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• How to break an object into chunks based on some property?

  - by CurlyFro

  public class InvestorMailing { public string To { get; set; } public IEnumerable<string> Attachments { get; set; } public int AttachmentCount { get; set; } public long AttachmentSize { get; set; } } i have an IList<InvestorMailing> mailingList. if the attachment size is greater than x, then i need to split my object into chunks. is there an easy linq-y way to do this? Edited: this is how i'm generating my mailings: var groupedMailings = mailingList.GroupBy(g => g.GroupBy); var investorMailings = groupedMailings.Select( g => new DistinctInvestorMailing { Id = g.Select(x => x.Id).FirstOrDefault(), To = g.Key.Trim(), From = g.Select(x => x.From).FirstOrDefault(), FromName = g.Select(x => x.FromName).FirstOrDefault(), Bcc = g.Select(x => x.Bcc).FirstOrDefault(), DeliveryCode = g.Select(x => x.DeliveryCode).FirstOrDefault(), Subject = g.Select(x => x.Subject).FirstOrDefault(), Body = g.Select(x => x.Body).FirstOrDefault(), CommentsOnStatus = g.Select(x => x.CommentsOnStatus).FirstOrDefault(), Attachments = g.Select(x => x.AttachmentPath), AttachmentCount = g.Select(x => x.AttachmentPath).Count(), AttachmentSize = g.Sum(x => x.AttachmentSize), MailType = g.Select(x => x.MessageType).FirstOrDefault() } ).ToList();

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• When my object is no longer referenced why do its events continue to run?

  - by Ryan Peschel

  Say I am making a game and have a base Buff class. I may also have a subclass named ThornsBuff which subscribes to the Player class's Damaged event. The Player may have a list of Buffs and one of them may be the ThornsBuff. For example: Test Class Player player = new Player(); player.ActiveBuffs.Add(new ThornsBuff(player)); ThornsBuff Class public ThornsBuff(Player player) { player.DamageTaken += player_DamageTaken; } private void player_DamageTaken(MessagePlayerDamaged m) { m.Assailant.Stats.Health -= (int)(m.DamageAmount * .25); } This is all to illustrate an example. If I were to remove the buff from the list, the event is not detached. Even though the player no longer has the buff, the event is still executed as if he did. Now, I could have a Dispel method to unregister the event, but that forces the developer to call Dispel in addition to removing the Buff from the list. What if they forget, increased coupling, etc. What I don't understand is why the event doesn't detatch itself automatically when the Buff is removed from the list. The Buff only existed in the list and that is its one reference. After it is removed shouldn't the event be detached? I tried adding the detaching code to the finalizer of the Buff but that didn't fix it either. The event is still running even after it has 0 references. I suppose it is because the garbage collector had not run yet? Is there any way to make it automatic and instant so that when the object has no references all its events are unregisted? Thanks.

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• Why does Java think my object is a variable?

  - by user2896898

  Ok so I'm trying to make a simple pong game. I have a paddle that follows the mouse and a ball that bounces around. I wrote a method collidesWith(Sprite s) inside of my Sprite class that checks if the ball collides with the paddle (this works and isn't the problem). I have two objects extending my sprite class, a ball and a paddle object. So inside of my ball class I'm trying to check if it collides with the paddle. So I've tried if(this.collidesWith(paddle) == true){ System.out.println("They touched"); } I've also tried ball.collidesWith(paddle) and other combinations but it always says the same thing about the paddle (and the ball when I use ball.collidesWith) "Cannot find symbol. Symbol: variable paddle(or ball). Location: class Ball" So if I'm reading this right, it thinks that the paddle (and ball) are variables and it's complaining because it can't find them. How can I make it understand I am passing in objects, not variables? For extra information, an earlier assignment had me make two boxes and for them to change colors when they were colliding. In that assignment I used very similar code to above with if(boxOne.collidesWith(boxTwo) == true){ System.out.println("yes"); } And in this code it worked just fine. The program knew that boxOne and boxTwo were child classes of my Sprite class. Anyone know why they wouldn't work the same?

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• TypeError: Error #1009: Cannot access a property or method of a null object reference. at RECOVER_fyp1_fla::MainTimeline/abc1()

  - by user2643323

  TypeError: Error #1009: Cannot access a property or method of a null object reference. at RECOVER_fyp1_fla::MainTimeline/abc1() Hi, what does this mean? Can anybody figure it out? Thanks. Code: swatter.addEventListener(Event.ENTER_FRAME,abc1); Mouse.hide(); function abc1(e:Event) { swatter.x = mouseX; swatter.y = mouseY; enter code here mosq1.y = mosq1.y + 2; mosq2.y = mosq2.y + 3; mosq3.y = mosq3.y + 4; mosq4.y = mosq4.y + 5; mosq5.y = mosq5.y + 6; if (mosq1.y > 640) { mosq1.y = -50; } if (mosq2.y > 640) { mosq2.y = -50; } if (mosq3.y > 640) { mosq3.y = -50; } if (mosq4.y > 640) { mosq4.y = -50; } if (mosq5.y > 640) { mosq5.y = -50; } if(swatter.hitTestObject(mosq1)) { //SoundMixer.stopAll(); //three_start_sound1.play(); mosq1.parent.removeChild(mosq1); } if(swatter.hitTestObject(mosq2)) { //SoundMixer.stopAll(); //three_start_sound1.play(); mosq2.parent.removeChild(mosq2); } if(swatter.hitTestObject(mosq3)) { //SoundMixer.stopAll(); //three_start_sound1.play(); mosq3.parent.removeChild(mosq3); } if(swatter.hitTestObject(mosq4)) { //SoundMixer.stopAll(); //three_start_sound1.play(); mosq4.parent.removeChild(mosq4); } if(swatter.hitTestObject(mosq5)) { //SoundMixer.stopAll(); //three_start_sound1.play(); mosq5.parent.removeChild(mosq5); } } enter code here

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• JPA exception: Object: ... is not a known entity type.

  - by Toto

  I'm new to JPA and I'm having problems with the autogeneration of primary key values. I have the following entity: package jpatest.entities; import java.io.Serializable; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; @Entity public class MyEntity implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; public Long getId() { return id; } public void setId(Long id) { this.id = id; } private String someProperty; public String getSomeProperty() { return someProperty; } public void setSomeProperty(String someProperty) { this.someProperty = someProperty; } public MyEntity() { } public MyEntity(String someProperty) { this.someProperty = someProperty; } @Override public String toString() { return "jpatest.entities.MyEntity[id=" + id + "]"; } } and the following main method in other class: public static void main(String[] args) { EntityManagerFactory emf = Persistence.createEntityManagerFactory("JPATestPU"); EntityManager em = emf.createEntityManager(); em.getTransaction().begin(); MyEntity e = new MyEntity("some value"); em.persist(e); /* (exception thrown here) */ em.getTransaction().commit(); em.close(); emf.close(); } This is my persistence unit: <?xml version="1.0" encoding="UTF-8"?> <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"> <persistence-unit name="JPATestPU" transaction-type="RESOURCE_LOCAL"> <provider>oracle.toplink.essentials.PersistenceProvider</provider> <class>jpatest.entities.MyEntity</class> <properties> <property name="toplink.jdbc.user" value="..."/> <property name="toplink.jdbc.password" value="..."/> <property name="toplink.jdbc.url" value="jdbc:mysql://localhost:3306/jpatest"/> <property name="toplink.jdbc.driver" value="com.mysql.jdbc.Driver"/> <property name="toplink.ddl-generation" value="create-tables"/> </properties> </persistence-unit> </persistence> When I execute the program I get the following exception in the line marked with the proper comment: Exception in thread "main" java.lang.IllegalArgumentException: Object: jpatest.entities.MyEntity[id=null] is not a known entity type. at oracle.toplink.essentials.internal.sessions.UnitOfWorkImpl.registerNewObjectForPersist(UnitOfWorkImpl.java:3212) at oracle.toplink.essentials.internal.ejb.cmp3.base.EntityManagerImpl.persist(EntityManagerImpl.java:205) at jpatest.Main.main(Main.java:...) What am I missing?

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• How do I serialize an object to xml but not have it be the root element of the xml document

  - by mezoid

  I have the following object: public class MyClass { public int Id { get; set;} public string Name { get; set; } } I'm wanting to serialize this to the following xml string: <MyClass> <Id>1</Id> <Name>My Name</Name> </MyClass> Unfortunately, when I use the XMLSerializer I get a string which looks like: <?xml version="1.0" encoding="utf-8"?> <MyClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <Id>1</Id> <Name>My Name</Name> </MyClass> I'm not wanting MyClass to be the root element the document, rather I'm eventually wanting to add the string with other similar serialized objects which will be within a larger xml document. i.e. Eventually I'll have a xml string which looks like this: <Classes> <MyClass> <Id>1</Id> <Name>My Name</Name> </MyClass> <MyClass> <Id>1</Id> <Name>My Name</Name> </MyClass> </Classes>" My first thought was to create a class as follows: public class Classes { public List<MyClass> MyClasses { get; set; } } ...but that just addes an additional node called MyClasses to wrap the list of MyClass.... My gut feeling is that I'm approaching this the wrong way and that my lack of experience with creating xml files isn't helping to point me to some part of the .NET framework or some other library that simplifies this.

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• Advantage of creating a generic repository vs. specific repository for each object?

  - by LuckyLindy

  We are developing an ASP.NET MVC application, and are now building the repository/service classes. I'm wondering if there are any major advantages to creating a generic IRepository interface that all repositories implement, vs. each Repository having its own unique interface and set of methods. For example: a generic IRepository interface might look like (taken from this answer): public interface IRepository : IDisposable { T[] GetAll<T>(); T[] GetAll<T>(Expression<Func<T, bool>> filter); T GetSingle<T>(Expression<Func<T, bool>> filter); T GetSingle<T>(Expression<Func<T, bool>> filter, List<Expression<Func<T, object>>> subSelectors); void Delete<T>(T entity); void Add<T>(T entity); int SaveChanges(); DbTransaction BeginTransaction(); } Each Repository would implement this interface (e.g. CustomerRepository:IRepository, ProductRepository:IRepository, etc). The alternate that we've followed in prior projects would be: public interface IInvoiceRepository : IDisposable { EntityCollection<InvoiceEntity> GetAllInvoices(int accountId); EntityCollection<InvoiceEntity> GetAllInvoices(DateTime theDate); InvoiceEntity GetSingleInvoice(int id, bool doFetchRelated); InvoiceEntity GetSingleInvoice(DateTime invoiceDate, int accountId); //unique InvoiceEntity CreateInvoice(); InvoiceLineEntity CreateInvoiceLine(); void SaveChanges(InvoiceEntity); //handles inserts or updates void DeleteInvoice(InvoiceEntity); void DeleteInvoiceLine(InvoiceLineEntity); } In the second case, the expressions (LINQ or otherwise) would be entirely contained in the Repository implementation, whoever is implementing the service just needs to know which repository function to call. I guess I don't see the advantage of writing all the expression syntax in the service class and passing to the repository. Wouldn't this mean easy-to-messup LINQ code is being duplicated in many cases? For example, in our old invoicing system, we call InvoiceRepository.GetSingleInvoice(DateTime invoiceDate, int accountId) from a few different services (Customer, Invoice, Account, etc). That seems much cleaner than writing the following in multiple places: rep.GetSingle(x => x.AccountId = someId && x.InvoiceDate = someDate.Date); The only disadvantage I see to using the specific approach is that we could end up with many permutations of Get* functions, but this still seems preferable to pushing the expression logic up into the Service classes. What am I missing?

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• Want to show <embed> and <object> tags from YUI editor as a text rather then a video.

  - by user208678

  I am using YUI rich text editor on my website (php/mysql), so that a user may enter textual matter/articles through it. But if a user copies and paste some embed code in the textarea, from any video sites like youtube, it should get saved as a text block and not as a playing video when showing the text content on the browser. Now YUI automatically converts the characters into html entities which ever is needed. Please note that if I put a new line in the yui editor (by pressing "Enter" key), it will be converted into a "<br>" tag in the background and this will not get html entity encoded when passing the value to my backend PHP script. But If I copy and paste any embed tag or for that reason any valid html tags in the textarea, it will be html entity encoded by YUI. Now to support UTF-8 characters, I am using a function (DBVarConv) in my php script before saving it into my database. The code for the function is given below function DBVarConv($var,$isEncoded = false) { if($isEncoded) return addslashes(htmlentities($var, ENT_QUOTES, 'UTF-8', false)); else return htmlentities ($var, ENT_QUOTES, 'UTF-8', false); } $myeditorData = DBVarConv($myeditorData, true); // Save $myeditorData in database. While showing the data in the browser, I am using another function called "smart_html_entity_decode". The code is given below. function smart_html_entity_decode($text, $isAddslashesUsed = false) { if($isAddslashesUsed) $tmp = stripslashes(html_entity_decode($text, ENT_QUOTES, 'UTF-8')); else $tmp = html_entity_decode($text, ENT_QUOTES, 'UTF-8'); if ($tmp == $text) return $tmp; return smart_html_entity_decode($tmp, $isAddslashesUsed); } // Get $myData from database $myData=smart_html_entity_decode($myData, true); echo $myData; The problem is that in doing so, it is also decoding the embed and object tags from their html encoded entities and as a result my obejct tags are shown as a video and not as a simple text. Try using the text editor at tumblr.com. If you paste an embed code in the editor, it will be shown as a text block not as a video. I am trying to build the same functionality on my website with UTF-8 support. Any help will be highly appreciated.

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• Python4Delphi: Returning a python object in a function. (DelphiWrapper)

  - by Gabriel Fonseca

  I am using python4delphi. ow can I return an object from a wrapped Delphi class function? Code Snippet: I have a simple Delphi Class that i wrapped to Python Script, right? TSimple = Class Private function getvar1:string; Public Published property var1:string read getVar1; function getObj:TSimple; end; ... function TSimple.getVar1:string; begin result:='hello'; end; function TSimple.getObj:TSimple; begin result:=self; end; I made the TPySimple like the demo32 to give class access to the python code. My python module name is test. TPyDado = class(TPyDelphiPersistent) // Constructors & Destructors constructor Create( APythonType : TPythonType ); override; constructor CreateWith( PythonType : TPythonType; args : PPyObject ); override; // Basic services function Repr : PPyObject; override; class function DelphiObjectClass : TClass; override; end; ... { TPyDado } constructor TPyDado.Create(APythonType: TPythonType); begin inherited; // we need to set DelphiObject property DelphiObject := TDado.Create; with TDado(DelphiObject) do begin end; Owned := True; // We own the objects we create end; constructor TPyDado.CreateWith(PythonType: TPythonType; args: PPyObject); begin inherited; with GetPythonEngine, DelphiObject as TDado do begin if PyArg_ParseTuple( args, ':CreateDado' ) = 0 then Exit; end; end; class function TPyDado.DelphiObjectClass: TClass; begin Result := TDado; end; function TPyDado.Repr: PPyObject; begin with GetPythonEngine, DelphiObject as TDado do Result := VariantAsPyObject(Format('',[])); // or Result := PyString_FromString( PAnsiChar(Format('(%d, %d)',[x, y])) ); end; And now the python code: import test a = test.Simple() # try access the property var1 and everything is right print a.var1 # work's, but.. b = a.getObj(); # raise a exception that not find any attributes named getObj. # if the function returns a string for example, it's work.

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• Good object/DB set-up for CMS-esque app for managing content and user permissions?

  - by sah302

  Hi all, so I am writing a big CMS-esque app to allow users to manage web content through web applications, I've got a pretty good db-driven user permission system going, but am having trouble coming up with a good way to handle content groups and pages, I've got a couple options and not sure which one to take. Furthermore, I am not sure how to handle static page updates that have no 'widgets' in them. My current set-up for permissions is this: Objects: User, UserGroup, UserUserGroup, UserGroupType Standard many to many relationship User -> UserUserGroup <- UserGroup each Usergroup has a UserGroupType, which could be anything from Title, Department, to PermissionGroup. PermissionGroup manages the permissions. Right now on a per page basis I check permissions based on their PermissionsGroups. So for a page which has CMS features for a news widget, I check for permission groups of "Site Admin" and "News Admin". Now the issue I am coming to is, the site has many different departments involved. No problem I think, I can just have a EntityContentGroup so any widget app can be used for any departments. So my HR department, each of their news items would be in the EntityContentGroup with the news item ID, and content group of "HR" or "HR News". But maybe this isn't the most efficient way to go about it? I don't want to put the content group simply as a NewsItemType because some news items could apply to multiple areas, so I want to be able to assign them to as many areas as I want. Likewise, all of my widget apps have this, so that's why I decided to choose EntityContentGroup and not just NewsItemContentGroup. I was also thinking well instead of doing a contentGroup do a Page object that says which page some entity should be on. It seems almost like the same thing, but would I want to use Page for something else? I was thinking Page would be used for static pages with no widgets, a simple Rich Text Editor can edit the content of that page and I save that item to a page?? And then instead of doing a page level check for UserGroup permissions, would it be better to associate a usergroup to a contentgroup, and then just depending on what contentGroup content on the page is displayed, determine the permissions through that relationship? Is that better? I am not sure at this point. I guess I am just getting a tad overwhelmed at this is the largest app in scope and size that I have ever written. What is the best approach for this based on my current user permission set-up?

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• Is there any way to add a MouseListener to a Graphic object ?

  - by Fahad

  Hi, Is there any way to add a MouseListener to a Graphic object. I have this simple GUI that draw an oval. What I want is handling the event when the user clicks on the oval import java.awt.*; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import javax.swing.*; public class Gui2 extends JFrame { JFrame frame = new JFrame(); MyDrawPanel drawpanel = new MyDrawPanel(); public static void main(String[] args) { Gui2 gui = new Gui2(); gui.go(); } public void go() { frame.getContentPane().add(drawpanel); // frame.addMouseListener(this); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(300, 300); frame.setVisible(true); } } class MyDrawPanel extends JComponent implements MouseListener { public void paintComponent(Graphics g) { int red = (int) (Math.random() * 255); int green = (int) (Math.random() * 255); int blue = (int) (Math.random() * 255); Color startrandomColor = new Color(red, green, blue); red = (int) (Math.random() * 255); green = (int) (Math.random() * 255); blue = (int) (Math.random() * 255); Color endrandomColor = new Color(red, green, blue); Graphics2D g2d = (Graphics2D) g; this.addMouseListener(this); GradientPaint gradient = new GradientPaint(70, 70, startrandomColor, 150, 150, endrandomColor); g2d.setPaint(gradient); g2d.fillOval(70, 70, 100, 100); } @Override public void mouseClicked(MouseEvent e) { if ((e.getButton() == 1) && (e.getX() >= 70 && e.getX() <= 170 && e.getY() >= 70 && e .getY() <= 170)) { this.repaint(); // JOptionPane.showMessageDialog(null,e.getX()+ "\n" + e.getY()); } } @Override public void mouseEntered(MouseEvent e) { // TODO Auto-generated method stub } @Override public void mouseExited(MouseEvent e) { // TODO Auto-generated method stub } @Override public void mousePressed(MouseEvent e) { // TODO Auto-generated method stub } @Override public void mouseReleased(MouseEvent e) { // TODO Auto-generated method stub } } This Works Except it fires when the click is within a virtual box around the oval. Could anyone help me to have it fire when the click is EXACTLY on the oval. Thanks in advance.

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• WPF DataGrid, Help with Binding to a List<X> where each X has a Dictionary<Y,object> property.

  - by panamack

  I'm building an application which helps someone manage an event and works with data originating from Excel. I want to use the WPF Toolkit DataGrid to display the incoming data but can't guarantee how many Columns there are going to be or what information they will contain. I'd like to have an Info class that stores column information and have each Visitor at my Event own a Dictionary that uses shared references to Info objects for the keys. Here's the general gist: public class Info{ public string Name{get;set;} public int InfoType{get;set;} } public class Visitor{ public Dictionary<Info,object> VisitorInfo {get;set;} } public class Event{ public List<Visitor> Visitors{get;set;} public Event(){ Info i1 = new Info(){ Name = "ID", InfoType = 0};// type 0 for an id Info i2 = new Info(){ Name = "Name", InfoType = 1};// type 1 for a string Info i3 = new Info(){ Name = "City", InfoType = 1}; Visitor v1 = new Visitor(); v1.VisitorInfo.Add(i1, 0); v1.VisitorInfo.Add(i2, "Foo Harris"); v1.VisitorInfo.Add(i3, "Barsville"); Visitor v2 = new Visitor(); ... this.Visitors.Add(v1); this.Visitors.Add(v2); ... } } XAML: <!-- Window1.xaml --> ... <local:Event x:Key="MyEvent"/> ... <wpftk:DataGrid DataContext="{StaticResource MyEvent}" ItemsSource="{Binding Path=Visitors}" /> Disappointingly, DataGrid just sees a collection of Visitors each having a VisitorInfo property and displays one column called VisitorInfo with the string "(Collection)" once for each Visitor. As a workaround I've created a ListTVisitorToDataTableConverter that maps Infos to DataColumns and Visitors to DataRows and used it like this: <wpftk:DataGrid DataContext="{StaticResource Event}" ItemsSource{Binding Path=Visitors, Converter={StaticResource MySmellyListTVisitorToDataTableConverter}}" /> I don't think this is good though, I haven't started trying to convert back yet which I guess I'll need to do if I want to be able to edit any data! How can I do better? Thanks.

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• Why does std::map operator[] create an object if the key doesn't exist?

  - by n1ck

  Hi, I'm pretty sure I already saw this question somewhere (comp.lang.c++? Google doesn't seem to find it there either) but a quick search here doesn't seem to find it so here it is: Why does the std::map operator[] create an object if the key doesn't exist? I don't know but for me this seems counter-intuitive if you compare to most other operator[] (like std::vector) where if you use it you must be sure that the index exists. I'm wondering what's the rationale for implementing this behavior in std::map. Like I said wouldn't it be more intuitive to act more like an index in a vector and crash (well undefined behavior I guess) when accessed with an invalid key? Refining my question after seeing the answers: Ok so far I got a lot of answers saying basically it's cheap so why not or things similar. I totally agree with that but why not use a dedicated function for that (I think one of the comment said that in java there is no operator[] and the function is called put)? My point is why doesn't map operator[] work like a vector? If I use operator[] on an out of range index on a vector I wouldn't like it to insert an element even if it was cheap because that probably mean an error in my code. My point is why isn't it the same thing with map. I mean, for me, using operator[] on a map would mean: i know this key already exist (for whatever reason, i just inserted it, I have redundancy somewhere, whatever). I think it would be more intuitive that way. That said what are the advantage of doing the current behavior with operator[] (and only for that, I agree that a function with the current behavior should be there, just not operator[])? Maybe it give clearer code that way? I don't know. Another answer was that it already existed that way so why not keep it but then, probably when they (the ones before stl) choose to implement it that way they found it provided an advantage or something? So my question is basically: why choose to implement it that way, meaning a somewhat lack of consistency with other operator[]. What benefit do it give? Thanks

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• Two collections and a for loop. (Urgent help needed) Checking an object variable against an inputted

  - by Elliott

  Hi there, I'm relatively new to java, I'm certain the error is trivial. But can't for the life of me spot it. I have an end of term exam on monday and currently trying to get to grips with past papers! Anyway heregoes, in another method (ALGO_1) I search over elements of and check the value H_NAME equals a value entered in the main. When I attempt to run the code I get a null pointer exception, also upon trying to print (with System.out.println etc) the H_NAME value after each for loop in the snippet I also get a null statement returned to me. I am fairly certain that the collection is simply not storing the data gathered up by the Scanner. But then again when I check the collection size with size() it is about the right size. Either way I'm pretty lost and would appreciate the help. Main questions I guess to ask are: from the readBackground method is the data.add in the wrong place? is the snippet simply structured wrongly? oh and another point when I use System.out.println to check the Background object values name, starttime, increment etc they print out fine. Thanks in advance.(PS im guessing the formatting is terrible, apologies.) snippet of code: for(Hydro hd: hydros){ System.out.println(hd.H_NAME); for(Background back : backgs){ System.out.println(back.H_NAME); if(back.H_NAME.equals(hydroName)){ //get error here public static Collection<Background> readBackground(String url) throws IOException { URL u = new URL(url); InputStream is = u.openStream(); InputStreamReader isr = new InputStreamReader(is); BufferedReader b = new BufferedReader(isr); String line =""; Vector<Background> data = new Vector<Background>(); while((line = b.readLine())!= null){ Scanner s = new Scanner(line); String name = s.next(); double starttime = Double.parseDouble(s.next()); double increment = Double.parseDouble(s.next()); double sum = 0; double p = 0; double nterms = 0; while((s.hasNextDouble())){ p = Double.parseDouble(s.next()); nterms++; sum += p; } double pbmean = sum/nterms; Background SAMP = new Background(name, starttime, increment, pbmean); data.add(SAMP); } return data; } Edit/Delete Message

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• How do I write object classes effectively when dealing with table joins?

  - by Chris

  I should start by saying I'm not now, nor do I have any delusions I'll ever be a professional programmer so most of my skills have been learned from experience very much as a hobby. I learned PHP as it seemed a good simple introduction in certain areas and it allowed me to design simple web applications. When I learned about objects, classes etc the tutor's basic examnples covered the idea that as a rule of thumb each database table should have its own class. While that worked well for the photo gallery project we wrote, as it had very simple mysql queries, it's not working so well now my projects are getting more complex. If I require data from two separate tables which require a table join I've instead been ignoring the class altogether and handling it on a case by case basis, OR, even worse been combining some of the data into the class and the rest as a separate entity and doing two queries, which to me seems inefficient. As an example, when viewing content on a forum I wrote, if you view a thread, I retrieve data from the threads table, the posts table and the user table. The queries from the user and posts table are retrieved via a join and not instantiated as an object, whereas the thread data is called using my Threads class. So how do I get from my current state of affairs to something a little less 'stupid', for want of a better word. Right now I have a DB class that deals with connection and escaping values etc, a parent db query class that deals with the common queries and methods, and all of the other classes (Thread, Upload, Session, Photo and ones thats aren't used Post, User etc ) are children of that. Do I make a big posts class that has the relevant extra attributes that I retrieve from the users (and potentially threads) table? Do I have separate classes that populate each of their relevant attributes with a single query? If so how do I do that? Because of the way my classes are written, based on what I was taught, my db update row method, or insert method both just take the attributes as an array and update all of that, if I have extra attributes from other db tables in each class then how do I rewrite those methods as obbiously updating automatically like that would result in errors? In short I think my understanding is limited right now and I'd like some pointers when it comes to the fundamentals of how to write more complex classes.

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• Error #1009 Cannot access a property or method of a null object reference.

  - by user288920

  Hey everyone, I'm trying to import an external SWF with a scrollbar, calling out to an external .AS, into my main SWF. Someone told me, it's an issue that my scrollbar isn't instantiated yet, but stopped short of helping me how to fix the problem. Here's the error below: TypeError: Error #1009: Cannot access a property or method of a null object reference. at Scrollbar/init() at Sample2_fla::MainTimeline/scInit() at flash.display::DisplayObjectContainer/addChild() at Sample2_fla::MainTimeline/frame1() On my main SWF, I was to click a button and load my external SWF. I want to then click another button in the external SWF and reveal my scrollbar (alpha=1;). The scrollbar is the issue. Here's my script: Sample1.swf (main) this.addEventListener(MouseEvent.CLICK, clickListener); var oldSection=null; function clickListener(evt:Event) { if (evt.target.name=="button_btn") { loadSection("Sample2.swf"); } } function loadSection(filePath:String) { var url:URLRequest=new URLRequest(filePath); var ldr:Loader = new Loader(); ldr.contentLoaderInfo.addEventListener(Event.COMPLETE, sectionLoadedListener); ldr.load(url); } function sectionLoadedListener(evt:Event) { var section=evt.target.content; if (oldSection) { removeChild(oldSection); } oldSection=section; addChild(section); section.x=0; section.y=0; } Sample2.SWF (external): import com.greensock.*; import com.greensock.easing.*; import com.greensock.plugins.*; scroll_mc.alpha=0; import Scrollbar; var sc:Scrollbar=new Scrollbar(scroll_mc.text,scroll_mc.maskmc,scroll_mc.scrollbar.ruler,scroll_mc.scrollbar.background,scroll_mc.area,true,6); sc.addEventListener(Event.ADDED, scInit); addChild(sc); function scInit(e:Event):void { sc.init(); } button2_btn.addEventListener(MouseEvent.CLICK, clickListener); function clickListener(evt:MouseEvent){ TweenMax.to(this.scroll_mc, 1,{alpha:1}); } I really appreciate your help. Cheers!

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• How do you make the scale animation begin at the middle of the object instead of the top left?

  - by Roy

  What I am trying to accomplish: 10 percent increase scale transformation of a rectangle via Silverlight storyboard animation. What I currently doing: While in Expression Blend 3, I created a rectangle, created a storyboard, and created the scale transformation. The preview looked correct because the increase in scale begins in the middle of the object. When I run the project the scale transformation begins at the top left. Is there some piece of code missing? Here is my current code: <UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="TestingGroundsWebsite.MainPage" Width="640" Height="480"> <UserControl.Resources> <Storyboard x:Name="RectangleAppear"> <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="rectangle" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleX)"> <EasingDoubleKeyFrame KeyTime="00:00:00" Value="0.1"/> <EasingDoubleKeyFrame KeyTime="00:00:01" Value="1.1"/> <EasingDoubleKeyFrame KeyTime="00:00:02" Value="1"/> </DoubleAnimationUsingKeyFrames> <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="rectangle" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleY)"> <EasingDoubleKeyFrame KeyTime="00:00:00" Value="0.1"/> <EasingDoubleKeyFrame KeyTime="00:00:01" Value="1.1"/> <EasingDoubleKeyFrame KeyTime="00:00:02" Value="1"/> </DoubleAnimationUsingKeyFrames> </Storyboard> </UserControl.Resources> <Canvas x:Name="LayoutRoot" Background="White"> <Rectangle x:Name="rectangle" Fill="#FFE80000" Stroke="Black" Height="75" Width="76" Canvas.Left="227" Canvas.Top="167" RenderTransformOrigin="0.5,0.5"> <Rectangle.RenderTransform> <TransformGroup> <ScaleTransform/> <SkewTransform/> <RotateTransform/> <TranslateTransform/> </TransformGroup> </Rectangle.RenderTransform> </Rectangle> </Canvas> </UserControl> Thanks

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• When an active_record is saved, is it saved before or after its associated object(s)?

  - by SeeBees

  In rails, when saving an active_record object, its associated objects will be saved as well. But has_one and has_many association have different order in saving objects. I have three simplified models: class Team < ActiveRecord::Base has_many :players has_one :coach end class Player < ActiveRecord::Base belongs_to :team validates_presence_of :team_id end class Coach < ActiveRecord::Base belongs_to :team validates_presence_of :team_id end I use the following code to test these models: t = Team.new team.coach = Coach.new team.save! team.save! returns true. But in another test: t = Team.new team.players << Player.new team.save! team.save! gives the following error: > ActiveRecord::RecordInvalid: > Validation failed: Players is invalid I figured out that when team.save! is called, it first calls player.save!. player needs to validate the presence of the id of the associated team. But at the time player.save! is called, team hasn't been saved yet, and therefore, team_id doesn't yet exist for player. This fails the player's validation, so the error occurs. But on the other hand, team is saved before coach.save!, otherwise the first example will get the same error as the second one. So I've concluded that when a has_many bs, a.save! will save bs prior to a. When a has_one b, a.save! will save a prior to b. If I am right, why is this the case? It doesn't seem logical to me. Why do has_one and has_many association have different order in saving? Any ideas? And is there any way I can change the order? Say I want to have the same saving order for both has_one and has_many. Thanks.

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• Dynamic Types and DynamicObject References in C#

  - by Rick Strahl

  I've been working a bit with C# custom dynamic types for several customers recently and I've seen some confusion in understanding how dynamic types are referenced. This discussion specifically centers around types that implement IDynamicMetaObjectProvider or subclass from DynamicObject as opposed to arbitrary type casts of standard .NET types. IDynamicMetaObjectProvider types  are treated special when they are cast to the dynamic type. Assume for a second that I've created my own implementation of a custom dynamic type called DynamicFoo which is about as simple of a dynamic class that I can think of:public class DynamicFoo : DynamicObject { Dictionary<string, object> properties = new Dictionary<string, object>(); public string Bar { get; set; } public DateTime Entered { get; set; } public override bool TryGetMember(GetMemberBinder binder, out object result) { result = null; if (!properties.ContainsKey(binder.Name)) return false; result = properties[binder.Name]; return true; } public override bool TrySetMember(SetMemberBinder binder, object value) { properties[binder.Name] = value; return true; } } This class has an internal dictionary member and I'm exposing this dictionary member through a dynamic by implementing DynamicObject. This implementation exposes the properties dictionary so the dictionary keys can be referenced like properties (foo.NewProperty = "Cool!"). I override TryGetMember() and TrySetMember() which are fired at runtime every time you access a 'property' on a dynamic instance of this DynamicFoo type. Strong Typing and Dynamic Casting I now can instantiate and use DynamicFoo in a couple of different ways: Strong TypingDynamicFoo fooExplicit = new DynamicFoo(); var fooVar = new DynamicFoo(); These two commands are essentially identical and use strong typing. The compiler generates identical code for both of them. The var statement is merely a compiler directive to infer the type of fooVar at compile time and so the type of fooExplicit is DynamicFoo, just like fooExplicit. This is very static - nothing dynamic about it - and it completely ignores the IDynamicMetaObjectProvider implementation of my class above as it's never used. Using either of these I can access the native properties:DynamicFoo fooExplicit = new DynamicFoo();// static typing assignmentsfooVar.Bar = "Barred!"; fooExplicit.Entered = DateTime.Now; // echo back static values Console.WriteLine(fooVar.Bar); Console.WriteLine(fooExplicit.Entered); but I have no access whatsoever to the properties dictionary. Basically this creates a strongly typed instance of the type with access only to the strongly typed interface. You get no dynamic behavior at all. The IDynamicMetaObjectProvider features don't kick in until you cast the type to dynamic. If I try to access a non-existing property on fooExplicit I get a compilation error that tells me that the property doesn't exist. Again, it's clearly and utterly non-dynamic. Dynamicdynamic fooDynamic = new DynamicFoo(); fooDynamic on the other hand is created as a dynamic type and it's a completely different beast. I can also create a dynamic by simply casting any type to dynamic like this:DynamicFoo fooExplicit = new DynamicFoo(); dynamic fooDynamic = fooExplicit; Note that dynamic typically doesn't require an explicit cast as the compiler automatically performs the cast so there's no need to use as dynamic. Dynamic functionality works at runtime and allows for the dynamic wrapper to look up and call members dynamically. A dynamic type will look for members to access or call in two places: Using the strongly typed members of the object Using theIDynamicMetaObjectProvider Interface methods to access members So rather than statically linking and calling a method or retrieving a property, the dynamic type looks up - at runtime  - where the value actually comes from. It's essentially late-binding which allows runtime determination what action to take when a member is accessed at runtime *if* the member you are accessing does not exist on the object. Class members are checked first before IDynamicMetaObjectProvider interface methods are kick in. All of the following works with the dynamic type:dynamic fooDynamic = new DynamicFoo(); // dynamic typing assignments fooDynamic.NewProperty = "Something new!"; fooDynamic.LastAccess = DateTime.Now; // dynamic assigning static properties fooDynamic.Bar = "dynamic barred"; fooDynamic.Entered = DateTime.Now; // echo back dynamic values Console.WriteLine(fooDynamic.NewProperty); Console.WriteLine(fooDynamic.LastAccess); Console.WriteLine(fooDynamic.Bar); Console.WriteLine(fooDynamic.Entered); The dynamic type can access the native class properties (Bar and Entered) and create and read new ones (NewProperty,LastAccess) all using a single type instance which is pretty cool. As you can see it's pretty easy to create an extensible type this way that can dynamically add members at runtime dynamically. The Alter Ego of IDynamicObject The key point here is that all three statements - explicit, var and dynamic - declare a new DynamicFoo(), but the dynamic declaration results in completely different behavior than the first two simply because the type has been cast to dynamic. Dynamic binding means that the type loses its typical strong typing, compile time features. You can see this easily in the Visual Studio code editor. As soon as you assign a value to a dynamic you lose Intellisense and you see which means there's no Intellisense and no compiler type checking on any members you apply to this instance. If you're new to the dynamic type it might seem really confusing that a single type can behave differently depending on how it is cast, but that's exactly what happens when you use a type that implements IDynamicMetaObjectProvider. Declare the type as its strong type name and you only get to access the native instance members of the type. Declare or cast it to dynamic and you get dynamic behavior which accesses native members plus it uses IDynamicMetaObjectProvider implementation to handle any missing member definitions by running custom code. You can easily cast objects back and forth between dynamic and the original type:dynamic fooDynamic = new DynamicFoo(); fooDynamic.NewProperty = "New Property Value"; DynamicFoo foo = fooDynamic; foo.Bar = "Barred"; Here the code starts out with a dynamic cast and a dynamic assignment. The code then casts back the value to the DynamicFoo. Notice that when casting from dynamic to DynamicFoo and back we typically do not have to specify the cast explicitly - the compiler can induce the type so I don't need to specify as dynamic or as DynamicFoo. Moral of the Story This easy interchange between dynamic and the underlying type is actually super useful, because it allows you to create extensible objects that can expose non-member data stores and expose them as an object interface. You can create an object that hosts a number of strongly typed properties and then cast the object to dynamic and add additional dynamic properties to the same type at runtime. You can easily switch back and forth between the strongly typed instance to access the well-known strongly typed properties and to dynamic for the dynamic properties added at runtime. Keep in mind that dynamic object access has quite a bit of overhead and is definitely slower than strongly typed binding, so if you're accessing the strongly typed parts of your objects you definitely want to use a strongly typed reference. Reserve dynamic for the dynamic members to optimize your code. The real beauty of dynamic is that with very little effort you can build expandable objects or objects that expose different data stores to an object interface. I'll have more on this in my next post when I create a customized and extensible Expando object based on DynamicObject.© Rick Strahl, West Wind Technologies, 2005-2012Posted in CSharp  .NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• ActAs and OnBehalfOf support in WIF

  - by cibrax

  I discussed a time ago how WIF supported a new WS-Trust 1.4 element, “ActAs”, and how that element could be used for authentication delegation.  The thing is that there is another feature in WS-Trust 1.4 that also becomes handy for this kind of scenario, and I did not mention in that last post, “OnBehalfOf”. Shiung Yong wrote an excellent summary about the difference of these two new features in this forum thread. He basically commented the following, “An ActAs RST element indicates that the requestor wants a token that contains claims about two distinct entities: the requestor, and an external entity represented by the token in the ActAs element. An OnBehalfOf RST element indicates that the requestor wants a token that contains claims only about one entity: the external entity represented by the token in the OnBehalfOf element. In short, ActAs feature is typically used in scenarios that require composite delegation, where the final recipient of the issued token can inspect the entire delegation chain and see not just the client, but all intermediaries to perform access control, auditing and other related activities based on the whole identity delegation chain. The ActAs feature is commonly used in multi-tiered systems to authenticate and pass information about identities between the tiers without having to pass this information at the application/business logic layer. OnBehalfOf feature is used in scenarios where only the identity of the original client is important and is effectively the same as identity impersonation feature available in the Windows OS today. When the OnBehalfOf is used the final recipient of the issued token can only see claims about the original client, and the information about intermediaries is not preserved. One common pattern where OnBehalfOf feature is used is the proxy pattern where the client cannot access the STS directly but is instead communicating through a proxy gateway. The proxy gateway authenticates the caller and puts information about him into the OnBehalfOf element of the RST message that it then sends to the real STS for processing. The resulting token is going to contain only claims related to the client of the proxy, making the proxy completely transparent and not visible to the receiver of the issued token.” Going back to WIF, “ActAs” and “OnBehalfOf” are both supported as extensions methods in the WCF client channel. public static class ChannelFactoryOperations {   public static T CreateChannelActingAs<T>(this ChannelFactory<T> factory,     SecurityToken actAs);     public static T CreateChannelOnBehalfOf<T>(this ChannelFactory<T> factory,     SecurityToken onBehalfOf); } Both methods receive the security token with the identity of the original caller.

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• OFM 11g: OAM SSO for Forms and ADF Faces

  - by olaf.heimburger

  In my blog entry OFM 11g: Implementing OAM SSO with Forms we set the foundation for providing a complete Single Sign-On solution based on Oracle Access Manager (OAM). This foundation should now be used to combine Forms 11g and ADF Faces 11g applications with a transparent login. The Beginning Before we start, lets re-consider the requirements to achieve the ultimate goal. These are:- Access to the Forms 11g Application must be authenticated by OAM (protected). Access to the ADF Faces 11g Application must be authenticated by OAM (protected). Switching from one application to the other should not result in a re-authentication (aka single sign-on). User identity should be availble to the application without any extra work in the application code. All these are the common requirements for a single sign-on solution. The challenge here is that Forms relies on Oracle AS SSO (OSSO or "the old SSO") while ADF Faces is quite open and can be protected by Oracle AS SSO and Oracle Access Manager SSO (OAM SSO or "the modern SSO"). Both application types can use their own login mechanism. The Forms 11g Application To demonstrate the SSO functionality, we use the standard Forms test (/forms/frmservlet?form=test.fmx). Although this shows nothing specific in the Forms application, it is good enough to demonstrate that it is protected. The ADF Faces 11g Application With ADF 11g you can develop quite a number of useful Faces based applications. Among many features, it comes with the ADF Security feature that provides you with functionality to protect your pages, regions, and even TaskFlows from un-authenticated usage in a declarative way.To demonstrate that functionality a sample application with different access levels plus a login dialog is used. This application comes with a publc page that has protected content (a button). Once you are authenticated for the application, the protected content and some personalisation (the users name) is shown. Protecting Forms 11g As already explained in the OFM 11g: Implementing OAM SSO with Forms, the easiest way to protect a Forms application is to configure it as a OSSO partner application, setup mod_osso, test it, migrate OSSO to OAM SSO with the Upgrade Agent, reconfigure mod_osso, and you are done.Sort of. By default the OAM is configured to run in co-exist mode. This means that a user has to re-authenticate to the Forms application when logged into an OAM SSO application before. To avoid this, you must disable the co-exist mode, for example by using WLST and issue the disableCoexistMode on the OAM server. Protecting ADF Faces 11g To protect an ADF Faces 11g application we have to consider two scenarios: Use a HTTPD server in front of WLS Use WLS without a HTTPD server Both scenarios have their pro's and cons' and we won't get into details and just describe how to configure both. Scenario 1: HTTPD Server with WLS In this scenario we have to setup the environment in some steps:- Configure a WebGate at OAMThis configuration can be done through the OAM console or by a script. No matter which way you choose, the WebGate configuration files will be created for you. Install the OAM WebGate into an HTTPD serverThe type of webgate you need to install depends on you HTTPD server. With Oracle HTTP Server 11g you can use the latest OAM 11g WebGate. With other HTTPD servers you must resort to OAM 10g WebGates. A OAM 11g WebGate can use the pre-created configuration files supplied during the WebGate configuration at OAM. An OAM 10g WebGate asks for the specific configuration and verifies it during installation. Configure the WLS plugin to forward the requests to WLSAgain, depending on your HTTPD Server you have different plugins to forward requests to WLS. With OHS 11g you can use the pre-installed mod_wl_ohs plugin. Its configuration is quite simple and straightforward. Configure an OAM SSPI Provider as a IdentityAsserter in WLS to retrieve the user identifierThis configuration is quite important as it retrieves the user identifier for the next step. If you have a SOA Suite installation within your OFM_HOME, the necessary software is already installed and you only need to setup your Security Realm within WLS.You can do this by pointing your browser to the WLS Console, log in as administrator, select the Security Realm (usually myrealm), and select Providers. We add the OAMIdentityAsserter as the first SSPI Provider. It is important that the Control Flag is set to SUFFICIENT. Every other configuration can be left as is, no changes are necessary here. Configure an OAM Identity Provider to get the real user identityIn OFM 11g: Implementing OAM SSO with Forms we have configured an OID as Identity Store. To get the user identity we need to configure the same OID as an SSPI Provider for WLS. This will retrieve the real user information from OID and creates the JAAS Subject and Principals to be used by any application within WLS.Again, you can do this by pointing your browser to the WLS Console, log in as administrator, select the Security Realm (usually myrealm), and select Providers. Now add the OIDAuthenticator as the second SSPI Provider. It is important that the Control Flag is set to OPTIONAL. After we saved this setup, we need to configure this provider by setting the Provider Specific details to access OID. Scenario 2: WLS only This scenario is a bit easier but requires more work in the WLS setup:- Configure a WebGate at OAMThis configuration can be done through the OAM console or by a script. No matter which way you choose, the WebGate configuration files will be created for you. Configure the OAM SSPI Provider as IdentityAuthenticator to authenticate and set the user identifierWhen using the OAM SSPI Provider as OAMAuthenticator we create it with the Control Flag as SUFFICIENT. Afte saving it, the Provider Specific settings must be configured to allow the OAM SSPI Provider to connect to the OAM Server. Configure an OAM Identity Provider to get the real user identity providerAgain, you can do this by pointing your browser to the WLS Console, log in as administrator, select the Security Realm (usually myrealm), and select Providers. Now add the OIDAuthenticator as the second SSPI Provider. It is important that the Control Flag is set to OPTIONAL. After we saved this setup, we need to configure this provider by setting the Provider Specific details to access OID. Configure ADF 11g Application for OAM Actually, there are no changes to be made within the ADF application. We only need to add the value CLIENT_CERT to the <auth-mode> tag in the <login-config> tag in the web.xml file. Testing To test the configuration, simply point your browser to one of both appliction URLs. OAM should kick in and redirect you to the OAM Login page. After you have entered the correct credentials, access to the URLs is granted and you will see the application. Enjoy!

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• SQL SERVER – Weekly Series – Memory Lane – #034

  - by Pinal Dave

  Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 UDF – User Defined Function to Strip HTML – Parse HTML – No Regular Expression The UDF used in the blog does fantastic task – it scans entire HTML text and removes all the HTML tags. It keeps only valid text data without HTML task. This is one of the quite commonly requested tasks many developers have to face everyday. De-fragmentation of Database at Operating System to Improve Performance Operating system skips MDF file while defragging the entire filesystem of the operating system. It is absolutely fine and there is no impact of the same on performance. Read the entire blog post for my conversation with our network engineers. Delay Function – WAITFOR clause – Delay Execution of Commands How do you delay execution of the commands in SQL Server – ofcourse by using WAITFOR keyword. In this blog post, I explain the same with the help of T-SQL script. Find Length of Text Field To measure the length of TEXT fields the function is DATALENGTH(textfield). Len will not work for text field. As of SQL Server 2005, developers should migrate all the text fields to VARCHAR(MAX) as that is the way forward. Retrieve Current Date Time in SQL Server CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} There are three ways to retrieve the current datetime in SQL SERVER. CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} Explanation and Comparison of NULLIF and ISNULL An interesting observation is NULLIF returns null if it comparison is successful, whereas ISNULL returns not null if its comparison is successful. In one way they are opposite to each other. Here is my question to you - How to create infinite loop using NULLIF and ISNULL? If this is even possible? 2008 Introduction to SERVERPROPERTY and example SERVERPROPERTY is a very interesting system function. It returns many of the system values. I use it very frequently to get different server values like Server Collation, Server Name etc. SQL Server Start Time We can use DMV to find out what is the start time of SQL Server in 2008 and later version. In this blog you can see how you can do the same. Find Current Identity of Table Many times we need to know what is the current identity of the column. I have found one of my developers using aggregated function MAX () to find the current identity. However, I prefer following DBCC command to figure out current identity. Create Check Constraint on Column Some time we just need to create a simple constraint over the table but I have noticed that developers do many different things to make table column follow rules than just creating constraint. I suggest constraint is a very useful concept and every SQL Developer should pay good attention to this subject. 2009 List Schema Name and Table Name for Database This is one of the blog post where I straight forward display script. One of the kind of blog posts, which I still love to read and write. Clustered Index on Separate Drive From Table Location A table devoid of primary key index is called heap, and here data is not arranged in a particular order, which gives rise to issues that adversely affect performance. Data must be stored in some kind of order. If we put clustered index on it then the order will be forced by that index and the data will be stored in that particular order. Understanding Table Hints with Examples Hints are options and strong suggestions specified for enforcement by the SQL Server query processor on DML statements. The hints override any execution plan the query optimizer might select for a query. 2010 Data Pages in Buffer Pool – Data Stored in Memory Cache One of my earlier year article, which I still read it many times and point developers to read it again. It is clear from the Resultset that when more than one index is used, datapages related to both or all of the indexes are stored in Memory Cache separately. TRANSACTION, DML and Schema Locks Can you create a situation where you can see Schema Lock? Well, this is a very simple question, however during the interview I notice over 50 candidates failed to come up with the scenario. In this blog post, I have demonstrated the situation where we can see the schema lock in database. 2011 Solution – Puzzle – Statistics are not updated but are Created Once In this example I have created following situation: Create Table Insert 1000 Records Check the Statistics Now insert 10 times more 10,000 indexes Check the Statistics – it will be NOT updated Auto Update Statistics and Auto Create Statistics for database is TRUE Now I have requested two things in the example 1) Why this is happening? 2) How to fix this issue? Selecting Domain from Email Address This is a straight to script blog post where I explain how to select only domain name from entire email address. Solution – Generating Zero Without using Any Numbers in T-SQL How to get zero digit without using any digit? This is indeed a very interesting question and the answer is even interesting. Try to come up with answer in next 10 minutes and if you can’t come up with the answer the blog post read this post for solution. 2012 Simple Explanation and Puzzle with SOUNDEX Function and DIFFERENCE Function In simple words - SOUNDEX converts an alphanumeric string to a four-character code to find similar-sounding words or names. DIFFERENCE function returns an integer value. The  integer returned is the number of characters in the SOUNDEX values that are the same. Read Only Files and SQL Server Management Studio (SSMS) I have come across a very interesting feature in SSMS related to “Read Only” files. I believe it is a little unknown feature as well so decided to write a blog about the same. Identifying Column Data Type of uniqueidentifier without Querying System Tables How do I know if any table has a uniqueidentifier column and what is its value without using any DMV or System Catalogues? Only information you know is the table name and you are allowed to return any kind of error if the table does not have uniqueidentifier column. Read the blog post to find the answer. Solution – User Not Able to See Any User Created Object in Tables – Security and Permissions Issue Interesting question – “When I try to connect to SQL Server, it lets me connect just fine as well let me open and explore the database. I noticed that I do not see any user created instances but when my colleague attempts to connect to the server, he is able to explore the database as well see all the user created tables and other objects. Can you help me fix it?” Importing CSV File Into Database – SQL in Sixty Seconds #018 – Video Here is interesting small 60 second video on how to import CSV file into Database. ColumnStore Index – Batch Mode vs Row Mode Here is the logic behind when Columnstore Index uses Batch Mode and when it uses Row Mode. A batch typically represents about 1000 rows of data. Batch mode processing also uses algorithms that are optimized for the multicore CPUs and increased memory throughput. Follow up – Usage of $rowguid and $IDENTITY This is an excellent follow up blog post of my earlier blog post where I explain where to use $rowguid and $identity.  If you do not know the difference between them, this is a blog with a script example. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Customizing Flowcharts in Oracle Tutor

  - by [email protected]

  Today we're going to look at how you can customize the flowcharts within Oracle Tutor procedures, and how you can share those changes with other authors within your company. Here is an image of a flowchart within a Tutor procedure with the default size and color scheme. You may want to change the size of your flowcharts as your end-users might have larger screens or need larger fonts. To change the size and number of columns, navigate to Tutor Author Author Options Flowcharts. The default is to have 4 columns appear in each flowchart, but, if I change it to six, my end-users will see a denser flowchart. This might be too dense for my end-users, so I will change it to 5 columns, and I will also deselect the option to have separate task boxes. Now let's look at how to customize the colors. Within the Flowchart options dialog, there is a button labeled "Colors." This brings up a dialog box of every object on a Tutor flowchart, and I can modify the color of each object, as well as the text within the object. If I click on the background, the "page" object appears in the Item field, and now I can customize the color and the title text by selecting Select Fill Color and/or Select Text Color. A dialog box with color choices appears. If I select Define Custom Colors, I can make my selections even more precise. Each time I change the color of an object, it appears in the selection screen. When the flowchart customization is finished, I can save my changes by naming the scheme. Although the color scheme I have chosen is rather silly looking, perhaps I want others to give me their feedback and make changes as they wish. I can share the color scheme with them by copying the FCP.INI file in the Tutor\Author directory into the same directory on their systems. If the other users have color schemes that they do not want to lose, they can copy the relevant lines from the FCP.INI file into their file. If I flowchart my document with the new scheme, I can see how it looks within the document. Sometimes just one or two changes to the default scheme are enough to customize the flowchart to your company's color palette. I have seen customers who have only changed the Start object to green and the End object to red, and I've seen another customer who changed every object to some variant of black and orange. Experiment! And let us know how you have customized your flowcharts. Mary R. Keane Senior Development Director, Oracle Tutor

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• What are the advantages of the delegate pattern over the observer pattern?

  - by JoJo

  In the delegate pattern, only one object can directly listen to another object's events. In the observer pattern, any number of objects can listen to a particular object's events. When designing a class that needs to notify other object(s) of events, why would you ever use the delegate pattern over the observer pattern? I see the observer pattern as more flexible. You may only have one observer now, but a future design may require multiple observers.

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• Next Generation Directory @ Oracle Open World

  - by Etienne Remillon

  Oracle OpenWorld 2012 is bigger, better, and more educational than ever before, and identity management activities are no exception. For all identity related activities check this entry, or this handy PDF. Do you focus more specifically on directory?Come and meet with the directory team at: Our session: Next Generation Directory: Oracle Unified Directory / session #CON946 / Tuesday Oct 2 5:00 pm / Moscone West L3, Room 3008 Our demo pod: Oracle Directory Services Plus: Performant, Cloud-Ready demo / Moscone South, Right - S-222 Demonstration Hours @ Moscone South: Mon 10:00 - 6:00 / Tues 09:45 - 6:00 / Wed 09:45 – 4:00

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