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• how to create a system-wide independent universal counter object primarily for Database keys?

  - by andora

  I would like to create/use a system-wide independent universal 'counter object' that can be called via COM in a thread-safe manner. The counter object will be passed an ID to identify which counter to return, handle the counting, 'persist' the count (occasionally), have reasonable performance (as fast as possible) perhaps capable of 1000 counts per second or better (1mS) and be accessible cross-process/out-of-process. The current count status must be persisted between object restarts/shutdowns. The counter object is liklely to be a 'singleton' type object implemented in some form of free-threaded dictionary, containing maybe 10 counters (perhaps 50 max). The count needs to be monotonic and consistent, (ie: guaranteed unique sequential values). Each counter should have a few methods, like reset, inc, dec, set, clear, remove. As a luxury, I would like to have a variable-increment (ie: 'step by' value). To support thread-safefty, perhaps some sorm of critical-section or mutex call. It just needs to return a long/4byte signed integer. I really want something that can be called from anywhere, including VBScript, so I figure COM is my preferred solution. The primary use of this is for database keys. I am unable to use autoinc or guid type keys and have ruled out database-generated counting systems at this point. I've spent days researching this and I have really struggled to find a solution. The best I can find is a free-threaded dictionary object that can be instantiated using COM+ from Motobit - it seems to offer all the 'basics' and I guess I could create some form of wrapper for this. So, here are my questions: Does such a 'general purpose counter-object already exist? Can you direct me to it? (MS did do an IIS/ASP object called 'MSWC.Counter' but this isn't 'cross-process'/ out-of-process component and isn't thread-safe. (but if it was, it would do!) What is the best way of creating such a Component? (I'd prefer VB6 right-now, [don't ask!] but can do in VB.NET2005 if I had to). I don't have the skills/knowledge/tools to use anything else. I am desparate for a workable solution. I need specific guidance! If anybody can code something up for me I am prepared to pay for it.

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• multithreading with database

  - by Darsin

  I am looking out for a strategy to utilize multithreading (probably asynchronous delegates) to do a synchronous operation. I am new to multithreading so i will outline my scenario first. This synchronous operation right now is done for one set of data (portfolio) based on the the parameters provided. The (psudeo-code) implementation is given below: public DataSet DoTests(int fundId, DateTime portfolioDate) { // Get test results for the portfolio // Call the database adapter method, which in turn is a stored procedure, // which in turns runs a series of "rule" stored procs and fills a local temp table and returns it back. DataSet resultsDataSet = GetTestResults(fundId, portfolioDate); try { // Do some local processing on the results DoSomeProcessing(resultsDataSet); // Save the results in Test, TestResults and TestAllocations tables in a transaction. // Sets a global transaction which is provided to all the adapter methods called below // It is defined in the Base class StartTransaction("TestTransaction"); // Save Test and get a testId int testId = UpdateTest(resultsDataSet); // Adapter method, uses the same transaction // Update testId in the other tables in the dataset UpdateTestId(resultsDataSet, testId); // Update TestResults UpdateTestResults(resultsDataSet); // Adapter method, uses the same transaction // Update TestAllocations UpdateTestAllocations(resultsDataSet); // Adapter method, uses the same transaction // It is defined in the base class CommitTransaction("TestTransaction"); } catch { RollbackTransaction("TestTransaction"); } return resultsDataSet; } Now the requirement is to do it for multiple set of data. One way would be to call the above DoTests() method in a loop and get the data. I would prefer doing it in parallel. But there are certain catches: StartTransaction() method creates a connection (and transaction) every time it is called. All the underlying database tables, procedures are the same for each call of DoTests(). (obviously). Thus my question are: Will using multithreading anyway improve performance? What are the chances of deadlock especially when new TestId's are being created and the Tests, TestResults and TestAllocations are being saved? How can these deadlocked be handled? Is there any other more efficient way of doing the above operation apart from looping over the DoTests() method repeatedly?

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• NSArraycontroller selectionIndexes bindings

  - by Michael Scherbaum

  Hi all, I have the following set-up: A Window that has a splitView in which I display I NSCollectionView in the left view and a detailView in the right view. Both views are set-up in separate xibs. Furthermore I have a Datacontroller (of class NSArrayController) that manages a mutable Array of NSMutableDictionaries (moviesForChoice). The dataController is set-up as application delegate. The movie objects in the array have properties like (name, plot, genre etc.) so far so good... In the xib for the NScollectionview I bound a NSArraycontroller content property to my datacontroller via Application.delegate.moviesForChoice The collectionView accesses the arraycontroller.arrrangedObjects and arraycontroller.selectionIndexes. This works fine the contents are displayed and the selection works fine in the collectionview (my collectionviewItem renders a selection color) In the xib for the detailView I want to display information for the selected object in the collectionview. Therefore I also added an arraycontroller to the xib, bound the content aray to Application.delegate.moviesForChoice and bound the NSTextfields in the view to e.g. arraycontroller.selection.name Here comes my issue: everytime I open the window with the two xibs, my collectionview displays all movies that are for choice correctly, and the detailview displays the information for the 1st object in my collectionview. Whenever I click on a different movie in the collectionView the res. item renders a selection color, but the detailView doesn't update. My understanding of it would be that the DataController is not informed about updates in the selectionIndexes and can therefore not trigger an update in the detailView. Correct me if I'm wrong... To remedy this I tried to bind the selectionIndexes property of the arraycontroller in the collectionView xib to Application.delegate.moviesForChoice.selecionIndexes but this failed with: addObserver:forKeyPath:options:context:] is not supported. Key path: selectionIndexes I could imagine that this means that the datacontroller is not KVO compliant for my Array moviesForChoice, but I implemented the following methods for it: -(void)insertObject:(NSDictionary *)dict inMoviesForChoiceAtIndex:(NSUInteger)index { [moviesForChoice insertObject:dict atIndex:index]; } -(void)removeObjectFromMoviesForChoiceAtIndex:(NSUInteger)index { [moviesForChoice removeObjectAtIndex:index]; } -(void)setMoviesForChoice:(NSMutableArray *)a { moviesForChoice = a; } -(NSArray*)moviesForChoice { return moviesForChoice; } -(NSUInteger)countOfMoviesForChoice { return [moviesForChoice count]; } - (void)addMovieForChoiceObject:(Movie *)anObject { [moviesForChoice addObject:anObject]; } So where am I wrong? How do I correctly bind to the selectionIndexes? You help is much appreciated! M

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• Can this way of storing typed objects be improved?

  - by Pindatjuh

  This is an "can it be improved"-question. Topic: Storing typed objects in memory. Background information: I'm building a compiler for the x86-32 Windows platform for my language. My goal includes typed objects. Idea: Every primitive is a semi-class (it can be used as if it was a normal class, but it's stored more compact). Every class is represented by primitives and some meta-data (containing class-properties, inheritance stuff, etc.). The meta-data is complex: it doesn't use fields but instead context-switches. For primitives, the meta-data is very small, compared to a "real" class, which is alot bigger. This enables another idea that "primitives are objects", in my language, which I found nessecairy. Example: If I have an array of 32 booleans, then the pure content of this array is exactly 4 byte (32 bits of booleans). The meta-data will contain flags that the type is an array of booleans, which contains 32 entries. The meta-data is very compacted, on bit-level: using a sort of "packing" mechanism, which is read by a FSM at runtime, when doing inspection of the type (like when passing the object to methods for checking, etc.) For instance (read from left to right, top to bottom, remember vertical position when going to the right, and check nearest column header for meaning of switch): Primitive? Array? Type-Meta 1 Byte? || Size (1 byte) 1 1 [...] 1 [...] done 0 2 Bytes? || Size (2 bytes) 1 [...] done || Size (4 bytes) 0 [...] done Integer? 1 Byte? 2 Bytes? 0 1 0 1 done 1 done 0 done Boolean? Byte? 0 1 0 done 1 done More-Primitives 0 .... Class-Stuff (Huge) 0 ... (After reaching done the data is inserted. || = byte alignment. [...] is variable sized. ... is not described here, for simplicity. And let's call them cost-based-data-structures.) For an array of 32 booleans containing all true values, the memory for this type would be (read top-down): 1 Primitive 1 Array 1 ArrayType: Primitive 0 Not-Array 0 Not-Integer 1 Boolean 0 Not-Byte (thus bit) 1 Integer Size: 1 Byte 00100000 Array size 01010101 01010101 01010101 01010101 Data (user defined) Thus, 8 bytes represent 32 booleans in an array: 11100101 00100000 01010101 01010101 01010101 01010101 How can I improve this? (Both performance- and memory-consumption wise)

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• Hibernate3: Self-Referencing Objects

  - by monojohnny

  Need some help on understanding how to do this; I'm going to be running recursive 'find' on a file system and I want to keep the information in a single DB table - with a self-referencing hierarchial structure: This is my DB Table structure I want to populate. DirObject Table: id int NOT NULL, name varchar(255) NOT NULL, parentid int NOT NULL); Here is the proposed Java Class I want to map (Fields only shown): public DirObject { int id; String name; DirObject parent; ... For the 'root' directory was going to use parentid=0; real ids will start at 1, and ideally I want hibernate to autogenerate the ids. Can somebody provide a suggested mapping file for this please; as a secondary question I thought about doing the Java Class like this instead: public DirObject { int id; String name; List<DirObject> subdirs; Could I use the same data model for either of these two methods ? (With a different mapping file of course). --- UPDATE: so I tried the mapping file suggested below (thanks!), repeated here for reference: <hibernate-mapping> <class name="my.proj.DirObject" table="category"> ... <set name="subDirs" lazy="true" inverse="true"> <key column="parentId"/> <one-to-many class="my.proj.DirObject"/> </set> <many-to-one name="parent" class="my.proj.DirObject" column="parentId" cascade="all" /> </class> ...and altered my Java class to have BOTH 'parentid' and 'getSubDirs' [returning a 'HashSet']. This appears to work - thanks, but this is the test code I used to drive this - I think I'm not doing something right here, because I thought Hibernate would take care of saving the subordinate objects in the Set without me having to do this explicitly ? DirObject dirobject=new DirObject(); dirobject.setName("/files"); dirobject.setParent(dirobject); DirObject d1, d2; d1=new DirObject(); d1.setName("subdir1"); d1.setParent(dirobject); d2=new DirObject(); d2.setName("subdir2"); d2.setParent(dirobject); HashSet<DirObject> subdirs=new HashSet<DirObject>(); subdirs.add(d1); subdirs.add(d2); dirobject.setSubdirs(subdirs); session.save(dirobject); session.save(d1); session.save(d2);

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• How can I create the XML::Simple data structure using a Perl XML SAX parser?

  - by DVK

  Summary: I am looking a fast XML parser (most likely a wrapper around some standard SAX parser) which will produce per-record data structure 100% identical to those produced by XML::Simple. Details: We have a large code infrastructure which depends on processing records one-by-one and expects the record to be a data structure in a format produced by XML::Simple since it always used XML::Simple since early Jurassic era. An example simple XML is: <root> <rec><f1>v1</f1><f2>v2</f2></rec> <rec><f1>v1b</f1><f2>v2b</f2></rec> <rec><f1>v1c</f1><f2>v2c</f2></rec> </root> And example rough code is: sub process_record { my ($obj, $record_hash) = @_; # do_stuff } my $records = XML::Simple->XMLin(@args)->{root}; foreach my $record (@$records) { $obj->process_record($record) }; As everyone knows XML::Simple is, well, simple. And more importantly, it is very slow and a memory hog—due to being a DOM parser and needing to build/store 100% of data in memory. So, it's not the best tool for parsing an XML file consisting of large amount of small records record-by-record. However, re-writing the entire code (which consist of large amount of "process_record"-like methods) to work with standard SAX parser seems like an big task not worth the resources, even at the cost of living with XML::Simple. I'm looking for an existing module which will probably be based on a SAX parser (or anything fast with small memory footprint) which can be used to produce $record hashrefs one by one based on the XML pictured above that can be passed to $obj->process_record($record) and be 100% identical to what XML::Simple's hashrefs would have been. I don't care much what the interface of the new module is; e.g whether I need to call next_record() or give it a callback coderef accepting a record.

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• iPhone: Can't animate contentInset while animating Nav Bar show/hide

  - by Cuzog

  In my app, I have a table view. When the user clicks a button, a UIView overlays part of that table view. It's essentially a partial modal. That table view is intentionally still scrollable while that modal is active. To allow the user to scroll to the bottom of the table view, I change the contentInset and scrollIndicatorInsets values to adjust for the smaller area above the modal. When the modal is taken away, I reset those inset values. The problem is that when the user has scrolled to the bottom of the newly adjusted inset and then dismisses the modal, the table view jumps abruptly to a new scroll position because the inset is changed instantly. I would like to animate it so there is a transition, but the beginAnimation/commitAnimations methods aren't affecting it for some reason. Edit: More info. I found the conflict. When presenting the modal, I also hide the navigation bar. The navigation bar natively animates the table view up and down as it shows and hides. When I stop animating the navigation bar, the inset animation works fine. Does anyone know what I can do to work around this conflict? Do I have to wait for the navigation bar animation to finish before adjusting the inset? If so, how to I hook onto that? Any help is greatly appreciated! The relevant code from the table view controller is here: - (void)viewDidLoad { [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(modalOpened) name:@"ModalStartedOpening" object:nil]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(modalDismissed) name:@"ModalStartedClosing" object:nil]; [super viewDidLoad]; } - (void)modalOpened { [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.5]; [UIView setAnimationDelegate:self]; self.tableView.contentInset = UIEdgeInsetsMake(0, 0, 201, 0); self.tableView.scrollIndicatorInsets = UIEdgeInsetsMake(0, 0, 201, 0); [UIView commitAnimations]; } - (void)modalDismissed { [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.5]; [UIView setAnimationDelegate:self]; self.tableView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0); self.tableView.scrollIndicatorInsets = UIEdgeInsetsMake(0, 0, 0, 0); [UIView commitAnimations]; }

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• Sorting a list of colors in one dimension?

  - by Ptah- Opener of the Mouth

  I would like to sort a one-dimensional list of colors so that colors that a typical human would perceive as "like" each other are near each other. Obviously this is a difficult or perhaps impossible problem to get "perfectly", since colors are typically described with three dimensions, but that doesn't mean that there aren't some sorting methods that look obviously more natural than others. For example, sorting by RGB doesn't work very well, as it will sort in the following order, for example: (1) R=254 G=0 B=0 (2) R=254 G=255 B=0 (3) R=255 G=0 B=0 (4) R=255 G=255 B=0 That is, it will alternate those colors red, yellow, red, yellow, with the two "reds" being essentially imperceivably different than each other, and the two yellows also being imperceivably different from each other. But sorting by HLS works much better, generally speaking, and I think HSL even better than that; with either, the reds will be next to each other, and the yellows will be next to each other. But HLS/HSL has some problems, too; things that people would perceive as "black" could be split far apart from each other, as could things that people would perceive as "white". Again, I understand that I pretty much have to accept that there will be some splits like this; I'm just wondering if anyone has found a better way than HLS/HSL. And I'm aware that "better" is somewhat arbitrary; I mean "more natural to a typical human". For example, a vague thought I've had, but have not yet tried, is perhaps "L is the most important thing if it is very high or very low", but otherwise it is the least important. Has anyone tried this? Has it worked well? What specifically did you decide "very low" and "very high" meant? And so on. Or has anyone found anything else that would improve upon HSL? I should also note that I am aware that I can define a space-filling curve through the cube of colors, and order them one-dimensionally as they would be encountered while travelling along that curve. That would eliminate perceived discontinuities. However, it's not really what I want; I want decent overall large-scale groupings more than I want perfect small-scale groupings. Thanks in advance for any help.

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• Multiple checkbox values search javascript

  - by JV10

  I have a list of keywords, and I've created a checkbox for each. My template has a form wrapping the content, so I can't have a nested form around the checkbox list. How can I send the selected checkbox values to my search results page? The form that wraps the content doesn't have any actions or methods applied: <form id="BoostMasterForm" runat="server"> This the HTML markup of my checkbox list: <div class="checkboxes"> <ul> <li> <input type="checkbox" name="search" class="options" value="one"> <label>one</label> </li> <li> <input type="checkbox" name="search" class="options" value="two"> <label>two</label> </li> <li> <input type="checkbox" name="search" class="options" value="three"> <label>three</label> </li> </ul> <input type="submit" value="Submit"/> </div> How can I use javascript or jQuery to submit the values of the multiple checkbox selections and on submit action them to the following URL: '/imagery/image-search.aspx' The resulting URL for a search where option 1 and 3 are submitted should be: '/imagery/image-search.aspx?search=one%20three' I'm using this javascript that I found on another post, however I need it to append the form an the action and the method. My website is ASP, where this post is for a PHP site: Sending multiple checkbox options $('.options').click(function() { var selectedItems = new Array(); $(".checkboxes input:checkbox[name=search]:checked").each(function() {selectedItems.push($(this).val());}); var data = selectedItems.join('|'); $("#opts").val(data); }); If anyone can help, it'd be greatly appreciated. Cheers, JV

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• How not to abort http response c#

  - by user194076

  I need to run several methods after sending file to a user for a download. What happens is that after I send a file to a user, response is aborted and I can no longer do anything after response.end(). for example, this is my sample code: Response.Clear(); Response.AddHeader("content-disposition", "attachment; filename=test.pdf"); Response.ContentType = "application/pdf"; byte[] a = System.Text.Encoding.UTF8.GetBytes("test"); Response.BinaryWrite(a); Response.End(); StartNextMethod(); Response.Redirect(URL); So, in this example StartNextMethod and Response.Redirect are not executing. What I tried is I created a separate handler(ashx) with the following code: public void ProcessRequest(HttpContext context) { context.Response.Clear(); context.Response.AddHeader("content-disposition", "attachment; filename=test.pdf"); context.Response.ContentType = "application/pdf"; byte[] a = System.Text.Encoding.UTF8.GetBytes("test"); context.Response.BinaryWrite(a); context.Response.End(); } and call it like this: Download d = new Download(); d.ProcessRequest(HttpContext.Current); StartNextMethod(); Response.Redirect(URL); but the same error happen. I've tryied to replace Response.End with CompleteRequest but it doesn't help. I guess the problem is that I'm using HttpContext.Current but should use a separate response stream. Is that correct? how do I do that in a separate method generically (Assume that I want my handler to accept byte array of data and content type and be downloadable from a separate response. I really do not want to use a separate page for a response. UPDATE I still didn't find a good solution. I'd like to do some actions after user has downloaded a file, but without using a separate page for a response\request thing.

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• Implementing events to communicate between two processes - C

  - by Jamie Keeling

  Hello all! I have an application consisting of two windows, one communicates to the other and sends it a struct constaining two integers (In this case two rolls of a dice). I will be using events for the following circumstances: Process a sends data to process b, process b displays data Process a closes, in turn closing process b Process b closes a, in turn closing process a I have noticed that if the second process is constantly waiting for the first process to send data then the program will be just sat waiting, which is where the idea of implementing threads on each process occurred and I have started to implement this already. The problem i'm having is that I don't exactly have a lot of experience with threads and events so I'm not sure of the best way to actually implement what I want to do. Following is a small snippet of what I have so far in the producer application; Create thread: case IDM_FILE_ROLLDICE: { hDiceRoll = CreateThread( NULL, // lpThreadAttributes (default) 0, // dwStackSize (default) ThreadFunc(hMainWindow), // lpStartAddress NULL, // lpParameter 0, // dwCreationFlags &hDiceID // lpThreadId (returned by function) ); } break; The data being sent to the other process: DWORD WINAPI ThreadFunc(LPVOID passedHandle) { HANDLE hMainHandle = *((HANDLE*)passedHandle); WCHAR buffer[256]; LPCTSTR pBuf; LPVOID lpMsgBuf; LPVOID lpDisplayBuf; struct diceData storage; HANDLE hMapFile; DWORD dw; //Roll dice and store results in variable storage = RollDice(); hMapFile = CreateFileMapping( (HANDLE)0xFFFFFFFF, // use paging file NULL, // default security PAGE_READWRITE, // read/write access 0, // maximum object size (high-order DWORD) BUF_SIZE, // maximum object size (low-order DWORD) szName); // name of mapping object if (hMapFile == NULL) { dw = GetLastError(); MessageBox(hMainHandle,L"Could not create file mapping object",L"Error",MB_OK); return 1; } pBuf = (LPTSTR) MapViewOfFile(hMapFile, // handle to map object FILE_MAP_ALL_ACCESS, // read/write permission 0, 0, BUF_SIZE); if (pBuf == NULL) { MessageBox(hMainHandle,L"Could not map view of file",L"Error",MB_OK); CloseHandle(hMapFile); return 1; } CopyMemory((PVOID)pBuf, &storage, (_tcslen(szMsg) * sizeof(TCHAR))); //_getch(); MessageBox(hMainHandle,L"Completed!",L"Success",MB_OK); UnmapViewOfFile(pBuf); return 0; } I'm trying to find out how I would integrate an event with the threaded code to signify to the other process that something has happened, I've seen an MSDN article on using events but it's just confused me if anything, I'm coming up on empty whilst searching on the internet too. Thanks for any help Edit: I can only use the Create/Set/Open methods for events, sorry for not mentioning it earlier.

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• A better UPDATE method in LINQ to SQL

  - by Refracted Paladin

  The below is a typical, for me, Update method in L2S. I am still fairly new to a lot of this(L2S & business app development) but this just FEELs wrong. Like there MUST be a smarter way of doing this. Unfortunately, I am having trouble visualizing it and am hoping someone can provide an example or point me in the right direction. To take a stab in the dark, would I have a Person Object that has all these fields as Properties? Then what, though? Is that redundant since L2S already mapped my Person Table to a Class? Is this just 'how it goes', that you eventually end up passing 30 parameters(or MORE) to an UPDATE statement at some point? For reference, this is a business app using C#, WinForms, .Net 3.5, and L2S over SQL 2005 Standard. Here is a typical Update Call for me. This is in a file(BLLConnect.cs) with other CRUD methods. Connect is the name of the DB that holds tblPerson When a user clicks save() this is what is eventually called with all of these fields having, potentially, been updated-- public static void UpdatePerson(int personID, string userID, string titleID, string firstName, string middleName, string lastName, string suffixID, string ssn, char gender, DateTime? birthDate, DateTime? deathDate, string driversLicenseNumber, string driversLicenseStateID, string primaryRaceID, string secondaryRaceID, bool hispanicOrigin, bool citizenFlag, bool veteranFlag, short ? residencyCountyID, short? responsibilityCountyID, string emailAddress, string maritalStatusID) { using (var context = ConnectDataContext.Create()) { var personToUpdate = (from person in context.tblPersons where person.PersonID == personID select person).Single(); personToUpdate.TitleID = titleID; personToUpdate.FirstName = firstName; personToUpdate.MiddleName = middleName; personToUpdate.LastName = lastName; personToUpdate.SuffixID = suffixID; personToUpdate.SSN = ssn; personToUpdate.Gender = gender; personToUpdate.BirthDate = birthDate; personToUpdate.DeathDate = deathDate; personToUpdate.DriversLicenseNumber = driversLicenseNumber; personToUpdate.DriversLicenseStateID = driversLicenseStateID; personToUpdate.PrimaryRaceID = primaryRaceID; personToUpdate.SecondaryRaceID = secondaryRaceID; personToUpdate.HispanicOriginFlag = hispanicOrigin; personToUpdate.CitizenFlag = citizenFlag; personToUpdate.VeteranFlag = veteranFlag; personToUpdate.ResidencyCountyID = residencyCountyID; personToUpdate.ResponsibilityCountyID = responsibilityCountyID; personToUpdate.EmailAddress = emailAddress; personToUpdate.MaritalStatusID = maritalStatusID; personToUpdate.UpdateUserID = userID; personToUpdate.UpdateDateTime = DateTime.Now; context.SubmitChanges(); } }

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• C++: Templates for static functions?

  - by Rosarch

  I have a static Utils class. I want certain methods to be templated, but not the entire class. How do I do this? This fails: #pragma once #include <string> using std::string; class Utils { private: template<class InputIterator, class Predicate> static set<char> findAll_if_rec(InputIterator begin, InputIterator end, Predicate pred, set<char> result); public: static void PrintLine(const string& line, int tabLevel = 0); static string getTabs(int tabLevel); template<class InputIterator, class Predicate> static set<char> Utils::findAll_if(InputIterator begin, InputIterator end, Predicate pred); }; Error: utils.h(10): error C2143: syntax error : missing ';' before '<' utils.h(10): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int utils.h(10): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int utils.h(10): error C2238: unexpected token(s) preceding ';' utils.h(10): error C2988: unrecognizable template declaration/definition utils.h(10): error C2059: syntax error : '<' What am I doing wrong? What is the correct syntax for this? Incidentally, I'd like to templatize the return value, too. So instead of: template<class InputIterator, class Predicate> static set<char> findAll_if_rec(InputIterator begin, InputIterator end, Predicate pred, set<char> result); I'd have: template<class return_t, class InputIterator, class Predicate> static return_t findAll_if_rec(InputIterator begin, InputIterator end, Predicate pred, set<char> result); How would I specify that: 1) return_t must be a set of some sort 2) InputIterator must be an iterator 3) InputIterator's type must work with return_t's type. Thanks.

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• Getting 404 when attempting to POST file to Google Cloud Storage from service account

  - by klactose

  I'm wondering if anyone can tell me the proper syntax & formatting for a service account to send a POST Object to bucket request? I'm attempting it programmatically using the HttpComponents library. I manage to get a token from my GoogleCredential, but every time I construct the POST request, I get: HTTP/1.1 403 Forbidden <?xml version='1.0' encoding='UTF-8'?><Error><Code>AccessDenied</Code><Message>Access denied.</Message><Detailsbucket-name</Details></Error The Google documentation that describes the request methods, mentions posting using html forms, but I'm hoping that wasn't suggesting the ONLY way to get the job done. I know that HttpComponents has a way to explicitly create form data by using UrlEncodedFormEntity, but it doesn't support multipart data. Which is why I went with using the MultipartEntity class. My code is below: MultipartEntity entity = new MultipartEntity( HttpMultipartMode.BROWSER_COMPATIBLE ); String token = credential.getAccessToken(); entity.addPart("Authorization", new StringBody("OAuth " + token)); String date = formatDate(new Date()); entity.addPart("Date", new StringBody(date)); entity.addPart("Content-Encoding", new StringBody("UTF-8")); entity.addPart("Content-Type", new StringBody("multipart/form-data")); entity.addPart("bucket", new StringBody(bucket)); entity.addPart("key", new StringBody("fileName")); entity.addPart("success_action_redirect", new StringBody("/storage")); File uploadFile = new File("pathToFile"); FileBody fileBody = new FileBody(uploadFile, "text/xml"); entity.addPart("file", fileBody); httppost.setEntity(entity); System.out.println("Posting URI = "+httppost.toString()); HttpResponse response = client.execute(httppost); HttpEntity resp_entity = response.getEntity(); As I mentioned, I am able to get an actual token, so I'm pretty sure the problem is in how I've formed the request as opposed to not being properly authenticated. Keep in mind: This is being performed by a service account. Which means that it does have Read/Write access Thanks for reading, and I appreciate any help!

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• UITableView: Mixing static and dynamic cells

  - by AlexR

  I am trying to mix dynamic and static cells in a grouped table view: I would like to get two sections with static cells at the top followed by a section of dynamic cells (please refer to the screenshot below). I have set the table view contents to static cells. I designed the static cells in Interface Builder and gave them identifiers related to their section and row: "section0static0", "section0static1", "section1static0" and "section1static1". I named the dynamic cell "section2dynamic". My delegate methods, in which I am trying to return the correct cell identifier (static or dynamic) are as follows: - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { switch (section) { case 0: return 2; break; case 1: return 2; break; case 2: return 0; break; default: break; } return 0; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @""; if (indexPath.section <= 1) CellIdentifier = [NSString stringWithFormat:@"section%istatic%i",indexPath.section,indexPath.row]; else CellIdentifier = [NSString stringWithFormat:@"section%idynamic",indexPath.section]; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath]; return cell; } Edit Based on AppleFreak's advice I have changed my code as follows: - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell; if (indexPath.section <= 1) { // section <= 1 indicates static cells cell = [super tableView:tableView cellForRowAtIndexPath:indexPath]; } else { // section > 1 indicates dynamic cells CellIdentifier = [NSString stringWithFormat:@"section%idynamic",indexPath.section]; cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath]; } return cell; } However, my app crashes with error message Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath:' for section 0 and row 0. The cell returned from cell = [super tableView:tableView cellForRowAtIndexPath:indexPath] for section 0 and row 0 is nil. What is wrong with my code? Could there be any problems with my outlets? I haven't set any outlets because I am subclassing UITableViewController and supposedly do not any outlets for tableview to be set (?). Any suggestions on how to better do it?

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• Passing objects to a UITypeEditor

  - by Kath

  I am currently hoping to use a PropertyGrid to allow users to edit some of my classes, however I've hit a wall with passing objects to the UITypeEditor(s) they use. When the user presses the drop down I want to show a listbox of already loaded textures to choose from, if they want to use a texture the application hasn't loaded yet they can click a button to choose one from a file dialog. In case I make no sense here a mock of the form: . My problem: To fill the listbox I need access to the class that manages the list of resources from the UITypeEditor. Now I've solved this problem for my own classes by giving them a reference on creation to their managing object. In the UITypeEditor I then use that reference to access what I need. However I can't do this for classes I haven't written, such as the XNA Texture2D class. Here are what the classes I'm using look like: class StaticGeometryChunk { // Geometry data to draw with. Contains a reference to its managing // class for use in its UITypeEditor. public GeometryData { get; set; } .... } class Material { // These are XNA classes. I can't just add a reference to its managing // class (I think?). public Texture2D Texture1 { get; set; } public Texture2D Texture2 { get; set; } .... } I've been looking at my options and they seem to be: Make the managing classes static. I don't really want to do this. There are several managing classes as each resource is loaded differently. There are also classes that need to be created before these and are passed in. Make the managing classes singletons. I don't really want to do this either. It seems like a quick and dirty way to "hide" the problem instead of "solve" it. I also might want the option of having several managing classes in the future which the singletons eliminate. Create a wrapper class which holds the reference to a managing class and its target (such as the XNA Texture2D). This is currently what I'm thinking of doing. Its would be quite simple and quick to do but something about it nags me but I don't know what. Any thoughts on the above or other methods to pass what I need into the UITypeEditor? Thank you for reading.

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• Updating UISearchDisplayController with Core Data results using GCD

  - by Brian Halpin

  I'm having trouble displaying the results from Core Data in my UISearchDisplayController when I implement GCD. Without it, it works, but obviously blocks the UI. In my SearchTableViewController I have the following two methods: - (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString { // Tell the table data source to reload when text changes [self filterContentForSearchText:searchString]; // Return YES to cause the search result table view to be reloaded. return YES; } // Update the filtered array based on the search text -(void)filterContentForSearchText:(NSString*)searchText { // Remove all objects from the filtered search array [self.filteredLocationsArray removeAllObjects]; NSPredicate *predicate = [CoreDataMaster predicateForLocationUsingSearchText:@"Limerick"]; CoreDataMaster *coreDataMaster = [[CoreDataMaster alloc] init]; // Filter the array using NSPredicate self.filteredLocationsArray = [NSMutableArray arrayWithArray: [coreDataMaster fetchResultsFromCoreDataEntity:@"City" UsingPredicate:predicate]]; } You can probably guess that my problem is with returning the array from [coreDataMaster fetchResultsFromCoreDataEntity]. Below is the method: - (NSArray *)fetchResultsFromCoreDataEntity:(NSString *)entity UsingPredicate:(NSPredicate *)predicate { NSMutableArray *fetchedResults = [[NSMutableArray alloc] init]; dispatch_queue_t coreDataQueue = dispatch_queue_create("com.coredata.queue", DISPATCH_QUEUE_SERIAL); dispatch_async(coreDataQueue, ^{ NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entityDescription = [NSEntityDescription entityForName:entity inManagedObjectContext:self.managedObjectContext]; NSSortDescriptor *nameSort = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES]; NSArray *sortDescriptors = [NSArray arrayWithObjects:nameSort, nil]; [fetchRequest setEntity:entityDescription]; [fetchRequest setSortDescriptors:sortDescriptors]; // Check if predicate is set if (predicate) { [fetchRequest setPredicate:predicate]; } NSError *error = nil; NSArray *fetchedManagedObjects = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error]; for (City *city in fetchedManagedObjects) { [fetchedResults addObject:city]; } NSDictionary *userInfo = [NSDictionary dictionaryWithObject:[NSArray arrayWithArray:fetchedResults] forKey:@"results"]; [[NSNotificationCenter defaultCenter] postNotificationName:@"fetchResultsComplete" object:nil userInfo:userInfo]; }); return [NSArray arrayWithArray:fetchedResults]; } So the thread hasn't finished executing by the time it returns the results to self.filteredLocationsArray. I've tried added a NSNotification which passes the NSDictionary to this method: - (void)updateSearchResults:(NSNotification *)notification { NSDictionary *userInfo = notification.userInfo; NSArray *array = [userInfo objectForKey:@"results"]; self.filteredLocationsArray = [NSMutableArray arrayWithArray:array]; [self.tableView reloadData]; } I've also tried refreshing the searchViewController like [self.searchDisplayController.searchResultsTableView reloadData]; but to no avail. I'd really appreciate it if someone could point me in the right direction and show me where I might be going wrong. Thanks

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• How to perform add/update of a model object that contains EntitySet

  - by David Liddle

  I have a similar concept to the SO questions/tags scenario however am trying to decide the best way of implementation. Tables Questions, QuestionTags and Tags Questions QuestionTags Tags --------- ------------ ---- QID QID TID QName TID TName When adding/updating a question I have 2 textboxes. The important part is a single textbox that allows users to enter in multiple Tags separated by spaces. I am using Linq2Sql so the Questions model has an EntitySet of QuestionTags with then link to Tags. My question is regarding the adding/updating of Questions (part 1), and also how to best show QuestionTags for a Question (part 2). Part 1 Before performing an add/update, my service layer needs to deal with 3 scenarios before passing to their respective repositories. Insert Tags that do not already exist Insert/Update Question Insert QuestionTags - when updating need to remove existing QuestionTags Here is my code below however started to get into a bit of a muddle. I've created extension methods on my repositories to get Tags WithNames etc. public void Add(Question q, string tags) { var tagList = tags.Split(new string[] { " " }, StringSplitOptions.RemoveEmptyEntries).ToList(); using (DB.TransactionScope ts = new DB.TransactionScope()) { var existingTags = TagsRepository.Get() .WithName(tagList) .ToList(); var newTags = (from t in tagList select new Tag { TName = t }).Except(existingTags, new TagsComparer()).ToList(); TagsRepository.Add(newTags); //need to insert QuestionTags QuestionsRepository.Add(q); ts.Complete(); } } Part 2 My second question is, when displaying a list of Questions how is it best to show their QuestionTags? For example, I have an Index view that shows a list of Questions in a table. One of the columns shows an image and when the user hovers over it shows the list of Tags. My current implementation is to create a custom ViewModel and show a List of QuestionIndexViewModel in the View. QuestionIndexViewModel { Question Question { get; set; } string Tags { get; set; } } However, this seems a bit clumsy and quite a few DB calls. public ViewResult Index() { var model= new List<QuestionIndexViewModel>(); //make a call to get a list of questions //foreach question make a call to get their QuestionTags, //to be able to get their Tag names and then join them //to form a single string. return View(model); } Also, just for test purposes using SQL Profiler, I decided to iterate through the QuestionTags entity set of a Question in my ViewModel however nothing was picked up in Profiler? What would be the reason for this?

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• Parallel Task Library WaitAny Design

  - by colithium

  I've just begun to explore the PTL and have a design question. My Scenario: I have a list of URLs that each refer to an image. I want each image to be downloaded in parallel. As soon as at least one image is downloaded, I want to execute a method that does something with the downloaded image. That method should NOT be parallelized -- it should be serial. I think the following will work but I'm not sure if this is the right way to do it. Because I have separate classes for collecting the images and for doing "something" with the collected images, I end up passing around an array of Tasks which seems wrong since it exposes the inner workings of how images are retrieved. But I don't know a way around it. In reality there is more to both of these methods but that's not important for this. Just know that they really shouldn't be lumped into one large method that both retrieves and does something with the image. Task<Image>[] downloadTasks = collector.RetrieveImages(listOfURLs); for (int i = 0; i < listOfURLs.Count; i++) { //Wait for any of the remaining downloads to complete int completedIndex = Task<Image>.WaitAny(downloadTasks); Image completedImage = downloadTasks[completedIndex].Result; //Now do something with the image (this "something" must happen serially) } /////////////////////////////////////////////////// public Task<Image>[] RetrieveImages(List<string> urls) { Task<Image>[] tasks = new Task<Image>[urls.Count]; int index = 0; foreach (string url in urls) { string lambdaVar = url; //Required... Bleh tasks[index] = Task<Image>.Factory.StartNew(() => { using (WebClient client = new WebClient()) { //TODO: Replace with live image locations string fileName = String.Format("{0}.png", i); client.DownloadFile(lambdaVar, Path.Combine(Application.StartupPath, fileName)); } return Image.FromFile(Path.Combine(Application.StartupPath, fileName)); }, TaskCreationOptions.LongRunning | TaskCreationOptions.AttachedToParent); index++; } return tasks; }

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• DRY-ing very similar specs for ASP.NET MVC controller action with MSpec (BDD guidelines)

  - by spapaseit

  Hi all, I have two very similar specs for two very similar controller actions: VoteUp(int id) and VoteDown(int id). These methods allow a user to vote a post up or down; kinda like the vote up/down functionality for StackOverflow questions. The specs are: VoteDown: [Subject(typeof(SomeController))] public class When_user_clicks_the_vote_down_button_on_a_post : SomeControllerContext { Establish context = () => { post = PostFakes.VanillaPost(); post.Votes = 10; session.Setup(s => s.Single(Moq.It.IsAny<Expression<Func<Post, bool>>>())).Returns(post); session.Setup(s => s.CommitChanges()); }; Because of = () => result = controller.VoteDown(1); It should_decrement_the_votes_of_the_post_by_1 = () => suggestion.Votes.ShouldEqual(9); It should_not_let_the_user_vote_more_than_once; } VoteUp: [Subject(typeof(SomeController))] public class When_user_clicks_the_vote_down_button_on_a_post : SomeControllerContext { Establish context = () => { post = PostFakes.VanillaPost(); post.Votes = 0; session.Setup(s => s.Single(Moq.It.IsAny<Expression<Func<Post, bool>>>())).Returns(post); session.Setup(s => s.CommitChanges()); }; Because of = () => result = controller.VoteUp(1); It should_increment_the_votes_of_the_post_by_1 = () => suggestion.Votes.ShouldEqual(1); It should_not_let_the_user_vote_more_than_once; } So I have two questions: How should I go about DRY-ing these two specs? Is it even advisable or should I actually have one spec per controller action? I know I Normally should, but this feels like repeating myself a lot. Is there any way to implement the second It within the same spec? Note that the It should_not_let_the_user_vote_more_than_once; requires me the spec to call controller.VoteDown(1) twice. I know the easiest would be to create a separate spec for it too, but it'd be copying and pasting the same code yet again... I'm still getting the hang of BDD (and MSpec) and many times it is not clear which way I should go, or what the best practices or guidelines for BDD are. Any help would be appreciated.

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• Recursion problem; completely lost

  - by timeNomad

  So I've been trying to solve this assignment whole day, just can't get it. The following function accepts 2 strings, the 2nd (not 1st) possibly containing *'s (asterisks). An * is a replacement for a string (empty, 1 char or more), it can appear appear (only in s2) once, twice, more or not at all, it cannot be adjacent to another * (ab**c), no need to check that. public static boolean samePattern(String s1, String s2) It returns true if strings are of the same pattern. It must be recursive, not use any loops, static & global variables. Can use local variables & method overloading. Can use only these methods: charAt(i), substring(i), substring(i, j), length(). Examples: 1: TheExamIsEasy; 2: "The*xamIs*y" --- true 1: TheExamIsEasy; 2: "Th*mIsEasy*" --- true 1: TheExamIsEasy; 2: "*" --- true 1: TheExamIsEasy; 2: "TheExamIsEasy" --- true 1: TheExamIsEasy; 2: "The*IsHard" --- FALSE I tried comparing the the chars one by one using charAt until an asterisk is encountered, then check if the asterisk is an empty one by comparing is successive char (i+1) with the char of s1 at position i, if true -- continue recursion with i+1 as counter for s2 & i as counter for s1; if false -- continue recursion with i+1 as counters for both. Continue this until another asterisk is found or end of string. I dunno, my brain loses track of things, can't concentrate, any pointers / hints? Am I in the right direction? Also, it's been told that a backtracking technique is to be used to solve this. My code so far (doesn't do the job, even theoretically): public static boolean samePattern(String s1, String s2) { if (s1.equals(s2) || s2 == "*") { return true; } return samePattern(s1, s2, 1); } public static boolean samePattern(String s1, String s2, int i) { if (s1.equals(s2)) return true; if (i == s2.length() - 1) // No *'s found -- not same pattern. return false; if (s1.substring(0, i).equals(s2.substring(0, i))) samePattern(s1, s2, i+1); else if (s2.charAt(i-1) == '*') samePattern(s1.substring(0, i-1), s2.substring(0, i), 1); // new smaller strings. else samePattern(s1.substring(1), s2, i); }

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• clarification on the concept of "web service"

  - by udit

  Im a little confused on the varying definitions and implementations of web services available as implementations. Need some clarification please. Ones I have used till now: If a vendor gives me a specific format of XML that I can send populated with data to request and I make a simple HTTP POST over the internet passing in the XML String as the payload, is this a web service call ? If so, is there a specific name to it, this kind of web service ? Because obviously, it does not use anything like Axis, WSDL or SOAP to establish this connection. A variant of this is If the vendor gives me an XSD, I use JAXB to make a java class out of it and pass in the serialized version of the object, which eventually works out to be the same as option 1. RESTful web service: Vendor gives me a URL like http://restfulservice/products and I can make HTTP Requests to the URL and depending on what HTTP verb I use, the appropropriate action is called and the response sent over the wire. Ones I have only read about\ have a vague idea about SOAP. How does this work?.. Ive read the W3Schools tutorial and I undertsand that there is a very specific form of XML that is standardized according to W3C standards that we use to pass the same kind of messages as we did in option 1. But how does this work in real life? Vendor sends me what? Do I generate classes? Do I serialize some objects and http post them over to an address? Or do the generated objects themselves have connection methods that will do them for me? What about WSDL? When does a vendor send me WSDL and what do I do with it ? I guess I can generate classes from it. If yes, then what do I do with the generated classes ? When do I need that axis jar to generate classes from something that the vendor sends ? As you can see, I have some clear and other mostly vague ideas about the different kinds of web services available. would help if someone ould clarify and\or point to more real-world resources. I've looked a little bit into Java Web Services on the internet and the numerous four letter acronyms that get thrown at me make me dizzy. Thanks

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• Using events in threads between processes - C

  - by Jamie Keeling

  Hello all! I have an application consisting of two windows, one communicates to the other and sends it a struct constaining two integers (In this case two rolls of a dice). I will be using events for the following circumstances: Process a sends data to process b, process b displays data Process a closes, in turn closing process b Process b closes a, in turn closing process a I have noticed that if the second process is constantly waiting for the first process to send data then the program will be just sat waiting, which is where the idea of implementing threads on each process occurred and I have started to implement this already. The problem i'm having is that I don't exactly have a lot of experience with threads and events so I'm not sure of the best way to actually implement what I want to do. Following is a small snippet of what I have so far in the producer application; Create thread: case IDM_FILE_ROLLDICE: { hDiceRoll = CreateThread( NULL, // lpThreadAttributes (default) 0, // dwStackSize (default) ThreadFunc(hMainWindow), // lpStartAddress NULL, // lpParameter 0, // dwCreationFlags &hDiceID // lpThreadId (returned by function) ); } break; The data being sent to the other process: DWORD WINAPI ThreadFunc(LPVOID passedHandle) { HANDLE hMainHandle = *((HANDLE*)passedHandle); WCHAR buffer[256]; LPCTSTR pBuf; LPVOID lpMsgBuf; LPVOID lpDisplayBuf; struct diceData storage; HANDLE hMapFile; DWORD dw; //Roll dice and store results in variable storage = RollDice(); hMapFile = CreateFileMapping( (HANDLE)0xFFFFFFFF, // use paging file NULL, // default security PAGE_READWRITE, // read/write access 0, // maximum object size (high-order DWORD) BUF_SIZE, // maximum object size (low-order DWORD) szName); // name of mapping object if (hMapFile == NULL) { dw = GetLastError(); MessageBox(hMainHandle,L"Could not create file mapping object",L"Error",MB_OK); return 1; } pBuf = (LPTSTR) MapViewOfFile(hMapFile, // handle to map object FILE_MAP_ALL_ACCESS, // read/write permission 0, 0, BUF_SIZE); if (pBuf == NULL) { MessageBox(hMainHandle,L"Could not map view of file",L"Error",MB_OK); CloseHandle(hMapFile); return 1; } CopyMemory((PVOID)pBuf, &storage, (_tcslen(szMsg) * sizeof(TCHAR))); //_getch(); MessageBox(hMainHandle,L"Completed!",L"Success",MB_OK); UnmapViewOfFile(pBuf); return 0; } I'm trying to find out how I would integrate an event with the threaded code to signify to the other process that something has happened, I've seen an MSDN article on using events but it's just confused me if anything, I'm coming up on empty whilst searching on the internet too. Thanks for any help Edit: I can only use the Create/Set/Open methods for events, sorry for not mentioning it earlier.

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• JButton Image Ignoring GridBagConstraints

  - by daemor

  I am working on an application and have a screen that needs to have elements (namely some custom JButtons) appear and disappear based on a user selection. However for some reason, when I add these buttons to their pane, the buttton image goes to the top corner, and leaves the text in the center, completely ignoring GridBagConstraints. I am completely stumped on this one as I have done this same exact thing dozens of times earlier in the program without any issues. Here is an image of the problem: The problem is in this method here, and occurs down towards the bottom. public void init(){ contentPane.removeAll(); // Setup jlabels JLabel countyLabel = new JLabel("County"); countyLabel.setFont(new Font("Times New Roman", Font.PLAIN, 18)); JLabel measureByLabel = new JLabel("Measure By: "); measureByLabel.setFont(new Font("Times New Roman", Font.PLAIN, 18)); String[] countyChoices = {"Washtenaw", "Oakland", "Livingston"}; // setup components JComboBox<String> countyCombo = new JComboBox<String>(countyChoices); // place baseComponents c.weightx = 0.5; c.weighty = 0.5; c.gridx = 0; c.gridy = 0; c.anchor = GridBagConstraints.NORTH; contentPane.add(countyLabel, c); c.gridx = 2; contentPane.add(countyCombo, c); c.gridy = 1; c.gridx = 0; contentPane.add(trenchButton, c); c.gridx = 2; contentPane.add(bedButton, c); c.gridy = 2; c.gridx = 1; contentPane.add(systemSelection, c); c.gridy = 3; c.gridx = 0; contentPane.add(lengthButton, c); c.fill = GridBagConstraints.BOTH; c.gridwidth = 4; c.gridy = 4; c.gridx = 0; contentPane.add(choicePane, c); GridBagConstraints con = new GridBagConstraints(); con.weightx = 0.5; con.weighty = 0.5; con.gridx = 0; con.gridy = 0; choicePane.add(lengthButton, c); // revalidate and repaint choicePane.revalidate(); choicePane.repaint(); contentPane.revalidate(); contentPane.repaint(); } I have tried doing this in separate methods, the button looks fine when added to the contentPane, the pane is for sure set to gridbagconstraints as I used the expression JPanel choicePane = new JPanel(new GridBagLayout()) to initialize it.

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• SSL Authentication with Certificates: Should the Certificates have a hostname?

  - by sixtyfootersdude

  Summary JBoss allows clients and servers to authenticate using certificates and ssl. One thing that seems strange is that you are not required to give your hostname on the certificate. I think that this means if Server B is in your truststore, Sever B can pretend to be any server that they want. (And likewise: if Client B is in your truststore...) Am I missing something here? Authentication Steps (Summary of Wikipeida Page) Client Server ================================================================================================= 1) Client sends Client Hello ENCRIPTION: None - highest TLS protocol supported - random number - list of cipher suites - compression methods 2) Sever Hello ENCRIPTION: None - highest TLS protocol supported - random number - choosen cipher suite - choosen compression method 3) Certificate Message ENCRIPTION: None - 4) ServerHelloDone ENCRIPTION: None 5) Certificate Message ENCRIPTION: None 6) ClientKeyExchange Message ENCRIPTION: server's public key => only server can read => if sever can read this he must own the certificate - may contain a PreMasterSecerate, public key or nothing (depends on cipher) 7) CertificateVerify Message ENCRIPTION: clients private key - purpose is to prove to the server that client owns the cert 8) BOTH CLIENT AND SERVER: - use random numbers and PreMasterSecret to compute a common secerate 9) Finished message - contains a has and MAC over previous handshakes (to ensure that those unincripted messages did not get broken) 10) Finished message - samething Sever Knows The client has the public key for the sent certificate (step 7) The client's certificate is valid because either: it has been signed by a CA (verisign) it has been self-signed BUT it is in the server's truststore It is not a replay attack because presumably the random number (step 1 or 2) is sent with each message Client Knows The server has the public key for the sent certificate (step 6 with step 8) The server's certificate is valid because either: it has been signed by a CA (verisign) it has been self-signed BUT it is in the client's truststore It is not a replay attack because presumably the random number (step 1 or 2) is sent with each message Potential Problem Suppose the client's truststore has certs in it: Server A Server B (malicous) Server A has hostname www.A.com Server B has hostname www.B.com Suppose: The client tries to connect to Server A but Server B launches a man in the middle attack. Since server B: has a public key for the certificate that will be sent to the client has a "valid certificate" (a cert in the truststore) And since: certificates do not have a hostname feild in them It seems like Server B can pretend to be Server A easily. Is there something that I am missing?

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