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  • h2 (embedded mode ) database files problem

    - by aeter
    There is a h2-database file in my src directory (Java, Eclipse): h2test.db The problem: starting the h2.jar from the command line (and thus the h2 browser interface on port 8082), I have created 2 tables, 'test1' and 'test2' in h2test.db and I have put some data in them; when trying to access them from java code (JDBC), it throws me "table not found exception". A "show tables" from the java code shows a resultset with 0 rows. Also, when creating a new table ('newtest') from the java code (CREATE TABLE ... etc), I cannot see it when starting the h2.jar browser interface afterwards; just the other two tables ('test1' and 'test2') are shown (but then the newly created table 'newtest' is accessible from the java code). I'm inexperienced with embedded databases; I believe I'm doing something fundamentally wrong here. My assumption is, that I'm accessing the same file - once from the java app, and once from the h2 console-browser interface. I cannot seem to understand it, what am I doing wrong here?

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  • Is Annotation in Javascript? If not, how to switch between debug/productive modes in declarative way

    - by Michael Mao
    Hi all: This is but a curious question. I cannot find any useful links from Google so it might be better to ask the gurus here. The point is: is there a way to make "annotation" in javascript source code so that all code snippets for testing purpose can be 'filtered out' when project is deployed from test field into the real environment? I know in Java, C# or some other languages, you can assign an annotation just above the function name, such as : // it is good to remove the annoying warning messages @SuppressWarnings("unchecked") public class Tester extends TestingPackage { ... } Basically I've got a lot of testing code that prints out something into FireBug console. I don't wanna manually "comment out" them because the guy that is going to maintain the code might not be aware of all the testing functions, so he/she might just miss one function and the whole thing can be brought down to its knees. One other thing, we might use a minimizer to "shrink" the source code into "human unreadable" code and boost up performance (just like jQuery.min), so trying to match testing section out of the mess is not possible for plain human eyes in the future. Any suggestion is much appreciated.

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  • unable to find a MessageBodyReader

    - by Cristian Boariu
    Hi guys, I have this interface: @Path("inbox") public interface InboxQueryResourceTest { @POST @Path("{membershipExternalId}/query") @Consumes(MediaType.APPLICATION_XML) @Produces("multipart/mixed") public MultipartOutput query(@PathParam("membershipExternalId") final String membershipExternalId, @QueryParam("page") @DefaultValue("0") final int page, @QueryParam("pageSize") @DefaultValue("10") final int pageSize, @QueryParam("sortProperty") final List<String> sortPropertyList, @QueryParam("sortReversed") final List<Boolean> sortReversed, @QueryParam("sortType") final List<String> sortTypeString, final InstanceQuery instanceQuery) throws IOException; } I have implemented the method to return a MultipartOutput. I am posting an xml query from Fiddler and i receive the result without any problem. BUT i have done an integration test for the same interface, i send the same objects and i put the response like: final MultipartOutput multiPartOutput = getClient().query(getUserRestAuth(), 0, 25, null, null, null, instanceQuery); But here, so from integration tests, i receive a strange error: Unable to find a MessageBodyReader of content-type multipart/mixed;boundary="74c5b6b4-e820-452d-abea-4c56ffb514bb" and type class org.jboss.resteasy.plugins.providers.multipart.MultipartOutput Anyone has any ideea why only in integration tests i receive this error? PS: Some of you will say that i do not send application/xml as ContentType but multipart, which of course is false because the objects are annotated with the required @XmlRootElement etc, otherways neither the POST from Fiddler would work.

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  • Good patterns for loose coupling in Java?

    - by Eye of Hell
    Hello. I'm new to java, and while reading documentation so far i can't find any good ways for programming with loose coupling between objects. For majority of languages i know (C++, C#, python, javascript) i can manage objects as having 'signals' (notification about something happens/something needed) and 'slots' (method that can be connected to signal and process notification/do some work). In all mentioned languages i can write something like this: Object1 = new Object1Class(); Object2 = new Object2Class(); Connect( Object1.ItemAdded, Object2.OnItemAdded ); Now if object1 calls/emits ItemAdded, the OnItemAdded method of Object2 will be called. Such loose coupling technique is often referred as 'delegates', 'signal-slot' or 'inversion of control'. Compared to interface pattern, technique mentioned don't need to group signals into some interfaces. Any object's methods can be connected to any delegate as long as signatures match ( C++Qt even extends this by allowing only partial signature match ). So i don't need to write additional interface code for each methods / groups of methods, provide default implementation for interface methods not used etc. And i can't see anything like this in Java :(. Maybe i'm looking a wrong way?

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  • Strategies for serializing an object for auditing/logging purpose in .NET?

    - by Jiho Han
    Let's say I have an application that processes messages. Messages are just objects in this case that implements IMessage interface which is just a marker. In this app, if a message fails to process, then I want to log it, first of all for auditing and troubleshooting purposes. Secondly I might want to use it for re-processing. Ideally, I want the message to be serialized into a format that is human-readable. The first candidate is XML although there are others like JSON. If I were to serialize the messages as XML, I want to know whether the message object is XML-serializable. One way is to reflect on the type and to see if it has a parameter-less constructor and the other is to require IXmlSerializable interface. I'm not too happy with either of these approaches. There is a third option which is to try to serialize it and catch exceptions. This doesn't really help - I want to, in some way, stipulate that IMessage (or a derived type) should be xml-serializable. The reflection route has obvious disadvantages such as security, performance, etc. IXmlSerializable route locks down my messages to one format, when in the future, I might want to change the serialization format to be JSON. The other thing is even the simplest objects now must implement ReadXml and WriteXml methods. Is there a route that involves the least amount of work that lets me serialize an arbitrary object (as long as it implements the marker interface) into XML but not lock future messages into XML?

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  • WCF Callbacks often break

    - by cdecker
    I'm having quite some trouble with the WCF Callback mechanism. They sometimes work but most of the time they don't. I have a really simple Interface for the callbacks to implement: public interface IClientCallback { [OperationContract] void Log(string content); } I then implmenent that interface with a class on the client: [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession)] [ServiceContract] internal sealed class ClientCallback : IClientCallback { public void Log(String content){ Console.Write(content); } } And on the client I finally connect to the server: NetTcpBinding tcpbinding = new NetTcpBinding(SecurityMode.Transport); EndpointAddress endpoint = new EndpointAddress("net.tcp://127.0.0.1:1337"); ClientCallback callback= new ClientCallback(); DuplexChannelFactory<IServer> factory = new DuplexChannelFactory<IServer>(callback,tcpbinding, endpoint); factory.Open(); _connection = factory.CreateChannel(); ((ICommunicationObject)_connection).Faulted += new EventHandler(RecreateChannel); try { ((ICommunicationObject)_connection).Open(); } catch (CommunicationException ce) { Console.Write(ce.ToString()); } To invoke the callback I use the following: OperationContext.Current.GetCallbackChannel().Log("Hello World!"); But it just hangs there, and after a while the client complains about timeouts. Is there a simple solution as to why?

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  • How to wrap a thirdparty library COM class for notifications in a C++ project

    - by geocoin
    A thirdparty vendor has provided a COM interface as an external API to their product, and for sending instructions to it, it's fine with the mechanism of generating class wrappers with visual studio by importing from the dll, then creating instances of the created classes, calling their CreateDispatch(), using the access functions and releasing when done. For return notifications, I'd normally create an EventsListener class derived from IDispatch using the Invoke function to handle events returning from the interface. This vendor has created an Events lass which I have to wrap and expose, then explicitly tell the installation where to look. all the example are given is C# where it's really easy, but I'm struggling on how to do it in C++ in the C# example, the interop dll provided is simply added as a reference and derived into a class like so: using System; using System.Runtime.InteropServices; using System.Windows.Forms; using System.Text; using <THIER INTEROP LIB> namespace some.example.namespace { [ComVisible(true)] public class EventViewer : IEvents //where IEvents is their events class { public void OnEvent(EventID EventID, object pData) //overridden function { //event handled here } } } In broad terms I assume that I must create a COM interface, since they require a ProgID from me to instantiate, but how do I derive that's been wrapped by the import and then expose the created class to COM I'm just not sure where to even start, as all the tutorials I've seen so far talk in terms of creating brand new classes not wrapping a third party one

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  • ASP.NET Model Binder and base type

    - by user137348
    My model inherits from an interface: public interface IGrid { ISearchExpression Search { get; set; } . . } public interface ISearchExpression { IRelationPredicateBucket Get(); } The model: public class Project : IGrid { public ISearchExpression Search { get; set; } public Project() { this.Search = new ProjectSearch(); } } The ProjectSearch: public class ProjectSearch: ISearchExpression { public string Name { get; set; } public string Number { get; set; } public IRelationPredicateBucket Get() {...} } And the strong typed partialview in the main view: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<ProjectSearch>" %> <%= Html.TextBoxFor(x=>x.Name)%> <%= Html.TextBoxFor(x => x.Number)%> .... When I submit the form, the Search property don't get bound properly. Everything is empty.The action takes an argument of ProjectSearch type. Why the Search don't get bound as supposed ?

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  • Getting content from PHP: Trouble with POST and query.

    - by vgm64
    Apologies for my longest question on SO ever. I'm trying to interface with a php frontend for a mysql database in ROOT (a CERN framework in C++ for high energy physics analysis). To start off with, I tried to get this php interface to play nice with wget and curl first because I'm more familiar with them. The following command works: wget --post-data "hostname=localhost:3306&un=joeuser&pw=psswd&myquery=show_spazio_databases;" http://some.host.edu/log/log_query_matlab.php The results are: database1 database2 That's good. If I leave out the --post-data then I get the result: Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'admin'@'localhost' (using password: NO) in /log/log_query_matlab.php on line 6 i'm dead! Access denied for user 'admin'@'localhost' (using password: NO) Warning: mysql_query() [function.mysql-query]: Access denied for user 'admin'@'localhost' (using password: NO) in /log/log_query_matlab.php on line 29 Warning: mysql_query() [function.mysql-query]: A link to the server could not be established in /log/log_query_matlab.php on line 29 I have access to the php script (read only), but the error itself isn't too important. What matters it that using ROOT, I use a function called as socket.SendRaw(message, message.Length()) (socket is a TSocket) and this gives me the same "error" as wget without the post data switch if my "message" is "POST http://some.host.edu/log/log_query_matlab.php?hostname=localhost:3306&un=joeuser&pw=psswd&myquery=show_spazio_databases" This may be in vain, but does someone knows a way I should format the "message" that includes something that is equivalent to the --post-data switch. Or, is there a standard way to format POST requests in a single line (I've seen multi-line stuff. Is that right?) Sorry I'm clueless! PS. The mysql query is show databases but the space has been replaced with _spazio_, Italian for space. The author of the db and php interface requires it (and various replacements for symbols), but has anyone seen this before? Trying to troubleshoot that was terrible!

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  • Expression Tree with Property Inheritance causes an argument exception

    - by Adam Driscoll
    Following this post: link text I'm trying to create an expression tree that references the property of a property. My code looks like this: public interface IFoo { void X {get;set;} } public interface IBar : IFoo { void Y {get;set;} } public interface IFooBarContainer { IBar Bar {get;set;} } public class Filterer { //Where T = "IFooBarContainer" public IQueryable<T> Filter<T>(IEnumerable<T> collection) { var argument = Expression.Parameter(typeof (T), "item"); //... //where propertyName = "IBar.X"; PropertyOfProperty(argument, propertyName); } private static MemberExpression PropertyOfProperty(Expression expr, string propertyName) { return propertyName.Split('.').Aggregate<string, MemberExpression>(null, (current, property) => Expression.Property(current ?? expr, property)); } } I receive the exception: System.ArgumentException: Instance property 'X' is not defined for type 'IBar' ReSharper turned the code in the link above into the condensed statement in my example. Both forms of the method returned the same error. If I reference IBar.Y the method does not fail.

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  • Need suggestions on how to extract data from .docx/.doc file then into mssql

    - by DarkPP
    I'm suppose to develop an automated application for my project, it will load past-year examination/exercises paper (word file), detect the sections accordingly, extract the questions and images in that section, and then store the questions and images into the database. (Preview of the question paper is at the bottom of this post) So I need some suggestions on how to extract data from a word file, then inserting them into a database. Currently I have a few methods to do so, however I have no idea how I could implement them when the file contains textboxes with background image. The question has to link with the image. Method One (Make use of ms office interop) Load the word file - Extract image, save into a folder - Extract text, save as .txt - Extract text from .txt then store in db Question: How i detect the section and question. How I link the image to the question. Extract text from word file (Working): private object missing = Type.Missing; private object sFilename = @"C:\temp\questionpaper.docx"; private object sFilename2 = @"C:\temp\temp.txt"; private object readOnly = true; object fileFormat = Word.WdSaveFormat.wdFormatText; private void button1_Click(object sender, EventArgs e) { Word.Application wWordApp = new Word.Application(); wWordApp.DisplayAlerts = Word.WdAlertLevel.wdAlertsNone; Word.Document dFile = wWordApp.Documents.Open(ref sFilename, ref missing, ref readOnly, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing); dFile.SaveAs(ref sFilename2, ref fileFormat, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing,ref missing, ref missing,ref missing,ref missing,ref missing,ref missing, ref missing,ref missing); dFile.Close(ref missing, ref missing, ref missing); } Extract image from word file (Doesn't work on image inside textbox): private Word.Application wWordApp; private int m_i; private object missing = Type.Missing; private object filename = @"C:\temp\questionpaper.docx"; private object readOnly = true; private void CopyFromClipbordInlineShape(String imageIndex) { Word.InlineShape inlineShape = wWordApp.ActiveDocument.InlineShapes[m_i]; inlineShape.Select(); wWordApp.Selection.Copy(); Computer computer = new Computer(); if (computer.Clipboard.GetDataObject() != null) { System.Windows.Forms.IDataObject data = computer.Clipboard.GetDataObject(); if (data.GetDataPresent(System.Windows.Forms.DataFormats.Bitmap)) { Image image = (Image)data.GetData(System.Windows.Forms.DataFormats.Bitmap, true); image.Save("C:\\temp\\DoCremoveImage" + imageIndex + ".png", System.Drawing.Imaging.ImageFormat.Png); } } } private void button1_Click(object sender, EventArgs e) { wWordApp = new Word.Application(); wWordApp.Documents.Open(ref filename, ref missing, ref readOnly, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing, ref missing); try { for (int i = 1; i <= wWordApp.ActiveDocument.InlineShapes.Count; i++) { m_i = i; CopyFromClipbordInlineShape(Convert.ToString(i)); } } finally { object save = false; wWordApp.Quit(ref save, ref missing, ref missing); wWordApp = null; } } Method Two Unzip the word file (.docx) - Copy the media(image) folder, store somewhere - Parse the XML file - Store the text in db Any suggestion/help would be greatly appreciated :D Preview of the word file: (backup link: http://i.stack.imgur.com/YF1Ap.png)

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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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  • GridView: How can I get rid of extra space from my GirdView object?

    - by Lajos Arpad
    Hello, I'm writing an application for Android phones for Human vs. Human chess play over the internet. I was looking at some tutorials, to learn how to develop Android applications and found a very nice example of making galleries (it was a GridView usage example for making a gallery about dogs) and the idea came to draw the chess table using a GridView, because the example project also handled the point & click event and I intended to use the same event in the same way, but for a different purpose. The game works well (currently it's a hotseat version), however, I'm really frustrated by the fact that whenever I rotate the screen of the phone, my GridView gets hysterical and puts some empty space in my chess table between the columns. I realized that the cause of this is that the GridView's width is the same as its parent's and the GridView tries to fill its parent in with, but there should (and probably is) be a simple solution to get rid of this problem. However, after a full day of researching, I haven't found any clue to help me to make a perfect drawing about my chess table without a negative side effect in functionality. The chess table looks fine if the phone is in Portrait mode, but in Landscape mode it's far from nice. This is how I can decide whether we are in Portrait or Landscape mode: ((((MainActivity)mContext).getWindow().getWindowManager().getDefaultDisplay().getWidth()) < ((MainActivity)mContext).getWindow().getWindowManager().getDefaultDisplay().getHeight()) In the main.xml file the GridView is defined in the following way: <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <GridView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/gridview" android:layout_width="wrap_content" android:layout_height="wrap_content" android:numColumns="8" android:verticalSpacing="0dp" android:horizontalSpacing="0dp" android:stretchMode="columnWidth" android:gravity="center" > </GridView> ... </LinearLayout> I appreciate any help with the problem and thank you for reading this.

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  • How to Bind Data and manipulate it in a GridView with MVP

    - by DotNetDan
    I am new to the whole MVP thing and slowly getting my head around it all. The a problem I am having is how to stay consistent with the MVP methodology when populating GridViews (and ddls, but we will tackle that later). Is it okay to have it connected straight to an ObjectDataSourceID? To me this seems wrong because it bypasses all the separation of concerns MVP was made to do. So, with that said, how do I do it? How do I handle sorting (do I send over handler events to the presentation layer, if so how does that look in code)? Right now I have a GridView that has no sorting. Code below. ListCustomers.aspx.cs: public partial class ListCustomers : System.Web.UI.Page, IlistCustomer { protected void Page_Load(object sender, EventArgs e) { //On every page load, create a new presenter object with //constructor recieving the // page's IlistCustomer view ListUserPresenter ListUser_P = new ListUserPresenter(this); //Call the presenter's PopulateList to bind data to gridview ListUser_P.PopulateList(); } GridView IlistCustomer.UserGridView { get { return gvUsers; } set { gvUsers = value; } } } Interface ( IlistCustomer.cs): is this bad sending in an entire Gridview control? public interface IlistCustomer { GridView UserGridView { set; get; } } The Presenter (ListUserPresenter.cs): public class ListUserPresenter { private IlistCustomer view_listCustomer; private GridView gvListCustomers; private DataTable objDT; public ListUserPresenter( IlistCustomer view) { //Handle an error if an Ilistcustomer was not sent in) if (view == null) throw new ArgumentNullException("ListCustomer View cannot be blank"); //Set local IlistCustomer interface view this.view_listCustomer = view; } public void PopulateList() { //Fill local Gridview with local IlistCustomer gvListCustomers = view_listCustomer.UserGridView; // Instantiate a new CustomerBusiness object to contact database CustomerBusiness CustomerBiz = new CustomerBusiness(); //Call CustomerBusiness's GetListCustomers to fill DataTable object objDT = CustomerBiz.GetListCustomers(); //Bind DataTable to gridview; gvListCustomers.DataSource = objDT; gvListCustomers.DataBind(); } }

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  • Flash - Uploading to and Downloading from localhost

    - by Md Derf
    I have an online flash application that acts as a front end for a server application built in delphi. The server can be installed/used on a remote computer or a personal version can be downloaded and the Flash app pointed at localhost to use it. However, Flash has issues with using the POST and GET functions on the localhost, which makes uploading data files and downloading results files difficult. To get past the difficulty with downloading results files I'm planning to just have the server app serve the results file as an attachment and have the Flash app open the address of the file up in another browser window using external interface. First off, is this likely to cause similar security issues? I.E. Flash will see "localhost" in the external interface call and stop it from working the same as when I try to use POST/GET functions with localhost? Secondly, for upload this seems just a bit little trickier, I'm planning on doing something similar, having flash use external interface to open a php script for a file upload. Is this feasible and, again, will Flash still have security issues? Lastly, if anyone knows how to get flash to execute POST and GET functions with localhost addresses, I'd love to have that information to avoid all this jumping through hoops.

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  • .Net Architecture challenge: The Change-prone Frankestein Model

    - by SDReyes
    Good Morning SO! We've been scratching our heads with with this interesting scenario at the office, and we're anxious to hear your ideas and approaches: We have a database, whose schema is prone to changes -lets call it Prony-. (is used to store configuration parameters for embedded devices. so if the embedded devices guy need a new table, property or relationship for the model, he should be able to adapt the schema in a easy way -happens so often- ). Prony needs a web interface to create/edit its data. We have another database containing data that also need to be loaded to the devices, after making some transformations - lets call this one Oddy- (this data it's generated by an already existent administrative web application). Finally we have Tracy, a server that communicates our DBs and our embedded devices. She should to auto-adapt herself, to our dbs schema changes and serialize the data to the devices. Nice puzzle, don't think so? : ) Our current candidates: Rady: The fast Lets create some views in Prony that make the data transformation from Oddy. then use DynamicData (or some RAD tool) to create/update a simple web interface for Prony (so he can even consult the transformated data from coming from Prony : ). About Tracy, she will need to be recompiled to update her DB schema (Entity framework should work) and use Reflection to explore recursively the schema and serialize data. Cons: We would have to recompile Tracy and the Prony's web interface. What do you think of the candidate(s)? What would you do?

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  • Is using YIELD a read-only way to return a collection?

    - by Eric
    I'm writing an interface which has a collection property which I want to be read only. I don't want users of the interface to be able to modify the collection. The typical suggestion I've found for creating a read only collection property is to set the type of the property to IEnumerable like this: private List<string> _mylist; public IEnumerable<string> MyList { get { return this._mylist; } } Yet this does not prevent the user from casting the IEnumerable back to a List and modifying it. If I use a Yield keyword instead of returning _mylist directly would this prevent users of my interface from being able to modify the collection. I think so because then I'm only returning the objects one by one, and not the actual collection. private List<string> _mylist; public IEnumerable<string> MyList { get { foreach(string str in this._mylist) { yield return str; } } }

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  • Java method keyword "final" and its use

    - by Lukas Eder
    When I create complex type hierarchies (several levels, several types per level), I like to use the final keyword on methods implementing some interface declaration. An example: interface Garble { int zork(); } interface Gnarf extends Garble { /** * This is the same as calling {@link #zblah(0)} */ int zblah(); int zblah(int defaultZblah); } And then abstract class AbstractGarble implements Garble { @Override public final int zork() { ... } } abstract class AbstractGnarf extends AbstractGarble implements Gnarf { // Here I absolutely want to fix the default behaviour of zblah // No Gnarf shouldn't be allowed to set 1 as the default, for instance @Override public final int zblah() { return zblah(0); } // This method is not implemented here, but in a subclass @Override public abstract int zblah(int defaultZblah); } I do this for several reasons: It helps me develop the type hierarchy. When I add a class to the hierarchy, it is very clear, what methods I have to implement, and what methods I may not override (in case I forgot the details about the hierarchy) I think overriding concrete stuff is bad according to design principles and patterns, such as the template method pattern. I don't want other developers or my users do it. So the final keyword works perfectly for me. My question is: Why is it used so rarely in the wild? Can you show me some examples / reasons where final (in a similar case to mine) would be very bad?

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  • Why does the Java Collections Framework offer two different ways to sort?

    - by dvanaria
    If I have a list of elements I would like to sort, Java offers two ways to go about this. For example, lets say I have a list of Movie objects and I’d like to sort them by title. One way I could do this is by calling the one-argument version of the static java.util.Collections.sort( ) method with my movie list as the single argument. So I would call Collections.sort(myMovieList). In order for this to work, the Movie class would have to be declared to implement the java.lang.Comparable interface, and the required method compareTo( ) would have to be implemented inside this class. Another way to sort is by calling the two-argument version of the static java.util.Collections.sort( ) method with the movie list and a java.util.Comparator object as it’s arguments. I would call Collections.sort(myMovieList, titleComparator). In this case, the Movie class wouldn’t implement the Comparable interface. Instead, inside the main class that builds and maintains the movie list itself, I would create an inner class that implements the java.util.Comparator interface, and implement the one required method compare( ). Then I'd create an instance of this class and call the two-argument version of sort( ). The benefit of this second method is you can create an unlimited number of these inner class Comparators, so you can sort a list of objects in different ways. In the example above, you could have another Comparator to sort by the year a movie was made, for example. My question is, why bother to learn both ways to sort in Java, when the two-argument version of Collections.sort( ) does everything the first one-argument version does, but with the added benefit of being able to sort the list’s elements based on several different criteria? It would be one less thing to have to keep in your mind while coding. You’d have one basic mechanism of sorting lists in Java to know.

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  • Core Data @sum aggregate

    - by nasim
    I am getting an exception when I try to get @sum on a column in iPhone Core-Data application. My two models are following - Task model: @interface Task : NSManagedObject { } @property (nonatomic, retain) NSString * taskName; @property (nonatomic, retain) NSSet* completion; @end @interface Task (CoreDataGeneratedAccessors) - (void)addCompletionObject:(NSManagedObject *)value; - (void)removeCompletionObject:(NSManagedObject *)value; - (void)addCompletion:(NSSet *)value; - (void)removeCompletion:(NSSet *)value; @end Completion model: @interface Completion : NSManagedObject { } @property (nonatomic, retain) NSNumber * percentage; @property (nonatomic, retain) NSDate * time; @property (nonatomic, retain) Task * task; @end And here is the fetch: NSFetchRequest *request = [[NSFetchRequest alloc] init]; request.entity = [NSEntityDescription entityForName:@"Task" inManagedObjectContext:context]; NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"taskName" ascending:YES]; request.sortDescriptors = [NSArray arrayWithObject:sortDescriptor]; NSError *error; NSArray *results = [context executeFetchRequest:request error:&error]; NSArray *parents = [results valueForKeyPath:@"taskName"]; NSArray *children = [results valueForKeyPath:@"[email protected]"]; NSLog(@"%@ %@", parents, children); [request release]; [sortDescriptor release]; The exception is thrown at the fourth line from bottom. The thrown exception is: *** -[NSCFSet decimalValue]: unrecognized selector sent to instance 0x3b25a30 *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSCFSet decimalValue]: unrecognized selector sent to instance 0x3b25a30' I would very much appreciate any kind of help. Thanks.

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  • Biztalk vs API for databroker layer

    - by jdt199
    My company is about to undergo a large project in which our client wants a large customer portal with a cms, crm implementing. This will require interaction with data from multiple sources across our customers business, these sources include XML office backend systems, sql datbases, webservices etc. Our proposed solution would be to write an API in c# to provide a common interface with all these systems. This would be scalable for future and concurrent projects within the company. Our client expressed an interest in using Biztalk rather than a custom API for this integration, as they feel it is an enterprise solution that any of their suppliers could pick up and use, and it will be better supported. We feel that the configuration work using Biztalk would be rather heavy for all their custom business rules which are required and an interface for the new application to get data to and from Biztalk would still need to be written. Are we right to prefer a custom API solution above Biztalk? Would Biztalk be suitable as a databroker layer to provide an interface for the new Customer portal we are writing. We have not experience with using Biztalk before so any input would be appreciated.

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  • C# POCO T4 template, generate interfaces?

    - by Jonna
    Does anyone know of any tweaked version of POCO T4 template that generates interfaces along with classes? i.e. if I have Movie and Actor entities in .edmx file, I need to get the following classes and interfaces. interface IMovie { string MovieName { get; set; } ICollection<IActor> Actors { get; set; } //instead of ICollection<Actor> } class Movie : IMovie { string MovieName { get; set; } ICollection<IActor> Actors { get; set; } //instead of ICollection<Actor> } interface IActor { string ActorName { get; set; } } class Actor { string ActorName { get; set; } } Also, just in case I write my own entities, does POCO proxies(I need them for lazy loading) work with the interface declarations as shown above?

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  • Easiest RPC client method in PHP

    - by T.K.
    I've been asked to help a friend's company to bring up a web application. I have very limited time and I reluctantly accepted the request, at one condition. As most of the logic goes on in the back-end, I suggested that I would finish the complete back-end only, allowing a front-end developer to simply interface with my backend. I plan to do the back-end in Java EE or Python (with Pylons). It does not really matter at this point. I plan to have my back-end completely ready and unit-tested, so that my input will hardly be needed after my work is done. I know they have a PHP programmer, but as far as I could tell he is a real rookie. I want him to basically interface with my backend's services in the easiest possible way, with no way of him "stuffing" it up. It's basically a CRUD-only application. I could implement the backend as accessible through a webservice such as XML-RPC or SOAP. Even a RESTful API could be possible. However, my main objective is to make something that complete "noob" PHP programmer can easily interface with without getting confused. Preferably I do not even want to talk to him because I generally have an extremely busy schedule, and doing "support calls" is not something I am willing to do. Which approach should I choose? I would welcome any suggestions and inputs!

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  • What is jasper report's algorithm for using a data source?

    - by spderosso
    Hi, I have created my custom data source by implementing the interface JRDataSource. This interface looks like this: public interface JRDataSource { /** * Tries to position the cursor on the next element in the data source. * @return true if there is a next record, false otherwise * @throws JRException if any error occurs while trying to move to the next element */ public boolean next() throws JRException; /** * Gets the field value for the current position. * @return an object containing the field value. The object type must be the field object type. */ public Object getFieldValue(JRField jrField) throws JRException; } My question is the following: In what way does jasper report call this functions for obtaining the fields in the .jrxml. E.g: if( next() )){ call getFieldValue for every field present in the page header while( next() ){ call getFieldValue for every field present in detail part } call getFieldValue for every field present the footer } The previous is just an example, experimentally in fact I found out that it is actually not like that. So my question arised. Thanks!

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  • .net runtime type casting when using reflection

    - by Mike
    I have need to cast a generic list of a concrete type to a generic list of an interface that the concrete types implement. This interface list is a property on an object and I am assigning the value using reflection. I only know the value at runtime. Below is a simple code example of what I am trying to accomplish: public void EmployeeTest() { IList<Employee> initialStaff = new List<Employee> { new Employee("John Smith"), new Employee("Jane Doe") }; Company testCompany = new Company("Acme Inc"); //testCompany.Staff = initialStaff; PropertyInfo staffProperty = testCompany.GetType().GetProperty("Staff"); staffProperty.SetValue(testCompany, (staffProperty.PropertyType)initialStaff, null); } Classes are defined like so: public class Company { private string _name; public string Name { get { return _name; } set { _name = value; } } private IList<IEmployee> _staff; public IList<IEmployee> Staff { get { return _staff; } set { _staff = value; } } public Company(string name) { _name = name; } } public class Employee : IEmployee { private string _name; public string Name { get { return _name; } set { _name = value; } } public Employee(string name) { _name = name; } } public interface IEmployee { string Name { get; set; } } Any thoughts? I am using .NET 4.0. Would the new covariant or contravariant features help? Thanks in advance.

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