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  • C# Reading and Writing a Char[] to and from a Byte[]

    - by Simon G
    Hi, I have a byte array of around 10,000 bytes which is basically a blob from delphi that contains char, string, double and arrays of various types. This need to be read in and updated via C#. I've created a very basic reader that gets the byte array from the db and converts the bytes to the relevant object type when accessing the property which works fine. My problem is when I try to write to a specific char[] item, it doesn't seem to update the byte array. I've created the following extensions for reading and writing: public static class CharExtension { public static byte ToByte( this char c ) { return Convert.ToByte( c ); } public static byte ToByte( this char c, int position, byte[] blob ) { byte b = c.ToByte(); blob[position] = b; return b; } } public static class CharArrayExtension { public static byte[] ToByteArray( this char[] c ) { byte[] b = new byte[c.Length]; for ( int i = 1; i < c.Length; i++ ) { b[i] = c[i].ToByte(); } return b; } public static byte[] ToByteArray( this char[] c, int positon, int length, byte[] blob ) { byte[] b = c.ToByteArray(); Array.Copy( b, 0, blob, positon, length ); return b; } } public static class ByteExtension { public static char ToChar( this byte[] b, int position ) { return Convert.ToChar( b[position] ); } } public static class ByteArrayExtension { public static char[] ToCharArray( this byte[] b, int position, int length ) { char[] c = new char[length]; for ( int i = 0; i < length; i++ ) { c[i] = b.ToChar( position ); position += 1; } return c; } } to read and write chars and char arrays my code looks like: Byte[] _Blob; // set from a db field public char ubin { get { return _tariffBlob.ToChar( 14 ); } set { value.ToByte( 14, _Blob ); } } public char[] usercaplas { get { return _tariffBlob.ToCharArray( 2035, 10 ); } set { value.ToByteArray( 2035, 10, _Blob ); } } So to write to the objects I can do: ubin = 'C'; // this will update the byte[] usercaplas = new char[10] { 'A', 'B', etc. }; // this will update the byte[] usercaplas[3] = 'C'; // this does not update the byte[] I know the reason is that the setter property is not being called but I want to know is there a way around this using code similar to what I already have? I know a possible solution is to use a private variable called _usercaplas that I set and update as needed however as the byte array is nearly 10,000 bytes in length the class is already long and I would like a simpler approach as to reduce the overall code length and complexity. Thank

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  • iPhone App is leaking memory; Instruments and Clang cannot find the leak

    - by Norbert
    Hi, i've developed an iPhone program which is kind of an image manipulation program: The user get an UIImagePickerController and selects an image. Then the program does some heavy calculating in a new thread (for responsiveness of the application). The thread has, of course, its own autorelease pool. When calculation is done, the seperated thread signals the main thread that the result can be presented. The app creates a new view controller, pushes it onto the navigation controller. In short: UIImagePickerController new thread (autorelease pool) does some heavy calculation with image data signal to main thread that it's done main thread creates view controller and pushes it onto navigation controller view controller presents image result My program works well, but if I dismiss the navigation controller's top view controller by tapping on the back button and repeat the whole process several times, my app crashes. But only on the device! Instruments cannot find any leaks (except for some minor ones which I don't feel responsible for: thread creation, NSCFString; overall about 10 kB). Even Clang static analyzer tells me that my could seems to be all right. I know that the UIImage class can cache images and objects returned from convenience methods get freed only whet their autorelease pool gets drained. But most of the time I work with CGImageRef and I use UIImage' alloc, init & release methods to free memory as soon as possible. Currently, I don't know how to isolate the problem. How would you approach this problem? Crash Log: Incident Identifier: F4C202C9-1338-48FC-80AD-46248E6C7154 CrashReporter Key: bb6f526d8b9bb680f25ea8e93bb071566ccf1776 OS Version: iPhone OS 3.1.1 (7C145) Date: 2009-09-26 14:18:57 +0200 Free pages: 372 Wired pages: 7754 Purgeable pages: 0 Largest process: _MY_APP_ Processes Name UUID Count resident pages _MY_APP_ <032690e5a9b396058418d183480a9ab3> 17766 (jettisoned) (active) debugserver <ec29691560aa0e2994f82f822181bffd> 107 syslog_relay <21e13fa2b777218bdb93982e23fb65d3> 62 notification_pro <8a7725017106a28b545fd13ed58bf98c> 64 notification_pro <8a7725017106a28b545fd13ed58bf98c> 64 afcd <98b45027fbb1350977bf1ca313dee527> 65 mediaserverd <eb8fe997a752407bea573cd3adf568d3> 319 ptpd <b17af9cf6c4ad16a557d6377378e8a1e> 142 syslogd <ec8a5bc4483638539fa1266363dee8b8> 68 BTServer <1bb74831f93b1d07c48fb46cc31c15da> 119 apsd <a639ba83e666cc1d539223923ce59581> 165 notifyd <2ed3a1166da84d8d8868e64d549cae9d> 101 CommCenter <f4239480a623fb1c35fa6c725f75b166> 161 SpringBoard <8919df8091fdfab94d9ae05f513c0ce5> 2681 (active) accessoryd <b66bcf6e77c3ee740c6a017f54226200> 90 configd <41e9d763e71dc0eda19b0afec1daee1d> 275 fairplayd <cdce5393153c3d69d23c05de1d492bd4> 108 mDNSResponder <f3ef7a6b24d4f203ed147f476385ec53> 103 lockdownd <6543492543ad16ff0707a46e512944ff> 297 launchd <73ce695fee09fc37dd70b1378af1c818> 71 **End**

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  • Dynamic Objects for ASPxGridview

    - by André Snede Hansen
    I have a dictionary that is populated with data from a table, we are doing this so we can hold multiple SQL tables inside this object. This approached cannot be discussed. The Dictionary is mapped as a , and contains SQL column name and the value, and each dictionary resembles one row entry in the Table. Now I need to display this on a editable gridview, preferably the ASPxGridView. I already figured out that I should use Dynamic Objects(C#), and everything worked perfectly, up to the part where I find out that the ASPxGridview is built in .NET 2.0 and not 4.0 where Dynamic objects where implemented, therefor I cannot use it... As you cannot, to my knowledge, add rows to the gridview programmatically, I am out of ideas, and seek your help guys! protected void Page_Load(object sender, EventArgs e) { UserValidationTableDataProvider uvtDataprovider = _DALFactory.getProvider<UserValidationTableDataProvider>(typeof(UserValidationTableEntry)); string[] tableNames = uvtDataprovider.TableNames; UserValidationTableEntry[] entries = uvtDataprovider.getAllrecordsFromTable(tableNames[0]); userValidtionTableGridView.Columns.Clear(); Dictionary<string, string> firstEntry = entries[0].Values; foreach (KeyValuePair<string, string> kvp in firstEntry) { userValidtionTableGridView.Columns.Add(new GridViewDataColumn(kvp.Key)); } var dynamicObjectList = new List<dynamic>(); foreach (UserValidationTableEntry uvt in entries) { //dynamic dynObject = new MyDynamicObject(uvt.Values); dynamicObjectList.Add(new MyDynamicObject(uvt.Values)); } } public class MyDynamicObject : DynamicObject { Dictionary<string, string> properties = new Dictionary<string, string>(); public MyDynamicObject(Dictionary<string, string> dictio) { properties = dictio; } // If you try to get a value of a property // not defined in the class, this method is called. public override bool TryGetMember(GetMemberBinder binder, out object result) { // Converting the property name to lowercase // so that property names become case-insensitive. string name = binder.Name.ToLower(); string RResult; // If the property name is found in a dictionary, // set the result parameter to the property value and return true. // Otherwise, return false. bool wasSuccesfull = properties.TryGetValue(name, out RResult); result = RResult; return wasSuccesfull; } // If you try to set a value of a property that is // not defined in the class, this method is called. public override bool TrySetMember(SetMemberBinder binder, object value) { // Converting the property name to lowercase // so that property names become case-insensitive. properties[binder.Name.ToLower()] = value.ToString(); // You can always add a value to a dictionary, // so this method always returns true. return true; } } Now, I am almost certain that his "Dynamic object" approach, is not the one I can go with from here on. I hope you guys can help me :)!

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  • c#: Design advice. Using DataTable or List<MyObject> for a generic rule checker

    - by Andrew White
    Hi, I have about 100,000 lines of generic data. Columns/Properties of this data are user definable and are of the usual data types (string, int, double, date). There will be about 50 columns/properties. I have 2 needs: To be able to calculate new columns/properties using an expression e.g. Column3 = Column1 * Column2. Ultimately I would like to be able to use external data using a callback, e.g. Column3 = Column1 * GetTemperature The expression is relatively simple, maths operations, sum, count & IF are the only necessary functions. To be able to filter/group the data and perform aggregations e.g. Sum(Data.Column1) Where(Data.Column2 == "blah") As far as I can see I have two options: 1. Using a DataTable. = Point 1 above is achieved by using DataColumn.Expression = Point 2 above is acheived by using DataTable.DefaultView.RowFilter & C# code 2. Using a List of generic Objects each with a Dictionary< string, object to store the values. = Point 1 could be achieved by something like NCalc = Point 2 is achieved using LINQ DataTable: Pros: DataColumn.Expression is inbuilt Cons: RowFilter & coding c# is not as "nice" as LINQ, DataColumn.Expression does not support callbacks(?) = workaround could be to get & replace external value when creating the calculated column GenericList: Pros: LINQ syntax, NCalc supports callbacks Cons: Implementing NCalc/generic calc engine Based on the above I would think a GenericList approach would win, but something I have not factored in is the performance which for some reason I think would be better with a datatable. Does anyone have a gut feeling / experience with LINQ vs. DataTable performance? How about NCalc? As I said there are about 100,000 rows of data, with 50 columns, of which maybe 20 are calculated. In total about 50 rules will be run against the data, so in total there will be 5 million row/object scans. Would really appreciate any insights. Thx. ps. Of course using a database + SQL & Views etc. would be the easiest solution, but for various reasons can't be implemented.

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  • Recommendations for a C++ polymorphic, seekable, binary I/O interface

    - by Trevor Robinson
    I've been using std::istream and ostream as a polymorphic interface for random-access binary I/O in C++, but it seems suboptimal in numerous ways: 64-bit seeks are non-portable and error-prone due to streampos/streamoff limitations; currently using boost/iostreams/positioning.hpp as a workaround, but it requires vigilance Missing operations such as truncating or extending a file (ala POSIX ftruncate) Inconsistency between concrete implementations; e.g. stringstream has independent get/put positions whereas filestream does not Inconsistency between platform implementations; e.g. behavior of seeking pass the end of a file or usage of failbit/badbit on errors Don't need all the formatting facilities of stream or possibly even the buffering of streambuf streambuf error reporting (i.e. exceptions vs. returning an error indicator) is supposedly implementation-dependent in practice I like the simplified interface provided by the Boost.Iostreams Device concept, but it's provided as function templates rather than a polymorphic class. (There is a device class, but it's not polymorphic and is just an implementation helper class not necessarily used by the supplied device implementations.) I'm primarily using large disk files, but I really want polymorphism so I can easily substitute alternate implementations (e.g. use stringstream instead of fstream for unit tests) without all the complexity and compile-time coupling of deep template instantiation. Does anyone have any recommendations of a standard approach to this? It seems like a common situation, so I don't want to invent my own interfaces unnecessarily. As an example, something like java.nio.FileChannel seems ideal. My best solution so far is to put a thin polymorphic layer on top of Boost.Iostreams devices. For example: class my_istream { public: virtual std::streampos seek(stream_offset off, std::ios_base::seekdir way) = 0; virtual std::streamsize read(char* s, std::streamsize n) = 0; virtual void close() = 0; }; template <class T> class boost_istream : public my_istream { public: boost_istream(const T& device) : m_device(device) { } virtual std::streampos seek(stream_offset off, std::ios_base::seekdir way) { return boost::iostreams::seek(m_device, off, way); } virtual std::streamsize read(char* s, std::streamsize n) { return boost::iostreams::read(m_device, s, n); } virtual void close() { boost::iostreams::close(m_device); } private: T m_device; };

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  • Given a trace of packets, how would you group them into flows?

    - by zxcvbnm
    I've tried it these ways so far: 1) Make a hash with the source IP/port and destination IP/port as keys. Each position in the hash is a list of packets. The hash is then saved in a file, with each flow separated by some special characters/line. Problem: Not enough memory for large traces. 2) Make a hash with the same key as above, but only keep in memory the file handles. Each packet is then put into the hash[key] that points to the right file. Problems: Too many flows/files (~200k) and it might run out of memory as well. 3) Hash the source IP/port and destination IP/port, then put the info inside a file. The difference between 2 and 3 is that here the files are opened and closed for each operation, so I don't have to worry about running out of memory because I opened too many at the same time. Problems: WAY too slow, same number of files as 2 so also impractical. 4) Make a hash of the source IP/port pairs and then iterate over the whole trace for each flow. Take the packets that are part of that flow and place them into the output file. Problem: Suppose I have a 60 MB trace that has 200k flows. This way, I would process, say, a 60 MB file 200k times. Maybe removing the packets as I iterate would make it not so painful, but so far I'm not sure this would be a good solution. 5) Split them by IP source/destination and then create a single file for each one, separating the flows by special characters. Still too many files (+50k). Right now I'm using Ruby to do it, which might've been a bad idea, I guess. Currently I've filtered the traces with tshark so that they only have relevant info, so I can't really make them any smaller. I thought about loading everything in memory as described in 1) using C#/Java/C++, but I was wondering if there wouldn't be a better approach here, especially since I might also run out of memory later on even with a more efficient language if I have to use larger traces. In summary, the problem I'm facing is that I either have too many files or that I run out of memory. I've also tried searching for some tool to filter the info, but I don't think there is one. The ones I've found only return some statistics and wouldn't scan for every flow as I need.

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  • ASP.NET- forcing child/container events to fire before parent onload?

    - by Hans Gruber
    I'm working on a questionnaire type application in which questions are stored in a database. Therefore, I create my controls dynamically on every Page.OnLoad. This works like a charm and ViewState is persisted between postbacks because I ensure that my dynamic controls always have the same generated Control.ID. In addition to the user control that dynamically populates the questions, my questionnaire page also contains a 'Status' section (also encapsulated by a user control) which represents the status of the questionnaire (choices are 'Complete', 'Started' or 'In Progress'). If the user changes the status of questionnaire (i.e. from 'In Progress' to 'Complete'), I need to postback to the server because the contents of the dynamic portion of the questionnaire depend on the selected status. Some questions are always present regardless of status, and yet others may not be present at all for the selected status. The point is, when the status changes, I have to postback to the page and render the right set of questions. Additionally, I need to preserve any user entered values for those questions which are 'always available'. However, due to the page life cycle in ASP.NET, the 'Status' user control's OnLoad, which contains the correct status needed to load the right questions from the DB, doesn't get executed until after the 'dynamic questions' user control has already been populated (with the wrong/stale values). To get around this, I raise an event from my 'Status' user control to the main page to indicate that the Status has changed. The main page then raises an event on the 'dynamic questions' user control. Since by the time this event bubbles up, the 'dynamic questions' user control has already loaded the 'wrong' questions from the DB, it first calls Controls.Clear. It then happily uses the new status to query the database for the 'correct' questions and does a Control.Add() on each. FYI, Control.IDs are consistent across postbacks. This solution works...sorta. The correct set of questions for the selected status do get rendered; however ViewState is getting lost for those 'always available' questions. I'm guessing this is because the 'dynamic questions' user control calls Controls.Clear when responding to the status changed event. This must somehow kill the association between ViewState and my dynamic controls, even though the Control.ID are consistent. This seems like such a common requirement, I'm virtually certain there is a better, cleaner and less error prone approach to accomplish this. In case its not plain obvious, I haven't been able to grok the ASP.NET page life-cycle despite working with it for the last year. Any help is much appreciated!

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  • How to know when a user has really released a key in Java?

    - by Luis Soeiro
    (Edited for clarity) I want to detect when a user presses and releases a key in Java Swing, ignoring the keyboard auto repeat feature. I also would like a pure Java approach the works on Linux, Mac OS and Windows. Requirements: When the user presses some key I want to know what key is that; When the user releases some key, I want to know what key is that; I want to ignore the system auto repeat options: I want to receive just one keypress event for each key press and just one key release event for each key release; If possible, I would use items 1 to 3 to know if the user is holding more than one key at a time (i.e, she hits 'a' and without releasing it, she hits "Enter"). The problem I'm facing in Java is that under Linux, when the user holds some key, there are many keyPress and keyRelease events being fired (because of the keyboard repeat feature). I've tried some approaches with no success: Get the last time a key event occurred - in Linux, they seem to be zero for key repeat, however, in Mac OS they are not; Consider an event only if the current keyCode is different from the last one - this way the user can't hit twice the same key in a row; Here is the basic (non working) part of code: import java.awt.event.KeyListener; public class Example implements KeyListener { public void keyTyped(KeyEvent e) { } public void keyPressed(KeyEvent e) { System.out.println("KeyPressed: "+e.getKeyCode()+", ts="+e.getWhen()); } public void keyReleased(KeyEvent e) { System.out.println("KeyReleased: "+e.getKeyCode()+", ts="+e.getWhen()); } } When a user holds a key (i.e, 'p') the system shows: KeyPressed: 80, ts=1253637271673 KeyReleased: 80, ts=1253637271923 KeyPressed: 80, ts=1253637271923 KeyReleased: 80, ts=1253637271956 KeyPressed: 80, ts=1253637271956 KeyReleased: 80, ts=1253637271990 KeyPressed: 80, ts=1253637271990 KeyReleased: 80, ts=1253637272023 KeyPressed: 80, ts=1253637272023 ... At least under Linux, the JVM keeps resending all the key events when a key is being hold. To make things more difficult, on my system (Kubuntu 9.04 Core 2 Duo) the timestamps keep changing. The JVM sends a key new release and new key press with the same timestamp. This makes it hard to know when a key is really released. Any ideas? Thanks

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  • Difficulty adding widgets to django form.

    - by codingJoe
    I have a django app that tracks activities that can benefit a classroom. Using the django examples, I was able to build a form to enter this data. But when I try to add widgets to that form, things get tricky. What I want is a calendar widget that lets the user enter the 'activity_date' field using a widget. If I use Admin interface. The AdminDateWidget works fine. however. This particular user isn't allowed access to the admin interface so I need a different way to present this widget. Also I couldn't figure out how to make the bring the admin widget over into non-admin pages. So I tried a custom widget. This is the first custom widget I've built, so I'm not quite sure what is supposed to be going on here. Any Expert Advice? How do I get my date widget to work? # The Model class Activity(models.Model): activity_date = models.DateField() activity_type = models.CharField(max_length=50, choices=ACTIVITY_TYPES) activity_description = models.CharField(max_length=200) activity_duration= models.DecimalField(decimal_places=2, max_digits=4) est_attendance = models.IntegerField("Estimated attendance") # The Form class ActivityForm(forms.ModelForm): # The following line causes lockup if enabled. # With the DateTimeWidget removed, the form functions correctly except that there is no widget. #activity_date = forms.DateField(label=_('Date'), widget=DateTimeWidget) ##!!! Point of Error !!! class Meta: model = Activity fields = ('activity_date', 'activity_type', 'activity_description', 'activity_duration', 'est_attendance') def __init__(self, *args, **kwargs): super(ActivityForm, self).__init__(*args, **kwargs) instance = getattr(self, 'instance', None) edit_aid = kwargs.get('edit_aid', False) # On a different approach, the following also didn't work. #self.fields['activity_date'].widget = widgets.AdminDateWidget() # The Widget # Example referenced: http://djangosnippets.org/snippets/391/ calbtn = u""" <button id="calendar-trigger">...</button> <img src="%s/site_media/images/icon_calendar.gif" alt="calendar" id="%s_btn" style="cursor: pointer; border: 1px solid #8888aa;" title="Select date and time" onmouseover="this.style.background='#444444';" onmouseout="this.style.background=''" /> <script type="text/javascript"> Calendar.setup({ trigger : "calendar-trigger", inputField : "%s" }); </script>""" class DateTimeWidget(forms.widgets.TextInput): dformat = '%Y-%m-%d %H:%M' def render(self, name, value, attrs=None): print "DTWgt render name=%s, value=%s" % name, value if value is None: value = '' final_attrs = self.build_attrs(attrs, type=self.input_type, name=name) if value != '': try: final_attrs['value'] = \ force_unicode(value.strftime(self.dformat)) except: final_attrs['value'] = \ force_unicode(value) if not final_attrs.has_key('id'): final_attrs['id'] = u'%s_id' % (name) id = final_attrs['id'] jsdformat = self.dformat #.replace('%', '%%') cal = calbtn % (settings.MEDIA_URL, id, id, jsdformat, id) a = u'<input%s />%s' % (forms.util.flatatt(final_attrs), cal) print "render return %s " % a return mark_safe(a) def value_from_datadict(self, data, files, name): print "DTWgt value_from_datadict" dtf = forms.fields.DEFAULT_DATETIME_INPUT_FORMATS empty_values = forms.fields.EMPTY_VALUES value = data.get(name, None) if value in empty_values: return None if isinstance(value, datetime.datetime): return value if isinstance(value, datetime.date): return datetime.datetime(value.year, value.month, value.day) for format in dtf: try: return datetime.datetime(*time.strptime(value, format)[:6]) except ValueError: continue return None

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  • Class hierarchy problem (with generic's variance!)

    - by devoured elysium
    The problem: class StatesChain : IState, IHasStateList { private TasksChain tasks = new TasksChain(); ... public IList<IState> States { get { return _taskChain.Tasks; } } IList<ITask> IHasTasksCollection.Tasks { get { return _taskChain.Tasks; } <-- ERROR! You can't do this in C#! I want to return an IList<ITask> from an IList<IStates>. } } Assuming the IList returned will be read-only, I know that what I'm trying to achieve is safe (or is it not?). Is there any way I can accomplish what I'm trying? I wouldn't want to try to implement myself the TasksChain algorithm (again!), as it would be error prone and would lead to code duplication. Maybe I could just define an abstract Chain and then implement both TasksChain and StatesChain from there? Or maybe implementing a Chain<T> class? How would you approach this situation? The Details: I have defined an ITask interface: public interface ITask { bool Run(); ITask FailureTask { get; } } and a IState interface that inherits from ITask: public interface IState : ITask { IState FailureState { get; } } I have also defined an IHasTasksList interface: interface IHasTasksList { List<Tasks> Tasks { get; } } and an IHasStatesList: interface IHasTasksList { List<Tasks> States { get; } } Now, I have defined a TasksChain, that is a class that has some code logic that will manipulate a chain of tasks (beware that TasksChain is itself a kind of ITask!): class TasksChain : ITask, IHasTasksList { IList<ITask> tasks = new List<ITask>(); ... public List<ITask> Tasks { get { return _tasks; } } ... } I am implementing a State the following way: public class State : IState { private readonly TaskChain _taskChain = new TaskChain(); public State(Precondition precondition, Execution execution) { _taskChain.Tasks.Add(precondition); _taskChain.Tasks.Add(execution); } public bool Run() { return _taskChain.Run(); } public IState FailureState { get { return (IState)_taskChain.Tasks[0].FailureTask; } } ITask ITask.FailureTask { get { return FailureState; } } } which, as you can see, makes use of explicit interface implementations to "hide" FailureTask and instead show FailureState property. The problem comes from the fact that I also want to define a StatesChain, that inherits both from IState and IHasStateList (and that also imples ITask and IHasTaskList, implemented as explicit interfaces) and I want it to also hide IHasTaskList's Tasks and only show IHasStateList's States. (What is contained in "The problem" section should really be after this, but I thought puting it first would be way more reader friendly). (pff..long text) Thanks!

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  • Core Animation performance on iphone

    - by nico
    I'm trying to do some animations using Core Animation on the iphone. I'm using CABasicAnimation on CALayer. It's a straight forward animation from a random place at the top of the screen to the bottom of the screen at random speed, I have 30 elements that doing the same animation continuously until another action happens. But the performance on the iPhone 3G is very sluggish when the animations start. The image is only 8k. Is this the right approach? How should I change so it performs better. // image cached somewhere else. CGImageRef imageRef = [[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:name ofType:@"png"]] CGImage]; - (void)animate:(NSTimer *)timer { int startX = round(radom() % 320); float speed = 1 / round(random() % 100 + 2); CALayer *layer = [CALayer layer]; layer.name = @"layer"; layer.contents = imageRef; // cached image layer.frame = CGRectMake(0, 0, CGImageGetWidth(imageRef), CGImageGetHeight(imageRef)); int width = layer.frame.size.width; int height = layer.frame.size.height; layer.frame = CGRectMake(startX, self.view.frame.origin.y, width, height); [effectLayer addSublayer:layer]; CGPoint start = CGPointMake(startX, 0); CGPoint end = CGPointMake(startX, self.view.frame.size.height); float repeatCount = 1e100; CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"]; animation.delegate = self; animation.fromValue = [NSValue valueWithCGPoint:start]; animation.toValue = [NSValue valueWithCGPoint:end]; animation.duration = speed; animation.repeatCount = repeatCount; animation.autoreverses = NO; animation.removedOnCompletion = YES; animation.fillMode = kCAFillModeForwards; [layer addAnimation:animation forKey:@"position"]; } The animations are fired off using a NSTimer. animationTimer = [NSTimer timerWithTimeInterval:0.2 target:self selector:@selector(animate:) userInfo:nil repeats:YES]; [[NSRunLoop currentRunLoop] addTimer:animationTimer forMode:NSDefaultRunLoopMode];

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  • Constructor or Explicit cast

    - by Felan
    In working with Linq to Sql I create a seperate class to ferry data to a web page. To simplify creating these ferry objects I either use a specialized constructor or an explicit conversion operator. I have two questions. First which approach is better from a readibility perspective? Second while the clr code that is generated appeared to be the same to me, are there situations where one would be treated different than the other by the compiler (in lambda's or such). Example code (DatabaseFoo uses specialized constructor and BusinessFoo uses explicit operator): public class DatabaseFoo { private static int idCounter; // just to help with generating data public int Id { get; set; } public string Name { get; set; } public DatabaseFoo() { Id = idCounter++; Name = string.Format("Test{0}", Id); } public DatabaseFoo(BusinessFoo foo) { this.Id = foo.Id; this.Name = foo.Name; } } public class BusinessFoo { public int Id { get; set; } public string Name { get; set; } public static explicit operator BusinessFoo(DatabaseFoo foo) { return FromDatabaseFoo(foo); } public static BusinessFoo FromDatabaseFoo(DatabaseFoo foo) { return new BusinessFoo {Id = foo.Id, Name = foo.Name}; } } public class Program { static void Main(string[] args) { Console.WriteLine("Creating the initial list of DatabaseFoo"); IEnumerable<DatabaseFoo> dafoos = new List<DatabaseFoo>() { new DatabaseFoo(), new DatabaseFoo(), new DatabaseFoo(), new DatabaseFoo(), new DatabaseFoo(), new DatabaseFoo()}; foreach(DatabaseFoo dafoo in dafoos) Console.WriteLine(string.Format("{0}\t{1}", dafoo.Id, dafoo.Name)); Console.WriteLine("Casting the list of DatabaseFoo to a list of BusinessFoo"); IEnumerable<BusinessFoo> bufoos = from x in dafoos select (BusinessFoo) x; foreach (BusinessFoo bufoo in bufoos) Console.WriteLine(string.Format("{0}\t{1}", bufoo.Id, bufoo.Name)); Console.WriteLine("Creating a new list of DatabaseFoo by calling the constructor taking BusinessFoo"); IEnumerable<DatabaseFoo> fufoos = from x in bufoos select new DatabaseFoo(x); foreach(DatabaseFoo fufoo in fufoos) Console.WriteLine(string.Format("{0}\t{1}", fufoo.Id, fufoo.Name)); } }

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  • Correct way to make datasources/resources a deploy-time setting

    - by Draemon
    I have a web-app that requires two settings: A JDBC datasource A string token I desperately want to be able to deploy one .war to various different containers (jetty,tomcat,gf3 minimum) and configure these settings at application level within the container. My code does this: InitialContext ctx = new InitialContext(); Context envCtx = (javax.naming.Context) ctx.lookup("java:comp/env"); token = (String)envCtx.lookup("token"); ds = (DataSource)envCtx.lookup("jdbc/datasource") Let's assume I've used the glassfish management interface to create two jdbc resources: jdbc/test-datasource and jdbc/live-datasource which connect to different copies of the same schema, on different servers, different credentials etc. Say I want to deploy this to glassfish with and point it at the test datasource, I might have this in my sun-web.xml: ... <resource-ref> <res-ref-name>jdbc/datasource</res-ref-name> <jndi-name>jdbc/test-datasource</jndi-name> </resource-ref> ... but sun-web.xml goes inside my war, right? surely there must be a way to do this through the management interface Am I even trying to do the right thing? Do other containers make this any easier? I'd be particularly interested in how jetty 7 handles this since I use it for development. EDIT Tomcat has a reasonable way to do this: Create $TOMCAT_HOME/conf/Catalina/localhost/webapp.xml with: <?xml version="1.0" encoding="UTF-8"?> <Context antiResourceLocking="false" privileged="true"> <!-- String resource --> <Environment name="token" value="value of token" type="java.lang.String" override="false" /> <!-- Linking to a global resource --> <ResourceLink name="jdbc/datasource1" global="jdbc/test" type="javax.sql.DataSource" /> <!-- Derby --> <Resource name="jdbc/datasource2" type="javax.sql.DataSource" auth="Container" driverClassName="org.apache.derby.jdbc.EmbeddedDataSource" url="jdbc:derby:test;create=true" /> <!-- H2 --> <Resource name="jdbc/datasource3" type="javax.sql.DataSource" auth="Container" driverClassName="org.h2.jdbcx.JdbcDataSource" url="jdbc:h2:~/test" username="sa" password="" /> </Context> Note that override="false" means the opposite. It means that this setting can't be overriden by web.xml. I like this approach because the file is part of the container configuration not the war, but it's not part of the global configuration; it's webapp specific. I guess I expect a bit more from glassfish since it is supposed to have a full web admin interface, but I would be happy enough with something equivalent to the above.

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  • Spring.NET & Immediacy CMS (or how to inject to server side controls without using PageHandlerFactor

    - by Simon Rice
    Is there any way to inject dependencies into an Immediacy CMS control using Spring.NET, ideally without having to use to ContextRegistry when initialising the control? Update, with my own answer The issue here is that Immediacy already has a handler defined in web.config that deals with all aspx pages, & so it's not possible add an entry for Spring.NET's PageHandlerFactory in web.config as per a normal webforms app. That rules out making the control implement ISupportsWebDependencyInjection. Furthermore, most of Immediacy's generated pages are aspx pages that don't physically exist on the drive. I have changed the title of the question to reflect this. What I have done to get Dependency Injection working is: Add the usual entries to web.config for Spring.NET as outlined in the documentation, except for the adding the entry to the <httpHandlers> section. In this case I've got my object definitions in Spring.config. Create the following abstract base class that will deal with all of the Dependency Injection work: DIControl.cs public abstract class DIControl : ImmediacyControl { protected virtual string DIName { get { return this.GetType().Name; } } protected override void OnInit(EventArgs e) { if (ContextRegistry.GetContext().GetObject(DIName, this.GetType()) != null) ContextRegistry.GetContext().ConfigureObject(this, DIName); base.OnInit(e); } } For non-immediacy controls, you can make this server side control inherit from Control or whatever subclass of that you like. For any control with which you wish to use with Spring.NET's Inversion of Control container, define it to inherit from DIControl & add the relelvant entry to Spring.config, for example: SampleControl.cs public class SampleControl : DIControl, INamingContainer { public string Text { get; set; } protected string InjectedText { get; set; } public SampleControl() : base() { Text = "Hello world"; } protected override void RenderContents(HtmlTextWriter output) { output.Write(string.Format("{0} {1}", Text, InjectedText)); } } Spring.config <objects xmlns="http://www.springframework.net"> <object id="SampleControl" type="MyProject.SampleControl, MyAssembly"> <property name="InjectedText" value="from Spring.NET" /> </object> </objects> You can optionally override DIName if you wish to name your entry in Spring.config differently from the name of your class. Provided everything's done correctly, you will have the control writing out "Hello world from Spring.NET!" when used in a page. This solution uses Spring.NET's ContextRegistry from within the control, but I would be surprised if there's no way around that for Immediacy at least since the page objects themselves aren't accessible. However, can this be improved at all from a Spring.NET perspective? Is there maybe an Immediacy plugin that already does this that I'm completely unaware of? Or is there an approach that does this in a more elegant way? I'm open to suggestions.

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  • Optimising movement on hex grid

    - by Mloren
    I am making a turn based hex-grid game. The player selects units and moves them across the hex grid. Each tile in the grid is of a particular terrain type (eg desert, hills, mountains, etc) and each unit type has different abilities when it comes to moving over the terrain (e.g. some can move over mountains easily, some with difficulty and some not at all). Each unit has a movement value and each tile takes a certain amount of movement based on its terrain type and the unit type. E.g it costs a tank 1 to move over desert, 4 over swamp and cant move at all over mountains. Where as a flying unit moves over everything at a cost of 1. The issue I have is that when a unit is selected, I want to highlight an area around it showing where it can move, this means working out all the possible paths through the surrounding hexes, how much movement each path will take and lighting up the tiles based on that information. I got this working with a recursive function and found it took too long to calculate, I moved the function into a thread so that it didn't block the game but still it takes around 2 seconds for the thread to calculate the moveable area for a unit with a move of 8. Its over a million recursions which obviously is problematic. I'm wondering if anyone has an clever ideas on how I can optimize this problem. Here's the recursive function I'm currently using (its C# btw): private void CalcMoveGridRecursive(int nCenterIndex, int nMoveRemaining) { //List of the 6 tiles adjacent to the center tile int[] anAdjacentTiles = m_ThreadData.m_aHexData[nCenterIndex].m_anAdjacentTiles; foreach(int tileIndex in anAdjacentTiles) { //make sure this adjacent tile exists if(tileIndex == -1) continue; //How much would it cost the unit to move onto this adjacent tile int nMoveCost = m_ThreadData.m_anTerrainMoveCost[(int)m_ThreadData.m_aHexData[tileIndex].m_eTileType]; if(nMoveCost != -1 && nMoveCost <= nMoveRemaining) { //Make sure the adjacent tile isnt already in our list. if(!m_ThreadData.m_lPassableTiles.Contains(tileIndex)) m_ThreadData.m_lPassableTiles.Add(tileIndex); //Now check the 6 tiles surrounding the adjacent tile we just checked (it becomes the new center). CalcMoveGridRecursive(tileIndex, nMoveRemaining - nMoveCost); } } } At the end of the recursion, m_lPassableTiles contains a list of the indexes of all the tiles that the unit can possibly reach and they are made to glow. This all works, it just takes too long. Does anyone know a better approach to this?

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  • How do I create a Spring 3 + Tiles 2 webapp using REST-ful URLs?

    - by Ichiro Furusato
    I'm having a heck of a time resolving URLs with Spring 3.0 MVC. I'm just building a HelloWorld to try out how to build a RESTful webapp in Spring, nothing theoretically complicated. All of the examples I've been able to find are based on configurations that pay attention to file extensions ("*.htm" or "*.do"), include an artificial directory name prefix ("/foo") or even prefix paths with a dot (ugly), all approaches that use some artificial regex pattern as a signal to the resolver. For a REST approach I want to avoid all that muck and use only the natural URL patterns of my application. I would assume (perhaps incorrectly) that in web.xml I'd set a url-pattern of "/*" and pass everything to the DispatcherServlet for resolution, then just rely on URL patterns in my controller. I can't reliably get my resolver(s) to catch the URL patterns, and in all my trials this results in a resource not found error, a stack overflow (loop), or some kind of opaque Spring 3 ServletException stack trace — one of my ongoing frustrations with Spring generally is that the error messages are not often very helpful. I want to work with a Tiles 2 resolver. I've located my *.jsp files in WEB-INF/views/ and have a single line index.jsp file at the application root redirecting to the index file set by my layout.xml (the Tiles 2 Configurer). I do all the normal Spring 3 high-level configuration: <mvc:annotation-driven /> <mvc:view-controller path="/" view-name="index"/> <context:component-scan base-package="com.acme.web.controller" /> ...followed by all sorts of combinations and configurations of UrlBasedViewResolver, InternalResourceViewResolver, UrlFilenameViewController, etc. with all manner of variantions in my Tiles 2 configuration file. Then in my controller I've trying to pick up my URL patterns. Problem is, I can't reliably even get the resolver(s) to catch the patterns to send to my controller. This has now stretched to multiple days with no real progress on something I thought would be very simple to implement. I'm perhaps trying to do too much at once, though I would think this should be a simple (almost a default) configuration. I'm just trying to create a simple HelloWorld-type application, I wouldn't expect this is rocket science. Rather than me post my own configurations (which have ranged all over the map), does anyone know of an online example that: shows a simple Spring 3 MVC + Tiles 2 web application that uses REST-ful URLs (i.e., avoiding forced URL patterns such as file extensions, added directory names or dots) and relies solely on Spring 3 code/annotations (i.e., nothing outside of Spring MVC itself) to accomplish this? Is there an easy way to do this? Thanks very much for any help.

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  • EF4 Import/Lookup thousands of records - my performance stinks!

    - by Dennis Ward
    I'm trying to setup something for a movie store website (using ASP.NET, EF4, SQL Server 2008), and in my scenario, I want to allow a "Member" store to import their catalog of movies stored in a text file containing ActorName, MovieTitle, and CatalogNumber as follows: Actor, Movie, CatalogNumber John Wayne, True Grit, 4577-12 (repeated for each record) This data will be used to lookup an actor and movie, and create a "MemberMovie" record, and my import speed is terrible if I import more than 100 or so records using these tables: Actor Table: Fields = {ID, Name, etc.} Movie Table: Fields = {ID, Title, ActorID, etc.} MemberMovie Table: Fields = {ID, CatalogNumber, MovieID, etc.} My methodology to import data into the MemberMovie table from a text file is as follows (after the file has been uploaded successfully): Create a context. For each line in the file, lookup the artist in the Actor table. For each Movie in the Artist table, lookup the matching title. If a matching Movie is found, add a new MemberMovie record to the context and call ctx.SaveChanges(). The performance of my implementation is terrible. My expectation is that this can be done with thousands of records in a few seconds (after the file has been uploaded), and I've got something that times out the browser. My question is this: What is the best approach for performing bulk lookups/inserts like this? Should I call SaveChanges only once rather than for each newly created MemberMovie? Would it be better to implement this using something like a stored procedure? A snippet of my loop is roughly this (edited for brevity): while ((fline = file.ReadLine()) != null) { string [] token = fline.Split(separator); string Actor = token[0]; string Movie = token[1]; string CatNumber = token[2]; Actor found_actor = ctx.Actors.Where(a => a.Name.Equals(actor)).FirstOrDefault(); if (found_actor == null) continue; Movie found_movie = found_actor.Movies.Where( s => s.Title.Equals(title, StringComparison.CurrentCultureIgnoreCase)).FirstOrDefault(); if (found_movie == null) continue; ctx.MemberMovies.AddObject(new MemberMovie() { MemberProfileID = profile_id, CatalogNumber = CatNumber, Movie = found_movie }); try { ctx.SaveChanges(); } catch { } } Any help is appreciated! Thanks, Dennis

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  • iOS: Gesture recogniser for smooth scrolling and flicking a View

    - by AppleDeveloper
    I am building an iPad app where I needed to allow resizing views functionality using divider view provided between two views. This divider view is just a 20px height view between two half screen content views - please refer attached images. When user scrolls this divider view up or down, both content views changes their sizes appropriately. I have extended UIView and implemented this using touchMoved delegate as code given below in touchesMoved delegate. It works fine. The only thing is missing with TouchMoved is you can't flick divider view to top or bottom directly. You have to scroll all the way to top or bottom! To support flicking the view I have tried UIPanGestureRecognizer but I don't see smooth scrolling with it. When I handle split position change in UIGestureRecognizerStateChanged state, just touching divider view flick it to top or bottom. Handling split position change in UIGestureRecognizerStateEnded does the same but I don't see content view resizing with dividerview scrolling! Could someone please tell me how could I achieve both smooth scrolling of divider view with resizing content views(like touchMoved) and flicking the view. Any alternative approach would also fine. Thanks. - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; if (touch) { CGPoint lastPt = [touch previousLocationInView:self]; CGPoint pt = [touch locationInView:self]; float offset = pt.y - lastPt.y; self.parentViewController.splitPosition = self.parentViewController.splitPosition + offset; } } - (void)handlePan:(UIPanGestureRecognizer*)recognizer { CGPoint translation = [recognizer translationInView:recognizer.view]; CGPoint velocity = [recognizer velocityInView:recognizer.view]; if (recognizer.state == UIGestureRecognizerStateBegan) { } else if (recognizer.state == UIGestureRecognizerStateChanged) { // If I change split position here, I don't see smooth scrolling dividerview...it directly jumps to the top or bottom! self.parentViewController.splitPosition = self.parentViewController.splitPosition + translation.y; } else if (recognizer.state == UIGestureRecognizerStateEnded) { // If I change split position here, the same thing happens at end and I don't see my divider view moving with my scrolling and resizing my views. self.parentViewController.splitPosition = self.parentViewController.splitPosition + translation.y; } } Initial screen Increased top view size by scrolling divider view Top view is totally hidden here but I have to scroll divider view all the way to top. I want to flick the divider view so that it directly goes from any position to top

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  • Changing text depending on rounded total from database

    - by NeonBlue Bliss
    On a website I have a number of small PHP scripts to automate changes to the text of the site, depending on a figure that's calculated from a MySQL database. The site is for a fundraising group, and the text in question on the home page gives the total amount raised. The amount raised is pulled from the database and rounded to the nearest thousand. This is the PHP I use to round the figure and find the last three digits of the total: $query4 = mysql_query("SELECT SUM(amountraised) AS full_total FROM fundraisingtotal;"); $result4 = mysql_fetch_array($query4); $fulltotal = $result4["full_total"]; $num = $fulltotal + 30000; $ftotalr = round($num,-3); $roundnum = round($num); $string = $roundnum; $length = strlen($string); $characters = 3; $start = $length - $characters; $string = substr($string , $start ,$characters); $figure = $string; (£30,000 is the amount that had been raised by the previous fundraising team from when the project first started, which is why I've added 30000 to $fulltotal for the $num variable) Currently the text reads: the bookstall and other fundraising events have raised more than &pound;<? echo number_format($ftotalr); ?> I've just realised though that because the PHP is rounding to the nearest thousand, if the total's for example £39,200 and it's rounded to £40,000, to say it's more than £40,000 is incorrect, and in that case I'd need it to say 'almost £40,000' or something similar. I obviously need to replace the 'more than' with a variable. Obviously I need to test whether the last three digits of the total are nearer to 0 or 1000, so that if the total was for example £39,2000, the text would read 'just over', if it was between £39,250 and £39,400 something like 'over', between £39,400 and £39,700 something like 'well over', and between £39,700 and £39,999, 'almost.' I've managed to get the last three digits of the total as a variable, and I think I need some sort of an if/else/elseif code block (not sure if that would be the right approach, or whether to use case/break), and obviously I'm going to have to check whether the figure meets each of the criteria, but I can't figure out how to do that. Could anyone suggest what would be the best way to do this please?

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  • How to properly downcast in C# with a SWIG generated interface?

    - by JG
    I've got a very large and mature C++ code base that I'm trying to use SWIG on to generate a C# interface for. I cannot change the actual C++ code itself but we can use whatever SWIG offers in the way of extending/updating it. I'm facing an issue where a function C++ is written as such: A* SomeClass::next(A*) The caller might do something like: A* acurr = 0; while( (acurr = sc->next(acurr)) != 0 ){ if( acurr isoftype B ){ B* b = (B*)a; ...do some stuff with b.. } elseif( acurr isoftype C ) ... } Essentially, iterating through a container elements that depending on their true type, do something different. The SWIG generated C# layer for the "next" function unfortunately does the following: return new A(); So the calling code in C# land cannot determine if the returned object is actually a derived class or not, it actually appears to always be the base class (which does make sense). I've come across several solutions: Use the %extend SWIG keyword to add a method on an object and ultimately call dynamic_cast. The downside to this approach, as I see it, is that this requires you to know the inheritance hierarchy. In my case it is rather huge and I see this is as a maintenance issue. Use the %factory keyword to supply the method and the derived types and have SWIG automatically generate the dynamic_cast code. This appears to be a better solution that the first, however upon a deeper look it still requires you to hunt down all the methods and all the possible derived types it could return. Again, a huge maintenance issue. I wish I had a doc link for this but I can't find one. I found out about this functionality by looking through the example code that comes with SWIG. Create a C# method to create an instance of the derived object and transfer the cPtr to the new instance. While I consider this clumsy, it does work. See an example below. public static object castTo(object fromObj, Type toType) { object retval = null; BaseClass fromObj2 = fromObj as BaseClass; HandleRef hr = BaseClass.getCPtr(fromObj2); IntPtr cPtr = hr.Handle; object toObj = Activator.CreateInstance(toType, cPtr, false); // make sure it actually is what we think it is if (fromObj.GetType().IsInstanceOfType(toObj)) { return toObj; } return retval; } Are these really the options? And if I'm not willing to dig through all the existing functions and class derivations, then I'm left with #3? Any help would be appreciated.

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  • Web development - relative URLs without duplicating files

    - by eshriek
    I have a site with index.php in the root folder, images in /img , and overview.php in /content . I have a sidebar.php file that is included in both index.php and overview.php . How should I refer to /img/image.gif if I include a link in each file? The location of image.gif changes relative to the location of the file that references it. Using /img/image.gif in sidebar.php will work in index.php, but it fails for the file located at /content/overview.php. The only solution that I can see is to either include a seperate sidebar.php in each subdirectory, or include an /img directory in every sub-directory. The best suggestion that I can find is to use the <base html tag as suggested here: Change relative link paths for included content in PHP However, in the same link, SamGoody suggests that the <base tag "is no longer properly supported in Internet Explorer, since version 7." I'd like some insight on the matter before committing to a course of action. Thanks. EDIT: I am using the wrong approach below with "../" Example- root/index.php: ... <link rel="stylesheet" type="text/css" href="style.css" /> <title>title</title> </head> <body> <?php include('include/header.php'); ?> <?php include('include/menu.php'); ?> ... root/include/header.php: ... <div id="header"> <span class="fl"><img src="img/dun1.png"/></span><span class="fr"><img src="img/dun2.png"/></span> ... root/content/overview.php: ... <link rel="stylesheet" type="text/css" href="../style.css" media="screen" /> <title>Overview</title> </head> <body> <?php include('../include/header.php'); ?> <?php include('../include/menu.php'); ?> ...

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  • How do I recover from an unchecked exception?

    - by erickson
    Unchecked exceptions are alright if you want to handle every failure the same way, for example by logging it and skipping to the next request, displaying a message to the user and handling the next event, etc. If this is my use case, all I have to do is catch some general exception type at a high level in my system, and handle everything the same way. But I want to recover from specific problems, and I'm not sure the best way to approach it with unchecked exceptions. Here is a concrete example. Suppose I have a web application, built using Struts2 and Hibernate. If an exception bubbles up to my "action", I log it, and display a pretty apology to the user. But one of the functions of my web application is creating new user accounts, that require a unique user name. If a user picks a name that already exists, Hibernate throws an org.hibernate.exception.ConstraintViolationException (an unchecked exception) down in the guts of my system. I'd really like to recover from this particular problem by asking the user to choose another user name, rather than giving them the same "we logged your problem but for now you're hosed" message. Here are a few points to consider: There a lot of people creating accounts simultaneously. I don't want to lock the whole user table between a "SELECT" to see if the name exists and an "INSERT" if it doesn't. In the case of relational databases, there might be some tricks to work around this, but what I'm really interested in is the general case where pre-checking for an exception won't work because of a fundamental race condition. Same thing could apply to looking for a file on the file system, etc. Given my CTO's propensity for drive-by management induced by reading technology columns in "Inc.", I need a layer of indirection around the persistence mechanism so that I can throw out Hibernate and use Kodo, or whatever, without changing anything except the lowest layer of persistence code. As a matter of fact, there are several such layers of abstraction in my system. How can I prevent them from leaking in spite of unchecked exceptions? One of the declaimed weaknesses of checked exceptions is having to "handle" them in every call on the stack—either by declaring that a calling method throws them, or by catching them and handling them. Handling them often means wrapping them in another checked exception of a type appropriate to the level of abstraction. So, for example, in checked-exception land, a file-system–based implementation of my UserRegistry might catch IOException, while a database implementation would catch SQLException, but both would throw a UserNotFoundException that hides the underlying implementation. How do I take advantage of unchecked exceptions, sparing myself of the burden of this wrapping at each layer, without leaking implementation details?

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  • Problem to focus JTextField

    - by Tom Brito
    I have used the approach of the ComponentListener to call focus in JTextField within a dialog, but for this case is just not working, I don't know why. It shows the focus in the text field and fast change to the button. Run and see: import java.awt.Component; import java.awt.GridLayout; import java.awt.event.ComponentEvent; import java.awt.event.ComponentListener; import javax.swing.JDialog; import javax.swing.JLabel; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JPasswordField; import javax.swing.JTextField; public class User { private String username = ""; private String password = ""; public User() { // default constructor } public User(String username, String password) { this.username = username; this.password = password; } /** Create a panel containing the componet and tha label. */ public JPanel createLabeledComponent(JLabel label, Component comp) { GridLayout layout = new GridLayout(2, 1); JPanel panel = new JPanel(layout); panel.add(label); panel.add(comp); label.setLabelFor(comp); return panel; } public void showEditDialog() { JLabel usernameLbl = new JLabel(username); final JTextField usernameField = new JTextField(); usernameField.setText(username); JPanel usernamePnl = createLabeledComponent(usernameLbl, usernameField); JLabel passwordLbl = new JLabel(password); JPasswordField passwordField = new JPasswordField(password); JPanel passwordPnl = createLabeledComponent(passwordLbl, passwordField); Object[] fields = { "User:", usernamePnl, "Password:", passwordPnl }; JOptionPane optionPane = new JOptionPane(fields, JOptionPane.PLAIN_MESSAGE, JOptionPane.OK_CANCEL_OPTION, null, null); JDialog dialog = optionPane.createDialog("User Data"); dialog.addComponentListener(new ComponentListener() { public void componentShown(ComponentEvent e) { usernameField.requestFocusInWindow(); } public void componentResized(ComponentEvent e) {} public void componentMoved(ComponentEvent e) {} public void componentHidden(ComponentEvent e) {} }); dialog.setVisible(true); } public static void main(String[] args) { new User().showEditDialog(); } } Any idea how to solve this?

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  • JSON or YAML encoding in GWT/Java on both client and server

    - by KennethJ
    I'm looking for a super simple JSON or YAML library (not particularly bothered which one) written in Java, and can be used in both GWT on the client, and in its original Java form on the server. What I'm trying to do is this: I have my models, which are shared between the client and the server, and these are the primary source of data interchange. I want to design the web service in between to be as simple as possible, and decided to take the RESTful approach. My problem is that I know our application will grow substantially in the future, and writing all the getters, setters, serialization, factories, etc. by hand fills me with absolute dread. So in order to avoid it, I decided to implement annotations to keep track of attributes on the models. The reason I can't just serialize everything directly, using GWT's own one, or one which works through reflection, is because we need a certain amount of logic going on in the serialization process. I.e. whether references to other models get serialized during the serialization of the original model, or whether an ID is just passed, and general simple things like that. I've then written an annotation processor to preprocess my shared models and generate an implementing class with all the getters, setters, serialization, lazy-loading, etc. To make a long story short, I need some type of simple YAML or JSON library, which allows me to encode and decode manually, so I can generate this code through my annotation processor. I have had a look around the interwebs, but every single one I ran into supported some reflection which, while all fine and dandy, make it pretty much useless for GWT. And in the case of GWT's own JSON library, it uses JSNI for speed purposes, making it useless server side. One solution I did think about involved writing writing two sets of serialization methods on the models, one for the client and one for the server, but I'd rather not do that. Also, I'm pretty new to GWT, and even though I have done a lot of Java, it was back in the 1.2 days, so it's a bit rusty. So if you think I'm going about this problem completely the wrong way, I'm open to suggestions.

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  • JSF 2.0: Preserving component state across multiple views

    - by tlind
    The web application I am developing using MyFaces 2.0.3 / PrimeFaces 2.2RC2 is divided into a content and a navigation area. In the navigation area, which is included into multiple pages using templating (i.e. <ui:define>), there are some widgets (e.g. a navigation tree, collapsible panels etc.) of which I want to preserve the component state across views. For example, let's say I am on the home page. When I navigate to a product details page by clicking on a product in the navigation tree, my Java code triggers a redirect using navigationHandler.handleNavigation(context, null, "/detailspage.jsf?faces-redirect=true") Another way of getting to that details page would be by directly clicking on a product teaser that is shown on the home page. The corresponding <h:link> would lead us to the details page. In both cases, the expansion state of my navigation tree (a PrimeFaces tree component) and my collapsible panels is lost. I understand this is because the redirect / h:link results in the creation of a new view. What is the best way of dealing with this? I am already using MyFaces Orchestra in my project along with its conversation scope, but I am not sure if this is of any help here (since I'd have to bind the expansion/collapsed state of the widgets to a backing bean... but as far as I know, this is not possible). Is there a way of telling JSF which component states to propagate to the next view, assuming that the same component exists in that view? I guess I could need a pointer into the right direction here. Thanks! Update 1: I just tried binding the panels and the tree to a session-scoped bean, but this seems to have no effect. Also, I guess I would have to bind all child components (if any) manually, so this doesn't seem like the way to go. Update 2: Binding UI components to non-request scoped beans is not a good idea (see link I posted in a comment below). If there is no easier approach, I might have to proceed as follows: When a panel is collapsed or the tree is expanded, save the current state in a session-scoped backing bean (!= the UI component itself) The components' states are stored in a map. The map key is the component's (hopefully) unique, relative ID. I cannot use the whole absolute component path here, since the IDs of the parent naming containers might change if the view changes, assuming these IDs are generated programmatically. As soon as a new view gets constructed, retrieve the components' states from the map and apply them to the components. For example, in case of the panels, I can set the collapsed attribute to a value retrieved from my session-scoped backing bean.

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