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  • Hibernate: Walk millions of rows and don't leak memory

    - by Autocracy
    The below code functions, but Hibernate never lets go of its grip of any object. Calling session.clear() causes exceptions regarding fetching a joined class, and calling session.evict(currentObject) before retrieving the next object also fails to free the memory. Eventually I exhaust my heap space. Checking my heap dumps, StatefulPersistenceContext is the garbage collector's root for all references pointing to my objects. public class CriteriaReportSource implements JRDataSource { private ScrollableResults sr; private Object currentObject; private Criteria c; private static final int scrollSize = 10; private int offset = 1; public CriteriaReportSource(Criteria c) { this.c = c; advanceScroll(); } private void advanceScroll() { // ((Session) Main.em.getDelegate()).clear(); this.sr = c.setFirstResult(offset) .setMaxResults(scrollSize) .scroll(ScrollMode.FORWARD_ONLY); offset += scrollSize; } public boolean next() { if (sr.next()) { currentObject = sr.get(0); if (sr.isLast()) { advanceScroll(); } return true; } return false; } public Object getFieldValue(JRField jrf) throws JRException { Object retVal = null; if(currentObject == null) { return null; } try { retVal = PropertyUtils.getProperty(currentObject, jrf.getName()); } catch (Exception ex) { Logger.getLogger(CriteriaReportSource.class.getName()).log(Level.SEVERE, null, ex); } return retVal; } }

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  • How to highlight the new created file in JTree

    - by newbie123
    I want to make it like when I click a button, it will create a new file. Then the jTree will highlight the new file. Below are my code. Currently I create new file, i will show the new file but no highlight the file. class FileTreeModel implements TreeModel { private FileNode root; public FileTreeModel(String directory) { root = new FileNode(directory); } public Object getRoot() { return root; } public Object getChild(Object parent, int index) { FileNode parentNode = (FileNode) parent; return new FileNode(parentNode, parentNode.listFiles()[index].getName()); } public int getChildCount(Object parent) { FileNode parentNode = (FileNode) parent; if (parent == null || !parentNode.isDirectory() || parentNode.listFiles() == null) { return 0; } return parentNode.listFiles().length; } public boolean isLeaf(Object node) { return (getChildCount(node) == 0); } public int getIndexOfChild(Object parent, Object child) { FileNode parentNode = (FileNode) parent; FileNode childNode = (FileNode) child; return Arrays.asList(parentNode.list()).indexOf(childNode.getName()); } public void valueForPathChanged(TreePath path, Object newValue) { } public void addTreeModelListener(TreeModelListener l) { } public void removeTreeModelListener(TreeModelListener l) { } } class FileNode extends java.io.File { public FileNode(String directory) { super(directory); } public FileNode(FileNode parent, String child) { super(parent, child); } @Override public String toString() { return getName(); } } jTree = new JTree(); jTree.setBounds(new Rectangle(164, 66, 180, 421)); jTree.setBackground(SystemColor.inactiveCaptionBorder); jTree.setBorder(BorderFactory.createTitledBorder(null, "", TitledBorder.LEADING, TitledBorder.TOP, new Font("Arial", Font.BOLD, 12), new Color(0, 0, 0))); FileTreeModel model = new FileTreeModel(root); jTree.setRootVisible(false); jTree.setModel(model); expandAll(jTree); public void expandAll(JTree tree) { int row = 0; while (row < tree.getRowCount()) { tree.expandRow(row); row++; } }

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  • Distribute budget over for ranked components in SQL

    - by Lee
    Assume I have a budget of $10 (any integer) and I want to distribute it over records which have rank field with varying needs. Example: rank Req. Fulfilled? 1 $3 Y 2 $4 Y 3 $2 Y 4 $3 N Those ranks from 1 to 3 should be fulfilled because they are within budget. whereas, the one ranked 4 should not. I want an SQL query to solve that. Below is my initial script: CREATE TABLE budget ( id VARCHAR (32), budget INTEGER, PRIMARY KEY (id)); CREATE TABLE component ( id VARCHAR (32), rank INTEGER, req INTEGER, satisfied BOOLEAN, PRIMARY KEY (id)); INSERT INTO budget (id,budget) VALUES ('1',10); INSERT INTO component (id,rank,req) VALUES ('1',1,3); INSERT INTO component (id,rank,req) VALUES ('2',2,4); INSERT INTO component (id,rank,req) VALUES ('3',3,2); INSERT INTO component (id,rank,req) VALUES ('4',4,3); Thanks in advance for your help. Lee

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  • Is there a better way to write this LINQ query?

    - by Raj Aththanayake
    Hi Is there a better simplified way to write this query. My logic is if collection contains customer ids and countrycodes, do the query ordey by customer id ascending. If there are no contain id in CustIDs then do the order by customer name. Is there a better way to write this query? I'm not really familiar with complex lambdas. var custIdResult = (from Customer c in CustomerCollection where (c.CustomerID.ToLower().Contains(param.ToLower()) && (countryCodeFilters.Any(item => item.Equals(c.CountryCode))) ) select c).ToList(); if (custIdResult.Count > 0) { return from Customer c in custIdResult where ( c.CustomerName.ToLower().Contains(param.ToLower()) && countryCodeFilters.Any(item => item.Equals(c.CountryCode))) orderby c.CustomerID ascending select c; } else { return from Customer c in CustomerCollection where (c.CustomerName.ToLower().Contains(param.ToLower()) && countryCodeFilters.Any(item => item.Equals(c.CountryCode))) orderby c.CustomerName descending select c; }

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  • Is there a default way to get hold of an internal property in jQueryUi widget?

    - by prodigitalson
    Im using an existing widget from the jquery-ui labs call selectmenu. It has callback options for the events close and open. The problem is i need in these event to animate a node that is part of the widget but not what its connected to. In order to do this i need access to this node. for example if i were to actually modify the widget code itself: // ... other methods/properties "open" : function(event){ // ... the original logic // this is my animation $(this.list).slideUp('slow'); // this is the orginal call to _trigger this._trigger('open', event, $this._uiHash()); }, // ... other methods/properties However when in the scope of the event handler i attach this is the orginal element i called the widget on. I need the widget instance or specifically the widget instance's list property. $('select#custom').selectmenu({ 'open': function(){ // in this scope `this` is an HTMLSelectElement not the ui widget } }); Whats the best way to go about getting the list property from the widget?

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  • Maven: Repository no longer exists! Now what?

    - by pek
    I have just begun my journey in Maven2 and found the dependency repositories logic a little weird... As far as I understand, I need to point Maven to a repository from which it can fetch the various POMs found in my dependencies. In other words, instead of downloading all the dependencies in my lib folder, as I did in the Ant era, I now have to look into various Maven repositories and, hopefully, find what I need. OK, thanks to MVNBrowser things get a little easier. But! What if the Maven repository no longer exists? For example, I use Slick in my project. Among the other dependencies, slick uses JNLP (for some reason). The artifact for jnlp is: <dependency> <groupId>javax.jnlp</groupId> <artifactId>jnlp</artifactId> <version>1.2</version> </dependency> According to MVNBrowser, javax.jnlp can only be found in one repository, Freehep. Which is no longer available. So now what?

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  • How do I push another viewController onto the navigationController from within a tabviewController?

    - by user207788
    Hi, I have a project set up using these two tutorials. http://twilloapp.blogspot.com/2009/03/how-to-embed-navigation-controller.html and the link for the second tutorial is at the bottom of the first. The tutorial is slightly outdated but I managed to get it to work as advertised. Now I want to push a new detailedView onto the NavigationController when a user touches a row in the table view. So I added this to my MyTableViewController.m file. - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { // Navigation logic may go here. Create and push another view controller. SecondViewController *detailViewController = [[SecondViewController alloc] initWithNibName:@"SecondViewController.xib" bundle:nil]; // ... // Pass the selected object to the new view controller. [self.navigationController pushViewController:detailViewController animated:YES]; [detailViewController release]; } Now when I run this project and touch a row in my table view I am getting an error: asm_Terminating_due_to_uncaught_exception IT seems to be having an issue loading the SecondViewController from nib, however I checked the detailViewController and it is not nil. I know I am missing something and it is more than likely something simple. Please help. Thanks, Bruce

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  • copy rows before updating them to preserve archive in Postgres

    - by punkish
    I am experimenting with creating a table that keeps a version of every row. The idea is to be able to query for how the rows were at any point in time even if the query has JOINs. Consider a system where the primary resource is books, that is, books are queried for, and author info comes along for the ride CREATE TABLE authors ( author_id INTEGER NOT NULL, version INTEGER NOT NULL CHECK (version > 0), author_name TEXT, is_active BOOLEAN DEFAULT '1', modified_on TIMESTAMP DEFAULT CURRENT_TIMESTAMP, PRIMARY KEY (author_id, version) ) INSERT INTO authors (author_id, version, author_name) VALUES (1, 1, 'John'), (2, 1, 'Jack'), (3, 1, 'Ernest'); I would like to be able to update the above like so UPDATE authors SET author_name = 'Jack K' WHERE author_id = 1; and end up with 2, 1, Jack, t, 2012-03-29 21:35:00 2, 2, Jack K, t, 2012-03-29 21:37:40 which I can then query with SELECT author_name, modified_on FROM authors WHERE author_id = 2 AND modified_on < '2012-03-29 21:37:00' ORDER BY version DESC LIMIT 1; to get 2, 1, Jack, t, 2012-03-29 21:35:00 Something like the following doesn't really work CREATE OR REPLACE FUNCTION archive_authors() RETURNS TRIGGER AS $archive_author$ BEGIN IF (TG_OP = 'UPDATE') THEN -- The following fails because author_id,version PK already exists INSERT INTO authors (author_id, version, author_name) VALUES (OLD.author_id, OLD.version, OLD.author_name); UPDATE authors SET version = OLD.version + 1 WHERE author_id = OLD.author_id AND version = OLD.version; RETURN NEW; END IF; RETURN NULL; -- result is ignored since this is an AFTER trigger END; $archive_author$ LANGUAGE plpgsql; CREATE TRIGGER archive_author AFTER UPDATE OR DELETE ON authors FOR EACH ROW EXECUTE PROCEDURE archive_authors(); How can I achieve the above? Or, is there a better way to accomplish this? Ideally, I would prefer to not create a shadow table to store the archived rows.

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  • Midiplayer stops playing sounds after 16 notes.

    - by user349673
    Hi. I am currently programming a Piano Keyboard editor, much like the one you can find in Cubase, Logic, Reason etc.. I have this big grid, double array new int [13][9], which makes it 13 rows, 9 columns. The first column [0-12][0] is the Keyboard, at the top there's "high C" (midi note 72) and at the bottom there's "low C" (midi note 60). That column is an array of JButtons and when you press for example "low C", note 60 is being played by the Synthesizer. I've gotten this to work pretty OK as for now, but one problem I have is that I can only play 16 notes in a row, then it's like the Synthesizer shuts down or something. Do you guys have ANY idea of what the problem is? A bit of the code: import java.awt.*; import javax.swing.*; import java.awt.event.*; import java.util.*; import javax.sound.midi.*; actionPerformed(ActionEvent ae){ for(int i = 0; i<13; i++){ if(o== instr[i]){//instr is the button array SpelaTangent(i); } } } public void SpelaTangent(int tangent){ int [] klaviatur = new int[13]; for(int i = 0; i<13; i++){ klaviatur[i] = (72-i); } try { Synthesizer synth = MidiSystem.getSynthesizer(); synth.open(); final MidiChannel[] mc = synth.getChannels(); Instrument[] instrument = synth.getDefaultSoundbank().getInstruments(); synth.loadInstrument(instrument[1]); mc[0].noteOn(klaviatur[tangent],350); mc[0].noteOff(klaviatur[tangent],350); } catch (MidiUnavailableException e) {} } Help is very much appreciated!

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  • Some languages don't work when using Word 2007 Spellcheck from Interop

    - by Tridus
    I'm using the Word 2007 spellchecker via Interop in a VB.net desktop app. When using the default language (English), it works fine. If I set the language to French via LanguageId, it also works. But if I set it to French (Canadian) (Word.WdLanguageID.wdFrenchCanadian), it doesn't work. There's no error message, it simply runs and says the document contains no errors. I know it does, if I paste the exact same text into Word itself and run it with the French (Canadian) dictionary, it finds errors. Just why that dictionary doesn't work is kind of a mystery to me. Full code below: Public Shared Function SpellCheck(ByVal text As String, ByVal checkGrammar As Boolean) As String ' If there is no data to spell check, then exit sub here. If text.Length = 0 Then Return text End If Dim objWord As Word.Application Dim objTempDoc As Word.Document ' Declare an IDataObject to hold the data returned from the ' clipboard. Dim iData As IDataObject objWord = New Word.Application() objTempDoc = objWord.Documents.Add objWord.Visible = False ' Position Word off the screen...this keeps Word invisible ' throughout. objWord.WindowState = 0 objWord.Top = -3000 ' Copy the contents of the textbox to the clipboard Clipboard.SetDataObject(text) ' With the temporary document, perform either a spell check or a ' complete ' grammar check, based on user selection. With objTempDoc .Content.Paste() .Activate() .Content.LanguageID = Word.WdLanguageID.wdFrenchCanadian If checkGrammar Then .CheckGrammar() Else .CheckSpelling() End If ' After user has made changes, use the clipboard to ' transfer the contents back to the text box .Content.Copy() iData = Clipboard.GetDataObject If iData.GetDataPresent(DataFormats.Text) Then text = CType(iData.GetData(DataFormats.Text), _ String) End If .Saved = True .Close() End With objWord.Quit() Return text End Function

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  • Java Code for calculating Leap Year, is this code correct ?

    - by Ibn Saeed
    Hello I am following "The Art and Science of Java" book and it shows how to calculate a leap year. The book uses ACM Java Task Force's library. Here is the code the books uses: import acm.program.*; public class LeapYear extends ConsoleProgram { public void run() { println("This program calculates leap year."); int year = readInt("Enter the year: "); boolean isLeapYear = ((year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0)); if (isLeapYear) { println(year + " is a leap year."); } else println(year + " is not a leap year."); } } Now, this is how I calculated the leap year. import acm.program.*; public class LeapYear extends ConsoleProgram { public void run() { println("This program calculates leap year."); int year = readInt("Enter the year: "); if ((year % 4 == 0) && year % 100 != 0) { println(year + " is a leap year."); } else if ((year % 4 == 0) && (year % 100 == 0) && (year % 400 == 0)) { println(year + " is a leap year."); } else { println(year + " is not a leap year."); } } } Is there anything wrong with my code or should i use the one provided by the book ? EDIT :: Both of the above code works fine, What i want to ask is which code is the best way to calculate the leap year.

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  • List local printers

    - by vladimir
    hi all, i am using this routine to list the local printers installed on on a machine... var p: pointer; hpi: _PRINTER_INFO_2A; hGlobal: cardinal; dwNeeded, dwReturned: DWORD; bFlag: boolean; i: dword; begin p := nil; EnumPrinters(PRINTER_ENUM_LOCAL, nil, 2, p, 0, dwNeeded, dwReturned); if (dwNeeded = 0) then exit; GetMem(p,dwNeeded); if (p = nil) then exit; bFlag := EnumPrinters(PRINTER_ENUM_LOCAL, nil, 2, p, dwneeded, dwNeeded, dwReturned); if (not bFlag) then exit; CbLblPrinterPath.Properties.Items.Clear; for i := 0 to dwReturned - 1 do begin CbLblPrinterPath.Properties.Items.Add(TPrinterInfos(p^)[i].pPrinterName); end; FreeMem(p); TPrinterInfos(p^)[i].pPrinterName returns a 'P' for printer name. i have a PdfCreator installed as a printer. TPrinterInfos is an array of _PRINTER_INFO_2A. how can i fix this?

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  • How to handle not-enough-isolatedstorage issue deep in data loader?

    - by Edward Tanguay
    I have a silverlight application which loads data from many external data sources into IsolatedStorage, and while loading any of these sources if it does not have enough IsolatedStorage, it ends up in a catch statement. At that point in that catch statement I would like to ask the user to click a button to approve silverlight to increase the IsolatedStorage capacity. The problem is, although I have a "SwitchPage()" method with which I display a page, if I access it at this point it is too deep in the loading process and the application always goes into an endless loop, hangs and crashes. I need a way to branch out of the application completely somehow to an independent UserControl which has a button and code behind which does the increase logic. What is a solution for an application to be able to branch out of a loading process catch statement like this, display a user control which has a button to ask the user to increase the IsolatedStorage? public static void SaveBitmapImageToIsolatedStorageFile(OpenReadCompletedEventArgs e, string fileName) { try { using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication()) { using (IsolatedStorageFileStream isfs = new IsolatedStorageFileStream(fileName, FileMode.Create, isf)) { Int64 imgLen = (Int64)e.Result.Length; byte[] b = new byte[imgLen]; e.Result.Read(b, 0, b.Length); isfs.Write(b, 0, b.Length); isfs.Flush(); isfs.Close(); isf.Dispose(); } } } catch (IsolatedStorageException) { //handle: present user with button to increase isolated storage } catch (TargetInvocationException) { //handle: not saved } }

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  • Parallel.Foreach loop creating multiple db connections throws connection errors?

    - by shawn.mek
    Login failed. The login is from an untrusted domain and cannot be used with Windows authentication I wanted to get my code running in parallel, so I changed my foreach loop to a parallel foreach loop. It seemed simple enough. Each loop connects to the database, looks up some stuff, performs some logic, adds some stuff, closes the connection. But I get the above error? I'm using my local sql server and entity framework (each loop uses it's own context). Is there some problem with connecting multiple times using the same local login or something? How did I get around this? I have (before trying to covert to a parallel.foreach loop) split my list of objects that I am foreach looping through into four groups (separate csv files) and run four concurrent instances of my program (which ran faster overall than just one, thus the idea for parallel). So it seems connecting to the db shouldn't be a problem? Any ideas? EDIT: Here's before var gtgGenerator = new CustomGtgGenerator(); var connectionString = ConfigurationManager.ConnectionStrings["BioEntities"].ConnectionString; var allAccessionsFromObs = _GetAccessionListFromDataFiles(collectionId); ForEach(cloneIdAndAccessions in allAccessionsFromObs) DoWork(gtgGenerator, taxonId, organismId, cloneIdAndAccessions, connectionString)); after var gtgGenerator = new CustomGtgGenerator(); var connectionString = ConfigurationManager.ConnectionStrings["BioEntities"].ConnectionString; var allAccessionsFromObs = _GetAccessionListFromDataFiles(collectionId); Parallel.ForEach(allAccessionsFromObs, cloneIdAndAccessions => DoWork(gtgGenerator, taxonId, organismId, cloneIdAndAccessions, connectionString)); Inside the DoWork I use the BioEntities using (var bioEntities = new BioEntities(connectionString)) {...}

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  • Serialized NHibernate Configuration objects - detect out of date or rebuild on demand?

    - by fostandy
    I've been using serialized nhibernate configuration objects (also discussed here and here) to speed up my application startup from about 8s to 1s. I also use fluent-nhibernate, so the path is more like ClassMap class definitions in code fluentconfiguration xml nhibernate configuration configuration serialized to disk. The problem from doing this is that one runs the risk of out of date mappings - if I change the mappings but forget to rebuild the serialized configuration, then I end up using the old mappings without realising it. This does not always result in an immediate and obvious error during testing, and several times the misbehaviour has been a real pain to detect and fix. Does anybody have any idea how I would be able to detect if my classmaps have changed, so that I could either issue an immediate warning/error or rebuild it on demand? At the moment I am comparing timestamps on my compiled assembly against the serialized configuration. This will pickup mapping changes, but unfortunately it generates a massive false positive rate as ANY change to the code results in an out of date flag. I can't move the classmaps to another assembly as they are tightly integrated into the business logic. This has been niggling me for a while so I was wondering if anybody had any suggestions?

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  • Why should I override hashCode() when I override equals() method?

    - by Bragaadeesh
    Ok, I have heard from many places and sources that whenever I override the equals() method, I need to override the hashCode() method as well. But consider the following piece of code package test; public class MyCustomObject { int intVal1; int intVal2; public MyCustomObject(int val1, int val2){ intVal1 = val1; intVal2 = val2; } public boolean equals(Object obj){ return (((MyCustomObject)obj).intVal1 == this.intVal1) && (((MyCustomObject)obj).intVal2 == this.intVal2); } public static void main(String a[]){ MyCustomObject m1 = new MyCustomObject(3,5); MyCustomObject m2 = new MyCustomObject(3,5); MyCustomObject m3 = new MyCustomObject(4,5); System.out.println(m1.equals(m2)); System.out.println(m1.equals(m3)); } } Here the output is true, false exactly the way I want it to be and I dont care of overriding the hashCode() method at all. This means that hashCode() overriding is an option rather being a mandatory one as everyone says. I want a second confirmation.

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  • How to figure out which key was pressed on a BlackBerry

    - by Skrud
    What I want: To know when the user has pressed the button that has the number '2' on it, for example. I don't care whether "Alt" or "Shift" has been pressed. The user has pressed a button, and I want to evaluate whether this button has '2' printed on it. Naturally, if I switch devices this key will change. On a Bold 9700/9500 this is the 'E' key. On a Pearl, this is the 'T'/'Y' key. I've managed to get this working in what appears to be a roundabout way, by looking up the keycode of the '2' character with the ALT button enabled and using Keypad.key() to get the actual button: // figure out which key the '2' is on: final int BUTTON_2_KEY = Keypad.key(KeypadUtil.getKeyCode('2', KeypadListener.STATUS_ALT, KeypadUtil.MODE_EN_LOCALE)); protected boolean keyDown(int keycode, int time) { int key = Keypad.key(keycode); if ( key == BUTTON_2_KEY ) { // do something return true; } return super.keyDown(keycode,time); } I can't help but wonder if there is a better way to do this. I've looked at the constants defined in KeypadListener and Keypad but I can't find any constants mapped to the actual buttons on the device. Would any more experienced BlackBerry devs care to lend a helping hand? Thanks!

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  • Adding <tr> from repeater's ItemDataBound Event

    - by nemiss
    My repeater's templates generate a table, where each item is a table row. When a very very specific condition is met (itemdata), I want to add an additional row to the table from this event. How can I do that? protected void rptData_ItemDataBound(object sender, RepeaterItemEventArgs e) { if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem) { bool tmp = bool.Parse(DataBinder.Eval(e.Item.DataItem, "somedata").ToString()); if (!tmp && e.Item.ItemIndex != 0) { //Add row after this item } } } I can use e.Item.Controls.Add() and add TableRow but for that I need to locate a table right? How can I solve that? UPDATE I will explain now why I need this: I am creating a sort of message board, where data entries are displayed in a tabled style. The first items in the table are "important" items after those items, i want to add this row. I could solved it using 2 repeaters, where the first repeater will be bounded to pinned items, and the second repeater will be bounded to refular items. But I don't want to have to repeaters nor I want to complex the business logic for separating the fetched data to pinned and not-pinned collection. I think the best opton is to do it "onfly", using one repeater and one datasource.

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  • Integration transport choice (Oracle + SQL Server)

    - by lak-b
    We have several systems with Oracle (A) and SQL Server (B) databases on backend. I have to consolidate data from those systems into the new SQL Server database. Something like that: (A) =>|---------------| | some software | => SQL Server (B) =>|---------------| where some software is: transport (A and B systems located in the network) processing business logic (custom .NET code) Due to first point, I need some queue software or something similar (like MSMQ, Service Broker or something). In another hand, I can implement a web-service instead of queue. (A) =>|---------------|-------------| | queue/service | custom code | => SQL Server (B) =>|---------------|-------------| The question is: which queue/transport framework should I use with Oracle and SQL Server databases? It would be nice, if I can post messages to MSMQ in both Oracle and SQL Server stored procedures (can I?) It would be nice, if I can call a web-service in both Oracle and SQL Server stored procedures (can I?) It would be nice, if I can use something similar in both Oracle and SQL Server stored procedures (what exactly?) What software should I prefer to my requirements?

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  • Interchange structured data between Haskell and C

    - by Eonil
    First, I'm a Haskell beginner. I'm planning integrating Haskell into C for realtime game. Haskell does logic, C does rendering. To do this, I have to pass huge complexly structured data (game state) from/to each other for each tick (at least 30 times per second). So the passing data should be lightweight. This state data may laid on sequential space on memory. Both of Haskell and C parts should access every area of the states freely. In best case, the cost of passing data can be copying a pointer to a memory. In worst case, copying whole data with conversion. I'm reading Haskell's FFI(http://www.haskell.org/haskellwiki/FFICookBook#Working_with_structs) The Haskell code look specifying memory layout explicitly. I have a few questions. Can Haskell specify memory layout explicitly? (to be matched exactly with C struct) Is this real memory layout? Or any kind of conversion required? (performance penalty) If Q#2 is true, Any performance penalty when the memory layout specified explicitly? What's the syntax #{alignment foo}? Where can I find the document about this? If I want to pass huge data with best performance, how should I do that? *PS Explicit memory layout feature which I said is just C#'s [StructLayout] attribute. Which is specifying in-memory position and size explicitly. http://www.developerfusion.com/article/84519/mastering-structs-in-c/ I'm not sure Haskell has matching linguistic construct matching with fields of C struct.

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  • I want to input JSONObject from jquery.post() to a a simple JS chart(bar chart)?

    - by ann-stack
    HI I am very new to both json and js charts. In the example of bar chart, they are giving a hard coded array like this, var myData = new Array(['U.S.A.', 69.5], ['Canada', 2.8], ['Japan & SE.Asia', 5.6] ); var myChart = new JSChart('graph', 'bar'); myChart.setDataArray(myData); Instead of that I want to use the response of $.post() method which is in json. Here is the piece of code. var myData=[]; $.post("JSONServlet", function(data) { $.each(data.Userdetails, function(i, data) { myData[i] = []; myData[i]['text'] = data['firstname']; myData[i]['id'] = data['ssn']; alert("first name " +myData[i]['text']+ " salary " +myData[i]['id']); // I am getting correct data here, but how to assign this myData to barchart }); }, "json"); is this the logic to use or how else can i get username and salary from the response and pass it to the barchart. Please help. I am stuck with this. thanks in advance.

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  • C++ iterators, default initialization and what to use as an uninitialized sentinel.

    - by Hassan Syed
    The Context I have a custom template container class put together from a map and vector. The map resolves a string to an ordinal, and the vector resolves an ordinal (only an initial string to ordinal lookup is done, future references are to the vector) to the entry. The entries are modified intrusively to contain a a bool "assigned" and an iterator_type which is a const_iterator to the container class's map. My container class will use RCF's serialization code (which models boost::serialization) to serialize my container classes to nodes in a network. Serializing iterator's is not possible, or a can of worms, and I can easily regenerate them onces the vectors and maps are serialized on the remote site. The Question I need to default initialize, and be able to test that the iterator has not been assigned to (if it is assigned it is valid, if not it is invalid). Since map iterators are not invalidated upon operations performed on it (unless of course items are removed :D) am I to assume that map<x,y>::end() is a valid sentinel (regardless of the state of the map -- i.e., it could be empty) to initialize to ? I will always have access to the parent map, I'm just unsure wheather end() is the same as the map contents change. I don't want to use another level of indirection (--i.e., boost::optional) to achieve my goal, I'd rather forego compiler checks to correct logic, but it would be nice if I didn't need to. Misc This question exists, but most of its content seems non-sense. Assigning a NULL to an iterator is invalid according to g++ and clang++. This is another similar question, but it focuses on the common use-cases of iterators, which generally tends to be using the iterator to iterate, ofcourse in this use-case the state of the container isn't meant to change whilst iteration is going on.

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  • template files in python

    - by saminny
    I am trying to use python for translating a set of templates to a set of configuration files based on values taken from a main configuration file. However, I am having certain issues. Consider the following example of a template file. file1.cfg.template %(CLIENT1)s %(HOST1)s %(PORT1)d C %(COMPID1)s %(CLIENT2)s %(HOST2)s %(PORT2)d C %(COMPID2)s This file contains an entry for each client. There are hundreds of config files like this and I don't want to have logic for each type of config file. Python should do the replacements and generate config files automatically given a set of global values read from a main xml config file. However, in the above example, if CLIENT2 does not exist, how do I delete that line? I expect Python would generate the config file using the following simple code: os.open("file1.cfg.template").read() & myhash where myhash is hash of all configuration parameters which may not contain CLIENT2 at all. In the case it does not contain CLIENT2, I want that line to disappear from the file. Is it possible to insert some 'IF' block in the file and have python evaluate it? Thanks for your help. Any suggestions most welcome.

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  • Circular dependency with generics

    - by devoured elysium
    I have defined the following interface: public interface IStateSpace<State, Action> where State : IState where Action : IAction<State, Action> // <-- this is the line that bothers me { void SetValueAt(State state, Action action); Action GetValueAt(State state); } Basically, an IStateSpace interface should be something like a chess board, and in each position of the chess board you have a set of possible movements to do. Those movements here are called IActions. I have defined this interface this way so I can accommodate for different implementations: I can then define concrete classes that implement 2D matrix, 3D matrix, graphs, etc. public interface IAction<State, Action> { IStateSpace<State, Action> StateSpace { get; } } An IAction, would be to move up(this is, if in (2, 2) move to (2, 1)), move down, etc. Now, I'll want that each action has access to a StateSpace so it can do some checking logic. Is this implementation correct? Or is this a bad case of a circular dependence? If yes, how to accomplish "the same" in a different way? Thanks

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  • Using a Context Menu to delete from a SQLite database in Android

    - by LordSnoutimus
    Hi, I have created a list view that displays the names and dates of items stored in a SQLite database, now I want to use a Context Menu to modify these items stored in the database such as edit the name, delete, and view. This is the code for the list view: public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.listview); SQLiteDatabase myDB = null; myDB = this.openOrCreateDatabase(MY_DB_NAME, MODE_PRIVATE, null); Cursor cur = myDB.rawQuery("SELECT _id, trackname, tracktime" + " FROM " + MY_DB_TABLE, null); ListAdapter adapter = new SimpleCursorAdapter(this, R.layout.listview, cur, new String[] { Constants.TRACK_NAME, Constants.TRACK_TIME}, new int[] { R.id.text1, R.id.text2}); ListView list = (ListView)findViewById(R.id.list); list.setAdapter(adapter); registerForContextMenu(list); } and the Context Menu... public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { super.onCreateContextMenu(menu, v, menuInfo); menu.setHeaderTitle("Track Options"); menu.add(0, CHANGE_NAME, 0, "Change name"); menu.add(0, VIEW_TRACK, 0, "View track"); menu.add(0, SEND_TRACK, 0, "Send track"); menu.add(0, DELETE_TRACK, 0, "Delete track"); } I have used a Switch statement to control the menu items.. public boolean onContextItemSelected(MenuItem item) { switch (item.getItemId()){ case CHANGE_NAME: changename(); return true; case DELETE_TRACK: deletetrack(); return true; default: return super.onContextItemSelected(item); } So how would I go ahead and map the deletetrack(); method to find the ID of the track stored in the database to the item that has been selected in the list view?

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