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• Saving tree-structures in Databases

  - by Nina Null

  Hello everyone. I use Hibernate/Spring and a MySQL Database for my data management. Currently I display a tree-structure in a JTable. A tree can have several branches, in turn a branch can have several branches (up to nine levels) again, or having leaves. Lately I have performanceproblemes, as soon as I want to create new branches on deeper levels. At this time a branch has a foreign key to its parent. The domainobject has access to its parent by calling getParent(), which returns the parent-branch. The deeper the level, the longer it takes to create a new branch. Microbenchmark results for creating a new branch are like: Level 1: 32 ms. Level 3: 80 ms. Level 9: 232 ms. Obviously the level (which means the number of parents) is responsible for this. So I wanted to ask, if there are any appendages to work around this kind of problem. I don’t understand why Hibernate needs to know about the whole object tree (all parents until the root) while creating a new branch. But as far as I know this can be the only reason for the delay while creating a new branch, because a branch doesn’t have any other relations to any other objects. I would be very thankful for any workarounds or suggestions. greets, jambusa

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• Is there any way to filter certain things in pages served by IIS?

  - by Ruslan

  Hello, This is my first time posting here so please keep that in mind... I'll try to be short and get right to defining the problem. We have an ASP.NET 2 application (eCommerce package) running on IIS (Windows Server 2003). The main site's page(s) are using plain HTTP (no SSL), but the whole checkout process and the shopping cart page is using SSL (HTTPS). Now, the problem is that the site's header is located in a template file, and inside it it has a plain HTML 'img' tag calling an image with the "http://" portion hard-coded into it... This header appears on absolutely every page (including the https pages), and due to its insecure image tag, a warning box pops up in IE on every stage of the checkout process... Now, the problem: The live application cannot be touched in any way (no changes can be made to the template (so simply changing "http://" to "//" is not an option), IIS cannot be restarted, and the website/app pool cannot be restarted). Is there any way in the world (maybe plugin for IIS or a setting somewhere) that I can filter the pages right before they are served to replace the '<img src="http://example.com/image.jpg">' with '<img src="//example.com/image.jpg">' in the final HTML? Possibly via a regular expression or something? Thanks to everybody in advance.

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• Server returns 500 error only when called by Java client using urlConnection/httpUrlConnection

  - by user455889

  Hi - I'm having a very strange problem. I'm trying to call a servlet (JSP) with an HTTP GET and a few parameters (http://mydomain.com/method?param1=test&param2=123). If I call it from the browser or via WGET in a bash session, it works fine. However, when I make the exact same call in a Java client using urlConnection or httpURLConnection, the server returns a 500 error. I've tried everything I have found online including: urlConn.setRequestProperty("Accept-Language", "en-us,en;q=0.5"); Nothing I've tried, however, has worked. Unfortunately, I don't have access to the server I'm calling so I can't see the logs. Here's the latest code: private String testURLConnection() { String ret = ""; String url = "http://localhost:8080/TestService/test"; String query = "param1=value1&param2=value2"; try { URLConnection connection = new URL(url + "?" + query).openConnection(); connection.setRequestProperty("Accept-Charset", "UTF-8"); connection.setRequestProperty("Accept-Language", "en-us,en;q=0.5"); BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream())); String line; StringBuilder content = new StringBuilder(); while ((line = bufferedReader.readLine()) != null) { content.append(line + "\n"); } bufferedReader.close(); metaRet = content.toString(); log.debug(methodName + " return = " + metaRet); } catch (Exception ex) { log.error("Exception: " + ex); log.error("stack trace: " + getStackTrace(ex)); } return metaRet; } Any help would be greatly appreciated!

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• c++ use of winmain()

  - by Jack

  Hi, I just started learning programming for windows in c++. I had this crazy image, that win32 programming is based on calling windows functions and sending parameters to and from them. Like, when you want to create window, you call some win32 function that handles windows GUI and say "Hi, please, create me new window, 100 x 100 px, with two buttons", and that GUI function says "Hi, no problem, when something happends, like user clicks one button, I will change this variable xy located in this location". So, I thought that it will be very similiar to console programming. But the very first instruction surprised me. I always thought that every program executes main() function first. So, when I launch app, windows stores some parameters on top of stack and run that application. So I assumed that initializing main() is just a c++ way to tell the compiler where the first instruction should be. But in win32 programming, there is function called winmain() which starts first. So I am little confused. I thought it´s rule that compiler must have main() to start with, that main just defines where ti start, like some start point identifier. So, please, why is there winmain() function instead of main()? When I thought that C++ programming is as logical as assembler, it confuses me once again.

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• c++ use of winmain()

  - by Jack

  Hi, I just started learning programming for windows in c++. I had this crazy image, that win32 programming is based on calling windows functions and sending parameters to and from them. Like, when you want to create window, you call some win32 function that handles windows GUI and say "Hi, please, create me new window, 100 x 100 px, with two buttons", and that GUI function says "Hi, no problem, when something happends, like user clicks one button, I will change this variable xy located in this location". So, I thought that it will be very similiar to console programming. But the very first instruction surprised me. I always thought that every program executes main() function first. So, when I launch app, windows stores some parameters on top of stack and run that application. So I assumed that initializing main() is just a c++ way to tell the compiler where the first instruction should be. But in win32 programming, there is function called winmain() which starts first. So I am little confused. I thought it´s rule that compiler must have main() to start with, that main just defines where ti start, like some start point identifier. So, please, why is there winmain() function instead of main()? When I thought that C++ programming is as logical as assembler, it confuses me once again.

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• How can I receive mouse events when a wrapped control has set capture?

  - by Greg

  My WndProc isn't seeing mouse-up notifications when I click with a modifier key (shift or control) pressed. I see them without the modifier key, and I see mouse-down notifications with the modifier keys. I'm trying to track user actions in a component I didn't write, so I'm using the Windows Forms NativeWindow wrapper (wrapping the component) to get Windows messages from the WndProc() method. I've tried tracking the notifications I do get, and I the only clue I see is WM_CAPTURECHANGED. I've tried calling SetCapture when I receive the WM_LBUTTONDOWN message, but it doesn't help. Without modifier (skipping paint, timer and NCHITTEST messages): WM_PARENTNOTIFY WM_MOUSEACTIVATE WM_MOUSEACTIVATE WM_SETCURSOR WM_LBUTTONDOWN WM_SETCURSOR WM_MOUSEMOVE WM_SETCURSOR WM_LBUTTONUP With modifier (skipping paint, timer and NCHITTEST messages): WM_KEYDOWN WM_PARENTNOTIFY WM_MOUSEACTIVATE WM_MOUSEACTIVATE WM_SETCURSOR WM_LBUTTONDOWN WM_SETCURSOR (repeats) WM_KEYDOWN (repeats) WM_KEYUP If I hold the mouse button down for a long time, I can usually get a WM_LBUTTONUP notification, but it should be possible to make it more responsive.. Edit: I've tried control-clicking outside of the component of interest and moving the cursor into it before releasing the mouse button, and then I do get a WM_LBUTTONUP notification, so it looks like the component is capturing the mouse on mouse-down. Is there any way to receive that notification when another window has captured the mouse? Thanks.

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• Common Lisp condition system for transfer of control

  - by Ken

  I'll admit right up front that the following is a pretty terrible description of what I want to do. Apologies in advance. Please ask questions to help me explain. :-) I've written ETLs in other languages that consist of individual operations that look something like: // in class CountOperation IEnumerable<Row> Execute(IEnumerable<Row> rows) { var count = 0; foreach (var row in rows) { row["record number"] = count++; yield return row; } } Then you string a number of these operations together, and call The Dispatcher, which is responsible for calling Operations and pushing data between them. I'm trying to do something similar in Common Lisp, and I want to use the same basic structure, i.e., each operation is defined like a normal function that inputs a list and outputs a list, but lazily. I can define-condition a condition (have-value) to use for yield-like behavior, and I can run it in a single loop, and it works great. I'm defining the operations the same way, looping through the inputs: (defun count-records (rows) (loop for count from 0 for row in rows do (signal 'have-value :value `(:count ,count @,row)))) The trouble is if I want to string together several operations, and run them. My first attempt at writing a dispatcher for these looks something like: (let ((next-op ...)) ;; pick an op from the set of all ops (loop (handler-bind ((have-value (...))) ;; records output from operation (setq next-op ...) ;; pick a new next-op (call next-op))) But restarts have only dynamic extent: each operation will have the same restart names. The restart isn't a Lisp object I can store, to store the state of a function: it's something you call by name (symbol) inside the handler block, not a continuation you can store for later use. Is it possible to do something like I want here? Or am I better off just making each operation function explicitly look at its input queue, and explicitly place values on the output queue?

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• Problem creating a custom input element using FluentHtml (MVCContrib)

  - by seth

  Hi there, I just recently started dabbling in ASP.NET MVC 1.0 and came across the wonderful MVCContrib. I had originally gone down the path of creating some extended html helpers, but after finding FluentHTML decided to try my hand at creating a custom input element. Basically I am wanting to ultimately create several custom input elements to make it easier for some other devs on the project I'm working on to add their input fields to the page and have all of my preferred markup to render for them. So, in short, I'd like to wrap certain input elements with additional markup.. A TextBox would be wrapped in an <li /> for example. I've created my custom input elements following Tim Scott's answer in another question on here: DRY in the MVC View. So, to further elaborate, I've created my class, "TextBoxListItem": public class TextBoxListItem : TextInput<TextBox> { public TextBoxListItem (string name) : base(HtmlInputType.Text, name) { } public TextBoxListItem (string name, MemberExpression forMember, IEnumerable<IBehaviorMarker> behaviors) : base(HtmlInputType.Text, name, forMember, behaviors) { } public override string ToString() { var liBuilder = new TagBuilder(HtmlTag.ListItem); liBuilder.InnerHtml = ToString(); return liBuilder.ToString(TagRenderMode.SelfClosing); } } I've also added it to my ViewModelContainerExtensions class: public static TextBox TextBoxListItem<T>(this IViewModelContainer<T> view, Expression<Func<T, object>> expression) where T : class { return new TextBoxListItem(expression.GetNameFor(view), expression.GetMemberExpression(), view.Behaviors) .Value(expression.GetValueFrom(view.ViewModel)); } And lastly, I've added it to ViewDataContainerExtensions as well: public static TextBox TextBoxListItem(this IViewDataContainer view, string name) { return new TextBox(name).Value(view.ViewData.Eval(name)); } I'm calling it in my view like so: <%= this.TextBoxListItem("username").Label("Username:") %> Anyway, I'm not getting anything other than the standard FluentHTML TextBox, not wrapped in <li></li> elements. What am I missing here? Thanks very much for any assistance.

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• Unsort: remembering a permutation and undoing it.

  - by dreeves

  Suppose I have a function f that takes a vector v and returns a new vector with the elements transformed in some way. It does that by calling function g that assumes the vector is sorted. So I want f to be defined like so: f[v_] := Module[{s, r}, s = Sort[v]; (* remember the permutation applied in order to sort v *) r = g[s]; Unsort[r] (* apply the inverse of that permutation *) ] What's the best way to do the "Unsort"? Or could we get really fancy and have this somehow work: answer = Unsort[g[Sort[v]]]; ADDED: Let's make this concrete with a toy example. Suppose we want a function f that takes a vector and transforms it by adding to each element the next smallest element, if any. That's easy to write if we assume the vector is sorted, so let's write a helper function g that makes that assumption: g[v_] := v + Prepend[Most@v, 0] Now for the function we really want, f, that works whether or not v is sorted: f[v_] := (* remember the order; sort it; call g on it; put it back in the original order; return it *)

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• Jquery cant get facebox working inside ajax call

  - by John

  From my main page I call an ajax file via jquery, in that ajax file is some additional jquery code. Original link looks like this: <a href="/page1.php" class="guest-action notify-function"><img src="/icon1.png"></a> Then the code: $(document).ready(function(){ $('a[rel*=facebox]').facebox(); $('.guest-action').click( function() { $.get( $(this).attr('href'), function(responseText) { $.jGrowl(responseText); }); return false; }); $('.notify-function').click( function() { $(this).find('img').attr('src','/icon2.png'); $(this).attr('href','/page2.php'); $(this).removeClass('guest-action').removeClass('notify-function').attr('rel','facebox'); }); }); So basically after notify-function is clicked I am changing the icon and the url of the link, I then am removing the classes so that the click wont be ran again and add rel="facebox" to the link so that the facebox window will pop up if they try to click the new icon2.png that shows up. The problem is after I click the initial icon everything works just fine except when I try to click the new icon2.png it still executes the jgrowl code from the guest-action. But when I view the source it shows this: <a href="/page2.php" rel="facebox" class=""><img src="/icon2.png"></a> So it seemed that should work right? What am I doing wrong? I tried adding the facebox code to the main page that is calling the ajax file as well and still same issue.

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• Cross-thread operation not valid: accessed from a thread other than the thread it was created on.

  - by user307524

  Hi, I want to remove checked items from checklistbox (winform control) in class file method which i am calling asynchronously using deletegate. but it showing me this error message:- Cross-thread operation not valid: Control 'checkedListBox1' accessed from a thread other than the thread it was created on. i have tried invoke required but again got the same error. Sample code is below: private void button1_Click(object sender, EventArgs e) { // Create an instance of the test class. Class1 ad = new Class1(); // Create the delegate. AsyncMethodCaller1 caller = new AsyncMethodCaller1(ad.TestMethod1); //callback delegate IAsyncResult result = caller.BeginInvoke(checkedListBox1, new AsyncCallback(CallbackMethod)," "); } In class file code for TestMethod1 is : - private delegate void dlgInvoke(CheckedListBox c, Int32 str); private void Invoke(CheckedListBox c, Int32 str) { if (c.InvokeRequired) { c.Invoke(new dlgInvoke(Invoke), c, str); c.Items.RemoveAt(str); } else { c.Text = ""; } } // The method to be executed asynchronously. public string TestMethod1(CheckedListBox chklist) { for (int i = 0; i < 10; i++) { string chkValue = chklist.CheckedItems[i].ToString(); //do some other database operation based on checked items. Int32 index = chklist.FindString(chkValue); Invoke(chklist, index); } return ""; }

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• problems with async jquery and loops

  - by Seth Vargo

  I am so confused. I am trying to append portals to a page by looping through an array and calling a method I wrote called addModule(). The method gets called the right number of times (checked via an alert statement), in the correct order, but only one or two of the portals actually populate. I have a feeling its something with the loop and async, but it's easier explained with the code: moduleList = [['weather','test'],['test']]; for(i in moduleList) { $('#content').append(''); for(j in moduleList[i]) { addModule(i,moduleList[i][j]); //column,name } } function addModule(column,name) { alert('adding module ' + name); $.get('/modules/' + name.replace(' ','-') + '.php',function(data){ $('#'+column).append(data); }); } for each array in the main array, I append a new column, since that's what each sub-array is - a column of portals. Then I loop through that sub array and call addModule on that column and the name of that module (which works correctly). Something buggy happens in my addModule method that it only adds the first and last modules, or sometimes a middle one, or sometimes none at all... im so confused!

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• Why is JavaMail Transport.send() a static method?

  - by skiphoppy

  I'm revising code I did not write that uses JavaMail, and having a little trouble understanding why the JavaMail API is designed the way it is. I have the feeling that if I understood, I could be doing a better job. We call: transport = session.getTransport("smtp"); transport.connect(hostName, port, user, password); So why is Eclipse warning me that this: transport.send(message, message.getAllRecipients()); is a call to a static method? Why am I getting a Transport object and providing settings that are specific to it if I can't use that object to send the message? How does the Transport class even know what server and other settings to use to send the message? It's working fine, which is hard to believe. What if I had instantiated Transport objects for two different servers; how would it know which one to use? In the course of writing this question, I've discovered that I should really be calling: transport.sendMessage(message, message.getAllRecipients()); So what is the purpose of the static Transport.send() method? Is this just poor design, or is there a reason it is this way?

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• [Ruby] Object assignment and pointers

  - by Jergason

  I am a little confused about object assignment and pointers in Ruby, and coded up this snippet to test my assumptions. class Foo attr_accessor :one, :two def initialize(one, two) @one = one @two = two end end bar = Foo.new(1, 2) beans = bar puts bar puts beans beans.one = 2 puts bar puts beans puts beans.one puts bar.one I had assumed that when I assigned bar to beans, it would create a copy of the object, and modifying one would not affect the other. Alas, the output shows otherwise. ^_^[jergason:~]$ ruby test.rb #<Foo:0x100155c60> #<Foo:0x100155c60> #<Foo:0x100155c60> #<Foo:0x100155c60> 2 2 I believe that the numbers have something to do with the address of the object, and they are the same for both beans and bar, and when I modify beans, bar gets changed as well, which is not what I had expected. It appears that I am only creating a pointer to the object, not a copy of it. What do I need to do to copy the object on assignment, instead of creating a pointer? Tests with the Array class shows some strange behavior as well. foo = [0, 1, 2, 3, 4, 5] baz = foo puts "foo is #{foo}" puts "baz is #{baz}" foo.pop puts "foo is #{foo}" puts "baz is #{baz}" foo += ["a hill of beans is a wonderful thing"] puts "foo is #{foo}" puts "baz is #{baz}" This produces the following wonky output: foo is 012345 baz is 012345 foo is 01234 baz is 01234 foo is 01234a hill of beans is a wonderful thing baz is 01234 This blows my mind. Calling pop on foo affects baz as well, so it isn't a copy, but concatenating something onto foo only affects foo, and not baz. So when am I dealing with the original object, and when am I dealing with a copy? In my own classes, how can I make sure that assignment copies, and doesn't make pointers? Help this confused guy out.

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• Is it possible to definitively identify whether a DML command was issued from a stored procedure?

  - by Ed Harper

  I have inherited a SQL Server 2008 database to which calling applications have access through stored procedures. Each table in the database has a shadow audit table into which Insert/Update/Delete operations for are logged. Performance testing on populating the audit tables showed that inserting the audit records using OUTPUT clauses was 20% or so faster than using triggers, so this has been implemented in the stored procedures. However, because this design cannot track changes made directly to the tables through DML statements issued directly against the tables, triggers have also been implemented which use the value of @@NESTLEVEL to determine whether or not to run the trigger (the assumption being that all DML run through stored procedures will have @@NESTLEVEL 1). i.e. the body of the trigger code looks something like: IF @@NESTLEVEL = 1 -- implies call is direct sql so generate history from here BEGIN ... insert into audit table This design is flawed because it won't track updates where DML statements are executed in dynamic SQL, or any other context where @@NESTLEVEL is raised above 1. Can anyone suggest a completely reliable method we can use in the triggers to execute them only if not triggered by a stored procedure? Or is this (as I suspect) not possible?

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• Stop an executing recursive javascript function

  - by DA

  Using jQuery, I've build an image/slide rotator. The basic setup is (in pseudocode): function setupUpSlide(SlideToStartWith){ var thisSlide = SlideToStartWith; ...set things up... fadeInSlide(thisSlide) } function fadeInSlide(thisSlide){ ...fade in this slide... fadeOutSlide(thisSlide) } function fadeOutSlide(thisSlide){ ...fade out this slide... setupUpSlide(nextSlide) } I call the first function and pass in a particular slide index, and then it does its thing calling chain of functions which then, in turn, calls the first function again passing in the next index. This then repeats infinitely (resetting the index when it gets to the last item). This works just fine. What I want to do now is allow someone to over-ride the slide show by being able to click on a particular slide number. Therefore, if slide #8 is showing and I click #3, I want the recursion to stop and then call the initial function passing in slide #3, which then, in turn, will start the process again. But I'm not sure how to go about that. How does one properly 'break' a recursive script. Should I create some sort of global 'watch' variable that if at any time is 'true' will return: false and allow the new function to execute?

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• SQL Server stored procedure + set error message from the records of a table

  - by lucky

  Hello, My question is I have a table with the set of records. I am calling a stored procedure for some other purpose. But when ever it finds some duplicate records. It need to return as error message back to php. C1 C2 c3 abc 32 21.03.2010 def 35 04.04.2010 pqr 45 30.03.2010 abc 12 04.05.2010 xyz 56 01.03.2010 ghi 21 06.05.2010 def 47 17.02.2010 klm 93 04.03.2010 xyz 11 01.03.2010 For the above set it need to check for the records that has the same c1. The stored procedure should return as abc,def,xyz are duplicate. I tried something like this. This will not work it has more than 1 set of duplicate records. Please help me to enhance this to solve the purpose. SET @duplicate = (SELECT c1 FROM temp GROUP BY c1 HAVING count(c1) > 1) --Check for duplicate concession Nr. IF(len(@duplicate) > '1') BEGIN SET @error = @error + ' Duplicate C1 Number:- ' + @duplicate SET @errorcount = @errorcount + 1 END As this one type error I am checking for errorcount. IF @errorcount <> '0' BEGIN GOTO E_General_Error END -- If an error occurs, rollback and exit E_General_Error: PRINT 'Error' SET @error = @error IF @@error <> 0 SET @error = 'Database update failed' ROLLBACK TRANSACTION update_database RETURN END Now it is able to return Duplicate c1 number abc. If there are more than 1 problem comes. Thanks in advance!

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• Dynamically invoke web service at runtime

  - by Ulrik Rasmussen

  So, our application needs support for dynamically calling web services which are unknown at compile time. The user should therefore be able to specify a URL to a WSDL, and specify some data bindings for the request and reply parameters. When Googling for answers, it seems like the way to do this is by actually compiling a web service proxy class at runtime, loading it, and invoking the methods using reflection. I think this seems like a rather clunky approach, given that I don't really need a strongly typed set of classes when I'm going to cast my data dynamically anyway. Dynamically compiling code for doing something that simple also just seems like The Wrong Way To Do It. Restricting ourself to the SOAP protocol, is there any library for C# that implements this protocol for dynamic use? I can imagine that it would be possible to generate runtime key/value data structures from the WSDL, which could be used to specify the request messages, as well as reading the replies. The library should then be able to send well-formed SOAP messages to the server, and parse the replies, without the programmer having to generate the XML manually (at least not the headers and other plumbing). I can't seem to find any library that actually does this. Is what I want to do really that esoteric, or have I just searched the wrong places? Thanks, Ulrik

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• Shared Memory and Process Sempahores (IPC)

  - by fsdfa

  This is an extract from Advanced Liniux Programming: Semaphores continue to exist even after all processes using them have terminated. The last process to use a semaphore set must explicitly remove it to ensure that the operating system does not run out of semaphores.To do so, invoke semctl with the semaphore identifier, the number of semaphores in the set, IPC_RMID as the third argument, and any union semun value as the fourth argument (which is ignored).The effective user ID of the calling process must match that of the semaphore’s allocator (or the caller must be root). Unlike shared memory segments, removing a semaphore set causes Linux to deallocate immediately. If a process allocate a shared memory, and many process use it and never set to delete it (with shmctl), if all them terminate, then the shared page continues being available. (We can see this with ipcs). If some process did the shmctl, then when the last process deattached, then the system will deallocate the shared memory. So far so good (I guess, if not, correct me). What I dont understand from that quote I did, is that first it say: "Semaphores continue to exist even after all processes using them have terminated." and then: "Unlike shared memory segments, removing a semaphore set causes Linux to deallocate immediately."

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• NullPointerException with Servlet

  - by RonaDona

  I am calling a Servlet using its URL address. This is the URL I am typing http://localhost:7001/ryan/olympics?action=selectCatalog&id=1 This is the Servlet's URL for sure; if I change the address I get page not found This is the code for the Servlet. public class Servlet extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet { private static final long serialVersionUID = 1L; public Servlet() { super(); } public void init(ServletConfig config) throws ServletException { System.out.println("*** initializing controller servlet."); super.init(config); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String action = request.getParameter("action"); if (action.equals("selectCatalog")) { String categoryId = request.getParameter("id"); ProductModelDAO dao4 = new ProductModelDAOImpl("jpac"); if (categoryId != null && !categoryId.trim().equals("")) { CategoryDAO dao1 = new CategoryDAOImpl("jpac"); try { Category category = dao1.getCategoryName(categoryId); request.setAttribute("category", category); } catch (Exception e) { e.printStackTrace(); } } try { @SuppressWarnings("unchecked") List<Product> products = dao4 .getProductsByCategory(categoryId); request.setAttribute("products", products); } catch (Exception e) { e.printStackTrace(); } url = "SelectCatalog.jsp"; RequestDispatcher requestDispatcher = getServletContext().getRequestDispatcher(url); requestDispatcher.forward(request, response); I get the NullPointerException pointing to the RequestDispatcher's line. Any help?

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• Help me clean up this crazy lambda with the out keyword

  - by Sarah Vessels

  My code looks ugly, and I know there's got to be a better way of doing what I'm doing: private delegate string doStuff( PasswordEncrypter encrypter, RSAPublicKey publicKey, string privateKey, out string salt ); private bool tryEncryptPassword( doStuff encryptPassword, out string errorMessage ) { ...get some variables... string encryptedPassword = encryptPassword(encrypter, publicKey, privateKey, out salt); ... } This stuff so far doesn't bother me. It's how I'm calling tryEncryptPassword that looks so ugly, and has duplication because I call it from two methods: public bool method1(out string errorMessage) { string rawPassword = "foo"; return tryEncryptPassword( (PasswordEncrypter encrypter, RSAPublicKey publicKey, string privateKey, out string salt) => encrypter.EncryptPasswordAndDoStuff( // Overload 1 rawPassword, publicKey, privateKey, out salt ), out errorMessage ); } public bool method2(SecureString unencryptedPassword, out string errorMessage) { return tryEncryptPassword( (PasswordEncrypter encrypter, RSAPublicKey publicKey, string privateKey, out string salt) => encrypter.EncryptPasswordAndDoStuff( // Overload 2 unencryptedPassword, publicKey, privateKey, out salt ), out errorMessage ); } Two parts to the ugliness: I have to explicitly list all the parameter types in the lambda expression because of the single out parameter. The two overloads of EncryptPasswordAndDoStuff take all the same parameters except for the first parameter, which can either be a string or a SecureString. So method1 and method2 are pretty much identical, they just call different overloads of EncryptPasswordAndDoStuff. Any suggestions? Edit: if I apply Jeff's suggestions, I do the following call in method1: return tryEncryptPassword( (encrypter, publicKey, privateKey) => { var result = new EncryptionResult(); string salt; result.EncryptedValue = encrypter.EncryptPasswordAndDoStuff( rawPassword, publicKey, privateKey, out salt ); result.Salt = salt; return result; }, out errorMessage ); Much the same call is made in method2, just with a different first value to EncryptPasswordAndDoStuff. This is an improvement, but it still seems like a lot of duplicated code.

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• Classic ASP application-wide initializations and object caching

  - by slack3r

  In classic ASP (which I am forced to use), I have a few factory functions, that is, functions that return classes. I use JScript. In one include file I use these factory functions to create some classes that are used throughout the application. This include file is included with the #include directive in all pages. These factory functions do some "heavy lifting" and I don't want them to be executed on every page load. So, to make this clear I have something like this: // factory.inc function make_class(arg1, arg2) { function klass() { //... } // ... Some heavy stuff return klass; } // init.inc, included everywhere <!-- #include FILE="factory.inc" --> // ... MyClass1 = make_class(myarg01, myarg02); MyClass2 = make_class(myarg11, myarg12); //... How can I achieve the same effect without calling make_class on every page load? I know that I can't cache the classes in the Application object I can't use the Application_OnStart hook in Global.asa I could probably create a scripting component, but I really don't want to do that So, is there something else I can do? Maybe some way to achieve caching of these classes, which are really objects in JScript. PS: [further clarification] In the above code "heavy stuff" is not so heavy, but I just want to know if there's a way to avoid it being executed all the time. It reads database meta information, builds a table of the primary keys in the database and another table that resolves strings to classes, etc.

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• Route WCF ServiceHost to another computer

  - by I2nfo

  GoodDay, I'm not a guru when it comes to WCF, but i do know the basics. My question is, how do i create a ServiceHost on machine X, while the code is on machine Y? if i build and run this code on my dev machine(localhost) : servicehost = new ServiceHost(typeof(MyService1)); servicehost.AddServiceEndpoint(typeof(IMyService1), new NetTcpBinding(),"net.tcp://my.datacenter.com/MyApp/MyService1"); //This is normally set to localhost. What implementation must be done on the datacenter server, so that if i had to point to http://my.datacenter.com/MyApp/MyService1 , it will route the service operation to my dev machine (localhost). However, the datacenter should not be accessible via the internet. It is a possible infrastructure that we researching to see if we can create a service bus type architecture so that all our customers can invoke other customer services running on their respective machines just by calling our datacenter url. We have looked at Windows Azure, but we have our own datacenter infrasture that we wish to leverage off. Come think of it, we kind of building our own Azure, on a very very basic scale. How does one go creating this? Thanks in Advance

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• Help a CRUD programmer think about an "approval workflow"

  - by gerdemb

  I've been working on a web application that is basically a CRUD application (Create, Read, Update, Delete). Recently, I've started working on what I'm calling an "approval workflow". Basically, a request is generated for a material and then sent for approval to a manager. Depending on what is requested, different people need to approve the request or perhaps send it back to the requester for modification. The approvers need to keep track of what to approve what has been approved and the requesters need to see the status of their requests. As a "CRUD" developer, I'm having a hard-time wrapping my head around how to design this. What database tables should I have? How do I keep track of the state of the request? How should I notify users of actions that have happened to their requests? Is their a design pattern that could help me with this? Should I be drawing state-machines in my code? I think this is a generic programing question, but if it makes any difference I'm using Django with MySQL.

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• How do I update a NSTableView when its data source has changed?

  - by Jergason

  I am working along with Cocoa Programming For Mac OS X (a great book). One of the exercises the book gives is to build a simple to-do program. The UI has a table view, a text field to type in a new item and an "Add" button to add the new item to the table. On the back end I have a controller that is the data source and delegate for my NSTableView. The controller also implements an IBAction method called by the "Add" button. It contains a NSMutableArray to hold the to do list items. When the button is clicked, the action method fires correctly and the new string gets added to the mutable array. However, my data source methods are not being called correctly. Here they be: - (NSInteger)numberOfRowsInTableView:(NSTableView *)aTableView { NSLog(@"Calling numberOfRowsInTableView: %d", [todoList count]); return [todoList count]; } - (id)tableView:(NSTableView *)aTableView objectValueForTableColumn:(NSTableColumn *)aTableColumn row:(NSInteger)rowIndex { NSLog(@"Returning %@ to be displayed", [todoList objectAtIndex:rowIndex]); return [todoList objectAtIndex:rowIndex]; } Here is the rub. -numberOfRowsInTableView only gets called when the app first starts, not every time I add something new to the array. -objectValueForTableColumn never gets called at all. I assume this is because Cocoa is smart enough to not call this method when there is nothing to draw. Is there some method I need to call to let the table view know that its data source has changed, and it should redraw itself?

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