS the processor is having to work harder causing it to get hotter then it would with the other OS. I can't say there is nothing wrong, but what could be happening is just that, it's getting hotter so the fan is spinning faster and moving more air so you are getting more of the smell then you would before. I would still continue to back it up, and take it to the Apple Store at a Genius Bar and have them look at it to make sure. Was the computer ever in a smoky environment??
-
I have a number of test systems that use a parallel model with labview. We have a good number of instruments(PXI).
What is the prefered method for open,closing and passing instrument handles in teststand using labview?
Solved!
Go to Solution.Hi,
No, Below is a bit from the Session Manager Help
Currently, Session Manager supports the following instrument session types:
IVI Sessions—Use an IVI session to obtain the C-based instance handle for an IVI logical or virtual instrument name. NI Session Manager does not support IVI-COM drivers at this time. When IVI-COM drivers are available, you can use an IVI session to obtain an ActiveX interface reference to an IVI-COM driver.
VXIplug&play Sessions—Use a VXIplug&play session to obtain a C-based instance handle for a VXIplug&play logical or virtual instrument name. Configure VXIplug&play names in the <VXIplug&play directory>\<Platform directory>\NISessionMgr.ini file.
VISA Sessions—Use a VISA instrument session to obtain a C-based viSession handle to a VISA resource or logical name. Configure VISA logical names in the <VXIplug&play directory>\<Platform directory>\NISessionMgr.ini file.
Custom Sessions—Use a custom session to create a data container object that shares ActiveX objects you create or other data between software components you write. Use the Attach and Get methods to attach data to and retrieve data from a session. A custom session does not initialize, close, or own an instrument handle. The data you share with a custom session does not have to be instrumentation related. You can create a custom session with any name you request.
Regards
Ray Farmer
Regards
Ray Farmer -
What is the better way to change name of a site with paths and links?
Hi!
i m using dreamweaver cs4 and i have a site already configured on dreamweaver
i need to change the name of the site and at the same time, every path names and every links
This site has about 50 pages so i would like to know what is the better steps to do for modified the name of the site unless problem?
I read the informations about 'manage site' but its not clear for me about links and path names!!
thank youJust use site manager to change the site name. Nothing complicated with that.
What exactly do you mean by changing path names? Do you want to change the name of folders in the site? If so, just change them within DW and it will prompt if you want to update links.
Maybe you are looking for
-
Rename State Service Database in SharePoint 2010
As the title says, I want to rename/change database for State Service Application. I did some experiments wit it as suggested by others but I think I somehow managed to broken my service. I can SharePoint Products Configuration again and I got anothe
-
Can't Install iOS 4.2 To My iPad....
I've been trying to install the iPad update software but it stops when it reaches the Step 2 of the backing up process. Then iTunes crashes and goes no further. I force quit iTunes and try a soft reboot of the iPad. The iPad remains dark and unrespon
-
Close popup on completion of procedure
I have built a custom popup that I use to record a value in conjunction with the current screen. The popup gathers values from the current screen, asks the user for a little more input, then saves the records. The procedure is working great. After th
-
How do i update ipad to ios5 or more recent?
How do i update ipad from 4.2.1 to a more recent version?
-
Having trouble loging in for the first time. I just installed the latest release from 10.2 on windows, tried admin/admin without any success. I noticed that only one of the htmldb services is running- dbcontrol, ascontrol is not running and gives an