Search Results

Search found 20211 results on 809 pages for 'language implementation'.

Page 573/809 | < Previous Page | 569 570 571 572 573 574 575 576 577 578 579 580  | Next Page >

  • How to synchronize static method in java.

    - by Summer_More_More_Tea
    Hi there: I come up with this question when implementing singleton pattern in Java. Even though the example listed blow is not my real code, yet very similar to the original one. public class ConnectionFactory{ private static ConnectionFactory instance; public static synchronized ConnectionFactory getInstance(){ if( instance == null ){ instance = new ConnectionFactory(); } return instance; } private ConnectionFactory(){ // private constructor implementation } } Because I'm not quite sure about the behavior of a static synchronized method, I get some suggestion from google -- do not have (or as less as possible) multiple static synchronized methods in the same class. I guess when implementing static synchronized method, a lock belongs to Class object is used so that multiple static synchronized methods may degrade performance of the system. Am I right? or JVM use other mechanism to implement static synchronized method? What's the best practice if I have to implement multiple static synchronized methods in a class? Thank you all! Kind regards!

    Read the article

  • Gwt-ext. Bean to record and record to bean.

    - by den bardadym
    I write a RIA application and my JPA beans must be decoded to push it in Store. My decisions are: Brute Force. If I have property 'aProp' in bean (and getter/setter for it) i create RecordDef, then Record, then Recrod.set('aProp', bean.getAProp()) and so on.. (it is terrible) I can write generator for creating a Factory of Records (it is my desision and i write it). For example: RecordFactory<User> factory = GWT.create(User.class); //User is entity I now that i need a reflection, BUT GWT have no implementation of reflection (some libraries emulates this, but they builds on generators) Exists the best way? Thanks, Den Bardadym.

    Read the article

  • simple putStrLn in Haskell/Yampa with arrows syntax

    - by sisif
    i'm using Haskell with the Yampa FRP library which uses the arrows language extension. how can i do a simple putStrLn in a SF? mySF = proc x -> do y <- identity -< x*x putStrLn "Hello World!" ++ show y returnA -< y the arrow syntax complains about the expression not bein an arrow (of course), but even with arrows i get no output output <- identity -< putStrLn "Hello World!"

    Read the article

  • Is there any real world reason to use throw ex?

    - by Michael Stum
    In C#, throw ex is almost always wrong, as it resets the stack trace. I just wonder, is there any real world use for this? The only reason I can think of is to hide internals of your closed library, but that's a really weak reason. Apart from that, I've never encountered in the real world. Edit: I do mean throw ex, as in throwing the exact same exception that was caught but with an empty stacktrace, as in doing it exactly wrong. I know that throw ex has to exist as a language construct to allow throwing a different exception (throw new DifferentException("ex as innerException", ex)) and was just wondering if there is ever a situration where a throw ex is not wrong.

    Read the article

  • Again: Android Stock browser vs. WebView?

    - by user2281606
    maybe a very easy question, but this drives me crazy... I work in company where we develope apps based on webviews. Everytime something went wrong, my boss tells me: "Hey look, the page runs nicely in the android browser, so it has to run that way in the app. Make it happen." I know that every manufacturer has his own implementation, discussed here: Android WebView VS Phone Browser But i want to keep my question simple: Is the android stock browser a pimped webview or in other words, extends the android browser from webview-class ? Thanks for any response?

    Read the article

  • Why wasn't C# designed with 'const' for variables and methods?

    - by spoulson
    I suspect const was simplified for the C# spec for general language simplicity. Was there a specific reason we can't declare variable references or methods as const like we can with C++? e.g.: const MyObject o = new MyObject(); // Want const cast referenece of MyObject o.SomeMethod(); // Theoretically legal because SomeMethod is const o.ChangeStuff(); // Theoretically illegal because ChangeStuff is not const class MyObject { public int val = 0; public void SomeMethod() const { // Do stuff, but can't mutate due to const declaration. } public void ChangeStuff() { // Code mutates this instance. Can't call with const reference. val++; } }

    Read the article

  • Differences between Ruby on Rails versions? Which should I use?

    - by Stephen Kellett
    I first used Rails when it was not so well known about, in 2005. I did some experimental work with it but it has languished due to lack of time. I'm now thinking of persuing the original idea again (with a new implementation) and when researching the latest Ruby and Ruby-on_Rails versions I see Ruby 1.9.2 and a Rails 3.0 beta. I haven't managed to find a concise description of the differences between any of the Rails major versions. I have looked on the official Rails site and a few others as well. No joy. Maybe i'm looking in the wrong places or for the wrong thing? My project isn't commercial in nature (it's a hobby thing) so the beta nature of Rails 3.0 doesn't put me off. I'd just like to know what the differences are. Can anyone explain please? If it makes any odds to the answer, I'll be working on a Linux box and/or a Windows box.

    Read the article

  • What is the '^' in Objective-C

    - by Chris Paterson
    What does the '^' mean in the code below? @implementation AppController - (IBAction) loadComposition:(id)sender { void (^handler)(NSInteger); NSOpenPanel *panel = [NSOpenPanel openPanel]; [panel setAllowedFileTypes:[NSArray arrayWithObjects: @"qtz", nil]]; handler = ^(NSInteger result) { if (result == NSFileHandlingPanelOKButton) { NSString *filePath = [[[panel URLs] objectAtIndex:0] path]; if (![qcView loadCompositionFromFile:filePath]) { NSLog(@"Could not load composition"); } } }; [panel beginSheetModalForWindow:qcWindow completionHandler:handler]; } @end === I've searched and searched - is it some sort of particular reference to memory?

    Read the article

  • How to save state of the app when app terminates?

    - by user164589
    Hi guys. I am trying to save the app state by encoding when the app terminates. I've found the solution related this issue. But I don't know how to use. I am really trying to make encoding and decoding like this: http://cocoaheads.byu.edu/wiki/nscoding in CustomObject.h @interface CustomObject : NSObject <NSCoding> { NSArray *someArray; } in CustomObject.m @implementation CustomObject // Other method implementations here - (void) encodeWithCoder:(NSCoder*)encoder { [encoder encodeObject:someArray forKey:@"someArray"]; } - (id) initWithCoder:(NSCoder*)decoder { if (self = [super init]) { someArray = [[decoder decodeObjectForKey:@"someArray"] retain]; } return self; } @end My object to save is another NSArray. Not "someArray" in CustomObject. We call it that "MySaveObject". I want to pass "MySaveObject" to "someArray" in CustomObject. Actually I don't know how to encode "MySaveObject" and to pass to "someArray" in CustomObject. Thanks in advance.

    Read the article

  • External Javascript file fails to receive variables from previous javascript block

    - by Franc
    I've been searching the net for several hours and can't find an answer in the whole "external js file"-jungle. I hope you guys can help! In short: My external javascript file doesn't seem to get the variables which I defined in the main.php file.. On main.php I define php variables and "transform" them into javascript variables <head>... <script type="text/javascript"> var phpmain_img = <?php echo json_encode($main_img); ?>; var phpvar1_large = <?php echo json_encode($var1_large); ?>; var phpvar2_large = <?php echo json_encode($var2_large); ?>; var phpvar3_large = <?php echo json_encode($var3_large); ?>; var phpvar4_large = <?php echo json_encode($var4_large); ?>; </script> ... <script language="javascript" type="text/javascript" src="/wshop/ext.js"></script> </head> In my ext.js file I want to process those variables. In the ext.js file I defined a the function swapImage() that will be used back in the main PHP: var imgArray = new Array( phpmain_img, phpvar1_large, phpvar2_large, phpvar3_large ); function swapImage(imgID) { var theImage = document.getElementById('theImage'); var newImg; newImg = imgArray[imgID]; theImage.src = newImg; } function preloadImages() { for(var i = 0; i < imgArray.length; i++) { var tmpImg = new Image; tmpImg.src = imgArray[i]; } } Result: The swapImage() in the main.php... doesnt work <div id="image"> <img id="theImage" src="<?=$main_img; ?>" alt="" /> </div> <div id="thumbs"> <?php echo "<img src=\"<$main_img_small\" alt=\"\" onmouseover=\"swapImage(0);\">"; echo "<img src=\"$var1_small\" alt=\"\" onmouseover=\"swapImage(1);\">"; echo "<img src=\"$var2_small\" alt=\"\" onmouseover=\"swapImage(2);\">"; echo "<img src=\"$var3_small\" alt=\"\" onmouseover=\"swapImage(3);\">"; ?> <br /> </div> Any help is greatly appreciated! UPDATE: I don't get a specific error, the swapImage functions doesn't work at mouseover. However, I tried to output the variables with e.g. document.write(phpimg_main) but nothing appears which makes me believe that there's something wrong with the handing over of the variables... here's the source code browser output `<html> <head> <link href="../demo.css" rel="stylesheet" type="text/css" /> <style type="text/css"> .... </style> <script type="text/javascript"> var phpmain_img = {"0":"http:\/\/path\/to\/main\/image.jpg"}; var phpvar1_large = {"0":"http:\/\/path\/to\/image1.jpg"}; var phpvar2_large = {"0":"http:\/\/path\/to\/image2.jpg"}; var phpvar3_large = null; var phpvar4_large = null; </script> <script language="javascript" type="text/javascript" src="/wshop/ext.js"></script> </head> <body onload="preloadImages()"> <div id="image"> <img id="theImage" src="http://path-to-main-image.jpg" alt="" /> </div> <div id="thumbs"> <img src="http://path-to-main-image.jpg" alt="" onmouseover="swapImage(0);"><img src="http://path-to-image1.jpg" alt="" onmouseover="swapImage(1);"><img src="http://path-to-image2.jpg" alt="" onmouseover="swapImage(2);"> <br /> </div> </body> `

    Read the article

  • byte-sized bit pattern in C and its relevance?

    - by Nikunj Banka
    I a reading Kerninghan and Ritchie's C programming language book and on page 37 it mentions byte sized bit patterns like : '\013' for vertical tab . '\007' for bell character . My doubts : What is byte sized in it and and what's a bit pattern ? What relevance does this hold and where can I apply it ? Is it in any sense related to escape sequences ? I can't seem to find any information what so ever about these byte sized bit patterns on the web . please help . thanks .

    Read the article

  • Google checkout callback API sending ack but nothing else?

    - by Chris Sobolewski
    I am putting together a test google checkout implementation and I cannot seem to get the code in the responsehandler demo to do anything aside from send acknowledgements. Even something as simple as uncommenting the folling lines case 'CHARGEABLE': { $Grequest->SendProcessOrder($data[$root]['google-order-number']['VALUE']); $Grequest->SendChargeOrder($data[$root]['google-order-number']['VALUE'],''); break; Isn't having the expected effect of causing the order to automatically be charged. The error log googlecheckout creates has no errors in it, and the message log shows that xml is being properly recieved and acknlowlegments are sent. Does anyone have a clue on how to start troubleshooting this? I am still rather fresh with PHP.

    Read the article

  • Simpler array declaration syntax in c++

    - by AareP
    In the spirit of Go-language, where simpler syntax is considered pretty important, here's a proposal for simpler array declaration in c++: int value; int_1 list; int_2 table; int_3 cube; RECT rect; RECT_1 rects; Using typedefs this can expand to: int value; vector<int> list; vector<int> table; vector<int> cube; RECT rect; vector<RECT> rects; Would you use it, or is there such a thing as too simple syntax?

    Read the article

  • How can I return something other than an enum from an NServiceBus endpoint exposed as a WCF service?

    - by Todd Stout
    I have a service exposed as WCF via NServiceBus. Ultimately, I'd like to call to this service from silverlight. My WCF Service Interface looks like this: [ServiceContract] public interface ISettingsService { [OperationContract(Action = "http://tempuri.org/IWcfServiceOf_RequestSettingsMessage_SettingsResponseMessage/Process", ReplyAction = "http://tempuri.org/IWcfServiceOf_RequestSettingsMessage_SettingsResponseMessage/ProcessResponse") ] SettingsResponseMessage FetchSettings(RequestSettingsMessage request); } My NSB WCF service is defined as: public class CoreService : WcfService<RequestSettingsMessage, SettingsResponseMessage> { } When I invoke the FetchSettings method on the service, I get an exception: System.TypeInitializationException: The type initializer for 'NServiceBus.WcfSer vice`2' threw an exception. ---- System.InvalidOperationException: Centerlink.Services.Core.Msg.Settings.SettingsResponseMessage must be an enum representing error codes returned by the server. It seems that the WcfService< class is restricting the return type of a WCF method to be an enum. How can I have my service return something other than an enum? Do I need to create a custom implementation of NServiceBus.WcfService<?

    Read the article

  • Aren't passwords written in inputbox vulnerable through a stack trace ?

    - by loursonwinny
    Hello, I am not a guru of the stack tracing, at all. I even don't know how to get some. Anyway, I am wondering if entering a password entered in an inputbox is safe. Can't it be retrieved by getting a stack trace ? A password entered that way will be found in many places : Caption property of the TEdit Result of the function which creates the inputbox probably, a variable that stores the Result of the InputBox Command etc... If the answer is "yes, it is a vulnerability", then my world collapses :p. What can be done to avoid that vulnerability hole ? NOTE : The InputBox is an example but it can be with a "homebrewed" login prompt. InputBox is a Delphi command but I haven't tagged the question with the Delphi tag because I suppose that the question concerns any language. Thanks for reading

    Read the article

  • Is it possible to run a compiled program with Xcode on Mac OS X in FreeBSD? (Objective-C/Cocoa)

    - by Eonil
    Hi. I have a plan to build a web-site which running CGI made with Cocoa. My final goal is develop on Mac OS X, and run on FreeBSD. Is this possible? As I know, there is a free implementation of some NextStep classes, the GNUStep. The web-site is almost built with only strings. I read GNUStep documents, classes are enough. DB connection will be made with C interfaces. Most biggest problem which I'm concerning is linking and binary compatibility. I'm currently configuring FreeBSD on VirtualBox, but I wanna know any possibility informations about this from experts. This is not a production server. Just a trial. Please feel free to saying anything.

    Read the article

  • Zend + Wamp = Cant use curl/fput for a url locally

    - by bluedaniel
    Ive got a page in Zend all set up that will for now just echo "Hello", this address is at http://dev.local/hello and works when visiting in the browser. However when I try to use curl or file_get_contents from a script in my zend 'public' folder I get a 500 Internal error message. UPDATE Its failing because my application tries to set the langauge based on the browsers default language, when using headers like I have below, how do I add this locale? "User-Agent: XXXXXXX/2.0\r\n" . "Accept: */*\r\n" . "Accept-Charset: utf-8;\r\n" .

    Read the article

  • How to write syntax highlighting? c++

    - by ML
    Hi All, I am embarking on some learning and I want to write my own syntax highlighting for files in C++. Can anyone give me ideas on how to go about doing this? To me it seems that when a file is opened: 1. it would need to be parsed and decided what type of source file it is. Trusting the extension might not be full-proof a way to know what keywords/commands apply to what language a way to decide what color each keyword/command gets I want to do this on OS X, C++ or Objective-C Can anyone provide pointers on how I might get started with this?

    Read the article

  • What's wrong with consuming ConfiguredTaskAwaitable from PortableClassLibrary's class under Debugger from MSTest Runner or Console App?

    - by Stas Shusha
    *Its only Debug-time error, but a very weird one. Problem: While running with Debugger attached and calling a method, exposed in separate Portable library, returning ConfiguredTaskAwaitable, we get InvalidProgramException. Repro: Having 2 projects: PortableClassLibrary (supporting .Net 4.5; Windows Store; Windows Phone 8) with 1 class: public class Weird { public static ConfiguredTaskAwaitable GetConfiguredTaskAwaitable() { return new ConfiguredTaskAwaitable(); } } ConsoleApplication with code: static void Main(string[] args) { Weird.GetConfiguredTaskAwaitable(); } Notes: replacing ConfiguredTaskAwaitable with ConfiguredTaskAwaitable<T> (a generic version) fixes this strange issue consuming this method form WP8 or Win8 app under Debugger works fine. Currently it causes problems cause I cant run my Unit Tests under Debugger. I'm forced to change my "ObjectUnderTest" implementation to return generic ConfiguredTaskAwaitable<T>, which is fine for the real project, but still is only a workaround. The Question is: does anybody knows the reason of this error? It definitely related to Portable Class Library magic.

    Read the article

  • Ranged integers in .NET (or C#)

    - by Mal Ross
    Am I being blind, or does the .NET framework not provide any kind of ranged integer class? That is, a type that would prevent you setting a value outside some given bounds that are not the full range of the basic data type. For example, an integer type that would restrict its values to between 1 and 100. Showing my age here, but back in '93, I remember using that sort of thing in Modula-2 (eeek!), but I've not seen explicit framework / language support for it since. Am I just missing something, or is it a case of "it's so simple to make your own that the framework doesn't bother"? Cheers.

    Read the article

  • Autorelease and properties

    - by ganuke
    I have few questions to ask about the following class #import <Cocoa/Cocoa.h> @interface SomeObject { NSString *title; } @property (retain) NSString *title; @end implementation SomeObject @synthesize title; -(id)init { if (self=[super init]) { self.title=[NSString stringWithFormat:@"allyouneed"]; } return self; } -(void)testMethod{ self.title=[[NSString alloc] init] ; } -(void)dealloc { self.title=nil; [super dealloc]; } In the .h file do we need to declare the title and sub when we add the property. is it not enough to add the @property (retain) NSString *title; line. 2.Do i need to autorelease both assignment to title in the init and testMethod. if So why? Can some one explain these things to me.

    Read the article

  • STL deque accessing by index is O(1)?

    - by jasonline
    I've read that accessing elements by position index can be done in constant time in a STL deque. As far as I know, elements in a deque may be stored in several non-contiguous locations, eliminating safe access through pointer arithmetic. For example: abc-defghi-jkl-mnop The elements of the deque above consists of a single character. The set of characters in one group indicate it is allocated in contiguous memory (e.g. abc is in a single block of memory, defhi is located in another block of memory, etc.). Can anyone explain how accessing by position index can be done in constant time, especially if the element to be accessed is in the second block? Or does a deque have a pointer to the group of blocks? Update: Or is there any other common implementation for a deque?

    Read the article

  • What are the main reasons against the Windows Registry?

    - by dbemerlin
    If i want to develop a registry-like System for Linux, which Windows Registry design failures should i avoid? Which features would be absolutely necessary? What are the main concerns (security, ease-of-configuration, ...)? I think the Windows Registry was not a bad idea, just the implementation didn't fullfill the promises. A common place for configurations including for example apache config, database config or mail server config wouldn't be a bad idea and might improve maintainability, especially if it has options for (protected) remote access. I once worked on a kernel based solution but stopped because others said that registries are useless (because the windows registry is)... what do you think?

    Read the article

  • Simple Serialization Faster Than JSON? (in Ruby)

    - by Sinan Taifour
    I have an application written in ruby (that runs in the JRuby VM). When profiling it, I realized that it spends a lot (actually almost all of) its time converting some hashes into JSON. These hashes have keys of symbols, values of other similar hashes, arrays, strings, and numbers. Is there a serialization method that is suitable for such an input, and would typically run faster than JSON? It would preferable if it is has a Java or JRuby-compatible gem, too. I am currently using the jruby-json gem, which is the fastest JSON implementation in JRuby (as I am told), so the move will most likely be to a different serialization method rather than just a different library. Any help is appreciated! Thanks.

    Read the article

  • What's a good book for learning BCPL?

    - by paxdiablo
    A long time ago, I worked on some BCPL code (very similar to C although even more basic, difficult though that is to imagine). Now, as part of a compiler course, we're going to be setting assignments for building some of the parts of the compiler (lexical and semantic analysis) and I'd like to know what the community thinks is the best book for learning about the language (and concrete why you think it's the best). Not how to write compilers for it, just on how to program in it. It'll be up to the students themselves to figure out how best to develop a compiler. We're using BCPL since the chance of people being able to plagiarise code for a compiler is very slim. Any suggestions?

    Read the article

< Previous Page | 569 570 571 572 573 574 575 576 577 578 579 580  | Next Page >