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  • jsp servlet exception: bean not found within scope.

    - by stu
    I'm getting this error: javax.servlet.ServletException: bean givingFormBean not found within scope on a page with this at the top. The class exists in the classpath, it worked this morning, and I don't get what not found within scope means. I've googled and googled and nothing useful came up.

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  • Several client waiting for the same event

    - by ff8mania
    I'm developing a communication API to be used by a lot of generic clients to communicate with a proprietary system. This proprietary system exposes an API, and I use a particular classes to send and wait messages from this system: obviously the system alert me that a message is ready using an event. The event is named OnMessageArrived. My idea is to expose a simple SendSyncMessage(message) method that helps the user/client to simply send a message and the method returns the response. The client: using ( Communicator c = new Communicator() ) { response = c.SendSync(message); } The communicator class is done in this way: public class Communicator : IDisposable { // Proprietary system object ExternalSystem c; String currentRespone; Guid currentGUID; private readonly ManualResetEvent _manualResetEvent; private ManualResetEvent _manualResetEvent2; String systemName = "system"; String ServerName = "server"; public Communicator() { _manualResetEvent = new ManualResetEvent(false); //This methods are from the proprietary system API c = SystemInstance.CreateInstance(); c.Connect(systemName , ServerName); } private void ConnectionStarter( object data ) { c.OnMessageArrivedEvent += c_OnMessageArrivedEvent; _manualResetEvent.WaitOne(); c.OnMessageArrivedEvent-= c_OnMessageArrivedEvent; } public String SendSync( String Message ) { Thread _internalThread = new Thread(ConnectionStarter); _internalThread.Start(c); _manualResetEvent2 = new ManualResetEvent(false); String toRet; int messageID; currentGUID = Guid.NewGuid(); c.SendMessage(Message, "Request", currentGUID.ToString()); _manualResetEvent2.WaitOne(); toRet = currentRespone; return toRet; } void c_OnMessageArrivedEvent( int Id, string root, string guid, int TimeOut, out int ReturnCode ) { if ( !guid.Equals(currentGUID.ToString()) ) { _manualResetEvent2.Set(); ReturnCode = 0; return; } object newMessage; c.FetchMessage(Id, 7, out newMessage); currentRespone = newMessage.ToString(); ReturnCode = 0; _manualResetEvent2.Set(); } } I'm really noob in using waithandle, but my idea was to create an instance that sends the message and waits for an event. As soon as the event arrived, checks if the message is the one I expect (checking the unique guid), otherwise continues to wait for the next event. This because could be (and usually is in this way) a lot of clients working concurrently, and I want them to work parallel. As I implemented my stuff, at the moment if I run client 1, client 2 and client 3, client 2 starts sending message as soon as client 1 has finished, and client 3 as client 2 has finished: not what I'm trying to do. Can you help me to fix my code and get my target? Thanks!

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  • Handling close-to-impossible collisions on should-be-unique values

    - by balpha
    There are many systems that depend on the uniqueness of some particular value. Anything that uses GUIDs comes to mind (eg. the Windows registry or other databases), but also things that create a hash from an object to identify it and thus need this hash to be unique. A hash table usually doesn't mind if two objects have the same hash because the hashing is just used to break down the objects into categories, so that on lookup, not all objects in the table, but only those objects in the same category (bucket) have to be compared for identity to the searched object. Other implementations however (seem to) depend on the uniqueness. My example (that's what lead me to asking this) is Mercurial's revision IDs. An entry on the Mercurial mailing list correctly states The odds of the changeset hash colliding by accident in your first billion commits is basically zero. But we will notice if it happens. And you'll get to be famous as the guy who broke SHA1 by accident. But even the tiniest probability doesn't mean impossible. Now, I don't want an explanation of why it's totally okay to rely on the uniqueness (this has been discussed here for example). This is very clear to me. Rather, I'd like to know (maybe by means of examples from your own work): Are there any best practices as to covering these improbable cases anyway? Should they be ignored, because it's more likely that particularly strong solar winds lead to faulty hard disk reads? Should they at least be tested for, if only to fail with a "I give up, you have done the impossible" message to the user? Or should even these cases get handled gracefully? For me, especially the following are interesting, although they are somewhat touchy-feely: If you don't handle these cases, what do you do against gut feelings that don't listen to probabilities? If you do handle them, how do you justify this work (to yourself and others), considering there are more probable cases you don't handle, like a supernonva?

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  • Exception if there is IBOutlet in view controller created by initWithNibName

    - by Kail
    When I create a Navigation-based application, the second view controller is created with initWithNibName, if I add a label onto the second view and connect it with IBOutlet in the second view controller. After I navigate to the second view by clicking table cell, and then back to the root view, the application aborts - send message retainCount to a freed object. I know this is caused by the IBOutlet label, which is retained, set nil in viewDidUnload and dealloc in dealloc. But I don't know why, and if I wanna still use IBOutlet, what can I do? Not dealloc it in viewcontroller's dealloc? Anybody could help? Thank you.

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  • Error handling in C++, constructors vs. regular methods

    - by Dennis Ritchie
    I have a cheesesales.txt CSV file with all of my recent cheese sales. I want to create a class CheeseSales that can do things like these: CheeseSales sales("cheesesales.txt"); //has no default constructor cout << sales.totalSales() << endl; sales.outputPieChart("piechart.pdf"); The above code assumes that no failures will happen. In reality, failures will take place. In this case, two kinds of failures could occur: Failure in the constructor: The file may not exist, may not have read-permissions, contain invalid/unparsable data, etc. Failure in the regular method: The file may already exist, there may not be write access, too little sales data available to create a pie chart, etc. My question is simply: How would you design this code to handle failures? One idea: Return a bool from the regular method indicating failure. Not sure how to deal with the constructor. How would seasoned C++ coders do these kinds of things?

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  • Is there a browser-agnostic way to detect client-side script errors with Watin?

    - by Michael
    We're using WatiN to test our web portals. During the course of an E2E test, we'll occasionally see client-side script errors on the IE status bar. I'd like to chain a handler onto the script error event and record the error for later analysis and bug filing. Problem is, I don't know that there's a global script error event or how to chain into it. And if there's not a browser-agnostic way to accomplish this, I can create MyIE and MyFF subclasses but then this becomes two browser-specific questions. In essence, I'm thinking of something like this entirely made-up call: browser.ScriptEngine.SetCustomErrorHandler(LogScriptingError); ... where LogScriptErrors is my code that does the obvious. Many of our client-side scripting errors don't necessarily prevent the test from continuing (a pretty UI element didn't animate, for example, but the underlying form is still submittable), so I'd like to log the error and forge ahead in most cases.

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  • In FLEX, How can you stop ENTER Key from my Alert being caught by the control that initiated the Al

    - by WeeJavaDude
    I am having an issue where I show an AlertBox message when the user hits ENTER and the focus is in a text area. The pop up works fine, but when the user hits enter the Alert closes as expected, but the TextArea listener receives the ENTER event from the Alert and pops the dialog up again. I have tried a number of ways to catch and eat the event but so far I have not been lucky. Is there way to accomplish this? public function init():void { myTextInput.addEventListener(KeyboardEvent.KEY_UP, handleKeyStrokes); } public function handleKeyStrokes(evt:KeyboardEvent):void { if(evt.keyCode == Keyboard.ENTER) { myAlert = Alert.show("This is a test and only a test", "Title", 4, null, alertCallBack); } } <mx:TextInput id="myTextInput" left="600" top="10"> </mx:TextInput>

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  • problem in handling menu - submenu based on spring security

    - by Nirmal
    Hi All... I have configured spring security core plugin using requestmap table inside the database.. Now inside requestmap table I have all the possible urls and it's equivalent roles who can access that url... Now I want to generate menus and submenus based on the urls stored in requestmap table... So my requirement is to check the urls of menu & submenus against the logged in users privileges... And if logged in user has any one privilege then I need to display that main menu and the available submenus.... For e.g. I have a menu in my project called user which has a following submenus : **Users (main menu)** Manage Users (sub menu) Import Users (sub menu) Now inside my header.gsp I have successfully achieved the above requirement using if else condition, like : if ( privs.contains("/users/manageUsers") || privs.contains("/users/importUsers")) here privs are the list of urls from requestmap table for logged in user. But I want to achieve these using spring security tag lib, so for comparing urls I have find following tag from spring security core documentation : <sec:access url="/users/manageUsers"> But i am bit confuse that how I can replace or condition using tag library.. Is there any tag available which checks from multiple urls and evaluate it to true or false ? Of course I can do using sec:access tag with some flag logic, but is there any tags available which can fulfill my requirement directly ? Thanks in advance...

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  • ArgumentException or ArgumentNullException for string parameters?

    - by Anna Lear
    Far as best practices are concerned, which is better: public void SomeMethod(string str) { if(string.IsNullOrEmpty(str)) { throw new ArgumentException("str cannot be null or empty."); } // do other stuff } or public void SomeMethod(string str) { if(str == null) { throw new ArgumentNullException("str"); } if(str == string.Empty) { throw new ArgumentException("str cannot be empty."); } // do other stuff } The second version seems more precise, but also more cumbersome than the first. I usually go with #1, but figured I'd check if there's an argument to be made for #2.

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  • Exception when access inner class reflectively

    - by MikeJiang
    Hi Folk, Here is a sample java program. I wonder why the two approaches reslut different stories. Is it a bug or kind of bitter java feature? And I run the sample upon java 1.5 package test; public class TestOut{ public static void main(String[] args){ new TestIn();//it works Class.forName("test.TestOut$TestIn").newInstance();// throw IllegalAccessException } private static class TestIn{} }

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  • Magento: Why do controller action predispatch events not fire if the controller is rewritten?

    - by mattalexx
    Why do controller action predispatch events not fire if the controller is rewritten? Here is a snippet of store/app/code/core/Mage/Core/Controller/Varien/Action.php: abstract class Mage_Core_Controller_Varien_Action { // [...] public function preDispatch() { // [...] if ($this->_rewrite()) { return; // [What is the purpose if this?] } // [...] // [This is where my event needs to be firing, but this code never gets // executed because the controller is rewritten] Mage::dispatchEvent( 'controller_action_predispatch_'.$this->getFullActionName(), array('controller_action'=>$this) ); } // [...] } I don't know where to start fixing this problem. Anyone out there ever dealt with this before?

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  • ASP.NET MVC - How to Preserve ModelState Errors Across RedirectToAction?

    - by RPM1984
    Hi Guys, I have the following two action methods (simplified for question): [HttpGet] public ActionResult Create(string uniqueUri) { // get some stuff based on uniqueuri, set in ViewData. return View(); } [HttpPost] public ActionResult Create(Review review) { // validate review if (validatedOk) { return RedirectToAction("Details", new { postId = review.PostId}); } else { ModelState.AddModelError("ReviewErrors", "some error occured"); return RedirectToAction("Create", new { uniqueUri = Request.RequestContext.RouteData.Values["uniqueUri"]}); } } So, if the validation passes, i redirect to another page (confirmation). If an error occurs, i need to display the same page with the error. If i do return View(), the error is displayed, but if i do return RedirectToAction (as above), it loses the Model errors. I'm not surprised by the issue, just wondering how you guys handle this? I could of course just return the same View instead of the redirect, but i have logic in the "Create" method which populates the view data, which i'd have to duplicate. Any suggestions?

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  • C++ Storing variables and inheritance

    - by Kaa
    Hello Everyone, Here is my situation: I have an event driven system, where all my handlers are derived from IHandler class, and implement an onEvent(const Event &event) method. Now, Event is a base class for all events and contains only the enumerated event type. All actual events are derived from it, including the EventKey event, which has 2 fields: (uchar) keyCode and (bool)isDown. Here's the interesting part: I generate an EventKey event using the following syntax: Event evt = EventKey(15, true); and I ship it to the handlers: EventDispatch::sendEvent(evt); // void EventDispatch::sendEvent(const Event &event); (EventDispatch contains a linked list of IHandlers and calls their onEvent(const Event &event) method with the parameter containing the sent event. Now the actual question: Say I want my handlers to poll the events in a queue of type Event, how do I do that? x Dynamic pointers with reference counting sound like too big of a solution. x Making copies is more difficult than it sounds, since I'm only receiving a reference to a base type, therefore each time I would need to check the type of event, upcast to EventKey and then make a copy to store in a queue. Sounds like the only solution - but is unpleasant since I would need to know every single type of event and would have to check that for every event received - sounds like a bad plan. x I could allocate the events dynamically and then send around pointers to those events, enqueue them in the array if wanted - but other than having reference counting - how would I be able to keep track of that memory? Do you know any way to implement a very light reference counter that wouldn't interfere with the user? What do you think would be a good solution to this design? I thank everyone in advance for your time. Sincerely, Kaa

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  • Writing exceptions in multihreaded windows service to event log

    - by Ziplin
    I have a multithreaded windows service that will unpredictably stop running once every 24 hours or so. I am writing to the event log and that's going through just fine, but whenever the service crashes there are no messages in the event log (even that the service stopped, despite having AutoLog=true). Is there a way to have uncaught exceptions written straight to the log, even if they aren't in the original thread?

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  • asp.net MVC ActionMethod causing null exception on parameter

    - by David Liddle
    I am trying to add filter functionality that sends a GET request to the same page to filter records in my table. The problem I am having is that the textbox complains about null object reference when a parameter is not passed. For example, when the person first views the page the url is '/mycontroller/myaction/'. Then when they apply a filter and submit the form it should be something like 'mycontroller/myaction?name=...' Obviously the problem stems from when the name value has not been passed (null) it is still trying to be bound to the 'name' textbox. Any suggestions on what I should do regarding this problem? UPDATE I have tried setting the DefaultValue attribute but I am assuming this is only for route values and not query string values ActionResult MyAction([DefaultValue("")] string name) //Action - /mycontroler/myaction ActionResult MyAction(string name) { ...do stuff } //View <div id="filter"> <% Html.BeginForm("myaction", "mycontroller", FormMethod.Get); %> Name: <%= Html.TextBox("name") %> .... </div> <table>...my list of filtered data

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  • error handling in asp.net

    - by user98454
    Hi How can i pass the different types of errors from Data access layer to presentation layer? suppose if we take the northwind database scenario I want to delete the customer, so i selected one customer in ui and clicked the "delete" button.It internally calls the "delete" in data access layer. The prerequisite for deleting the customer is that the customer doesn't have any orders.So in data access layer we wil check whether that customer has any orders.If the customer has orders how can we pass the message from dal to presentation layer that the customer has orders and we don't delete. Am i doing right?is there any other ways to deal with this type? Thanks in advance

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  • WCF net.tcp server disconnects - how to handle properly on client side?

    - by RoastedBattleSquirrel
    I'm stuck with a bit of an annoying problem right now. I've got a Silverlight 4 application (which runs OOB by default). It uses WCF with net.tcp as means of communicating with the server. The client uses a central instance of the wcf client proxy. As long as everything keeps running on the server side, everything's fine. If i kill the server in the middle of everything, i drown in an avalanche of exceptions on the client side (connection lost, channel faulted etc etc). Now i'm looking for a way to handle this in a clean and centralized way (if centralized is possible). The SL app has one central client object sitting in App.cs (public static MyClient Client { get;set;}), which gets initialized on application start. Any idea how to properly handle any connectivity problems on the client object?

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  • Proper handling of confirmation page in PHP

    - by wnoveno
    Hi, I have a sign up page written in php, that goes to a confirmation page after processing. In the confirmation/ thank you page there is a 3rd party script that counts the number of successful registrants. how would I limit the script to be loaded per successful registration?

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  • Show friendly message on ASP.NET Ajax error

    - by balexandre
    You all know how annoying is this: I do have a log system and the correct error is well explicit there, but I want to give a better message to the user. I keep trying several ways but I'm using Telerik components and well jQuery and I ended up using both ASP.NET Ajax methods and jQuery, so I use function pageLoad() { try { var manager = Sys.WebForms.PageRequestManager.getInstance(); manager.add_endRequest(endRequest); manager.add_beginRequest(OnBeginRequest); manager } catch (err) { alert(err); } } as well $(document).ready(function() { ... } that alert(err) is never fired even upon OnClick events what's the best approach to avoid this message errors and provide a cleaner way? all this happens in <asp:UpdatePanel> as I use that when I didn't know better (3 years ago!) and I really don't want to mess up and build all again from scratch :( Any help is greatly appreciated Updated with more error windows after volpav solution

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