Search Results

Search found 7182 results on 288 pages for 'factory pattern'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 68/288 | < Previous Page | 64 65 66 67 68 69 70 71 72 73 74 75  | Next Page >

  • Can you find a pattern to sync files knowing only dates and filenames?

    - by Robert MacLean
    Imagine if you will a operating system that had the following methods for files Create File: Creates (writes) a new file to disk. Calling this if a file exists causes a fault. Update File: Updates an existing file. Call this if a file doesn't exist causes a fault. Read File: Reads data from a file. Enumerate files: Gets all files in a folder. Files themselves in this operating system only have the following meta data: Created Time: The original date and time the file was created, by the Create File method. Modified Time: The date and time the file was last modified by the Update File method. If the file has never been modified, this will equal the Create Time. You have been given the task of writing an application which will sync the files between two directories (lets call them bill and ted) on a machine. However it is not that simple, the client has required that The application never faults (see methods above). That while the application is running the users can add and update files and those will be sync'd next time the application runs. Files can be added to either the ted or bill directories. File names cannot be altered. The application will perform one sync per time it is run. The application must be almost entirely in memory, in other words you cannot create a log of filenames and write that to disk and then check that the next time. The exception to point 6 is that you can store date and times between runs. Each date/time is associated with a key labeled A through J (so you have 10 to use) so you can compare keys between runs. There is no way to catch exceptions in the application. Answer will be accepted based on the following conditions: First answer to meet all requirements will be accepted. If there is no way to meet all requirements, the answer which ensures the smallest amount of missed changes per sync will be accepted. A bounty will be created (100 points) as soon as possible for the prize. The winner will be selected one day before the bounty ends. Please ask questions in the comments and I will gladly update and refine the question on those.

    Read the article

  • What algorithm .Net use for searching a pattern in a string?

    - by Hun1Ahpu
    I'm studying string searching algorithms now and wondering what algorithm is used for .NET String.Contains function for example. Reflector shows that this function is used but I have no idea what its name means. private static extern int InternalFindNLSStringEx(IntPtr handle, string localeName, int flags, string source, int sourceCount, int startIndex, string target, int targetCount);

    Read the article

  • How do I maintain coherency between model and view-model in MVVM pattern?

    - by Mike Garrett
    Problem Statement I'm writing a very basic WPF application to alter the contents of a configuration file. The data format is an XML file with a schema. I want to use it as a learning project for MVVM, so I have duly divided the code into Model: C# classes auto-generated from xsd.exe View-Model: View-friendly representation of the Model. View: Xaml and empty code behind I understand how the View-Model can make View-binding a breeze. However, doesn't that leave the View-Model <- Model semantics very awkward? Xsd.exe generates C# classes with arrays for multiple XML elements. However, at the V-VM level you need Observable Collections. Questions: Does this really mean I have to keep two completely different collection types representing the same data in coherence? What are the best practices for maintaining coherence between the Model and the View-Model?

    Read the article

  • Spring Security and the Synchronizer Token J2EE pattern, problem when authentication fails.

    - by dfuse
    Hey, we are using Spring Security 2.0.4. We have a TransactionTokenBean which generates a unique token each POST, the bean is session scoped. The token is used for the duplicate form submission problem (and security). The TransactionTokenBean is called from a Servlet filter. Our problem is the following, after a session timeout occured, when you do a POST in the application Spring Security redirects to the logon page, saving the original request. After logging on again the TransactionTokenBean is created again, since it is session scoped, but then Spring forwards to the originally accessed url, also sending the token that was generated at that time. Since the TransactionTokenBean is created again, the tokens do not match and our filter throws an Exception. I don't quite know how to handle this elegantly, (or for that matter, I can't even fix it with a hack), any ideas? This is the code of the TransactionTokenBean: public class TransactionTokenBean implements Serializable { public static final int TOKEN_LENGTH = 8; private RandomizerBean randomizer; private transient Logger logger; private String expectedToken; public String getUniqueToken() { return expectedToken; } public void init() { resetUniqueToken(); } public final void verifyAndResetUniqueToken(String actualToken) { verifyUniqueToken(actualToken); resetUniqueToken(); } public void resetUniqueToken() { expectedToken = randomizer.getRandomString(TOKEN_LENGTH, RandomizerBean.ALPHANUMERICS); getLogger().debug("reset token to: " + expectedToken); } public void verifyUniqueToken(String actualToken) { if (getLogger().isDebugEnabled()) { getLogger().debug("verifying token. expected=" + expectedToken + ", actual=" + actualToken); } if (expectedToken == null || actualToken == null || !isValidToken(actualToken)) { throw new IllegalArgumentException("missing or invalid transaction token"); } if (!expectedToken.equals(actualToken)) { throw new InvalidTokenException(); } } private boolean isValidToken(String actualToken) { return StringUtils.isAlphanumeric(actualToken); } public void setRandomizer(RandomizerBean randomizer) { this.randomizer = randomizer; } private Logger getLogger() { if (logger == null) { logger = Logger.getLogger(TransactionTokenBean.class); } return logger; } } and this is the Servlet filter (ignore the Ajax stuff): public class SecurityFilter implements Filter { static final String AJAX_TOKEN_PARAM = "ATXTOKEN"; static final String TOKEN_PARAM = "TXTOKEN"; private WebApplicationContext webApplicationContext; private Logger logger = Logger.getLogger(SecurityFilter.class); public void init(FilterConfig config) { setWebApplicationContext(WebApplicationContextUtils.getWebApplicationContext(config.getServletContext())); } public void destroy() { } public void doFilter(ServletRequest req, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest request = (HttpServletRequest) req; if (isPostRequest(request)) { if (isAjaxRequest(request)) { log("verifying token for AJAX request " + request.getRequestURI()); getTransactionTokenBean(true).verifyUniqueToken(request.getParameter(AJAX_TOKEN_PARAM)); } else { log("verifying and resetting token for non-AJAX request " + request.getRequestURI()); getTransactionTokenBean(false).verifyAndResetUniqueToken(request.getParameter(TOKEN_PARAM)); } } chain.doFilter(request, response); } private void log(String line) { if (logger.isDebugEnabled()) { logger.debug(line); } } private boolean isPostRequest(HttpServletRequest request) { return "POST".equals(request.getMethod().toUpperCase()); } private boolean isAjaxRequest(HttpServletRequest request) { return request.getParameter("AJAXREQUEST") != null; } private TransactionTokenBean getTransactionTokenBean(boolean ajax) { return (TransactionTokenBean) webApplicationContext.getBean(ajax ? "ajaxTransactionTokenBean" : "transactionTokenBean"); } void setWebApplicationContext(WebApplicationContext context) { this.webApplicationContext = context; } }

    Read the article

  • PHP - REGEX - use string for pattern but exclude it from being removed!

    - by aSeptik
    Hi All guys! i'm pretty new on regex, i have learned something by the way, but is still pour knowledge! so i want ask you for clarification on how it work! assuming i have the following strings, as you can see they can be formatted little different way one from another but they are very similar! DTSTART;TZID="America/Chicago":20030819T000000 DTEND;TZID="America/Chicago":20030819T010000 DTSTART;TZID=US/Pacific DTSTART;VALUE=DATE now i want replace everything between the first A-Z block and the colon so for example i would keep DTSTART:20030819T000000 DTEND:20030819T010000 DTSTART DTSTART so on my very noobs knowledge i have worked out this shitty regex! :-( preg_replace( '/^[A-Z](?!;[A-Z]=[\w\W]+):$/m' , '' , $data ); but why i'm sure this regex will not work!? :-) Pls help me! PS: the title of question is pretty explaned, i want also know how for example use a well know string block for match another... preg_replace( '/^[DTSTART](?!;[A-Z]=[\w\W]+):$/m' , '' , $data ); ..without delete DTSTART Thanks for the time! Regards Luca Filosofi

    Read the article

  • How do I implement a listener pattern over RMI using Spring?

    - by predhme
    So here is a generalized version of our application desgin: @Controller public class MyController { @Autowired private MyServiceInterface myServiceInterface; @RequestMapping("/myURL") public @ResponseBody String doSomething() { MyListenerInterface listener = new MyListenerInterfaceImpl(); myServiceInterface.doThenCallListener(listener); // do post stuff } } public interface MyListenerInterface { public void callA(); public void callB(); } public class MyListenerInterfaceImpl implements MyListenerInterface { // ... omitted for clarity } public interface MyServiceInterface { public void doThenCallListener(MyListenerInterface listener); } public class MyServiceImpl { public void doThenCallListener(MyListenerInterface listener) { // do stuff listener.callA(); } } Basically I have a controller that is being called via AJAX in which I am looking to return a response as a string. However, I need to make a call to the backend (MyServiceInterface). That guy is exposed through RMI by using Spring (man that was easy). But the service method as described requires a listener to be registered for invokation completion purposes. So what I assume I need to achieve is transparently to the backend make it so that when the listener methods are called, really the call is going over RMI. I would have thought Spring would have a simple way to wrap a POJO (not a service singleton) with RMI calls. I looked through their documentation but they had nothing besides exposing services via RMI. Could someone point me in the right direction?

    Read the article

  • Is this a valid pattern for raising events in C#?

    - by Will Vousden
    Update: For the benefit of anyone reading this, since .NET 4, the lock is unnecessary due to changes in synchronization of auto-generated events, so I just use this now: public static void Raise<T>(this EventHandler<T> handler, object sender, T e) where T : EventArgs { if (handler != null) { handlerCopy(sender, e); } } And to raise it: SomeEvent.Raise(this, new FooEventArgs()); Having been reading one of Jon Skeet's articles on multithreading, I've tried to encapsulate the approach he advocates to raising an event in an extension method like so (with a similar generic version): public static void Raise(this EventHandler handler, object @lock, object sender, EventArgs e) { EventHandler handlerCopy; lock (@lock) { handlerCopy = handler; } if (handlerCopy != null) { handlerCopy(sender, e); } } This can then be called like so: protected virtual void OnSomeEvent(EventArgs e) { this.someEvent.Raise(this.eventLock, this, e); } Are there any problems with doing this? Also, I'm a little confused about the necessity of the lock in the first place. As I understand it, the delegate is copied in the example in the article to avoid the possibility of it changing (and becoming null) between the null check and the delegate call. However, I was under the impression that access/assignment of this kind is atomic, so why is the lock necessary? Update: With regards to Mark Simpson's comment below, I threw together a test: static class Program { private static Action foo; private static Action bar; private static Action test; static void Main(string[] args) { foo = () => Console.WriteLine("Foo"); bar = () => Console.WriteLine("Bar"); test += foo; test += bar; test.Test(); Console.ReadKey(true); } public static void Test(this Action action) { action(); test -= foo; Console.WriteLine(); action(); } } This outputs: Foo Bar Foo Bar This illustrates that the delegate parameter to the method (action) does not mirror the argument that was passed into it (test), which is kind of expected, I guess. My question is will this affect the validity of the lock in the context of my Raise extension method? Update: Here is the code I'm now using. It's not quite as elegant as I'd have liked, but it seems to work: public static void Raise<T>(this object sender, ref EventHandler<T> handler, object eventLock, T e) where T : EventArgs { EventHandler<T> copy; lock (eventLock) { copy = handler; } if (copy != null) { copy(sender, e); } }

    Read the article

  • Which type of design pattern should be used to create an emulator?

    - by Facon
    I have programmed an emulator, but I have some doubts about how to organizate it properly, because, I see that it has some problems about classes connection (CPU <- Machine Board). For example: I/O ports, interruptions, communication between two or more CPU, etc. I need for the emulator to has the best performance and good understanding of the code. PD: Sorry for my bad English. EDITED: Asking for multiple patterns.

    Read the article

  • Qt Creator draws up build issue: "target pattern contains no %. Stop."

    - by Louis93
    The compile output says no% in line 240 of the makefile. Here is an extract of that portion in the Makefile: debug/lv.simplon.class.o: c:/SimplonQt/include/lv.simplon.class.cpp $(CXX) -c $(CXXFLAGS) $(INCPATH) -o debug/lv.simplon.class.o c:/SimplonQt/include/lv.simplon.class.cpp I'm loading a project I have saved in my C drive in Windows, but I am not sure what exactly is the cause of the problem. Thanks in advance!

    Read the article

  • What OOP pattern to use when only adding new methods, not data?

    - by Jonathon Reinhart
    Hello eveyone... In my app, I have deal with several different "parameters", which derive from IParameter interface, and also ParamBase abstract base class. I currently have two different parameter types, call them FooParameter and BarParameter, which both derive from ParamBase. Obviously, I can treat them both as IParameters when I need to deal with them generically, or detect their specific type when I need to handle their specific functionality. My question lies in specific FooParameters. I currently have a few specific ones with their own classes which derive from FooParameter, we'll call them FP12, FP13, FP14, etc. These all have certain characteristics, which make me treat them differently in the UI. (Most have names associated with the individual bits, or ranges of bits). Note that these specific, derived FP's have no additional data associated with them, only properties (which refer to the same data in different ways) or methods. Now, I'd like to keep all of these parameters in a Dictionary<String, IParameter> for easy generic access. The problem is, if I want to refer to a specific one with the special GUI functions, I can't write: FP12 fp12 = (FP12)paramList["FP12"] because you can't downcast to a derived type (rightfully so). But in my case, I didn't add any data, so the cast would theoretically work. What type of programming model should I be using instead? Thanks!

    Read the article

  • Is There a Good Pattern for Creating a Unique Id based on a Type?

    - by Michael Kelley
    I have a template that creates a unique identifier for each type it is instanced. Here's a streamlined version of the template: template <typename T> class arType { static const arType Id; // this will be unique for every instantiation of arType<>. } // Address of Id is used for identification. #define PA_TYPE_TAG(T) (&arType<T >::Id) This works when you have an executable made purely of static libraries. Unfortunately we're moving to an executable made up of dlls. Each dlls could potentially have its own copy of Id for a type. One obvious solution is to explicitly instantiate all instances of arType. Unfortunately this is cumbersome, and I'd like to ask if anyone can propose a better solution?

    Read the article

  • How can I capture a multiline pattern using a regular expressions in java?

    - by lampShade
    I have a text file that I need to parse using regular expressions. The text that I need to capture is in multiline groups like this: truck zDoug Doug's house (123) 456-7890 [email protected] 30 61234.56 8/10/2003 vehicle eRob Rob's house (987) 654-3210 [email protected] For this example I need to capture truck followed by the next seven lines.In other words, in this "block" I have 8 groups. This is what I've tried but it will not capture the next line: (truck)\n(\w). NOTE: I'm using the program RegExr to test my regex before I port it to Java.

    Read the article

  • How might I wrap the FindXFile-style APIs to the STL-style Iterator Pattern in C++?

    - by BillyONeal
    Hello everyone :) I'm working on wrapping up the ugly innards of the FindFirstFile/FindNextFile loop (though my question applies to other similar APIs, such as RegEnumKeyEx or RegEnumValue, etc.) inside iterators that work in a manner similar to the Standard Template Library's istream_iterators. I have two problems here. The first is with the termination condition of most "foreach" style loops. STL style iterators typically use operator!= inside the exit condition of the for, i.e. std::vector<int> test; for(std::vector<int>::iterator it = test.begin(); it != test.end(); it++) { //Do stuff } My problem is I'm unsure how to implement operator!= with such a directory enumeration, because I do not know when the enumeration is complete until I've actually finished with it. I have sort of a hack together solution in place now that enumerates the entire directory at once, where each iterator simply tracks a reference counted vector, but this seems like a kludge which can be done a better way. The second problem I have is that there are multiple pieces of data returned by the FindXFile APIs. For that reason, there's no obvious way to overload operator* as required for iterator semantics. When I overload that item, do I return the file name? The size? The modified date? How might I convey the multiple pieces of data to which such an iterator must refer to later in an ideomatic way? I've tried ripping off the C# style MoveNext design but I'm concerned about not following the standard idioms here. class SomeIterator { public: bool next(); //Advances the iterator and returns true if successful, false if the iterator is at the end. std::wstring fileName() const; //other kinds of data.... }; EDIT: And the caller would look like: SomeIterator x = ??; //Construct somehow while(x.next()) { //Do stuff } Thanks! Billy3

    Read the article

  • How to make TwoWay binding on properties of ObservableCollection of custom class using mvvm pattern?

    - by mill
    I have the following class: public class UserGroup { public string GroupName { get; set; } public bool IsIntheGroup{ get; set; } } I want to bind an ObservableCollection of UserGroup items to listbox containing checkbox’s for each item in the collection and the checkbox is cheked based on the IsIntheGroup property of the UserGroup. In my ViewModel I made an ObservableCollection of the UserGroup class: public ObservableCollection Groups { get; set; } and loaded its contents (instances of UserGroup) from my database model I used the following code in my view: ListBox ItemsSource="{Binding Groups, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}" ListBox.ItemTemplate DataTemplate StackPanel Orientation="Horizontal" CheckBox IsChecked="{Binding IsIntheGroup, Mode=TwoWay}"/ TextBlock Text="{Binding GroupName}" / /StackPanel /DataTemplate /ListBox.ItemTemplate /ListBox The problem is I am not notified when the user checks/unchecks a check box in the list so my two way binding failed… How do I do a two way binding in such a case?

    Read the article

  • How Do I Remove The First 4 Characters From A String If It Matches A Pattern In Ruby

    - by James
    I have the following string: "h3. My Title Goes Here" I basically want to remove the first 4 characters from the string so that I just get back: "My Title Goes Here". The thing is I am iterating over an array of strings and not all have the h3. part in front so I can't just ditch the first 4 characters blindly. I have checked the docs and the closest think I could find was chomp, but that only works for the end of a string. Right now I am doing this: "h3. My Title Goes Here".reverse.chomp(" .3h").reverse This gives me my desired output, but there has to be a better way right? I mean I don't want to reverse a string twice for no reason. I am new to programming so I might have missed something obvious, but I didn't see the opposite of chomp anywhere in the docs. Is there another method that will work? Thanks!

    Read the article

  • How can I refactor that code ? (state pattern ?)

    - by alex
    Hello guys, How can I refactor that code ? public enum enum1 { value1 = 0x01, value2 = 0x02, value3 = 0x03, value4 = 0x04, value5 = 0x05, UNKNOWN = 0xFF } class class1 { private const string STR_VALUE1 = "some text description of value1"; private const string STR_VALUE2 = "some text description of value2"; private const string STR_VALUE3 = "some text description of value3"; private const string STR_VALUE4 = "some text description of value4"; private const string STR_VALUE5 = "some text description of value5"; private const string STR_VALUE6 = "some text description of unknown type"; public static string GetStringByTypeCode(enum1 type) { switch(type) { case enum1.value1: return STR_VALUE1; case enum1.value2: return STR_VALUE2; case enum1.value3: return STR_VALUE3; case enum1.value4: return STR_VALUE4; case enum1.value5: return STR_VALUE5; default: return STR_VALUE6; } } } PS: there are many enum1...enumX and GetStringByTypeCode(enum1) ... GetStringByTypeCode(enumX) methods.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 64 65 66 67 68 69 70 71 72 73 74 75  | Next Page >