Search Results

Search found 14639 results on 586 pages for 'coding environment'.

Page 507/586 | < Previous Page | 503 504 505 506 507 508 509 510 511 512 513 514  | Next Page >

  • Ruby on Rails bizarre behavior with ActiveRecord error handling

    - by randombits
    Can anyone explain why this happens? mybox:$ ruby script/console Loading development environment (Rails 2.3.5) >> foo = Foo.new => #<Foo id: nil, customer_id: nil, created_at: nil, updated_at: nil> >> bar = Bar.new => #<Bar id: nil, bundle_id: nil, alias: nil, real: nil, active: true, list_type: 0, body_record_active: false, created_at: nil, updated_at: nil> >> bar.save => false >> bar.errors.each_full { |msg| puts msg } Real can't be blank Real You must supply a valid email => ["Real can't be blank", "Real You must supply a valid email"] So far that is perfect, that is what i want the error message to read. Now for more: >> foo.bars << bar => [#<Bar id: nil, bundle_id: nil, alias: nil, real: nil, active: true, list_type: 0, body_record_active: false, created_at: nil, updated_at: nil>] >> foo.save => false >> foo.errors.to_xml => "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<errors>\n <error>Bars is invalid</error>\n</errors>\n" That is what I can't figure out. Why am I getting Bars is invalid versus the error messages displayed above, ["Real can't be blank", "Real you must supply a valid email"] etc. My controller simply has a respond_to method with the following in it: format.xml { render :xml => @foo.errors, :status => :unprocessable_entity } How do I have this output the real error messages so the user has some insight into what they did wrong?

    Read the article

  • Global Temporary Table "On commit delete rows" functionality discrepancy.

    - by TomatoSandwich
    I have a global temporary table. I called my GTT, for that was it's initials. My GTT never hurt anyone, and did everything I bade of it. I asked my GTT to delete rows on commit. This is a valid function in the creation script of my GTT in oracle. I wanted to be able to have different users see GTT with their own data, and not the data of other people's sessions. 'Delete rows on commit' worked perfectly in our test environment. GTT and I were happy. But then, I deployed GTT as part of an update to functionality to a client's database. The database doesn't like to play well with GTT. GTT called me up all upset and worried, because it wasn't holding any data any more, and didn't know why. GTT told me that if someone did: insert into my_GTT (description) values ('Happy happy joy joy') he would sing-song back: 1 row inserted. However, if the same person tried select * from my_GTT; GTT didn't know what to do, and he replied 0 rows returned. GTT was upset that he didn't know what his playmate had inserted. Please, Stackoverflow, why would GTT forget what was placed into him? He can remember perfectly well at home, but out in the cold harsh world, he just gets so scared. :(

    Read the article

  • Loading Jscript files into Firefox extension

    - by colon3l
    Hi ! Let's get directly to the problem : I'm actually doing a firefox extension in which i would like to implement the jWebsocket API in order to build a small chat. I got my main script file, named test.js, and the jWebsocket lib into a js folder. Just for you to know, this is my first firefox extension ever. So in my XUL file I got this (for the script part only of course, the interface code is not shown) : <overlay id="test-overlay" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"> <script type="application/x-javascript" src="chrome://test/content/test.js" /> <script type="application/x-javascript" src="chrome://test/content/js/jwebsocket.js" /> jwebsocket.js being the file I need to call according to jWebsocket website. In my main script file test.js I start with : if (jws.browserSupportsWebSockets()) { jWebSocketClient = new jws.jWebSocketJSONClient(); } else { var lMsg = jws.MSG_WS_NOT_SUPPORTED; alert(lMsg); } jws being the namespace created into the jwebsocket.js file. Of course I've got the required stand-alone server running in background, and working. So from what I understood looking on various websites, is that if a js file is loaded into the javascript allocated memory space (with the tag), all namespace/function should be available between each file. But this was mostly for HTML-oriented issues, so I'm not sure if it applies to XUL/Firefox environment. But the script keep failing at the first jws call. Any ideas on what goes wrong here ? I'm stuck for 2 days now :/

    Read the article

  • Questions on method to use: Facebook Business Page with Flash or Facebook Application?

    - by Jay
    Hi there, I'm new to Facebook's Graph API / FBML / etc. So if at any point in my post I make a mistake or wrong assumption, please point them out. One of the projects that I am working on has a need to get data/info from an existing web site in addition to the friends list and such that FB can provide. This is for a platform that allows people from all over the world to help out in small scale projects that will benefit various communities. These projects are usually to help out people in unfortunate / less than ideal situations / living conditions so that their environment improves. You can read about it in detail at http://www.getitdone.org. The initial idea was to develop a Business Page (this is the same as a Fan Page right?) for each Project with a Static FBML tag to do the displaying. However, iframes are not allowed in Pages (as far as I know, iframes are only allowed in an FB Application). So it is no longer possible to get data from the web site to be displayed in the FB Page. So one of the options is to embed a Flash in the Page's Tab. I am fairly certain that the Flash can retrieve data on the User's friends and connections in an Application's context (because of all of those darn FB games that I'm addicted to :p). However, I would like to confirm if it can do the same if it's embedded in a Business Page's Tab. Could someone please confirm on this issue? The other option that we arrived at was (if the earlier options fails) to have an Application built instead. However, this means that we would need to create an Application for each Project. Not an ideal situation. Is there any other option that we have missed that can help us achieve the desired result with as little hassle as possible? Any help that you can provide on this matter is most welcome. Thank you.

    Read the article

  • Global hotkey capture in VB.net

    - by ggonsalv
    I want to have my app which is minimized to capture data selected in another app's window when the hot key is pressed. My app definitely doesn't have the focus. Additionally when the hot key is pressed I want to present a fading popup (Outlook style) so my app never gets focus. At a minimum I want to capture the Window name, Process ID and the selected data. The app which has focus is not my application? I know one option is to sniff the Clipboard, but are there any other solutions. This is to audit the rate of data-entry in to another system of which I have no control. It is a mainframe emulation client program(attachmate). The plan is complete data entry in Application X. Select a certain section of the screen in App X which is proof of data entry (transaction ID). Press the Magic Hotkey, which then 'sends' the selection to my App. From System.environment or system.Threading I can find the Windows logon. Similiarly I can also capture the time. All the data will be logged to SQL. Once Complete show Outlook style pop up saying the data entry has been logged. Any thoughts.

    Read the article

  • Should I write more SQL to be more efficient, or less SQL to be less buggy?

    - by RenderIn
    I've been writing a lot of one-off SQL queries to return exactly what a certain page needs and no more. I could reuse existing queries and issue a number of SQL requests linear to the number of records on the page. As an example, I have a query to return People and a query to return Job Details for a person. To return a list of people with their job details I could query once for people and then once for each person to retrieve their job details. I've found that in most cases that solution returns things in a reasonable amount of time, but I don't know how well it will scale in my environment. Instead I've been writing queries to join people + job details, or people + salary history, etc. I'm looking at my models and I see how I could shave off maybe 30% of my code if I were to re-use existing queries. This is a big temptation. Is it a bad thing to go for reuse over efficiency in general or does it all come down to the specific situation? Should I first do it the easy way and then optimize later, or is it best to get the code knocked out while everything is fresh in my mind? Thoughts, experiences?

    Read the article

  • How to append \line into RTF using RichTextBox control

    - by Steve Sheldon
    When using the Microsoft RichTextBox control it is possible to add new lines like this... richtextbox.AppendText(System.Environment.NewLine); // appends \r\n However, if you now view the generated rtf the \r\n characters are converted to \par not \line How do I insert a \line control code into the generated RTF? What does't work: Token Replacement Hacks like inserting a token at the end of the string and then replacing it after the fact, so something like this: string text = "my text"; text = text.Replace("||" "|"); // replace any '|' chars with a double '||' so they aren't confused in the output. text = text.Replace("\r\n", "_|0|_"); // replace \r\n with a placeholder of |0| richtextbox.AppendText(text); string rtf = richtextbox.Rtf; rtf.Replace("_|0|_", "\\line"); // replace placeholder with \line rtf.Replace("||", "|"); // set back any || chars to | This almost worked, it breaks down if you have to support right to left text as the right to left control sequence always ends up in the middle of the placeholder. Sending Key Messages public void AppendNewLine() { Keys[] keys = new Keys[] {Keys.Shift, Keys.Return}; SendKeys(keys); } private void SendKeys(Keys[] keys) { foreach(Keys key in keys) { SendKeyDown(key); } } private void SendKeyDown(Keys key) { user32.SendMessage(this.Handle, Messages.WM_KEYDOWN, (int)key, 0); } private void SendKeyUp(Keys key) { user32.SendMessage(this.Handle, Messages.WM_KEYUP, (int)key, 0); } This also ends up being converted to a \par Is there a way to post a messaged directly to the msftedit control to insert a control character? I am totally stumped, any ideas guys? Thanks for your help!

    Read the article

  • Can't send smtp email from network using C#, asp.net website

    - by Kaysar
    Hi, I have my code here, it works fine from my home, where my user is administrator, and I am connected to internet via a cable network. But, problem is when I try this code from my work place, it does not work. Shows error: "unable to connect to the remote server" From a different machine in the same network: "A socket operation was attempted to an unreachable network 209.xxx.xx.52:25" I checked with our network admin, and he assured me that all the mail ports are open [25,110, and other ports for gmail]. Then, I logged in with administrative privilege, there was a little improvement, it did not show any error, but the actual email was never received. Please note that, the code was tested from development environment, visual studio 2005 and 2008. Any suggestion will be much appreciated. Thanks in advance try { MailMessage mail_message = new MailMessage("[email protected]", txtToEmail.Text, txtSubject.Text, txtBody.Text); SmtpClient mail_client = new SmtpClient("SMTP.y7mail.com"); NetworkCredential Authentic = new NetworkCredential("[email protected]", "xxxxx"); mail_client.UseDefaultCredentials = true; mail_client.Credentials = Authentic; mail_message.IsBodyHtml = true; mail_message.Priority = MailPriority.High; try { mail_client.Send(mail_message); lblStatus.Text = "Mail Sent Successfully"; } catch (Exception ex) { System.Diagnostics.Debug.WriteLine(ex.Message); lblStatus.Text = "Mail Sending Failed\r\n" + ex.Message; } } catch (Exception ex) { lblStatus.Text = "Mail Sending Failed\r\n" + ex.Message; }

    Read the article

  • After interruption, delayed audio route change notifications when recording

    - by Frank Shearar
    My iPhone application requires that I know when a user has/has not plugged in her headphones. That's easy. AudioSessionAddPropertyListener with a callback listening to kAudioSessionProperty_AudioRouteChange. I write logs with NSLog as things happen. User plugs the headphones in? Get a notification, and a line in the gdb console. User unplugs the headphones? Ditto. At the same time I'm sensing the noise level of the environment by starting a recording audio queue. This, too, works great: I can get the mic noise level and listen for audio route changes just fine. What I find is that after an interruption, and I've reactivated the audio session and restored the audio category to kAudioSessionCategory_RecordAudio, the audio route notifications go a bit haywire. When I plug in the headphones, I see no notification. When I unplug the headphones I see BOTH the "plugged in" notification AND the "unplugged" notification, in rapid succession. It's like the "plugged in" notification's delayed and, when the "unplugged" notification arrives, the queue of pending notifications is flushed. What am I doing wrong? How do I correctly restore the audio session to get timeous notifications? EDIT: iPhone OS 3.1.2, running on an iPhone 3G. I'm running a program compiled with the 3.0 SDK (from within XCode 3.1.2).

    Read the article

  • Postgres error with Sinatra/Haml/DataMapper on Heroku

    - by sevennineteen
    I'm trying to move a simple Sinatra app over to Heroku. Migration of the Ruby app code and existing MySQL database using Taps went smoothly, but I'm getting the following Postgres error: PostgresError - ERROR: operator does not exist: text = integer LINE 1: ...d_at", "post_id" FROM "comments" WHERE ("post_id" IN (4, 17,... ^ HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts. It's evident that the problem is related to a type mismatch in the query, but this is being issued from a Haml template by the DataMapper ORM at a very high level of abstraction, so I'm not sure how I'd go about controlling this... Specifically, this seems to be throwing up on a call of p.comments from my Haml template, where p represents a given post. The Datamapper models are related as follows: class Post property :id, Serial ... has n, :comments end class Comment property :id, Serial ... belongs_to :post end This works fine on my local and current hosted environment using MySQL, but Postgres is clearly more strict. There must be hundreds of Datamapper & Haml apps running on Postgres DBs, and this model relationship is super-conventional, so hopefully someone has seen (and determined how to fix) this. Thanks!

    Read the article

  • What's a way for a client to automatically resolve the ip address of a server?

    - by zooropa
    The project I am working on is a client/server architecture. In a LAN environment, I want the client's to be able to automatically determine the server's address. I want to avoid having to manually configure each client with the ip address of the server. What is the best way to do this? Some alternatives I have thought about doing are: The server could listen for broadcast packets from the clients. The message from the client would be a request for the IP address of the server. The server would respond with its address. The machine running my project's server could also have a bind server running. The LAN's router could be configured to use it as one of its DNS servers. I think I saw that there is a bind library. Does that mean I can build the bind service into my server so that bind doesn't have to be installed on the server? Any other ideas? What have you done in the past? What are the pros/cons of these approaches and others that might be suggested? Thanks for your help!

    Read the article

  • Fix hard-coded display setting without source (24-bit, need 32-bit)

    - by FerretallicA
    I wrote a program about 10 years ago in Visual Basic 6 which was basically a full-screen game similar to Breakout / Arkanoid but had 'demoscene'-style backgrounds. I found the program, but not the source code. Back then I hard-coded the display mode to 800x600x24, and the program crashes whenever I try to run it as a result. No virtual machine seems to support 24-bit display when the host display mode is 16/32-bit. It uses DirectX 7 so DOSBox is no use. I've tried all sorts of decompiler and at best they give me the form names and a bunch of assembly calls which mean nothing to me. The display mode setting was a DirectX 7 call but there's no clear reference to it in the decompilation. In this situation, is there any pointers on how I can: pin-point the function call in the program which is setting the display mode to 800x600x24 (ResHacker maybe?) and change the value being passed to it so it sets 800x600x32 view/intercept DirectX calls being made while it's running or if that's not possible, at least run the program in an environment that emulates a 24-bit display I don't need to recover the source code (as nice as it would be) so much as just want to get it running.

    Read the article

  • Rails wont install at create Makefile stage

    - by mattc
    I am getting this error after running sudo gem install rails /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb creating Makefile make xcrun cc -I. - I/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/universal-darwin12.0 -I/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/universal-darwin12.0 -I. -DJSON_GENERATOR -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE -fno-common -arch i386 -arch x86_64 -g -O3 -pipe -fno-common -DENABLE_DTRACE -fno-common -pipe -fno-common -c generator.c xcrun: Error: failed to exec real xcrun. (No such file or directory) cc -arch i386 -arch x86_64 -pipe -bundle -undefined dynamic_lookup -o generator.bundle generator.o -L. -L/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib -L. -arch i386 -arch x86_64 -lruby -lpthread -ldl -lobjc i686-apple-darwin11-llvm-gcc-4.2: generator.o: No such file or directory i686-apple-darwin11-llvm-gcc-4.2: generator.o: No such file or directory lipo: can't figure out the architecture type of: /var/tmp//ccHCNNwM.out make: *** [generator.bundle] Error 1 I have Homebrew installed, Xcode 4.4 with command line tools installed, Osx 10.6.2 I run gem env and get this but not sure what I'm looking for: RubyGems Environment: - RUBYGEMS VERSION: 1.8.24 - RUBY VERSION: 1.8.7 (2012-02-08 patchlevel 358) [universal-darwin12.0] - INSTALLATION DIRECTORY: /Library/Ruby/Gems/1.8 - RUBY EXECUTABLE: /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby - EXECUTABLE DIRECTORY: /usr/bin - RUBYGEMS PLATFORMS: - ruby - universal-darwin-12 - GEM PATHS: - /Library/Ruby/Gems/1.8 - /Users/matthewcleghorn/.gem/ruby/1.8 - /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8 - GEM CONFIGURATION: - :update_sources => true - :verbose => true - :benchmark => false - :backtrace => false - :bulk_threshold => 1000 - REMOTE SOURCES: - http://rubygems.org/ Any help greatly appreciated. Thanks.

    Read the article

  • iphone: cross platform references and referencing external framework resources

    - by dan
    hi there working on an iphone app and separate framework. the separate framework is for an API that i'm building for use in multiple future apps. this api now needs to reference resources (images). what i would like to do is keep the resources WITH the API framework as local set of resources. i followed the instructions from http://www.clintharris.net/2009/iphone-app-shared-libraries/ to setup my app's project to use the headers from the separate API framework. what i can't seem to figure out is how to automatically load the framework's resources into the app's xcode environment so they can be linked in at app compile time. sure, i can drag the resources across from the framework into the main app's set of resources. but that seems kinda ugly and another step that possibly can be automated (??) anyone know of a better way? it would be great if any changes from the framework would be automatically available in the main app (due to the project 'link-age'). thanks for any help/tips/suggestions...

    Read the article

  • Syncing magento database froms development to production

    - by ringerce
    I use git for version control. I have a development, staging and production environment. When I finish in development I push to staging for review by the client. When approved, I push changes from staging to production. That works fine as long as there is no database changes. What happens if I install modules via Magento connect on local development and it makes database modifications. How would I push those changes up to the production server since the production server is always changing? Edit: I wrote two shell scripts. One that pulls the production database down to my development server, replaces base url with develpment url and updates my development db accordingly. It also leaves the production sql dump behind to be added to my git repo. I'm not really sure if it's beneficial to keep the raw dumps in source control but I'm going to try it out. The second scripts moves the development database up to staging and essentially performs the same operations as the first. Now when it comes time to move to production I pull the updated production repo into the production server and allow magento to do it's thing. I also started using SQLYog recently and it has a database comparison wizard which will give me the differences in my development and production databases and allow me to merge the changes in selectively. It always creates a migration script that I added to source control as well. If anything goes wrong I can run the comparison to see if anything was missed. Does this sounds like a decent workflow to you guys?

    Read the article

  • G++ Multi-platform memory leak detection tool

    - by indyK1ng
    Does anyone know where I can find a memory memory leak detection tool for C++ which can be either run in a command line or as an Eclipse plug-in in Windows and Linux. I would like it to be easy to use. Preferably one that doesn't overwrite new(), delete(), malloc() or free(). Something like GDB if its gonna be in the command line, but I don't remember that being used for detecting memory leaks. If there is a unit testing framework which does this automatically, that would be great. This question is similar to other questions (such as http://stackoverflow.com/questions/283726/memory-leak-detection-under-windows-for-gnu-c-c ) however I feel it is different because those ask for windows specific solutions or have solutions which I would rather avoid. I feel I am looking for something a bit more specific here. Suggestions don't have to fulfill all requirements, but as many as possible would be nice. Thanks. EDIT: Since this has come up, by "overwrite" I mean anything which requires me to #include a library or which otherwise changes how C++ compiles my code, if it does this at run time so that running the code in a different environment won't affect anything that would be great. Also, unfortunately, I don't have a Mac, so any suggestions for that are unhelpful, but thank you for trying. My desktop runs Windows (I have Linux installed but my dual monitors don't work with it) and I'd rather not run Linux in a VM, although that is certainly an option. My laptop runs Linux, so I can use that tool on there, although I would definitely prefer sticking to my desktop as the screen space is excellent for keeping all of the design documentation and requirements in view without having to move too much around on the desktop. NOTE: While I may try answers, I won't mark one as accepted until I have tried the suggestion and it is satisfactory. EDIT2: I'm not worried about the cross-platform compatibility of my code, it's a command line application using just the C++ libraries.

    Read the article

  • Good tools for keeping the content in test/staging/live environments synchronized

    - by David Stratton
    I'm looking for recommendations on automated folder synchronization tools to keep the content in our three environments synchronized automatically. Specifically, we have several applications where a user can upload content (via a File Upload page or a similar mechanism), such as images, pdf files, word documents, etc. In the past, we had the user doing this to our live server, and as a result, our test and staging servers had to be manually synchronized. Going forward, we will have them upload content to the staging server, and we would like some software to automatically copy the files off to the test and live servers EITHER on a scheduled basis OR as the files get uploaded. I was planning on writing my own component, and either set it up as a scheduled task, or use a FileSystemWatcher, but it occurred to me that this has probably already been done, and I might be better off with some sort of synchronization tool that already exists. On our web site, there are a limited number of folders that we want to keep synchronized. In these folders, it is an all or nothing - we want to make sure the folders are EXACT duplicates. This should make it fairly straightforward, and I would think that any software that can synchronize folders would be OK, except that we also would like the software to log changes. (This rules out simple BATCH files.) So I'm curious, if you have a similar environment, how did you solve the challenge of keeping everything synchronized. Are you aware of a tool that is reliable, and will meet our needs? If not, do you have a recommendation for something that will come close, or better yet, an open source solution where we can get the code and modify it as needed? (preferably .NET). Added Also, I DID google this first, but there are so many options, I am interested mostly in knowing what actually works well vs what they SAY works, which is why I'm asking here.

    Read the article

  • Thread-safe data structure design

    - by Inso Reiges
    Hello, I have to design a data structure that is to be used in a multi-threaded environment. The basic API is simple: insert element, remove element, retrieve element, check that element exists. The structure's implementation uses implicit locking to guarantee the atomicity of a single API call. After i implemented this it became apparent, that what i really need is atomicity across several API calls. For example if a caller needs to check the existence of an element before trying to insert it he can't do that atomically even if each single API call is atomic: if(!data_structure.exists(element)) { data_structure.insert(element); } The example is somewhat awkward, but the basic point is that we can't trust the result of "exists" call anymore after we return from atomic context (the generated assembly clearly shows a minor chance of context switch between the two calls). What i currently have in mind to solve this is exposing the lock through the data structure's public API. This way clients will have to explicitly lock things, but at least they won't have to create their own locks. Is there a better commonly-known solution to these kinds of problems? And as long as we're at it, can you advise some good literature on thread-safe design? EDIT: I have a better example. Suppose that element retrieval returns either a reference or a pointer to the stored element and not it's copy. How can a caller be protected to safely use this pointer\reference after the call returns? If you think that not returning copies is a problem, then think about deep copies, i.e. objects that should also copy another objects they point to internally. Thank you.

    Read the article

  • How to prevent chrome from injecting content to webpage

    - by Nazariy
    Recently I have discovered that my application is misbehaving in Google Chrome. On a page with a form, after it was submitted, my application reloads page using simple method like this: header('Location: ' . $url); after that, page is rendered incorrectly and this content is injected to DOM <div id="sbi_camera_button" class="sbi_search" style="left: 0px; top: 0px; position: absolute; width: 29px; height: 27px; border: none; margin: 0px; padding: 0px; z-index: 2147483647; display: none; "></div> After manual page refresh everything works as expected. I'm not sure what causing this behavior, as I'm working in closed local environment and application works fine in Firefox. My application using following libraries (hosted locally): jQuery v1.7.1 jQuery UI 1.8.16 Bootstrap.js v 2.1.1 Can someone suggest me what can possibly cause this issue?

    Read the article

  • Internet zone is opened when broswer is opened from installer created by .Net 3.5sp1

    - by priya
    Hi All, I have project created in VS2005 and .Net 2.0. The installation is a web-based installation. After installing the proe-requisites the installer opens up the browser to continue with web-based install. On this, it opens up in intranet zone and works perfectly. I recently migrated the project to VS2008 Sp1 and .Net 3.5sp1. No change in my code and the test environment. Here the browser gets opened up in the Internet zone which prevents it from moving forward, until unless I open up a new browser manually and copy paste the url. The internet security options on the both the case are - Internet --- High. For the case2, if i have the security internet option to be 'Medium', it works well. I am not sure why this issue comes up when I change the VS and .Net version. More over the browser gets opened with system priveleges rather than administrator privileges. Please let me know any solution on this. Thanks, Priya.R

    Read the article

  • java singleton instantiation

    - by jurchiks
    I've found three ways of instantiating a Singleton, but I have doubts as to whether any of them is the best there is. I'm using them in a multi-threaded environment and prefer lazy instantiation. Sample 1: private static final ClassName INSTANCE = new ClassName(); public static ClassName getInstance() { return INSTANCE; } Sample 2: private static class SingletonHolder { public static final ClassName INSTANCE = new ClassName(); } public static ClassName getInstance() { return SingletonHolder.INSTANCE; } Sample 3: private static ClassName INSTANCE; public static synchronized ClassName getInstance() { if (INSTANCE == null) INSTANCE = new ClassName(); return INSTANCE; } The project I'm using ATM uses Sample 2 everywhere, but I kind of like Sample 3 more. There is also the Enum version, but I just don't get it. The question here is - in which cases I should/shouldn't use any of these variations? I'm not looking for lengthy explanations though (there's plenty of other topics about that, but they all eventually turn into arguing IMO), I'd like it to be understandable with few words.

    Read the article

  • java GC periodically enters into several full GC cycles

    - by Peter
    Environment: sun JDK 1.6.0_16 vm settings: -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -Xms1024 -Xmx1024M -XX:MaxNewSize=448m -XX:NewSize=448m -XX:SurvivorRatio=4(6 also checked) -XX:MaxPermSize=128M OS: windows server 2003 processor: 4 cores of INTEL XEON 5130, 2000 Hz my application description: high intensity of concurrent(java 5 concurrency used) operations completed each time by commit to oracle. it's about 20-30 threads run non stop, doing tasks. application runs in JBOSS web container. My GC starts work normally, I see a lot of small GCs and all that time CPU shows good load, like all 4 cores loaded to 40-50%, CPU graph is stable. Then , after 1 min of good work, CPU starts drop to 0% on 2 cores from 4, it's graph becomes unstable, goes up and down("teeth"). I see, that my threads work slower(I have monitoring), I see that GC starts produce a lot of FULL GC during that time and next 4-5 minutes this situation remains as is, then for short period of time, like 1 minute, it gets back to normal situation, but shortly after that all bad thing repeats. Question: Why I have so frequent full GC??? How to prevent that? I played with SurvivorRatio - does not help. I noticed, that application behaves normally until first FULL GC occurs, while I have enough memory. Then it runs badly. my GC LOG: starts good then long period of FULL GCs(many of them) 1027.861: [GC 942200K-623526K(991232K), 0.0887588 secs] 1029.333: [GC 803279K(991232K), 0.0927470 secs] 1030.551: [GC 967485K-625549K(991232K), 0.0823024 secs] 1030.634: [GC 625957K(991232K), 0.0763656 secs] 1033.126: [GC 969613K-632963K(991232K), 0.0850611 secs] 1033.281: [GC 649899K(991232K), 0.0378358 secs] 1035.910: [GC 813948K(991232K), 0.3540375 secs] 1037.994: [GC 967729K-637198K(991232K), 0.0826042 secs] 1038.435: [GC 710309K(991232K), 0.1370703 secs] 1039.665: [GC 980494K-972462K(991232K), 0.6398589 secs] 1040.306: [Full GC 972462K-619643K(991232K), 3.7780597 secs] 1044.093: [GC 620103K(991232K), 0.0695221 secs] 1047.870: [Full GC 991231K-626514K(991232K), 3.8732457 secs] 1053.739: [GC 942140K(991232K), 0.5410483 secs] 1056.343: [Full GC 991232K-634157K(991232K), 3.9071443 secs] 1061.257: [GC 786274K(991232K), 0.3106603 secs] 1065.229: [Full GC 991232K-641617K(991232K), 3.9565638 secs] 1071.192: [GC 945999K(991232K), 0.5401515 secs] 1073.793: [Full GC 991231K-648045K(991232K), 3.9627814 secs] 1079.754: [GC 936641K(991232K), 0.5321197 secs]

    Read the article

  • What kind of storage with two-way replication for multi site C# application?

    - by twk
    Hi I have a web-based system written using asp.net backed by mssql. A synchronized replica of this system is to be run on mobile locations and must be available regardless of the state of the connection to the main system (few hours long interruptions happens). For now I am using a copy of the main web application and a copy of the mssql server with merge replication to the main system. This works unreliably, and setting the replication is a pain. The amount of data the system contains is not huge, so I can migrate to different storage type. For the new version of this system I would like to implement a new replication system. I am considering migration to db4o for storage with it's replication support. I am thinking about other possible solutions like couchdb which had native replication support. I would like to stay with C#. Could you recommend a way to go for such a distributed environment? PS. Master-Slave replication is not an option: any side must be allowed to add/update data.

    Read the article

  • Optimal Eclipse CDT (C++) experience in March of 2010

    - by ahoffer
    I am a student who will be using C++ next quarter. I really enjoyed using the Galileo release of Eclipse with Java and I would like to continue using Eclipse for for C++ development. I am now experimenting with C++ development on Eclipse. I am running Eclipse 3.5 SR2 with CDT 6.02. My operating system is Windows 7 and I have installed MinGW-5.1.6. Version 6.3 of GDB is installed. I have it compiling and stepping through code. However, I have the suspicion that I'm just crawling along and have yet to "shift the car out of first gear". I've spent about a week poking around on the Web to learn what constitutes and "optimal" C++ Eclipse experience. In particular, I'm interested in round-tripping with UML and unit testing. My exploration of the Web became an archeological dig. I turned up how-to articles from 2003, alternative MinGW distros, references to plugins, dead-links, more references to plugins, passionate discussions on gdb bugs, and more references to plugins. I no longer have any idea what might constitute an optimal C++ Eclipse environment. Would members of the community like to weigh-in on what they consider to be the current optimal experience for C++ development using Eclipse?

    Read the article

  • How can I optimize the SELECT statement running on an Oracle database?

    - by Elvis Lou
    I have a SELECT statement in ORACLE: SELECT COUNT(DISTINCT ds1.endpoint_msisdn) multiple30, dss1.service, dss1.endpoint_provisioning_id, dss1.company_scope, Nvl(x.subscription_status, dss1.subscription_status) subscription_status FROM daily_summary ds1 join daily_summary ds2 ON ds1.endpoint_msisdn = ds2.endpoint_msisdn, daily_summary_static dss1, daily_summary_static dss2, (SELECT NULL subscription_status FROM dual UNION ALL SELECT -2 subscription_status FROM dual) x WHERE ds1.summary_ts >= To_date('10-04-2012', 'dd-mm-yyyy') - 30 AND ds1.summary_ts <= To_date('10-04-2012', 'dd-mm-yyyy') AND dss1.last_active >= To_date('10-04-2012', 'dd-mm-yyyy') - 30 AND dss1.last_active <= To_date('10-04-2012', 'dd-mm-yyyy') AND dss2.last_active >= To_date('10-04-2012', 'dd-mm-yyyy') - 30 AND dss2.last_active <= To_date('10-04-2012', 'dd-mm-yyyy') AND dss1.service <> dss2.service AND ( dss1.company_scope = 2 OR dss1.company_scope = 5 ) AND ( dss2.company_scope = 2 OR dss2.company_scope = 5 ) AND dss1.company_scope = dss2.company_scope AND ds1.endpoint_noc_id = dss1.endpoint_noc_id AND ds1.endpoint_host_id = dss1.endpoint_host_id AND ds1.endpoint_instance_id = dss1.endpoint_instance_id AND ds2.endpoint_noc_id = dss2.endpoint_noc_id AND ds2.endpoint_host_id = dss2.endpoint_host_id AND ds2.endpoint_instance_id = dss2.endpoint_instance_id AND dss1.endpoint_provisioning_id = dss2.endpoint_provisioning_id AND Least(1, ds1.total_actions) = 1 AND Least(1, ds2.total_actions) = 1 GROUP BY dss1.service, dss1.endpoint_provisioning_id, dss1.company_scope, Nvl(x.subscription_status, dss1.subscription_status); This query took about 26 minutes to return in my environment, but if I remove the section: dss1.last_active >= to_date('10-04-2012','dd-mm-yyyy') - 30 AND dss1.last_active <= to_date('10-04-2012','dd-mm-yyyy') AND dss2.last_active >= to_date('10-04-2012','dd-mm-yyyy') - 30 AND dss2.last_active <= to_date('10-04-2012','dd-mm-yyyy') AND it only took 20 seconds to run. We have index on the column last_active, I don't know why the section slow down the performance so much? any ideas?

    Read the article

< Previous Page | 503 504 505 506 507 508 509 510 511 512 513 514  | Next Page >