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  • using Mutex causing application to hang on Win XP X64

    - by Mohsan
    hi. I used the following code to verify the single instance of application. On Win XP X86 it is working fine, but on X64 after 3 to 4 minutes System generates StackOverflowException and causes the application to hang. after removing this check application is working fine.. Please tell me what should be the reason. code is static void Main() { bool instanceCountOne = false; using (Mutex mtex = new Mutex(true, "AppName", out instanceCountOne)) { if (instanceCountOne) { #if (DEBUG) RunInDebugMode(); #else RunInReleaseMode(); #endif mtex.ReleaseMutex(); } else { MessageBox.Show( "An application instance is already running", "App Name", MessageBoxButtons.OK, MessageBoxIcon.Information); } } } it crashes when single instance of application is running.

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  • Is it bad practice to have state in a static class?

    - by Matthew
    I would like to do something like this: public class Foo { // Probably really a Guid, but I'm using a string here for simplicity's sake. string Id { get; set; } int Data { get; set; } public Foo (int data) { ... } ... } public static class FooManager { Dictionary<string, Foo> foos = new Dictionary<string, Foo> (); public static Foo Get (string id) { return foos [id]; } public static Foo Add (int data) { Foo foo = new Foo (data); foos.Add (foo.Id, foo); return foo; } public static bool Remove (string id) { return foos.Remove (id); } ... // Other members, perhaps events for when Foos are added or removed, etc. } This would allow me to manage the global collection of Foos from anywhere. However, I've been told that static classes should always be stateless--you shouldn't use them to store global data. Global data in general seems to be frowned upon. If I shouldn't use a static class, what is the right way to approach this problem? Note: I did find a similar question, but the answer given doesn't really apply in my case.

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  • How to use application config file in C#?

    - by badpanda
    I am trying to use a config file in my C# console application. I created the file within the project by going New -- Application Configuration File, and naming it myProjectName.config. My config file looks like this: <?xml version="1.0" encoding="utf-8" ?> <configuration> <appSettings> <add key="SSDirectory" value="D:\Documents and Settings\****\MyDocuments\****" /> </appSettings> </configuration> The code to access it looks like this: private FileValidateUtil() { sSDirFilePath = ConfigurationSettings.AppSettings["SSDirectory"]; if (sSDirFilePath == null) Console.WriteLine("config file not reading in."); } Can anyone lend a hint as to why this is not working? (I am getting the error message.) Thanks!! badPanda

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  • List/Grid Toggle for Photo Gallery with Shadowbox

    - by InfamouslyBubbly
    so I'm new to this site, and new to jquery, and javascript as a whole really, but I have very good comprehension of HTML and CSS. For a class in school, I'm making a photo gallery webpage using the Shadowbox plugin. I have that part all down, but one of the requirements is to add some sort of user option that the user can change that will get saved in a cookie. (I haven't gotten to the cookie part yet) For my option, I decided to add a toggle that will switch the view of the page from a grid view (default) with images, to a list view of just the captions of the images. I figured out how to do that, but decided it could probably done in a much simpler fashion with the use of loops. Here is the HTML I have: <body> <div id="preferences"> <h1>My Photo Gallery</h1> <ul id="options"> <li><a href="#" id="list"><img src="media/listview.png" alt="List view"/></a></li> <li><a href="#" id="grid"><img src="media/gridview.png" alt="List view"/></a></li> </ul> </div> <div id="gallery"> <a rel="shadowbox[Gallery]" class="l1 img" href="media/img1.jpg" title="Black and White Leopard Pattern"><img src="media/thumb1.jpg" alt="Black and White Leopard Pattern"/></a> <a rel="shadowbox[Gallery]" class="l2 img" href="media/img2.jpg" title="Snow Leopard Pattern"><img src="media/thumb2.jpg" alt="Snow Leopard Pattern"/></a> <a rel="shadowbox[Gallery]" class="l3 img" href="media/img3.jpg" title="Colorful Triangle Pattern"><img src="media/thumb3.jpg" alt="Colurful Triangle Pattern"/></a> <a rel="shadowbox[Gallery]" class="l4 img" href="media/img4.jpg" title="Tie Dye Zebra Stripe Pattern"><img src="media/thumb4.jpg" alt="Tie Dye Zebra Stripe Pattern"/></a> <a rel="shadowbox[Gallery]" class="l5 img" href="media/img5.jpg" title="Blue Knitted Pattern"><img src="media/thumb5.jpg" alt="Blue Knitted Pattern"/></a> <a rel="shadowbox[Gallery]" class="l6 img" href="media/img6.jpg" title="Black and White Damask Pattern"><img src="media/thumb6.jpg" alt="Black and White Damask Pattern"/></a> <a rel="shadowbox[Gallery]" class="l7 img" href="media/img7.jpg" title="Wooden Panel Pattern"><img src="media/thumb7.jpg" alt="Wooden Panel Pattern"/></a> <a rel="shadowbox[Gallery]" class="l8 img" href="media/img8.jpg" title="Brick Pattern"><img src="media/thumb8.jpg" alt="Brick Pattern"/></a> <a rel="shadowbox[Gallery]" class="l9 img" href="media/img9.jpg" title="Watercolor Pattern"><img src="media/thumb9.jpg" alt="Watercolor Pattern"/></a> <a rel="shadowbox[Gallery]" class="l10 img" href="media/img10.jpg" title="Orange Stripe Pattern"><img src="media/thumb10.jpg" alt="Orange Stripe Pattern"/></a> <a rel="shadowbox[Gallery]" class="l11 img" href="media/img11.jpg" title="Blue Scales Pattern"><img src="media/thumb11.jpg" alt="Blue Scales Pattern"/></a> <a rel="shadowbox[Gallery]" class="l12 img" href="media/img12.jpg" title="Woven Pattern"><img src="media/thumb12.jpg" alt="Woven Pattern"/></a> </div> </body> So here is the sample that works (for the list portion anyways), but seems excessive in terms of code since I'd have to repeat for each image: $(document).ready(function(){ $( "#list" ).click(function() { $( "a.l1" ).removeClass( "img" ); $( "a.l1" ).addClass( "lst" ); $( "a.l1" ).text( $( "a.l1" ).attr( "title" ); //repeat for l1 through l12 (that`s the letter L not a 1) }); $( "#grid" ).click(function() { $( "a.l1" ).removeClass( "lst" ); $( "a.l1" ).addClass( "grid" ); //actually have no idea at all how to get this back to the original img tag other than maybe .innerHTML??? //repeat for l1 through l12 (again, that`s the letter L not a 1) }); }): And here is kinda how I'd like it (Y'know, except in a way that works) $(document).ready(function(){ var i = 1; var selcur = $( "'a.l" + i + "'" ); var title = selcur.attr( "title" ); var image = '<img src="media/thumb' + i + '.jpg" alt="' + title + '"/>'; $( "#list" ).click(function() { while (1<=12) { selcur.addClass("lst"); selcur.removeClass("img"); selcur.text( title ); i++; } i = 1; }); $( "#grid" ).click(function() { while (1<=12) { selcur.removeClass("lst"); selcur.addClass("img"); selcur.text( image ); i++; } i = 1; }); }); Please tell me how I am going about this wrong, keep in mind again I'm new to this, I appreciate any and all responses! Is there a better way to do this? I really want to keep it simple.

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  • dao as a member of a servlet - normal?

    - by EugeneP
    I guess, DAO is thread safe, does not use any class members. So can it be used without any problem as a private field of a Servlet ? We need only one copy, and multiple threads can access it simultaneously, so why bother creating a local variable, right?

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  • How to find all initializations of instance variables in a Java package?

    - by Hank Gay
    I'm in the midst of converting a legacy app to Spring. As part of the transition, we're converting our service classes from an "instantiate new ones whenever you need one" style to a Springleton style, so I need a way to make sure they don't have any state. I'm comfortable on the *nix command-line, and I have access to IntelliJ (this strikes me as a good fit for Structural Search and Replace, if I could figure out how to use it), and I could track down an Eclipse install, if that would help. I just want to make absolutely sure I've found all the possible problems. UPDATE: Sorry for the confusion. I don't have a problem finding places where the old constructor was being called. What I'm looking for is a "bullet-proof" why to search all 100+ service classes for any sort of internal state. The most obvious one I could think of (and the only one I've really found so far) is cases where we use memoization in the classes, so they have instance variables that get initialized internally instead of via Spring. This means that when the same Springleton gets used for different requests, data can leak between them. Thanks.

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  • how to make objects globally accessible?

    - by fayer
    i have this code: class IC_Core { /** * Database * @var IC_Database */ public static $db = NULL; /** * Core * @var IC_Core */ protected static $_instance = NULL; private function __construct() { } public static function getInstance() { if ( ! is_object(self::$_instance)) { self::$_instance = new self(); self::initialize(self::$_instance); } return self::$_instance; } private static function initialize(IC_Core $IC_Core) { self::$db = new IC_Database($IC_Core); } } but when i wanna access IC_Database with: $IC = IC_Core::getInstance(); $IC->db->add() // it says that its not an object. i think the problem lies in self::$db = new IC_Database($IC_Core); but i dont know how to make it work. could someone give me a hand=) thanks!

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  • CodeIgniter static class question

    - by Josh K
    If I would like to have several static methods in my models so I can say User::get_registered_users() and have it do something like public static function get_registered_users() { $sql = "SELECT * FROM `users` WHERE `is_registered` = 0"; $this->db->query($sql); // etc... } Is it possible to access the $this->db object or create a new one for a static method?

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  • [iphone] method created in a seperate class returns "out of scope"

    - by Dror Sabbag
    Hey, I have created a Class (subclass of NSObject) which will hold all my SQLs/dbConnections etc.. in a seperate viewcontroller, i have instantiated the SQL's class and performed some actions, all went trough OK. but. one of my methods in the SQL's class is a method defined as follows: -(NSString *)queryTable:(NSUInteger *)fieldnum //query from db, and assign the field value into "fieldName" dbEntity = fieldName; [fieldName release]; } sqlite3_finalize(statement); } return dbEntity; } dbEntity is defined as NSString, and i have set it as a nonatoimc-retain property @property (nonatomic,retain) NSString *dbEntity; when ever i call this method out from my viewController and debug step by step, i see that the method is running, it is quering from the db as expected, but when it passes the value into dbEntity the values in dbEntity are suddenly "out of scope" that is... if i browse this specific action: dbEntity = fieldName; i can see values inside fieldName, but see "out of scope" in dbEntity. Why is that?!? what is wrong with dbEntity definitions? Any help will be appriciated.

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  • Creating instance in java class

    - by aladine
    Please advise me the difference between two ways of declaration of java constructor public class A{ private static A instance = new A(); public static A getInstance() { return instance; } public static void main(String[] args) { A a= A.getInstance(); } } AND public class B{ public B(){}; public static void main(String[] args) { B b= new B(); } } Thanks

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  • Is there a way to have customised text instead of subject in Thunderbird's inbox list?

    - by peterp
    I am getting a lot of informational emails like "You've got a new message from ..." or "Notification of Donation Received", which often do not contain any information in the subject so that I have to open the email to see who sent the message or who donated which amount. I'd love to be able to make TB parse incoming emails and then display something interesting instead of the original subject, e.g. by defining a regular expression pattern. I know how to write regular expressions, but I do not know whether there is a way or an addon to modify the displayed text in the messages view. EDIT for clarification: I would like donation notifications from Paypal not to be displayed as original Notification of Donation Received but rather Paypal: John Doe has donated 50$

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  • logparser not matching on a LIKE pattern

    - by user79339
    Hi I seem to have the strangest problem. I am using logparser to search an event log for some text that I know is there (i copied and pasted the string from the event into the sql search string). But the sql LIKE statement is returning a empty results. But other LIKE statments seem to be working file. I have even tried using two '%' symbols in case the shell was trying to replace the search pattern with an environment variable '%%NavigationOccuredEventHandler%%', escaping the % with a \ and with a ' but all these just give me "No valid LIKE mask" error My logparser command - C:\Program Files\Log Parser 2.2LogParser.exe "select * from D:\Temp\07i132ppa1_app.evt where Message like '%NavigationOccuredEventHandler%' " -i:EVT -o:Datagrid The Entry in event log (found using "Select * from D:\Temp\07i132ppa1_app.evt" and doing a copy paste of relevant row) - 'D:\Temp\07i132ppa1_app.evt 5976788 2010-03-09 11:53:23 2010-03-09 11:53:23 2 1 Error event 0 None ICP Timestamp: 9/03/2010 1:53:23 AM Message: Error # 068464030040-07I132PPA1 System.Web.HttpUnhandledException: Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.NullReferenceException: Object reference not set to an instance of an object. at ClientRegistration.Controller.ContactDetailsController.NavigationOccuredEventHandler(Object sender, NavigateEventArgs e) at Microsoft.ApplicationBlocks.UIProcess.UIPManager.NavigateEventHandler.Invoke(Object sender, NavigateEventArgs e) at Microsoft.ApplicationBlocks.UIProcess.UIPManager.InvokeEventHandlers(State state) in . . . Truncated for brevity ' output Statistics: Elements processed: 240993 Elements output: 0 Execution time: 59.47 seconds But if i searched for the pattern '%object reference not set%' it works fine, returns results. I copied and pasted the string into a dummy sql table and ran the sql query there and it works fine. Just doesn't seem to work in logparser. Very baffling. Any help would be much appreciated

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  • Using Unit of Work design pattern / NHibernate Sessions in an MVVM WPF

    - by Echiban
    I think I am stuck in the paralysis of analysis. Please help! I currently have a project that Uses NHibernate on SQLite Implements Repository and Unit of Work pattern: http://blogs.hibernatingrhinos.com/nhibernate/archive/2008/04/10/nhibernate-and-the-unit-of-work-pattern.aspx MVVM strategy in a WPF app Unit of Work implementation in my case supports one NHibernate session at a time. I thought at the time that this makes sense; it hides inner workings of NHibernate session from ViewModel. Now, according to Oren Eini (Ayende): http://msdn.microsoft.com/en-us/magazine/ee819139.aspx He convinces the audience that NHibernate sessions should be created / disposed when the view associated with the presenter / viewmodel is disposed. He presents issues why you don't want one session per windows app, nor do you want a session to be created / disposed per transaction. This unfortunately poses a problem because my UI can easily have 10+ view/viewmodels present in an app. He is presenting using a MVP strategy, but does his advice translate to MVVM? Does this mean that I should scrap the unit of work and have viewmodel create NHibernate sessions directly? Should a WPF app only have one working session at a time? If that is true, when should I create / dispose a NHibernate session? And I still haven't considered how NHibernate Stateless sessions fit into all this! My brain is going to explode. Please help!

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  • ASP MVC Ajax Controller pattern?

    - by Kevin Won
    My MVC app tends to have a lot of ajax calls (via JQuery.get()). It's sort of bugging me that my controller is littered with many tiny methods that get called via ajax. It seems to me to be sort of breaking the MVC pattern a bit--the controller is now being more of a data access component then a URI router. I refactored so that I have my 'true' controller for a page just performing standard routing responses (returing ActionResponse objects). So a call to /home/ will obviously kick up the HomeController class that will respond in the canonical controller fashion by returning a plain-jane View. I then moved my ajax stuff into a new controller class whose name I'm prefacing with 'Ajax'. So, for example, my page might have three different sections of functionality (say shopping cart or user account). I have an ajax controller for each of these (AjaxCartController, AjaxAccountController). There is really nothing different about moving the ajax call stuff into its own class--it's just to keep things cleaner. on client side obviously the JQuery would then use this new controller thusly: //jquery pseudocode call to specific controller that just handles ajax calls $.get('AjaxAccount/Details'.... (1) is there a better pattern in MVC for responding to ajax calls? (2) It seems to me that the MVC model is a bit leaky when it comes to ajax--it's not really 'controlling' stuff. It just happens to be the best and least painful way of handling ajax calls (or am I ignorant)? In other words, the 'Controller' abstraction doesn't seem to play nice with Ajax (at least from a patterns perspective). Is there something I'm missing?

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  • Regex pattern failing

    - by Scott Chamberlain
    I am trying a substring to find from the beginning of the string to the point that has the escape sequence "\r\n\r\n" my regex is Regex completeCall = new Regex(@"^.+?\r\n\r\n", RegexOptions.Compiled); it works great as long as you only have strings like 123\r\n\r\n however once you have the pattern 123\r\n 456\r\n\r\n the pattern no longer matches. Any advice on what I am doing wrong? Regex completeCall = new Regex(@"^.+?\r\n\r\n", RegexOptions.Compiled); Regex junkLine = new Regex(@"^\D", RegexOptions.Compiled); private void ClientThread() { StringBuilder stringBuffer = new StringBuilder(); (...) while(true) { (...) Match match = completeCall.Match(stringBuffer.ToString()); while (Match.Success) //once stringBuffer has somthing like "123\r\n 456\r\n\r\n" Match.Success always returns false. { if (junkLine.IsMatch(match.Value)) { (...) } else { (...) } stringBuffer.Remove(0, match.Length); // remove the processed string match = completeCall.Match(stringBuffer.ToString()); // check to see if more than 1 call happened while the thread was sleeping. } Thread.Sleep(1000); }

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  • Best pattern for storing (product) attributes in SQL Server

    - by EdH
    We are starting a new project where we need to store product and many product attributes in a database. The technology stack is MS SQL 2008 and Entity Framework 4.0 / LINQ for data access. The products (and Products Table) are pretty straightforward (a SKU, manufacturer, price, etc..). However there are also many attributes to store with each product (think industrial widgets). These may range from color to certification(s) to pipe size. Every product may have different attributes, and some may have multiples of the same attribute (Ex: Certifications). The current proposal is that we will basically have a name/value pair table with a FK back to the product ID in each row. An example of the attributes Table may look like this: ProdID AttributeName AttributeValue 123 Color Blue 123 FittingSize 1.25 123 Certification AS1111 123 Certification EE2212 123 Certification FM.3 456 Pipe 11 678 Color Red 999 Certification AE1111 ... Note: Attribute name would likely come from a lookup table or enum. So the main question here is: Is this the best pattern for doing something like this? How will the performance be? Queries will be based on a JOIN of the product and attributes table, and generally need many WHEREs to filter on specific attributes - the most common search will be to find a product based on a set of known/desired attributes. If anyone has any suggestions or a better pattern for this type of data, please let me know. Thanks! -Ed

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  • Flexible Decorator Pattern?

    - by Omar Kooheji
    I was looking for a pattern to model something I'm thinking of doing in a personal project and I was wondering if a modified version of the decorator patter would work. Basicly I'm thinking of creating a game where the characters attributes are modified by what items they have equiped. The way that the decorator stacks it's modifications is perfect for this, however I've never seen a decorator that allows you to drop intermediate decorators, which is what would happen when items are unequiped. Does anyone have experience using the decorator pattern in this way? Or am I barking up the wrong tree? Clarification To explain "Intermediate decorators" if for example my base class is coffe which is decorated with milk which is decorated with sugar (using the example in Head first design patterns) milk would be an intermediate decorator as it decorates the base coffee, and is decorated by the sugar. Yet More Clarification :) The idea is that items change stats, I'd agree that I am shoehorning the decorator into this. I'll look into the state bag. essentially I want a single point of call for the statistics and for them to go up/down when items are equiped/unequiped. I could just apply the modifiers to the characters stats on equiping and roll them back when unequiping. Or whenever a stat is asked for iterate through all the items and calculate the stat. I'm just looking for feedback here, I'm aware that I might be using a chainsaw where scissors would be more appropriate...

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  • Best Pattern for AllowUnsafeUpdates

    - by webwires
    So far, in my research I have seen that it is unwise to set AllowUnsafeUpdates on GET request operation to avoid cross site scripting. But, if it is required to allow this, what is the proper way to handle the situation to mitigate any exposure? Here is my best first guess on a reliable pattern if you absolutely need to allow web or site updates on a GET request. Best Practice? protected override void OnLoad(System.EventArgs e) { if(Request.HttpMethod == "POST") { SPUtility.ValidateFormDigest(); // will automatically set AllowSafeUpdates to true } // If not a POST then AllowUnsafeUpdates should be used only // at the point of update and reset immediately after finished // NOTE: Is this true? How is cross-site scripting used on GET // and what mitigates the vulnerability? } // Point of item update SPSecurity.RunWithElevatedPrivledges(delegate() { using(SPSite site = new SPSite(SPContext.Current.Site.Url)) { using (SPWeb web = site.RootWeb) { bool allowUpdates = web.AllowUnsafeUpdates; //store original value web.AllowUnsafeUpdates = true; //... Do something and call Update() ... web.AllowUnsafeUpdates = allowUpdates; //restore original value } } }); Feedback on the best pattern is appreciated.

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  • Design pattern to use instead of multiple inheritance

    - by mizipzor
    Coming from a C++ background, Im used to multiple inheritance. I like the feeling of a shotgun squarely aimed at my foot. Nowadays, I work more in C# and Java, where you can only inherit one baseclass but implement any number of interfaces (did I get the terminology right?). For example, lets consider two classes that implement a common interface but different (yet required) baseclasses: public class TypeA : CustomButtonUserControl, IMagician { public void DoMagic() { // ... } } public class TypeB : CustomTextUserControl, IMagician { public void DoMagic() { // ... } } Both classes are UserControls so I cant substitute the base class. Both needs to implement the DoMagic function. My problem now is that both implementations of the function are identical. And I hate copy-and-paste code. The (possible) solutions: I naturally want TypeA and TypeB to share a common baseclass, where I can write that identical function definition just once. However, due to having the limit of just one baseclass, I cant find a place along the hierarchy where it fits. One could also try to implement a sort of composite pattern. Putting the DoMagic function in a separate helper class, but the function here needs (and modifies) quite a lot of internal variables/fields. Sending them all as (reference) parameters would just look bad. My gut tells me that the adapter pattern could have a place here, some class to convert between the two when necessery. But it also feels hacky. I tagged this with language-agnostic since it applies to all languages that use this one-baseclass-many-interfaces approach. Also, please point out if I seem to have misunderstood any of the patterns I named. In C++ I would just make a class with the private fields, that function implementation and put it in the inheritance list. Whats the proper approach in C#/Java and the like?

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  • Help regarding composite pattern with hibernate

    - by molleman
    Hello, So i am stuck, i am creating a gwt web application, i will be using a tree(gwt Tree and TreeItems) structure to show a list of folders(class Folder) and files(class FileLocation), the folder and filelocation class will all implement a Hierarchy interface basing the classes on the composite pattern. but i am using hibernate to store my data , and i am using annotations for the mapping of the data to the database. my trouble is i do not know how to annotate my interface. have any of you guys used the composite pattern while persisting the data with hibernate public interface Hierarchy(){ // a few abstract methods that will be implemented by the sub classes } @Entity @Table() public class Folder extends Hierarchy implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "folder_id", updatable = false, nullable = false) private int id; @OneToMany(cascade = CascadeType.ALL,fetch = FetchType.EAGER) @JoinTable(name = "FOLDER_FILELOCATION", joinColumns = { @JoinColumn(name = "folder_id") }, inverseJoinColumns = { @JoinColumn(name = "file_information_id") }) private List<Hierarchy> children = new ArrayList<Hierarchy>() ; @Column(name = "folder_name") private String folderName; @Column(name = "tree_item") private TreeItem item; @Column (name = "parent") private Hierarchy parent; @Entity @Table(name = "FILE_INFORMATION_TABLE") public class FileInformation extends Hierarchy implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "file_information_id", updatable = false, nullable = false) private int fiId; @Column (name = "location") private String location; @Column(name = "tree_item") private TreeItem item; @Column (name = "parent") private Hierarchy parent;

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