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  • Hibernate collection multiple types

    - by CaptainAwesomePants
    I have a class Player that contains a list of Accessory objects. There are two kinds of Accessories. SocketedAccessories have a list of SocketJewels, and MagicAccessories have a list of MagicEnchantments. At the database level, there is a players table that represents the player, and an accessories table that contains a list of accessories. Accessories have a type field that indicates whether they are socketed or magical, and the columns that are only used by one type are just left blank by entries of the other type. There are socket_jewels and magic_enchantments tables, representing the socket jewels or the magic enchantments on each accessory. I am trying to figure out the correct way to map this with Hibernate. One way would be for the player to have two lists of accessories, one for SocketedAccessories and one for MagicAccessories. That seems undesirable, though. What I want is a way to specify that player should have a field List<Accessory> accessories that contains both types of thing. Is there a way to tell Hibernate, in either hbm.xml or annotations, to do this?

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  • LinQ XML mapping to a generic type

    - by Manuel Navarro
    I´m trying to use an external XML file to map the output from a stored procedure into an instance of a class. The problem is that my class is of a generic type: public class MyValue<T> { public T Value { get; set; } } Searching through a lot of blogs an articles I've managed to get this: <?xml version="1.0" encoding="utf-8" ?> <Database Name="" xmlns="http://schemas.microsoft.com/linqtosql/mapping/2007"> <Table Name="MyValue" Member="MyNamespace.MyValue`1" > <Type Name="MyNamespace.MyValue`1"> <Column Name="Category" Member="Value" DbType="VarChar(100)" /> </Type> </Table> <Function Method="GetResourceCategories" Name="myprefix_GetResourceCategories" > <ElementType Name="MyNamespace.MyValue`1"/> </Function> </Database> The MyNamespace.MyValue`1 trick works fine, and the class is recognized. I expect four rows from the stored procedure, and I'm getting four MyValue<string> instances, but the big problem is that the property Value for the all four instances is null. The property is not getting mapped and I don't really get why. Maybe worth noting that the property Value is generic, and that when the mapping is done using attributes it works perfect. Anyone have a clue? BTW the method GetResourceCategories: public ISingleResult<MyValue<string>> GetResourceCategories() { IExecuteResult result = this.ExecuteMethodCall( this, (MethodInfo)MethodInfo.GetCurrentMethod()); return (ISingleResult<MyValue<string>>)result.ReturnValue; }

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  • A dynamic array of a class, inside another separate class?

    - by pinnacler
    I'm working on a robot localization simulator and I created a class called "landmark". The end result is going to be a robot that is always centered and always faces the top of the screen. As it turns, the birds eye view map will rotate around the robot. To accomplish this, I'm assuming I can rotate one class and have all elements inside rotate as well. So, the landmark class has properties x,y, label, and radius. This is suppose to simulate a tree location in a forest. To test everything, I need "forest data," and I wrote a script to generate 100 trees in a 100m x 100m area. The script automatically generates values within an acceptable range for x,y, radius. The generated data is stored in an object called tempForest and is 100x3. Ideally, I want to create a class called "landmarks" (plural) that has 100 landmark instances inside. How would I instantiate 100 instances of landmark in one instance of landmarks using that randomly generated data? Ideally, I'd just type treeBeacons = landmarks(); and it would randomly populate 100 (user definable, set in config file) instances with x, y, radius data. I'm not sure how to deal with a dynamic array of class "Landmark", inside another single class "landmarks." Any ideas?

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  • Mapping one column in a table to multiple tables

    - by user1721814
    I am working on a new product development creating a WMS system. I have done it in past using ASP, VB, and other techniques where we did not hard code the mapping. But now i am working on it using MVC and entity frame work and i am stumped. How can i map one column in transaction table to a column in multiple tables. I have transaction table trans Transid orderref TType productid qty ....(More Columns) now the orderref will hold either Receiptkey, orderkey , movementkey, adjustmentkey and the TType column will tell me which type of transaction i am dealing with and based on that i would know which table to link further. Now how can i achieve this in Entity Frame work. This is the most important step. I have done this many times in my other languages but now using EF i am stuck. Please help. I have checked a lot online but i have not found it. I am new to MVC and entity frame work architecture. Any guidance would be highly appreciated. Ranjit

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  • How to make Entity Key Mapping in Entity Framework like sql's foreign key?

    - by programmerist
    I try to give entity map on my entity app. But how can I do it? I try to make it like below: var test = ( from k in Kartlar where k.Rehber..... above codes k.(can not see Rehber or not working ) if you are correct , i can write k.Rehber.ID and others. i can not write: from k in Kartlar where k.Rehber.ID = 123 //assuming that navigation property name is Rehbar and its primary key of Rehbar table is ID && k.Kampanya.ID = 345 //assuming that navigation property name is Kampanya and its primary //key of Kampanya table is ID && k.Birim.ID = 567 //assuming that navigation property name is Birim and its primary key of Birim table is ID select k images you can see: also: You should look : http://i42.tinypic.com/2nqyyc6.png I have a table it includes 3 foreign key field like that: My Table: Kartlar ID (Pkey) RehberID (Fkey) KampanyaID (Fkey) BrimID (Fkey) Name Detail How can i write entity query with LINQ ? select * from Kartlar where RehberID=123 and KampanyaID=345 and BrimID=567 BUT please be careful I can not see RehberID, KampanyaID, BrimID in entity they are foreign key. I should use entity key but how?

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  • Intermittent Issue Writing to Google Appengine Datastore

    - by user242153
    Hi, I have a functioning app and recently have had intermittent problems writing to the datastore. I did not make any relevant code changes, however in the last few days my attempts to write to the datastore sometimes work and sometimes don't. I am trying to save an object that is in a many to one relationship with an existing persisted parent. So, the logic works like this: 1) Parent pulled from the datastore 2) Child created / instantiated using constructor 3) Parent.addSingleChild(child); // the "addSingleChild" method just adds the object argument to the collection of children 4) child.setParent(Parent); // sets the Parent object to the parent field I am using transactions as explained in the documentation ending with "finally {if (tx.isActive()) {tx.rollback(); } }" When the servlet is called, the parent is called from the datastore and the child object is created and added to the many to one mapping to the pre-existing parent. The child should automatically be persisted, since the parent is already persistent, and the child is added to the collection of children that map to the parent. And it worked this way in the past. However, to be sure, i did add a pm.makePersistent(child). Doesn't seem to help, still have the intermittent problem. Any suggestions would be appreciated, and if you need to see the actual code I can post. Thanks

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  • Scala newbie vproducer/consumer attempt running out of memory

    - by Nick
    I am trying to create a producer/consumer type Scala app. The LoopControl just sends a message to the MessageReceiver continually. The MessageReceiver then delegates work to the MessageCreatorActor (whose work is to check a map for an object, and if not found create one and start it up). Each MessageActor created by this MessageCreatorActor is associated with an Id. Eventually this is where I want to do business logic. But I run out of memory after 15 minutes. Its finding the cached actors,but quickly runs out of memory. Any help is appreciated. Or any one has any good code on producers consumers doing real stuff (not just adding numbers), please post. import scala.actors.Actor import java.util.HashMap import scala.actors.Actor._ case object LoopControl case object MessageReceiver case object MessageActor case object MessageActorCreator class MessageReceiver(msg: String) extends Actor { var messageActorMap = new HashMap[String, MessageActor] val messageCreatorActor = new MessageActorCreator(null, null) def act() { messageCreatorActor.start loop { react { case MessageActor(messageId) => if (msg.length() > 0) { var messageActor = messageActorMap.get(messageId); if(messageActor == null) { messageCreatorActor ! MessageActorCreator(messageId, messageActorMap) }else { messageActor ! MessageActor } } } } } } case class MessageActorCreator(msg:String, messageActorMap: HashMap[String, MessageActor]) extends Actor { def act() { loop { react { case MessageActorCreator(messageId, messageActorMap) => if(messageId != null ) { var messageActor = new MessageActor(messageId); messageActorMap.put(messageId, messageActor) println(messageActorMap) messageActor.start messageActor ! MessageActor } } } } } class LoopControl(messageReceiver:MessageReceiver) extends Actor { var count : Int = 0; def act() { while (true) { messageReceiver ! MessageActor ("00-122-0X95-FEC0" + count) //Thread.sleep(100) count = count +1; if(count > 5) { count = 0; } } } } case class MessageActor(msg: String) extends Actor { def act() { loop { react { case MessageActor => println() println("MessageActor: Got something-> " + msg) } } } } object messages extends Application { val messageReceiver = new MessageReceiver("bootstrap") val loopControl = new LoopControl(messageReceiver) messageReceiver.start loopControl.start }

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  • Is it possible to embed a flash player in a table and retain the table properties

    - by user1494241
    I'd like to embed a music (flash) player in a table with clickable images but the embed code seems to throw the table properties off - it extends the width of the table. Is it possible to embed the player on the same row as the image whilst still retaining the table width? Here's what I've been using: <table width="620" border="0" cellspacing="0" cellpadding="0"> <tr> <td> <div align="left"><object height="18" width="100%"> <param name="movie" value="https://player.soundcloud.com/player.swf?url=http%3A%2F%2Fapi.soundcloud.com%2Fplaylists%2F1253725&amp;auto_play=false&amp;player_type=tiny&amp;font=Georgia&amp;color=9a6600&show_playcount=false&default_width=375&default_height=40&show_user=false"></param> <param name="allowscriptaccess" value="always"></param> <param name="wmode" value="transparent"></param><embed wmode="transparent" allowscriptaccess="always" height="18" src="https://player.soundcloud.com/player.swf?url=http%3A%2F%2Fapi.soundcloud.com%2Fplaylists%2F1253725&amp;auto_play=false&amp;player_type=tiny&amp;font=Georgia&amp;color=9a6600&show_playcount=false&default_width=375&default_height=40&show_user=false" type="application/x-shockwave-flash" width="100%"></embed> </object> </td> <td> <div align="right"><img src="http://dl.dropbox.com/u/31856944/Virb/splash_freedownload-2.png" border="0" width="245" height="42" usemap="#Map" /></div> </td> <tr> <td> <div align="right"><img src="http://dl.dropbox.com/u/31856944/Virb/splash_share-2.png" border="0" width="620" height="31" usemap="#Map2" /></div> </td> </tr> </table>

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  • C++ syntax issue

    - by Doug
    It's late and I can't figure out what is wrong with my syntax. I have asked other people and they can't find the syntax error either so I came here on a friend's advice. template <typename TT> bool PuzzleSolver<TT>::solve ( const Clock &pz ) { possibConfigs_.push( pz.getInitial() ); vector< Configuration<TT> > next_; //error is on next line map< Configuration<TT> ,Configuration<TT> >::iterator found; while ( !possibConfigs_.empty() && possibConfigs_.front() != pz.getGoal() ) { Configuration<TT> cfg = possibConfigs_.front(); possibConfigs_.pop(); next_ = pz.getNext( cfg ); for ( int i = 0; i < next_.size(); i++ ) { found = seenConfigs_.find( next_[i] ); if ( found != seenConfigs_.end() ) { possibConfigs_.push( next_[i] ); seenConfigs_.insert( make_pair( next_[i], cfg ) ); } } } } What is wrong? Thanks for any help.

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  • Initializing Detail View from nib with parameters passed from Root View

    - by culov
    I'm have a map view with a number of annotations on it... once the callout is clicked, i need to pass several parameters to the DetailViewController, so ive been trying to do this through the constructor. I've debugged a bit and discovered that the arguments are being passed properly and are being received as expected within the constructor, but for some reason whenever I try to change the values of the IBOutlets I've positioned in the nib, it never has an effect. Here's what im passing (btw, im getting a "No initWithNibName : bundle : header' method found" warning at this line): DetailViewController *dvc = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil header:headerText]; [self.navigationController pushViewController:dvc animated:YES]; Now heres my constructor: - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil header:(UILabel*)headerLabel { if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) { self.headerTextView = headerLabel; NSLog(@"header:%@", headerLabel.text); } return self; } Once again, the problem is that headerLabel.text is printed properly in the console, but the line self.headerTextView = headerLabel; doesnt seem to be doing what I want it to do. Thanks!

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  • Dependency Injection into your Singleton

    - by Langali
    I have a singleton that has a spring injected Dao (simplified below): public class MyService<T> implements Service<T> { private final Map<String, T> objects; private static MyService instance; MyDao myDao; public void set MyDao(MyDao myDao) { this. myDao = myDao; } private MyService() { this.objects = Collections.synchronizedMap(new HashMap<String, T>()); // start a background thread that runs for ever } public static synchronized MyService getInstance() { if(instance == null) { instance = new MyService(); } return instance; } public void doSomething() { myDao.persist(objects); } } My spring config will probably look like this: <bean id="service" class="MyService" factory-method="getInstance"/> But this will instantiate the MyService during startup. Is there a programmatic way to do a dependency injection of MyDao into MyService, but not have spring manage the MyService? Basically I want to be able to do this from my code: MyService.getInstance().doSomething(); while having spring inject the MyDao for me.

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  • help me reason about F# threads

    - by Kevin Cantu
    In goofing around with some F# (via MonoDevelop), I have written a routine which lists files in a directory with one thread: let rec loop (path:string) = Array.append ( path |> Directory.GetFiles ) ( path |> Directory.GetDirectories |> Array.map loop |> Array.concat ) And then an asynchronous version of it: let rec loopPar (path:string) = Array.append ( path |> Directory.GetFiles ) ( let paths = path |> Directory.GetDirectories if paths <> [||] then [| for p in paths -> async { return (loopPar p) } |] |> Async.Parallel |> Async.RunSynchronously |> Array.concat else [||] ) On small directories, the asynchronous version works fine. On bigger directories (e.g. many thousands of directories and files), the asynchronous version seems to hang. What am I missing? I know that creating thousands of threads is never going to be the most efficient solution -- I only have 8 CPUs -- but I am baffled that for larger directories the asynchronous function just doesn't respond (even after a half hour). It doesn't visibly fail, though, which baffles me. Is there a thread pool which is exhausted? How do these threads actually work?

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  • Updating an application OTA

    - by Bostjan
    I'm developing an application that will be available from a website (market probably as well). The problem I'm having at the moment is how to handle the updates to the app. I know how to check the version against the current one and I know if I need to update it. Question is...how? Is there a way I can download an APK from the website and start the install process? The user will have to confirm of course, but I just want to be able to start it for him. At the moment I'm doing this: private void doUpgrade() { // TODO Auto-generated method stub Builder builder = new AlertDialog.Builder(this); builder.setTitle(getString(R.string.upgrade)); builder.setIcon(R.drawable.help); builder.setMessage(getString(R.string.needUpgrade)); builder.setPositiveButton(getString(R.string.ok), new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub Map<String, String> data = new HashMap<String, String>(); try { HttpResponse re = Registration.doPost("http://www.android-town.com/appRelease/AndroidTown.apk",data); int statusCode = re.getStatusLine().getStatusCode(); closeApp(); } catch (ClientProtocolException e) { e.printStackTrace(); Toast.makeText(getApplicationContext(), getString(R.string.noURLAccess), Toast.LENGTH_SHORT).show(); closeApp(); } catch (IOException e) { e.printStackTrace(); Toast.makeText(getApplicationContext(), getString(R.string.noURLAccess), Toast.LENGTH_SHORT).show(); closeApp(); } } }); builder.setNegativeButton(getString(R.string.cancel), new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub dialog.cancel(); closeApp(); } }); builder.show(); } But it doesn't really do anything...should I open a webView with the URL? A new runnable thread? Any other way? Please help :) Cheers

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  • Matlab matrix translation and rotation multiple times

    - by pinnacler
    I have a map of individual trees from a forest stored as x,y points in a matrix. I call it fixedPositions. It's cartesian and (0,0) is the origin. I would like 0/360 degrees to be the top of the screen and 90 degrees to be to the right. Given a velocity and a heading, i.e. .5 m/s and 60 degrees (2 o'clock equivalent on a watch), how do I rotate that x,y points, so that the new origin is centered at (.5cos(60),.5sin(60)) and 60 degrees is now at the top of the screen? Then if I were to give you another heading and speed, i.e. 0 degrees and 2m/s, it should calculate it from the last point, not the original fixedPositions origin. I've wasted my day trying to figure this out. I wish I took matrix algebra but I'm at a loss. I tried doing cos(30) and even those wouldn't compute correctly, which after an hour I realize were in radians.

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  • Creating a RESTful API - HELP!

    - by Martin Cox
    Hi Chaps Over the last few weeks I've been learning about iOS development, which has naturally led me into the world of APIs. Now, searching around on the Internet, I've come to the conclusion that using the REST architecture is very much recommended - due to it's supposed simplicity and ease of implementation. However, I'm really struggling with the implementation side of REST. I understand the concept; using HTTP methods as verbs to describe the action of a request and responding with suitable response codes, and so on. It's just, I don't understand how to code it. I don't get how I map a URI to an object. I understand that a GET request for domain.com/api/user/address?user_id=999 would return the address of user 999 - but I don't understand where or how that mapping from /user/address to some method that queries a database has taken place. Is this all coded in one php script? Would I just have a method that grabs the URI like so: $array = explode("/", ltrim(rtrim($_SERVER['REQUEST_URI'], "/"), "/")) And then cycle through that array, first I would have a request for a "user", so the PHP script would direct my request to the user object and then invoke the address method. Is that what actually happens? I've probably not explained my thought process very well there. The main thing I'm not getting is how that URI /user/address?id=999 somehow is broken down and executed - does it actually resolve to code? class user(id) { address() { //get user address } } I doubt I'm making sense now, so I'll call it a day trying to explain further. I hope someone out there can understand what I'm trying to say! Thanks Chaps, look forward to your responses. Martin p.s - I'm not a developer yet, I'm learning :)

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  • Nhibernate beginner - asking for directions

    - by George
    Hello guys. I'm starting off with NHibernate now and I still don't have a testable environment. I would like to know from you, experienced fellows if there is a problem to map IList to an Set in .hbm file. Like this: //c# IList<TrechoItem> trechos_item; <!-- xml .hbm --> <set name="TrechosItem" table="trecho_item" lazy="true" inverse="true" fetch="select"> <key column="id_item"/> <one-to-many class="TrechoItem"/> </set> Or, in this: IList<Autor> Autores; <set name="Autores" lazy="true" table="item_possui_autor"> <key column="id_item"/> <many-to-many class="Autor" column="id_autor"/> </set> Is this possible? Or am I doing the wrong thing? I tried using and but these did not gave me all the options in . Thanks in advanced

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  • prototype findElements querySelectorAll error

    - by JD
    i'm call the "down" function but am getting an invalid argument using 1.6.1_rc2 here's the html snippet: <TR id=000000214A class="activeRow searchResultsDisplayOver" conceptID="0000001KIU"> <TD> <DIV class=gridRowWrapper> <SPAN class=SynDesc>Asymmetric breasts</SPAN> <DIV class=buttonWrapper> <SPAN class=btnAddFav title="Add to Favorites">&nbsp;</SPAN> </DIV> </DIV> </TD> </TR> here's the code: var description = row.down('span.SynDesc').innerHTML; row is a dom reference to the element. prototype is appending a # then the id of the element: findElements: function(root) { root = root || document; var e = this.expression, results; switch (this.mode) { case 'selectorsAPI': if (root !== document) { var oldId = root.id, id = $(root).identify(); id = id.replace(/[\.:]/g, "\\$0"); e = "#" + id + " " + e; } results = $A(root.querySelectorAll(e)).map(Element.extend); <-- e = "#000000214A span.SynDesc" root.id = oldId; return results; case 'xpath': return document._getElementsByXPath(this.xpath, root); default: return this.matcher(root); } i get an "invalid argument" error? if i put a breakpoint before the offending line and change e to be equal to "span.SynDesc" it works fine. help. :)

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  • C++ How to read a string of text and create object of their class

    - by user1777711
    After reading a text file... The following information is available Point2D, [3, 2] Line3D, [7, 12, 3], [-9, 13, 68] Point3D, [1, 3, 8] Line2D, [5, 7], [3, 8] Point2D, [3, 2] Line3D, [7, -12, 3], [9, 13, 68] Point3D, [6, 9, 5] Point2D, [3, 2] Line3D, [70, -120, -3], [-29, 1, 268] Line3D, [25, -69, -33], [-2, -41, 58] Point3D, [6, 9, -50] The first data separate by the delimiter comma is the class name. for each of the 4 class Point2D,Line3D,Point3D,Line2D How do i like store them into relevant object base on their class means.. when it read first line Point2D, [3, 2] It will store it as Point2D object with the Data [3, 2] But the issue is what dataset should i pick, Vector, Set , Map or List I was thinking to actually create a data set then but i can't use new Point2D(); since Point2D is parent of Point3D Line2D is parent of Line3D and theres no parent class of Point2D and Line2D. how can i like create a object of them in a data set like e.g Vector so Vector[0] is of Point2D class with data [3,2] , then Vector[1] is of Line3D class with data [7, 12, 3], [-9, 13, 68] Thanks for helping.!

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  • What database strategy to choose for a large web application

    - by Snoopy
    I have to rewrite a large database application, running on 32 servers. The hardware is up to date, each machine has two quad core Xeon and 32 GByte RAM. The database is multi-tenant, each customer has his own file, around 5 to 10 GByte each. I run around 50 databases on this hardware. The app is open to the web, so I have no control on the load. There are no really complex queries, so SQL is not required if there is a better solution. The databases get updated via FTP every day at midnight. The database is read-only. C# is my favourite language and I want to use ASP.NET MVC. I thought about the following options: Use two big SQL servers running SQL Server 2012 to serve the 32 servers with data. On the 32 servers running IIS hosting providing REST services. Denormalize the database and use Redis on each webserver. Use booksleeve as a Redis client. Use a combination of SQL Server and Redis Use SQL Server 2012 together with Hadoop Use Hadoop without SQL Server What is the best way for a read-only database, to get the best performance without loosing maintainability? Does Map-Reduce make sense at all in such a scenario? The reason for the rewrite is, the old app written in C++ with ISAM technology is too slow, the interfaces are old fashioned and not nice to use from an website, especially when using ajax. The app uses a relational datamodel with many tables, but it is possible to write one accerlerator table where all queries can be performed on, and all other information from the other tables are possible by a simple key lookup.

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  • Database insertion not happening

    - by Pramod Setlur
    int i=0; ContentValues values = null; for ( SortedMap.Entry<Integer, String> entry : mapDefect.entrySet() ) { if( i++ < count ) continue; if( i < arrlst.size() ) { values = new ContentValues(); Log.d("MAP", "Id :"+entry.getKey()+"Des :"+entry.getValue()+"Co :"+ arrlst.get(i)); values.put( MARKER_COORD, arrlst.get( i ) ); values.put( MARKER_ID, entry.getKey() ); values.put( DEFECT_DESCRIPTION, entry.getValue() ); values.put( IMAGE_ID_F, imageID + 1 ); Log.d( "Err", "in insertNewDefectsDescription" ); long rowId = db.insert( TABLE_DEFECTS, null, values ); long rowId1 = rowId; i++; } } So, I want to access the arraylist only after the count variable, which is why the:- if(i++<count) continue; But, when I insert a break point at the 'insert' line, it is not working. The line is not executing at all, and hence the data is not being inserted into the database. What has gone wrong?? The 'values' are null.

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  • Scala: Correcting type inference of representation type over if statement

    - by drhagen
    This is a follow-up to two questions on representation types, which are type parameters of a trait designed to represent the type underlying a bounded type member (or something like that). I've had success creating instances of classes, e.g ConcreteGarage, that have instances cars of bounded type members CarType. trait Garage { type CarType <: Car[CarType] def cars: Seq[CarType] def copy(cars: Seq[CarType]): Garage def refuel(car: CarType, fuel: CarType#FuelType): Garage = copy( cars.map { case `car` => car.refuel(fuel) case other => other }) } class ConcreteGarage[C <: Car[C]](val cars: Seq[C]) extends Garage { type CarType = C def copy(cars: Seq[C]) = new ConcreteGarage(cars) } trait Car[C <: Car[C]] { type FuelType <: Fuel def fuel: FuelType def copy(fuel: C#FuelType): C def refuel(fuel: C#FuelType): C = copy(fuel) } class Ferrari(val fuel: Benzin) extends Car[Ferrari] { type FuelType = Benzin def copy(fuel: Benzin) = new Ferrari(fuel) } class Mustang(val fuel: Benzin) extends Car[Mustang] { type FuelType = Benzin def copy(fuel: Benzin) = new Mustang(fuel) } trait Fuel case class Benzin() extends Fuel I can easily create instances of Cars like Ferraris and Mustangs and put them into a ConcreteGarage, as long as it's simple: val newFerrari = new Ferrari(Benzin()) val newMustang = new Mustang(Benzin()) val ferrariGarage = new ConcreteGarage(Seq(newFerrari)) val mustangGarage = new ConcreteGarage(Seq(newMustang)) However, if I merely return one or the other, based on a flag, and try to put the result into a garage, it fails: val likesFord = true val new_car = if (likesFord) newFerrari else newMustang val switchedGarage = new ConcreteGarage(Seq(new_car)) // Fails here The switch alone works fine, it is the call to ConcreteGarage constructor that fails with the rather mystical error: error: inferred type arguments [this.Car[_ >: this.Ferrari with this.Mustang <: this.Car[_ >: this.Ferrari with this.Mustang <: ScalaObject]{def fuel: this.Benzin; type FuelType<: this.Benzin}]{def fuel: this.Benzin; type FuelType<: this.Benzin}] do not conform to class ConcreteGarage's type parameter bounds [C <: this.Car[C]] val switchedGarage = new ConcreteGarage(Seq(new_car)) // Fails here ^ I have tried putting those magic [C <: Car[C]] representation type parameters everywhere, but without success in finding the magic spot.

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  • Database for managing large volumes of (system) metrics

    - by symcbean
    Hi, I'm looking at building a system for managing and reporting stats on web page performance. I'll be collecting a lot more stats than are available in the standard log formats (approx 20 metrics) but compared to most types of database applications, the base data structure will be very simple. My problem is that I'll be accumulating a lot of data - in the region of 100,000 records (i.e. sets of metrics) per hour. Of course, resources are very limited! So that its possible to sensibly interact with the data, I'd need to consolidate each metric into one minute bins, broken down by URL, then for anything more than 1 day old, consolidated into 10 minute bins, then at 1 week, hourly bins. At the front end, I want to provide a view (prefereably as plots) of the last hour of data, with the facility for users to drill up/down through defined hierarchies of URLs (which do not always map directly to the hierarchy expressed in the path of the URL) and to view different time frames. Rather than coding all this myself and using a relational database, I was wondering if there were tools available which would facilitate both the management of the data and the reporting. I had a look at Mondrian however I can't see from the documentation I've looked at whether it's possible to drop the more granular information while maintaining the consolidated views of the data. RRDTool looks promising in terms of managing the data consolidation, but seems to be rather limited in terms of querying the dataset as a multi-dimensional/relational database. What else whould I be looking at?

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  • Strategies for dealing with Circular references caused by JPA relationships?

    - by ams
    I am trying to partition my application into modules by features packaged into separate jars such as feature-a.jar, feature-b.jar, ... etc. Individual feature jars such as feature-a.jar should contain all the code for a feature a including jpa entities, business logic, rest apis, unit tests, integration test ... etc. The problem I am running into is that bi-directional relationships between JPA entities cause circular references between the jar files. For example Customer entity should be in customer.jar and the Order should be in order.jar but Customer references order and order references customer making it hard to split them into separate jars / eclipse projects. Options I see for dealing with the circular dependencies in JPA entities: Option 1: Put all the entities into one jar / one project Option 2: Don't map certain bi-directianl relationships to avoid circular dependencies across projects. Questions: What rules / principles have you used to decide when to do bi-directional mapping vs. not? Have you been able to break jpa entities into their own projects / jar by features if so how did you avoid the circular dependencies issues?

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  • Java HashMap containsKey always false

    - by Dennis
    I have the funny situation, that I store a Coordinate into a HashMap<Coordinate, GUIGameField>. Now, the strange thing about it is, that I have a fragment of code, which should guard, that no coordinate should be used twice. But if I debug this code: if (mapForLevel.containsKey(coord)) { throw new IllegalStateException("This coordinate is already used!"); } else { ...do stuff... } ... the containsKey always returns false, although I stored a coordinate with a hashcode of 9731 into the map and the current coord also has the hashcode 9731. After that, the mapForLevel.entrySet() looks like: (java.util.HashMap$EntrySet) [(270,90)=gui.GUIGameField@29e357, (270,90)=gui.GUIGameField@ca470] What could I have possibly done wrong? I ran out of ideas. Thanks for any help! public class Coordinate { int xCoord; int yCoord; public Coordinate(int x, int y) { ...store params in attributes... } ...getters & setters... @Override public int hashCode() { int hash = 1; hash = hash * 41 + this.xCoord; hash = hash * 31 + this.yCoord; return hash; } }

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  • Ruby syntax error: unexpected $end, expecting keyword_end

    - by user2839246
    I am supposed to: Capitalize the first letter of string. Capitalize every word except articles (the, a, an), conjunctions (and), and prepositions (in). Capitalize i (as in "I am male."). Specify the first word of a string (I actually have no idea what this means. I'm trying to run the spec file to test other functions). Here's my code: class Book def initialize(string) title(string) end def title(string) arts_conjs_preps = %w{ a an the and but or nor for yet so although because since unless despite in to } array = string.downcase.split array.each do |word| if (word == array[0] || word == "i") then word = word.capitalize if arts_conjs_preps !include?(word) then word = word.capitalize end puts array.join(' ') end end puts Book.new("inferno") Ruby says I'm messing up at: puts Book.new("inferno") <--(right after the last line of code) I get exactly the same error message with this test code: def title(string) array = string.downcase.split array.each do |word| if word == array[0] then word = word.capitalize end array.join(' ') end puts title("dante's inferno") The only other Stack Overflow thread regarding this particular syntax error that did not suggest trailing or missing ends or .s as the root of the problem is here. The last comment recommends deleting and recreating the gemset, Which sounds scary. And I'm not sure how to do. Any thoughts? Simple solution? Resources to help? Solution class Book def initialize(string) title(string) end def title(string) arts_conjs_preps = %w{ a an the and but or nor for yet so although because since unless despite of in to } array = string.downcase.split title = array.map do |word| if (word == array[0] || word == "i") || !arts_conjs_preps.include?(word) word = word.capitalize else word end end puts title.join(' ') end end Book.new("dante's the inferno")

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