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  • Dispatcher.CheckAccess() isn't working from my console application, is there a better way.

    - by zimmer62
    I wrote an application in WPF / VB and separated the business logic and UI into different projects. The business layer uses a serial port which runs on a different thread, Now that I'm trying to write a command line interface for the same business layer, it seems to fail when .Invoke() is called. (no error, just doesn't work) I'm pretty sure the reason I had to add in checkaccess and .invoke was because I have collections that would be changed during processing the serial port data and wanted the NotifyCollectionChanged to be handled by WPF data binding. (The reason I'm not 100% sure is because it was months ago I wrote that part and it all worked great from the GUI, now adding the console app has made me rethink some of this) I would like my business layer to run these processes on the thread they were created, I need this to work from both my GUI version and the command line version. Am I misusing the Dispatcher in my business layer? Is there a better way to handle an event from the serial port, and then return to the main thread to processes the data?

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  • Blackberry horizontal scroll in bottom menu bar

    - by Dachmt
    Hi, I have a MainScreen that has an overlay menu at the bottom of the screen, over a map. To do that, I have an MenuHoster (extends HorizontalFieldManager) that takes all width of the screen, 45px height and at the bottom of the screen. It overlays a map. In my MenuHoster, and add another HorizontalFieldManager that has a background image (my menu bar image) and focusable buttons. I have too many buttons to be all in my screen, so I want to an horizontal screen. When I create my second HorizontalFieldManager that hosts the buttons, I define the Manager.HORIZONTAL_SCROLL as style. My buttons are focusable, but nothing happens... The focus change to the next buttons but my HorizontalFieldManager does not scroll... I tried putting the same parameter in my MenuHoster HorizontalFieldManager, the scroll is working but all my screen goes right or left, and I want only the content of my menu bar... So there is my map and my menu going left, my buttons at the bottom and the rest of the screen white. Any idea why my second HorizontalFieldManager hosting the buttons does not scoll? Thank you!

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  • Presenting UINavigationController modally -- problem setting up tool and nav bar items in root view controller viewDidLoad

    - by Bogatyr
    In my iOS app I'm creating and presenting a UINavigationController modally like so: MyViewController *myvc = [[[MyViewController alloc] initWithNibName:@"MyViewController" bundle:nil] autorelease]; UINavigationController *navVC = [[[UINavigationController alloc] initWithRootViewController:myvc] autorelease]; [self presentModalViewController:navVC animated:YES]; In the MyViewController viewDidLoad I'm creating and setting toolbar items for the navigation controller's toolbar, like so: self.navigationController.toolbar.items = [NSArray arrayWithObjects:(items...), nil]; the problem I'm having is that the items don't show up. If instead I call a method from MyViewController's viewDidLoad method that adds the toolbar items via performSelector:withObject:afterDelay:0, then it works perfectly. So there's obviously some race condition going on here with the initial presentation of the UINavigationController, initialization of its toolbar/navbar, and the initialization of the nav bar's specified initial root view controller. I verified in the debugger that the root view controller's viewDidLoad is called after the UINavigationController's viewDidLoad method. In fact, the root view controller's viewDidLoad method is not called until presentModalViewController: is called, and the UINavigationController's viewDidLoad is called within initWithRootViewController, so doesn't that imply that the UINavigationController object should be "all ready to go", including its nav bar and toolbars? I thought at first that the navigation controller's toolbar object may not exist yet at MyViewController's viewDidLoad time, but it clearly does. At least, NSLog shows that it is not nil during MyViewController's viewDidLoad method. In fact, the UINavigationController's toolbar object is identical at both times: in the root view controller's viewDidLoad, and in the "setupToolbar" method that I called with performSelector:withObject:afterDelay, so it's not getting "re-initialized" somehow. So, what's going on here? Why aren't my toolbar modifications "sticking" in MyViewController's viewDidLoad, and why does performing them in the next iteration of the runloop (performSelector:withObject:afterDelay:0) make it work? What is the "right" way of setting up initial navbar / toolbar items in code from the rootViewController of the UINavigationController?

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  • pushViewController Not Displaying UIView/Nib with tabbar and nav bar

    - by james
    I'm relatively new to objective c but not programming and am stuck with my iphone app. I created a nav based app with both a navbar and a tab bar controller. I set the tab bar as the root controller. I'm able to switch between each tab without any issues to various UIViews and UITableViews. My issue is that in one of my UITableViews that I call from the TabBarController, didSelectRowAtIndexPath function is suppose to display a new UIView. The below code does not give any errors and runs fine but does not show the new Nib. if(newViewController == nil) { NSLog(@"yes nil"); BookViewController *aNewViewController = [[BookViewController alloc] initWithNibName:@"BookOptionView" bundle:nil]; self.newViewController = aNewViewController; [aNewViewController release]; } BookAppDelegate *delegate = (BookAppDelegate *)[[UIApplication sharedApplication] delegate]; [delegate.appNavBar pushViewController:newViewController animated:YES]; Now when I do the below, it works fine but it gets rid of the nav and tab which I'm assuming because its a modal call instead of pushing the view controller. BookViewController *screen = [[BookViewController alloc] initWithNibName:@"BookOptionView" bundle:[NSBundle mainBundle]]; screen.modalTransitionStyle = UIModalTransitionStyleCoverVertical; [self presentModalViewController:screen animated:YES]; [screen release]; Any ideas why I can't get the View Controller to push correctly? In my application delegate file, I declared an AppNavBarController object (inherit from UINavigationController) called appNavBar. Any help would be appreciated!

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  • Can I trigger PHP garbage collection to happen automatically if I have circular references?

    - by Beau Simensen
    I seem to recall a way to setup the __destruct for a class in such a way that it would ensure that circular references would be cleaned up as soon as the outside object falls out of scope. However, the simple test I built seems to indicate that this is not behaving as I had expected/hoped. Is there a way to setup my classes in such a way that PHP would clean them up correctly when the outermost object falls out of scope? I am not looking for alternate ways to write this code, I am looking for whether or not this can be done, and if so, how? I generally try to avoid these types of circular references where possible. class Bar { private $foo; public function __construct($foo) { $this->foo = $foo; } public function __destruct() { print "[destroying bar]\n"; unset($this->foo); } } class Foo { private $bar; public function __construct() { $this->bar = new Bar($this); } public function __destruct() { print "[destroying foo]\n"; unset($this->bar); } } function testGarbageCollection() { $foo = new Foo(); } for ( $i = 0; $i < 25; $i++ ) { echo memory_get_usage() . "\n"; testGarbageCollection(); } The output looks like this: 60440 61504 62036 62564 63092 63620 [ destroying foo ] [ destroying bar ] [ destroying foo ] [ destroying bar ] [ destroying foo ] [ destroying bar ] [ destroying foo ] [ destroying bar ] [ destroying foo ] [ destroying bar ] What I had hoped for: 60440 [ destorying foo ] [ destorying bar ] 60440 [ destorying foo ] [ destorying bar ] 60440 [ destorying foo ] [ destorying bar ] 60440 [ destorying foo ] [ destorying bar ] 60440 [ destorying foo ] [ destorying bar ] 60440 [ destorying foo ] [ destorying bar ]

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  • Modifying UINavigation Bar Buttons in SubViews

    - by james
    I'm having trouble trying to modify the navigation bar in the subview portion of my application. self.navigationItem.rightBarButtonItem = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(add_Clicked:)] autorelease]; I have no issues modifying the navigation bar in any of my UIViewControllers classes. The simplified application class outline is as such: AppDelegate - UIViewControllerA (has a left and a right navigationBarButton) - Subview is displayed when a SegmentControl is selected. (Within the subview, I'm trying to modify the right NavigationBarButton that is displayed) [self.view addSubview:newControllerName.view]; Methods I have attempted: Trying to set self.navigationItem.rightBarButtonItem within my subview to a new UIBarButtonItem. Creating a pointer to UIViewControllerA within my AppDelegate. The UIViewControllerA contains a function setNavButton I wrote to set the rightBarButtonItem to a button. Then I am referencing the AppDelegate's reference to UIViewControllerA and attempting to call setNavButton. I included a NSLog call to see if that function is being called and it is executing but the NavigationBar isn't being modified. I'm trying to avoid having to push a UIViewController after the SegmentControl is clicked in UIViewControllerA so that I can simulate the SegmentControl as tabs. I'm not getting any errors during compile or run time. Anyone have any ideas?

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  • MAgento top-nav bar

    - by itsandy
    Hi Everyone, I am working with the free redtheme to make a website. This is my first week into magento and designing any website. I have installed and started having a look at magento admin interface. I am not sure how to get top navigational bar working. Which files needs to be changed to get a top nav bar. While googling and reading a few articles I found that top.phtml file and added my tags with menus. But they don’t seem to work. {{ maybe this is why everyone is saying magento is slow }} Finally got it working but now unable to get drop down menus. Can anyone help with this. Which files do i need to edit to get a drop down horizontal menu. My next question is regarding red theme. I installed the theme and was playing with it. Trying to get the banner using the red theme user guide pdf but couldnt find the add new banner option anywhere. Any help would be much appreciated. Thanks

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  • How to add View Controller with Tab Bar interfaced View Controller

    - by TechFusion
    I have created Window based Tab Bar controller app, One Tab Bar of viewController has been interfaced with WebVIew ..I am looking to create another view once touch event happened in that WebView.. //TabBarViewController.m - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { TabMainView *mainView = [[TabMainView alloc] init]; mainView.hidesBottomBarWhenPushed = YES; [self.navigationController pushViewController: mainView animated:YES]; [mainView release]; } I have created MainView, which is UIViewController Subclass. //TabMainView.m - (void)loadView { CGRect frame = CGRectMake(0.0, 0.0, 480, 320); WebView = [[[UIWebView alloc] initWithFrame:frame] autorelease]; WebView.backgroundColor = [UIColor whiteColor]; WebView.scalesPageToFit = YES; WebView.autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleTopMargin); WebView.autoresizesSubviews = YES; WebView.exclusiveTouch = YES; //self.WebView.UserInteractionEnabled = NO; WebView.clearsContextBeforeDrawing = YES; self.view = WebView; [WebView release]; } - (void)viewWillAppear:(BOOL)animated { [self.WebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.apple.com"]]]; } Here when touch event happened then it is not passing control to TabMainView.m 's Viewload function although I am pushing it's view? TabBarView is also UIViewController subclass not a UINavigationController.

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  • Handling Status Bar notification

    - by MAkS
    in my app a background service starts and from that service i want to set Status bar notification, that the service has Started following is the code : Context context = getApplicationContext(); String ns = Context.NOTIFICATION_SERVICE; int icon = R.drawable.icon; CharSequence tickerText = "Hello"; long when = System.currentTimeMillis(); Notification notification = new Notification(icon, tickerText, when); CharSequence contentTitle = "My notification"; CharSequence contentText = "Hello World!"; Intent notificationIntent = new Intent(MyService.this, MyClass.class); notificationIntent.setFlags( Intent.FLAG_ACTIVITY_NEW_TASK); PendingIntent contentIntent = PendingIntent.getActivity(this,0,notificationIntent,0); notification.setLatestEventInfo(context, contentTitle, contentText, contentIntent); NotificationManager mNotificationManager = (NotificationManager) getSystemService(ns); mNotificationManager.notify(1, notification); Notification is displayed in Status bar But whin i click on that MyClass.class is not fired.And in log cat it shows "Input Manager Service Window already focused ignoring focuson ...." so plz provide solution. thanks in advance

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  • Assign click event to addon icon on navigation bar

    - by Charsee
    We have created a chrome extension for our app. Where we call a METHOD from a "js file" on CLICK event of the "extension icon" placed on the navigation bar. For this we use message passing between the app.js (file containing the METHOD to be called on icon click) and background.html (using a js file included in this html). The script used to pass message is:(from background.html) chrome.browserAction.onClicked.addListener(function (tab) { chrome.tabs.sendMessage(tab.id, "showPopup"); }); and to listen the message :(in app.js) chrome.extension.onMessage.addListener(function(request) { if (request === "showPopup") { showPopup(); } }); The click event works as expected. But now we want to do same thing in mozilla extension. and we can't pass message to app.js on the click of the icon,so that it can execute the containing methods. We have also added the app.js using pageMod, something like this exports.main = function(options, callbacks) { pageMod.PageMod({ include: ["*"], contentScriptWhen: 'start', contentScriptFile: [data.url('jquery-1.7.1.min.js'),data.url('app.js')] }); createAndAddNavBarButton(); }; function createAndAddNavBarButton() { var navBar = document.getElementById('nav-bar');//assume document has been defined if (!navBar){return;}; var nbBtn = document.createElement('navbaricon'); nbBtn.setAttribute('id', 'navButton'); nbBtn.setAttribute('image', data.url('icon_16.png')); nbBtn.onclick = function(){ showPopup(); return true; } navBar.appendChild(btn); } But the click event does nothing and showPopup() is undefined. When a new page loads event associated with it in the app.js executes without any error but the click event doesn't work. Is there a method from where we can assign click event directly to this icon, as we have done in the case of chrome extension.

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  • Detect and handle, or override, clicks on a navigation bar

    - by Henrik Erlandsson
    I have an app where I've pushed two items onto the navigation bar. The top item, which ends up as a 'back' button, should have the function to jump all the way back to the start page, which is a list of web news. The other one simply displays a logo. The boss wants a navigation bar look and feel but with a simple function, so the user can click around the news site, but always be able to jump to the news list page with just the one click. Is the only option to create a fixed navbar with two items in IB, so that I can connect an outlet to the clickable item - or is there some way to intercept clicks to the navbar to make a requestURL? touchesBegan or touchUpInside would be fine, but I've found no way of implementing that so far. It's okay if the whole navbar is clickable, I just need some hint how to make it happen. Add a transparent UIlabel on top and detect clicks for that, maybe? A bonus would be to hide the item in the 'back' position without popping it from the stack.

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  • Lambda Functions in PHP aren't Logical

    - by Chacha102
    Note: I have condensed this article into my person wiki: http://wiki.chacha102.com/Lambda - Enjoy I am having some troubles with Lambda style functions in PHP. First, This Works: $foo = function(){ echo "bar"; }; $foo(); Second, This Works: class Bar{ public function foo(){ echo "Bar"; } Third, This works: $foo = new stdClass; $foo->bar = function(){ echo "bar"; }; $test = $foo->bar; $test(); But, this does not work: $foo = new stdClass; $foo->bar = function(){ echo "bar"; }; $foo->bar(); And, this does not work class Bar{ public function foo(){ echo "Bar"; } $foo = new Bar; $foo->foo = function(){ echo "foo"; }; $foo->foo(); // echo's bar instead of Foo. My Question is Why?, and how can I assure that both this: $foo->bar = function(){ echo "test"; }; $foo->bar(); and this $foo = new Bar; $foo->bar(); are called properly? Extra Points if you can point to documentation stating why this problem occurs.

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  • Synthetic click doesn't switch application's menu bar (Mac OS X)

    - by Rok
    Hi. I'm developing some sort of air mouse application for iPhone platform. This applications connects to one computer service which generates mouse events on Mac OS X. I'm generating this events with CGEventCreateMouseEvent() and CGEventPost(). But I've encountered one problem. Let's say you are using Safari and then you click on free desktop space. If you do this with regular mouse it will hide Safari's top menu bar and show Finder menu bar. But on these synthetic events it doesn't act like that. Do I have to post some other event or set some additional properties? Here is my code for mouse up, mouse down: - (void)mouseUp:(int)button { int type = (button == LEFT_BUTTON) ? kCGEventLeftMouseUp : kCGEventRightMouseUp; int mouseButton = (button == LEFT_BUTTON) ? kCGMouseButtonLeft : kCGMouseButtonRight; leftMouseDown = (button == LEFT_BUTTON) ? NO : leftMouseDown; rightMouseDown = (button == RIGHT_BUTTON) ? NO : rightMouseDown; CGEventSourceRef source = CGEventSourceCreate(kCGEventSourceStateHIDSystemState); CGEventRef event = CGEventCreateMouseEvent (source, type, CGSCurrentInputPointerPosition(), mouseButton); CGEventSetType(event, type); CGEventPost(kCGHIDEventTap, event); CFRelease(event); } - (void)mouseDown:(int)button { int type = (button == LEFT_BUTTON) ? kCGEventLeftMouseDown : kCGEventRightMouseDown; int mouseButton = (button == LEFT_BUTTON) ? kCGMouseButtonLeft : kCGMouseButtonRight; leftMouseDown = (button == LEFT_BUTTON) ? YES : leftMouseDown; rightMouseDown = (button == RIGHT_BUTTON) ? YES : rightMouseDown; CGEventSourceRef source = CGEventSourceCreate(kCGEventSourceStateHIDSystemState); CGEventRef event = CGEventCreateMouseEvent (source, type, CGSCurrentInputPointerPosition(), mouseButton); CGEventSetType(event, type); CGEventPost(kCGHIDEventTap, event); CFRelease(event); }

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  • iPad search bar bad memory access?

    - by Geoff Baum
    Hello all, So I am trying to implement a search bar in my app and am very close but can't seem to figure out where this memory error is occurring. This is what part of my search method looks like: filters = [[NSMutableArray alloc] init]; NSString *searchText = detailSearch.text; NSMutableArray *searchArray = [[NSMutableArray alloc] init]; // Normally holds the object (ex: 70 locations) searchArray = self.copyOfFilters ; //This is the line that is breaking after ~2-3 letters are entered in the search for (NSString *sTemp in searchArray) { NSRange titleResultsRange = [sTemp rangeOfString:searchText options:NSCaseInsensitiveSearch]; if (titleResultsRange.length > 0) [filters addObject:sTemp]; } displayedFilters = filters; copyOfFilters is a deep copy of the displayed filters that appear when the view first loads via: self.copyOfFilters = [[NSMutableArray alloc] initWithArray:displayedFilters copyItems:YES]; I have traced through the entry of letters and it is accurate after 2 letters, but once you try and enter a letter after a space in the search bar, it crashes. The value of copyOfFilters = {(int)[$VAR count]} objects. Does anyone know what may be causing this? Thanks!

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  • [ASP.NET 4.0] Persisting Row Selection in Data Controls

    - by HosamKamel
    Data Control Selection Feature In ASP.NET 2.0: ASP.NET Data Controls row selection feature was based on row index (in the current page), this of course produce an issue if you try to select an item in the first page then navigate to the second page without select any record you will find the same row (with the same index) selected in the second page! In the sample application attached: Select the second row in the books GridView. Navigate to second page without doing any selection You will find the second row in the second page selected. Persisting Row Selection: Is a new feature which replace the old selection mechanism which based on row index to be based on the row data key instead. This means that if you select the third row on page 1 and move to page 2, nothing is selected on page 2. When you move back to page 1, the third row is still selected. Data Control Selection Feature In ASP.NET 3.5 SP1: The Persisting Row Selection was initially supported only in Dynamic Data projects Data Control Selection Feature In ASP.NET 4.0: Persisted selection is now supported for the GridView and ListView controls in all projects. You can enable this feature by setting the EnablePersistedSelection property, as shown below: Important thing to note, once you enable this feature you have to set the DataKeyNames property too because as discussed the full approach is based on the Row Data Key Simple feature but  is a much more natural behavior than the behavior in earlier versions of ASP.NET. Download Demo Project

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  • Selecting Your Theme

    - by Ruth
    Would you like to personalize CRM On Demand? You can quite easily with CRM On Demand Release 17. Whether your company wants a custom theme that matches your company brand, or you have a preference about the look and feel of the application, you can select your theme in a few clicks. If you are interested in creating a custom theme, take a look at the Themes - Create Your CRM Style blog article. Selecting Your Company Theme If you are the company administrator, you can select the company theme from the company profile. Click the Admin link. Navigate to Company Administration Company Profile. In the Company Theme Setting section, click the Theme Name field to select a new theme. Selecting Your Personal Theme Even if you are not an administrator, you can select a theme for CRM On Demand on your computer. Your company may not allow access to this option, so talk to your company administrator if you are unable to select your theme. Click the My Setup link. Click the My Profile link. Click the Personal Profile link. In the Additional Information section, select the theme that you want in the Theme Name picklist. Here are some standard themes to help you find the look that you want:

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  • What is ODBC?

    According to Microsoft, ODBC is a specification for a database API.  This API is database and operating system agnostic due to the fact that the primary goal of the ODBC API is to be language-independent. Additionally, the open functions of the API are created by the manufactures of DBMS-specific drivers. Developers can use these exposed functions from within their own custom applications so that they can communicate with DBMS through the language-independent drivers. ODBC Advantages Multiple ODBC drivers for each DBSM Example Oracle’s ODBC Driver Merant’s Oracle Driver Microsoft’s Oracle Driver ODBC Drivers are constantly updated for the latest data types ODBC allows for more control when querying ODBC allows for Isolation Levels ODBC Disadvantages ODBC Requires DSN ODBC is the proxy between an application and a database ODBC is dependent on third party drivers ODBC Transaction Isolation Levels are related to and limited by the transaction management capabilities of the data source. Transaction isolation levels:  READ UNCOMMITTED Data is allowed to be read prior to the committing of a transaction.  READ COMMITTED Data is only accessible after a transaction has completed  REPEATABLE READ The same data value is read during the entire transaction  SERIALIZABLE Transactions have no effect on other transactions

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  • Java Spotlight Episode 84: Anil Gaur on JavaEE 7

    - by Roger Brinkley
    Tweet Interview with Anil Gaur, VP of Java Platform for Enterprise Edition and GlassFish Server, on JavaEE 7. Joining us this week on the Java All Star Developer Panel are Dalibor Topic, Java Free and Open Source Software Ambassador and Arun Gupta, Java EE Guy. Right-click or Control-click to download this MP3 file. You can also subscribe to the Java Spotlight Podcast Feed to get the latest podcast automatically. If you use iTunes you can open iTunes and subscribe with this link:  Java Spotlight Podcast in iTunes. Show Notes News Tori Wieldt - Judges Selected for Duke's Choice Awards Donald Smith - #OpenJDK interview in Java Magazine Henrik Ståhl - Java 7 adoption at 23% JavaOne Kicks Off with Sunday Keynotes at Masonic Auditorium Jersey 2.0 M4 JSF 2.2 Latest Snapshot NetBeans IDE 7.2 - Deploy to Cloud Events May 30, OTN Java Developer Day, Redwood Shores June 11-14, Cloud Computing Expo, New York City June 12, Boulder JUG June 13, Denver JUG June 13, Eclipse Juno DemoCamp, Redwoood Shore June 13, JUG Münster June 14, Java Klassentreffen, Vienna, Austria June 18-20, QCon, New York City June 26-28, Jazoon, Zurich, Switzerland July 5, Java Forum, Stuttgart, Germany July 30-August 1, JVM Language Summit, Santa Clara Feature InterviewAnil Gaur is the Vice President of Java Platform, Enterprise Edition, and GlassFish Server at Oracle in the Fusion Middleware Group. Is responsible for creation of Java EE Specifications, Reference Implementation, and Compatibility Test Suites. Leading the evolution on Java EE into Cloud and PaaS environment through the Java EE 7 standard. Prior to that, managed the delivery of Java EE 6 Platform and SDK which quickly gained momentum in enterprise application development and deployments. In this episode we talk about GlassFish 3.1 release. Mail Bag What’s Cool RFR (L): Adding core file parsing on Mac OS X to SA Sergio Del Valle @swdelvalle is the 1,000 @JavaSpotlight twitter follower

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  • Class Loading Deadlocks

    - by tomas.nilsson
    Mattis follows up on his previous post with one more expose on Class Loading Deadlocks As I wrote in a previous post, the class loading mechanism in Java is very powerful. There are many advanced techniques you can use, and when used wrongly you can get into all sorts of trouble. But one of the sneakiest deadlocks you can run into when it comes to class loading doesn't require any home made class loaders or anything. All you need is classes depending on each other, and some bad luck. First of all, here are some basic facts about class loading: 1) If a thread needs to use a class that is not yet loaded, it will try to load that class 2) If another thread is already loading the class, the first thread will wait for the other thread to finish the loading 3) During the loading of a class, one thing that happens is that the <clinit method of a class is being run 4) The <clinit method initializes all static fields, and runs any static blocks in the class. Take the following class for example: class Foo { static Bar bar = new Bar(); static { System.out.println("Loading Foo"); } } The first time a thread needs to use the Foo class, the class will be initialized. The <clinit method will run, creating a new Bar object and printing "Loading Foo" But what happens if the Bar object has never been used before either? Well, then we will need to load that class as well, calling the Bar <clinit method as we go. Can you start to see the potential problem here? A hint is in fact #2 above. What if another thread is currently loading class Bar? The thread loading class Foo will have to wait for that thread to finish loading. But what happens if the <clinit method of class Bar tries to initialize a Foo object? That thread will have to wait for the first thread, and there we have the deadlock. Thread one is waiting for thread two to initialize class Bar, thread two is waiting for thread one to initialize class Foo. All that is needed for a class loading deadlock is static cross dependencies between two classes (and a multi threaded environment): class Foo { static Bar b = new Bar(); } class Bar { static Foo f = new Foo(); } If two threads cause these classes to be loaded at exactly the same time, we will have a deadlock. So, how do you avoid this? Well, one way is of course to not have these circular (static) dependencies. On the other hand, it can be very hard to detect these, and sometimes your design may depend on it. What you can do in that case is to make sure that the classes are first loaded single threadedly, for example during an initialization phase of your application. The following program shows this kind of deadlock. To help bad luck on the way, I added a one second sleep in the static block of the classes to trigger the unlucky timing. Notice that if you uncomment the "//Foo f = new Foo();" line in the main method, the class will be loaded single threadedly, and the program will terminate as it should. public class ClassLoadingDeadlock { // Start two threads. The first will instansiate a Foo object, // the second one will instansiate a Bar object. public static void main(String[] arg) { // Uncomment next line to stop the deadlock // Foo f = new Foo(); new Thread(new FooUser()).start(); new Thread(new BarUser()).start(); } } class FooUser implements Runnable { public void run() { System.out.println("FooUser causing class Foo to be loaded"); Foo f = new Foo(); System.out.println("FooUser done"); } } class BarUser implements Runnable { public void run() { System.out.println("BarUser causing class Bar to be loaded"); Bar b = new Bar(); System.out.println("BarUser done"); } } class Foo { static { // We are deadlock prone even without this sleep... // The sleep just makes us more deterministic try { Thread.sleep(1000); } catch(InterruptedException e) {} } static Bar b = new Bar(); } class Bar { static { try { Thread.sleep(1000); } catch(InterruptedException e) {} } static Foo f = new Foo(); }

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  • Monitoring the Application alongside SQL Server

    - by Tony Davis
    Sometimes, on Simple-Talk, it takes a while to spot strange and unexpected patterns of user activity, or small bugs. For example, one morning we spotted that an article’s comment count had leapt to 1485, but that only four were displayed. With some rooting around in Google Analytics, and the endlessly annoying Community Server admin-interface, we were able to work out that a few days previously the article had been subject to a spam attack and that the comment count was for some reason including both accepted and unaccepted comments (which in turn uncovered a bug in the SQL). This sort of incident made us a lot keener on monitoring Simple-talk website usage more effectively. However, the metrics we wanted are troublesome, because they are far too specific for Google Analytics to measure, and the SQL Server backend doesn’t keep sufficient information to enable us to plot trends. The latter could provide, for example, the total number of comments made on, or votes cast for, articles, over all time, but not the number that occur by hour over a set time. We lacked a baseline, in other words. We couldn’t alter the database, as it is a bought-in package. We had neither the resources nor inclination to build-in dedicated application monitoring. Possibly, we could investigate a third-party tool to do the job; but then it occurred to us that we were already using a monitoring tool (SQL Monitor) to keep an eye on the database. It stored data, made graphs and sent alerts. Could we get it to monitor some aspects of the application as well? Of course, SQL Monitor’s single purpose is to check and monitor SQL Server, over time, rather than to monitor applications that use SQL Server. However, how different is the business of gathering and plotting SQL Server Wait Stats, from gathering and plotting various aspects of user activity on the site? Not a lot, it turns out. The latest version allows us to write our own custom monitoring scripts, meaning that we could now monitor any metric in the application that returns an integer. It took little time to write a simple SQL Query that collects basic metrics of the total number of subscribers, votes cast, comments made, or views of articles, over time. The SQL Monitor database polls Simple-Talk every second or so in order to get the latest totals, and can then store and plot this information, or even correlate SQL Server usage to application usage. You can see the live data by visiting monitor.red-gate.com. Click the "Analysis" tab, and select one of the "Simple-talk:" entries in the "Show" box and an appropriate data range (e.g. last 30 days). It’s nascent, and we’re still working on it, but it’s already given us more confidence that we’ll spot quickly trends, bugs, or bursts of ‘abnormal’ activity. If there is a sudden rise in comments, we get an alert, and if it’s due to a spam attack, we can moderate or ban the perpetrator very quickly. We’ve often argued that a tool should perform a single job well rather than turn into a Swiss-army knife, but ironically we’ve rather appreciated being able to make best use of what’s there anyway for a slightly different purpose. Is this a good or common practice? What do you think? Cheers, Tony.

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  • 30 Steps to Master ASP.NET MVC Application development

    - by Rajesh Pillai
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Welcome Readers!,   I am starting out a new series on ASP.NET  MVC skill building which will be posted over the next couple of weeks.  Let me know your thoughts on the content, which I have planned and a couple of them has been taken from ASP.NET MVC2 Cookbook. (NOTE: Only the heading has been taken, the content will be not :)).   Do let me know what you would like to see, or any additional inputs or ideas to cover in this topics.  The 30 steps are oultined below for quick reference.  Will start filling this out quickly.   Outlined is the ‘30’ step to master ASP.NET MVC.   A Peek Into Model What is a model? Different types of model Presentation/ViewModel Model Mapping (AutoMapper)   A Peak into View How view works in ASP.NET MVC? View Engine Design Custom View Engine View Best Practices Templated Helpers Partial Views   A Peak into Controller Introduction Controller Design Controller Best Practices Asynchronous Controller Custom Action Result Action Filters Controller Factory to use with IOC   Routes Explanation Routes from the database Routes from XML More complex routing   Master Pages Basics Setting Master Page Dynamically   Working with data in the view Repeating Views Array of check boxes Array of radio buttons Paged data CRUD Client side action Confirmation Dialog (modal window) jqGrid   Working with Forms   Validation Model Validation with DataAnnotations Using the xVal validation framework Client side validation with jQuery Validation Fluent Validation Model Binders   Templating Create strongly typed helper using T4 Custom View Templates with T4 Create custom MVC project template using T4   IOC AutoFac Ninject Unity Application   Areas   jQuery, Ajax and jQuery Plugins   State Maintenance Application State User state Cookies Webfarm   Error Handling View error handling Controller error handling ELMAH (Error Logging Modules and Handlers)   Authentication and Authorization User Registration form SignOn Process Password Reminder Membership and Roles Windows authentication Restricting access to all pages Restricting access to selected pages Restricting access to pages by role Restricting access to a controller Restricting access to selected area   Profiles and Themes Using Profiles Inheriting a Profile Migrating an anonymous profile Creating custom themes Using themes User personalized themes   Configuration Adding custom application settings in web.config Displaying custom error messages Accessing other web.config configuration elements Adding custom configuration elements to web.config Encrypting web.config sections   Tracing, Debugging and Logging   Caching Caching a whole page Caching pages based on route details Caching pages based on browser type and version Caching pages based custom strings Caching partial pages Caching application data Object Caching Using Microsoft Velocity Using MemCache Using AppFabric cache   Localization   HTTP Handlers and Modules   Security XSS/CSRF AnitForgery Encoding   HtmlHelpers Strongly typed helpers Writing custom helpers   Repository Pattern (Data access)   WF/WCF   Unit Testing   Mocking Framework   Integration Testing   Load / Performance Testing   Deployment    Once again let me know your thoughts on this.   Till then, Enjoy MVC'ing!!!

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  • Troubleshooting EBS Discovery Issues - Part 2

    - by Kenneth E.
    Part 1 of “Troubleshooting EBS Discovery Issues”, which was posted on May 17th, focused on the diagnostics associated with the initial discovery of an EBS instances (e.g., Forms servers, APPL_TOPs, databases, etc.).Part 2 focuses on verifying parameters of the Change Management features, also called "Pack Diagnostics, specifically for Customization Manager, Patch Manager, Setup Manager, Automated Cloning, and User Monitoring.  As stated in the first post, there can be numerous reasons that Discovery fails - credentials, file-level permissions, patch levels - just to name a few.The Discovery Wizard can be accessed from the EBS homepage.  From the home page, click "Pack Diagnostics"Click "Create" to define the diagnostic processProvide the required inputs; Name, Module (i.e., Customization Manager, Patch Manager, Setup Manager, Automated Cloning, and User Monitoring), Show Details (typically "All"), and Category (typically check both Generic and User Specific).  Add the appropriate targets.Once the diagnostic process has completed, view the results.  Click on "Succeeded" or "Failed" in the Status column.Expand the entire tree and click on each "Succeeded/Failed" status to see the results of each test within that task.Sample output verifying o/s user name and required patches Additional sample output showing a failed testComplete descriptions of, as well as recommended corrective actions for, all of the diagnostic tests that are run in EM 12c is found in this spreadsheet.  Additional information can be found in the Application Management Pack User Guide.

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  • Why does "quickly share --ppa share" abort with a "can't create" error?

    - by desgua
    I can not figure out what I am doing wrong. The package builds ok with quickly package, I could submit it, but I can not update my ppa. Here is what I got: desgua@desguai7:~/quickly/sbk$ quickly share --ppa sbk Get Launchpad Settings Launchpad connection is ok ..........An error has occurred when creating debian packaging ERROR: can't create or update ubuntu package ERROR: share command failed Aborting Edit The name of my ppa was wrong, but even using ppa:desgua/sbk still doesn't work: desgua@desguai7:~/quickly/sbk$ quickly share --ppa ppa:desgua/sbk Get Launchpad Settings Traceback (most recent call last): File "/usr/share/quickly/templates/ubuntu-application/share.py", line 101, in launchpad = launchpadaccess.initialize_lpi() File "/usr/lib/python2.7/dist-packages/quickly/launchpadaccess.py", line 91, in initialize_lpi allow_access_levels=["WRITE_PRIVATE"]) File "/usr/lib/python2.7/dist-packages/launchpadlib/launchpad.py", line 539, in login_with credential_save_failed, version) File "/usr/lib/python2.7/dist-packages/launchpadlib/launchpad.py", line 359, in _authorize_token_and_login service_root, cache, timeout, proxy_info, version) File "/usr/lib/python2.7/dist-packages/launchpadlib/launchpad.py", line 198, in __init__ credentials, service_root, cache, timeout, proxy_info, version) File "/usr/lib/python2.7/dist-packages/lazr/restfulclient/resource.py", line 460, in __init__ self._wadl = self._browser.get_wadl_application(self._root_uri) File "/usr/lib/python2.7/dist-packages/lazr/restfulclient/_browser.py", line 299, in get_wadl_application response, content = self._request(url, media_type=wadl_type) File "/usr/lib/python2.7/dist-packages/lazr/restfulclient/_browser.py", line 242, in _request str(url), method=method, body=data, headers=headers) File "/usr/lib/python2.7/dist-packages/lazr/restfulclient/_browser.py", line 211, in _request_and_retry url, method=method, body=body, headers=headers) File "/usr/lib/python2.7/dist-packages/httplib2/__init__.py", line 1414, in request (response, new_content) = self._request(conn, authority, uri, request_uri, method, body, headers, redirections, cachekey) File "/usr/lib/python2.7/dist-packages/launchpadlib/launchpad.py", line 126, in _request LaunchpadOAuthAwareHttp, self)._request(*args) File "/usr/lib/python2.7/dist-packages/lazr/restfulclient/_browser.py", line 130, in _request redirections, cachekey) File "/usr/lib/python2.7/dist-packages/httplib2/__init__.py", line 1196, in _request (response, content) = self._conn_request(conn, request_uri, method, body, headers) File "/usr/lib/python2.7/dist-packages/httplib2/__init__.py", line 1138, in _conn_request raise ServerNotFoundError("Unable to find the server at %s" % conn.host) httplib2.ServerNotFoundError: Unable to find the server at api.launchpad.net ERROR: share command failed Aborting Any ideas? How could I troubleshot this error?

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  • A tiny Utility to recycle an IIS Application Pool

    - by Rick Strahl
    In the last few weeks I've annoyingly been having problems with an area on my Web site. It's basically ancient articles that are using ASP classic pages and for reasons unknown ASP classic locks up on these pages frequently. It's not an individual page, but ALL ASP classic pages lock up. Ah yes, gotta old tech gone bad. It's not super critical since the content is really old, but still a hassle since it's linked content that still gets quite a bit of traffic. When it happens all ASP classic in that AppPool dies. I've been having a hard time tracking this one down - I suspect an errant COM object I have a Web Monitor running on the server that's checking for failures and while the monitor can detect the failures when the timeouts occur, I didn't have a good way to just restart that particular application pool. I started putzing around with PowerShell, but - as so often seems the case - I can never get the PowerShell syntax right - I just don't use it enough and have to dig out cheat sheets etc. In any case, after about 20 minutes of that I decided to just create a small .NET Console Application that does the trick instead, and in a few minutes I had this:using System; using System.Collections.Generic; using System.Text; using System.DirectoryServices; namespace RecycleApplicationPool { class Program { static void Main(string[] args) { string appPoolName = "DefaultAppPool"; string machineName = "LOCALHOST"; if (args.Length > 0) appPoolName = args[0]; if (args.Length > 1) machineName = args[1]; string error = null; DirectoryEntry root = null; try { Console.WriteLine("Restarting Application Pool " + appPoolName + " on " + machineName + "..."); root = new DirectoryEntry("IIS://" + machineName + "/W3SVC/AppPools/" +appPoolName); Console.WriteLine(root.InvokeGet("Name")); root.Invoke("Recycle"); Console.WriteLine("Application Pool recycling complete..."); } catch(Exception ex) { error = "Error: Unable to access AppPool: " + ex.Message; } if ( !string.IsNullOrEmpty(error) ) { Console.WriteLine(error); return; } } } } To run in you basically provide the name of the ApplicationPool and optionally a machine name if it's not on the local box. RecyleApplicationPool.exe "WestWindArticles" And off it goes. What's nice about AppPool recycling versus doing a full IISRESET is that it only affects the AppPool, and more importantly AppPool recycles happen in a staggered fashion - the existing instance isn't shut down immediately until requests finish while a new instance is fired up to handle new requests. So, now I can easily plug this Executable into my West Wind Web Monitor as an action to take when the site is not responding or timing out which is a big improvement than hanging for an unspecified amount of time. I'm posting this fairly trivial bit of code just in case somebody (maybe myself a few months down the road) is searching for ApplicationPool recyling code. It's clearly trivial, but I've written batch files for this a bunch of times before and actually having a small utility around without having to worry whether Powershell is installed and configured right is actually an improvement. Next time I think about using PowerShell remind me that it's just easier to just build a small .NET Console app, 'k? :-) Resources Download Executable and VS Project© Rick Strahl, West Wind Technologies, 2005-2012Posted in IIS7  .NET  Windows   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Netretail's online retail operation benefits from personal contact

    - by christopher.jones
    Hot on oracle.com is a snapshot of Netretail Holding B.V. profiling their use of PHP and Oracle technology such as Oracle RAC cluster database to become a leading online retailer across Central and Eastern Europe. We've also just refreshed our key PHP Scalability and High Availability whitepaper which talks about connection pooling (DRCP) and Fast Application Notification (FAN). We brought it up to date for 11gR2 and PHP 5.3. It now includes the new 11gR2 V$CPOOL_CONN_INFO view, the new columns for DBA_CPOOL_INFO, information about LOGOFF triggers, and information about the support for Client Result Caching with DRCP. Back to Netretail. Two of their secrets to success are keeping technically up to date, and networking. That is, networking in the business sense. I had the pleasure of meeting Michal Táborský (@whizz), the Chief System Architect, when he was in California for a Velocity conference. Michal took time to visit Oracle HQ and talk with our developers about his then current architecture and future needs. I also met his manager at last year's Oracle OpenWorld conference. Having built up a relationship with us, Netretail now has access to Oracle Development staff. While this will never bypass Oracle Support (which have tools, systems etc that are needed and useful for resolving issues), it makes communication easier for some classes of questions. It helps discussions that will let us improve Oracle products, and make Netretail stronger. I like this. And there's no reason why you can't talk with us too. You know where to email me.

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