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  • Creating a new object destroys an older object with different name in C++

    - by Mikael
    First question here! So, I am having some problems with pointers in Visual C++ 2008. I'm writing a program which will control six cameras and do some processing on them so to clean things up I have created a Camera Manager class. This class handles all operations which will be carried out on all the cameras. Below this is a Camera class which interacts with each individual camera driver and does some basic image processing. Now, the idea is that when the manager is initialised it creates two cameras and adds them to a vector so that I can access them later. The catch here is that when I create the second camera (camera2) the first camera's destructor is called for some reason, which then disconnects the camera. Normally I'd assume that the problem is somewhere in the Camera class, but in this case everything works perfectly as long as I don't create the camera2 object. What's gone wrong? CameraManager.h: #include "stdafx.h" #include <vector> #include "Camera.h" class CameraManager{ std::vector<Camera> cameras; public: CameraManager(); ~CameraManager(); void CaptureAll(); void ShowAll(); }; CameraManager.cpp: #include "stdafx.h" #include "CameraManager.h" CameraManager::CameraManager() { printf("Camera Manager: Initializing\n"); [...] Camera *camera1 = new Camera(NodeInfo,1, -44,0,0); cameras.push_back(*camera1); // Adding the following two lines causes camera1's destructor to be called. Why? Camera *camera2 = new Camera(NodeInfo,0, 44,0,0); cameras.push_back(*camera2); printf("Camera Manager: Ready\n"); }

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  • JPA - Real primary key generated ID for references

    - by Val
    I have ~10 classes, each of them, have composite key, consist of 2-4 values. 1 of the classes is a main one (let's call it "Center") and related to other as one-to-one or one-to-many. Thinking about correct way of describing this in JPA I think I need to describe all the primary keys using @Embedded / @PrimaryKey annotations. Question #1: My concern is - does it mean that on the database level I will have # of additional columns in each table referring to the "Center" equal to number of column in "Center" PK? If yes, is it possible to avoid it by using some artificial unique key for references? Could you please give an idea how real PK and the artificial one needs to be described in this case? Note: The reason why I would like to keep the real PK and not just use the unique id as PK is - my application have some data loading functionality from external data sources and sometimes they may return records which I already have in local database. If unique ID will be used as PK - for new records I won't be able to do data update, since the unique ID will not be available for just downloaded ones. At the same time it is normal case scenario for application and it just need to update of insert new records depends on if the real composite primary key matches. Question #2: All of the 10 classes have common field "date" which I described in an abstract class which each of them extends. The "date" itself is never a key, but it always a part of composite key for each class. Composite key is different for each class. To be able to use this field as a part of PK should I describe it in each class or is there any way to use it as is? I experimented with @Embedded and @PrimaryKey annotations and always got an error that eclipselink can't find field described in an abstract class. Thank you in advance! PS. I'm using latest version of eclipselink & H2 database.

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  • Show Div When Radio Checked

    - by maniootek
    I tried to use this code: <script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js" type="text/javascript"></script> <style type="text/css"> div {display: none} </style> <script type="text/javascript"> $('.radio1').click(function () { $('.div1').show(); }); $('.radio2').click(function () { $('.div2').show(); }); </script> <label><input type="radio" name="group1" class="radio1"></label> <label><input type="radio" name="group1" class="radio2"></label> <div class="div1">Radio1 selected !</div> <div class="div2">Radio2 selected !</div> But when I check any radio then notthing happens. I tried with Fiddle: http://jsfiddle.net/Ac9c4/ and same no results Any idea?

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  • Conting of objects created in stack and heap for many classes

    - by viswanathan
    What is the best way to count the total number of objects created in both stack and heap for different classes. I know that in C++ new and delete operators can be overloaded and hence in the default constructor and destructor the object count can be incremented or decremented as and when the objects get created or destroyed. Further if i am to extend the same thing for object counting of objects of different classes, then i can create a dummy class and write the object count code in that class and then when i create any new class i can derive it from the Dummy class. Is there any other optimal solution to the same problem.

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  • Questions about use lib for perl

    - by Tyug
    I use use lib "./DIR" to grab a library from a folder elsewhere. However, it doesn't seem to work on my server, but it works fine on my local desktop. Any particular reasons? And one more question, does use lib get propagated within several modules? Two situations: Say I make a base class that requires a few libraries, but I know that it needs to be extended and the extended class will need to use another library. Can I put the use lib command in the base class? or will I need to put it in every extending class? Finally, can I just have a use package where package contains a bunch of use lib, will it propagate the use lib statements over to my current module? <-- I don't think so, but asking anyways Thanks in advance! Tyug

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  • Upload file using jquery dialog not working

    - by kandroid
    i want to upload file using jquery dialog. I have created a partial view and showing that partial view in the dialog. The problem is, when I directly browse the partial view and upload a file, it works perfect. BUT when I put the partial view inside a jquery dialog, it submits the form, but don't submits the file. So i have null value. I really dont understand what is the difference here!! Hope someone can help me to identify the problem. here is some codes; jquery codes: $('#UploadDialog').dialog({ autoOpen: false, width: 580, resizable: false, modal: true, open: function (event, ui) { $(this).load('@Url.Action("Upload","Notes")'); }, buttons: { "Upload": function () { $("#upload-message").html(''); $("#noteUploadForm").submit(); }, "Cancel": function () { $(this).dialog("close"); } } }); $(".uploadLink").click(function () { $('#UploadDialog').dialog('open'); }); return false; }); partial view: @using (Ajax.BeginForm("Upload", "Notes", null, new AjaxOptions { UpdateTargetId = "upload-message", InsertionMode = InsertionMode.Replace, HttpMethod = "POST", OnSuccess = "uploadSuccess" }, new { id = "noteUploadForm" , enctype="multipart/form-data"})) { <div> <div id="upload-message"></div> <div class="editLabel"> @Html.LabelFor(m => m.Notes.NoteTitle) </div> <div class="editText"> @Html.TextBoxFor(m => m.Notes.NoteTitle) </div> <div class="clear"></div> <div class="editLabel"> @Html.Label("Upload file") </div> <div class="editText"> <input type="file" name="file" />(100MB max size) </div> </div> }

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  • overloading new/delete problem

    - by hidayat
    This is my scenario, Im trying to overload new and delete globally. I have written my allocator class in a file called allocator.h. And what I am trying to achieve is that if a file is including this header file, my version of new and delete should be used. So in a header file "allocator.h" i have declared the two functions extern void* operator new(std::size_t size); extern void operator delete(void *p, std::size_t size); I the same header file I have a class that does all the allocator stuff, class SmallObjAllocator { ... }; I want to call this class from the new and delete functions and I would like the class to be static, so I have done this: template<unsigned dummy> struct My_SmallObjectAllocatorImpl { static SmallObjAllocator myAlloc; }; template<unsigned dummy> SmallObjAllocator My_SmallObjectAllocatorImpl<dummy>::myAlloc(DEFAULT_CHUNK_SIZE, MAX_OBJ_SIZE); typedef My_SmallObjectAllocatorImpl<0> My_SmallObjectAllocator; and in the cpp file it looks like this: allocator.cc void* operator new(std::size_t size) { std::cout << "using my new" << std::endl; if(size > MAX_OBJ_SIZE) return malloc(size); else return My_SmallObjectAllocator::myAlloc.allocate(size); } void operator delete(void *p, std::size_t size) { if(size > MAX_OBJ_SIZE) free(p); else My_SmallObjectAllocator::myAlloc.deallocate(p, size); } The problem is when I try to call the constructor for the class SmallObjAllocator which is a static object. For some reason the compiler are calling my overloaded function new when initializing it. So it then tries to use My_SmallObjectAllocator::myAlloc.deallocate(p, size); which is not defined so the program crashes. So why are the compiler calling new when I define a static object? and how can I solve it?

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  • ASP.NET MVC ActionLink in jquery-tmpl template

    - by Justin
    I have a jquery-tmpl defined: <script id="postTemplate" type="text/x-jquery-tmpl"> <div class="div-msg-actions-inner"> @Html.ActionLink("Edit", "Edit", "Post", new { postId = "${PostId}" }, new { @class = "button" }) @Html.ActionLink("Reply", "Reply", "Post", new { topicId = "${TopicId}" }, new { @class = "button" }) </div> </script> The action link results in the "$" being encoded into "%24". Is there a way around this so the ID in my action link will get replaced correctly?

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  • What happens if a bean attempts to load the Spring application context in its constructor?

    - by Derek Mahar
    Given the following Spring application context and class A, what happens when you run class A? applicationContext.xml (in classpath): <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"> <bean name="a" class="A"/> </beans> A.java: class A { private ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml"); public static void main(String[] args) { A a = new A(); } }

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  • How can one describe a rock-paper-scissors relationship between 3 items?

    - by Madara Uchiha
    Let's say I have the following structure: abstract class Hand {} class Rock extends Hand {} class Paper extends Hand {} class Scissors extends Hand {} The goal is to make a function (or a method) Hand::compareHands(Hand $hand1, Hand $hand2), which would return the winning hand in a rock-paper-scissors match. That would be very easy with a bunch of ifs, but the point is to have a more robust structure, that's relying on polymorphism rather than on procedural code. P.S. this is done in actual production code, if someone is asking. This isn't some sort of challenge or homework. (It's not really rock-paper-scissors, but you get the point).

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  • Load iframe in html, only with jquery

    - by phpExe
    In this jquery code: $(document).ready(function(){ $list = $(".channeList li"); $list.click(function(){ var $this = $(this); var $mainDesc = $(".ply"); var iframe = $("a", $this).attr("rel"); $("iframe", $mainDesc).attr("src", iframe); } ); } ); There is a list o channels in left that iframe loads from a rel's. I want to load first iframe in <div class="ply"></div> In html, I dont want insert the first item. Can we do this without load first item in html and do this only with jquery? The php function channel() { if (is_numeric($_GET['kanalID'])) { $kanalID = $_GET['kanalID']; } if ($_GET['kanalID'] == "") { $kanalID = 1;} $channel = '<ul class="channeList">'; foreach ($tv as $id => $kanal) { $class = $kanalID == $id ? $class = "currentt": ''; $channel .= '<li> <a href="#" rel="http://mysite.com/index.php?id='.$id.'&w=500&h=320" >'.$kanal.'</a></li>'; } $channel .= '</ul>'; $channel .= '<div class="ply"><iframe frameborder=0 width="500" height="320"></iframe></div>'; return $channel; } Thanks in advance

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  • How to retrieve last primary Id from mdb's table?

    - by William
    I got table with next columns: Id, Name, Age, Class I am trying to insert new row in db like this: INSERT INTO MyTable (Name, Age, Class) VALUES (@name, @age, @class) And get an exeption: "Index or primary key cannot contain a Null value." The question is how to add a new row without knowing next primary Id, or maybe there is a way to get this Id from the table with the help of another query ?

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  • Why are we getting a WCF "Framing error" on some machines but not others

    - by Ian Ringrose
    We have just found we are getting “framing errors” (as reported by the WCF logs) when running our system on some customer test machine. It all works ok on our development machines. We have an abstract base class, with KnownType attributes for all its sub classes. One of it’s subclass is missing it’s DataContract attribute. However it all worked on our test machine! On the customers test machine, we got “framing error” showing up the WCF logs, this is not the error message I have seen in the past when missing a DataContract attribute, or a KnownType attribute. I wish to get to the bottom of this, as we can no longer have confidence in our ability to test the system before giving it to the customer until we can make our machines behave the some as the customer’s machines. Code that try to show what I am talking about, (not the real code) [DataContract()] [KnownType(typeof(SubClass1))] [KnownType(typeof(SubClass2))] // other subclasses with data members public abstract class Base { [DataMember] public int LotsMoreItemsThenThisInRealLife; } /// <summary> /// This works on some machines (not not others) when passed to Contract::DoIt, /// note the missing [DataContract()] /// </summary> public class SubClass1 : Base { // has no data members } /// <summary> /// This works in all cases when passed to Contract::DoIt /// </summary> [DataContract()] public class SubClass2 : Base { // has no data members } public interface IContract { void DoIt(Base[] items); } public static class MyProgram { public static IContract ConntectToServerOverWCF() { // lots of code ... return null; } public static void Startup() { IContract server = ConntectToServerOverWCF(); // this works all of the time server.DoIt(new Base[]{new SubClass2(){LotsMoreItemsThenThisInRealLife=2}}); // this works "in develperment" e.g. on our machines, but not on the customer's test machines! server.DoIt(new Base[] { new SubClass1() { LotsMoreItemsThenThisInRealLife = 2 } }); } }

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  • Android Notification with AlarmManager, Broadcast and Service

    - by user2435829
    this is my code for menage a single notification: myActivity.java public class myActivity extends Activity { protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.mylayout); cal = Calendar.getInstance(); // it is set to 10.30 cal.set(Calendar.HOUR, 10); cal.set(Calendar.MINUTE, 30); cal.set(Calendar.SECOND, 0); long start = cal.getTimeInMillis(); if(cal.before(Calendar.getInstance())) { start += AlarmManager.INTERVAL_FIFTEEN_MINUTES; } Intent mainIntent = new Intent(this, myReceiver.class); pIntent = PendingIntent.getBroadcast(this, 0, mainIntent, PendingIntent.FLAG_UPDATE_CURRENT); AlarmManager myAlarm = (AlarmManager)getSystemService(ALARM_SERVICE); myAlarm.setRepeating(AlarmManager.RTC_WAKEUP, start, AlarmManager.INTERVAL_FIFTEEN_MINUTES, pIntent); } } myReceiver.java public class myReceiver extends BroadcastReceiver { @Override public void onReceive(Context c, Intent i) { Intent myService1 = new Intent(c, myAlarmService.class); c.startService(myService1); } } myAlarmService.java public class myAlarmService extends Service { @Override public IBinder onBind(Intent arg0) { return null; } @Override public void onCreate() { super.onCreate(); } @SuppressWarnings("deprecation") @Override public void onStart(Intent intent, int startId) { super.onStart(intent, startId); displayNotification(); } @Override public void onDestroy() { super.onDestroy(); } public void displayNotification() { Intent mainIntent = new Intent(this, myActivity.class); PendingIntent pIntent = PendingIntent.getActivity(this, 0, mainIntent, PendingIntent.FLAG_UPDATE_CURRENT); NotificationManager nm = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE); Notification.Builder builder = new Notification.Builder(this); builder.setContentIntent(pIntent) .setAutoCancel(true) .setSmallIcon(R.drawable.ic_noti) .setTicker(getString(R.string.notifmsg)) .setContentTitle(getString(R.string.app_name)) .setContentText(getString(R.string.notifmsg)); nm.notify(0, builder.build()); } } AndroidManifest.xml <uses-permission android:name="android.permission.WAKE_LOCK" /> ... ... ... <service android:name=".myAlarmService" android:enabled="true" /> <receiver android:name=".myReceiver"/> IF the time has NOT past yet everything works perfectly. The notification appears when it must appear. BUT if the time HAS past (let's assume it is 10.31 AM) the notification fires every time... when I close and re-open the app, when I click on the notification... it has a really strange behavior. I can't figure out what's wrong in it. Can you help me please (and explain why, if you find a solution), thanks in advance :)

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  • The Java interface doesn't declare any exception. How to manage checked exception of the implementat

    - by Frór
    Let's say I have the following Java interface that I may not modify: public interface MyInterface { public void doSomething(); } And now the class implementing it is like this: class MyImplementation implements MyInterface { public void doSomething() { try { // read file } catch (IOException e) { // what to do? } } } I can't recover from not reading the file. A subclass of RuntimeException can clearly help me, but I'm not sure if it's the right thing to do: the problem is that that exception would then not be documented in the class and a user of the class would possibly get that exception an know nothing about solving this. What can I do?

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  • CSS overflow : list in a div

    - by Felicita
    I have an image gallery and I dont want give an extra class to third list item: <div class="row"> <ul class="rowUl"> <li>ssss</li> <li>ssss</li> <li>ssss</li> </ul> </div> and css .row { width: 620px; clear: both; overflow: hidden; } .rowUl { width: 645px; float: left; } .rowUl li { width: 220px; float: left; } but the third list item drop in other row. How can I solve this without extra class?

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  • how to use listctrl in notebook wxPython

    - by ???
    I have one question.. wxPython listctrl in notebook I created 2 tab use notebook. I added button in first tab and added Listctrl in second tab. If i click the button, Add value in Listctrl to second tab. how to solve this problem? import wx class PageOne(wx.Panel): def __init__(self, parent): wx.Panel.__init__(self, parent) self.query_find_btn = wx.Button(self, 4, "BTN", (40,40)) self.Bind(wx.EVT_BUTTON, self.AddList, id = 4) def AddList(self, evt): self.list1.InsertStringItem(0,'Hello') class PageTwo(wx.Panel): def __init__(self, parent): wx.Panel.__init__(self, parent) self.list1 = wx.ListCtrl(self,-1,wx.Point(0,0),wx.Size(400,400),style=wx.LC_REPORT | wx.SUNKEN_BORDER) self.list1.InsertColumn(0,'values') class MyFrame(wx.Frame): def __init__(self, parent, id, title): wx.Frame.__init__(self,parent,id,title,size=(400,400),pos=wx.Point(100,100), style=wx.SYSTEM_MENU |wx.CAPTION ) p = wx.Panel(self) nb = wx.Notebook(p) MainFrame = PageOne(nb) SecondFrame = PageTwo(nb) nb.AddPage(MainFrame, "One") nb.AddPage(SecondFrame, "Two") sizer = wx.BoxSizer() sizer.Add(nb, 1, wx.EXPAND) p.SetSizer(sizer) class MyApp(wx.App): def OnInit(self): self.frame=MyFrame(None,-1,'Unknown.py') self.frame.Centre() self.frame.Show() return True if __name__ == '__main__': app = MyApp(False) app.MainLoop()

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  • How can I sync three classes?

    - by TheMachineCharmer
    class Foo { Bar b; List<Foo> Neighbours; } class Bar { Spam s; List<Bar> Neighbours; } class Spam { List<string> Neighbours; } Each of these classes have AddNeighbour,RemoveNeighbour methods. User can add/remove Neighbours from any of the class at random. I want these three objects to be in sync. How can I do this?

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  • What is Ruby's double-colon (::) all about?

    - by Meltemi
    I'd probably be able to answer this for myself if "::" wasn't so hard to Google. Didn't see anything on SO so thought I'd try my luck. What is this double-colon :: all about? I see it everywhere in Rails: class User < ActiveRecord::Base or… ActionController::Routing::Routes.draw do |map| I found a definition from this guy: The :: is a unary operator that allows: constants, instance methods and class methods defined within a class or module, to be accessed from anywhere outside the class or module. but that just leads to more questions. What good is scope (private, protected) if you can just use :: to expose anything?

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  • JPA entitylisteners and @embeddable

    - by seanizer
    I have a class hierarchy of JPA entities that all inherit from a BaseEntity class: @MappedSuperclass @EntityListeners( { ValidatorListener.class }) public abstract class BaseEntity implements Serializable { // other stuff } I want all entities that implement a given interface to be validated automatically on persist and/or update. Here's what I've got. My ValidatorListener: public class ValidatorListener { private enum Type { PERSIST, UPDATE } @PrePersist public void checkPersist(final Object entity) { if (entity instanceof Validateable) { this.check((Validateable) entity, Type.PERSIST); } } @PreUpdate public void checkUpdate(final Object entity) { if (entity instanceof Validateable) { this.check((Validateable) entity, Type.UPDATE); } } private void check(final Validateable entity, final Type persist) { switch (persist) { case PERSIST: if (entity instanceof Persist) { ((Persist) entity).persist(); } if (entity instanceof PersistOrUpdate) { ((PersistOrUpdate) entity).persistOrUpdate(); } break; case UPDATE: if (entity instanceof Update) { ((Update) entity).update(); } if (entity instanceof PersistOrUpdate) { ((PersistOrUpdate) entity).persistOrUpdate(); } break; default: break; } } } and here's my Validateable interface that it checks against (the outer interface is just a marker, the inner contain the methods): public interface Validateable { interface Persist extends Validateable { void persist(); } interface PersistOrUpdate extends Validateable { void persistOrUpdate(); } interface Update extends Validateable { void update(); } } All of this works, however I would like to extend this behavior to Embeddable classes. I know two solutions: call the validation method of the embeddable object manually from the entity validation method: public void persistOrUpdate(){ // validate my own properties first // then manually validate the embeddable property: myEmbeddable.persistOrUpdate(); // this works but I'd like something that I don't have to call manually } use reflection, checking all properties to see if their type is of one of their interface types. This would work, but it's not pretty. Is there a more elegant solution?

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  • Appropriate uses of Monad `fail` vs. MonadPlus `mzero`

    - by jberryman
    This is a question that has come up several times for me in the design code, especially libraries. There seems to be some interest in it so I thought it might make a good community wiki. The fail method in Monad is considered by some to be a wart; a somewhat arbitrary addition to the class that does not come from the original category theory. But of course in the current state of things, many Monad types have logical and useful fail instances. The MonadPlus class is a sub-class of Monad that provides an mzero method which logically encapsulates the idea of failure in a monad. So a library designer who wants to write some monadic code that does some sort of failure handling can choose to make his code use the fail method in Monad or restrict his code to the MonadPlus class, just so that he can feel good about using mzero, even though he doesn't care about the monoidal combining mplus operation at all. Some discussions on this subject are in this wiki page about proposals to reform the MonadPlus class. So I guess I have one specific question: What monad instances, if any, have a natural fail method, but cannot be instances of MonadPlus because they have no logical implementation for mplus? But I'm mostly interested in a discussion about this subject. Thanks! EDIT: One final thought occured to me. I recently learned (even though it's right there in the docs for fail) that monadic "do" notation is desugared in such a way that pattern match failures, as in (x:xs) <- return [] call the monad's fail. It seems like the language designers must have been strongly influenced by the prospect of some automatic failure handling built in to haskell's syntax in their inclusion of fail in Monad.

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  • Extending existing data structure in Scala.

    - by Lukasz Lew
    I have a normal tree defined in Scala. sealed abstract class Tree case class Node (...) extends Tree case class Leaf (...) extends Tree Now I want to add a member variable to all nodes and leaves in the tree. Is it possible with extend keyword or do I have to modify the tree classes by adding [T]?

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  • Loading Java applet from WEB-INF/classes by JSP

    - by Bruce
    Hi guys, Ive got a problem with loading an applet from WEB-INF/classes directory. The main class of an applet (MainApplet.class) is there in the package aaa, but when loading I got the exception java.lang.ClassNotFoundException. Where am I wrong? My jsp is in Web Pages dir. < jsp:plugin type="applet" code="aaa/MainApplet.class" jreversion="1.6" width="700" height="500" Thanks in advance for the reply!

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  • Can JMX operations take interfaces as parameters?

    - by Thor84no
    I'm having problems with an MBean that takes a Map<String, Object> as a parameter. If I try to execute it via JMX using a proxy object, I get an Exception: Caused by: javax.management.ReflectionException at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:231) at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:668) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) Caused by: java.lang.IllegalArgumentException: Unable to find operation updateProperties(java.util.HashMap) It appears that it attempts to use the actual implementation class rather than the interface, and doesn't check if this is a child of the required interface. The same thing happens for extended classes (for example declare HashMap, pass in LinkedHashMap). Does this mean it's impossible to use an interface for such methods? At the moment I'm getting around it by changing the method signature to accept a HashMap, but it seems odd that I wouldn't be able to use interfaces (or extended classes) in my MBeans. Edit: The proxy object is being created by an in-house utility class called JmxInvocationHandler. The (hopefully) relevant parts of it are as follows: public class JmxInvocationHandler implements InvocationHandler { ... public static <T> T createMBean(final Class<T> iface, SFSTestProperties properties, String mbean, int shHostID) { T newProxyInstance = (T) Proxy.newProxyInstance(iface.getClassLoader(), new Class[] { iface }, (InvocationHandler) new JmxInvocationHandler(properties, mbean, shHostID)); return newProxyInstance; } ... private JmxInvocationHandler(SFSTestProperties properties, String mbean, int shHostID) { this.mbeanName = mbean + MBEAN_SUFFIX + shHostID; msConfig = new MsConfiguration(properties.getHost(0), properties.getMSAdminPort(), properties.getMSUser(), properties.getMSPassword()); } ... public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { if (management == null) { management = ManagementClientStore.getInstance().getManagementClient(msConfig.getHost(), msConfig.getAdminPort(), msConfig.getUser(), msConfig.getPassword(), false); } final Object result = management.methodCall(mbeanName, method.getName(), args == null? new Object[] {} : args); return result; } }

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  • Effective Data Validation

    - by John Conde
    What's an effective way to handle data validation, say, from a form submission? Originally I had a bunch of if statements that checked each value and collected invalid values in an array for later retrieval (and listing). // Store errors here $errors = array(); // Hypothetical check if a string is alphanumeric if (!preg_match('/^[a-z\d]+$/i', $fieldvalue)) { $errors[$fieldname] = 'Please only use letters and numbers for your street address'; } // etc... What I did next was create a class that handles various data validation scenarios and store the results in an internal array. After data validation was complete I would check to see if any errors occurred and handle accordingly: class Validation { private $errorList = array(); public function isAlphaNumeric($string, $field, $msg = '') { if (!preg_match('/^[a-z\d]+$/i', $string)) { $this->errorList[$field] = $msg; } } // more methods here public function creditCard($cardNumber, $field, $msg = '') { // Validate credit card number } // more methods here public function hasErrors() { return count($this->errorList); } } /* Client code */ $validate = new Validation(); $validate->isAlphaNumeric($fieldvalue1, $fieldname1, 'Please only use letters and numbers for your street address'); $validate->creditCard($fieldvalue2, $fieldname2, 'Please enter a valid credit card number'); if ($validate->hasErrors()) { // Handle as appropriate } Naturally it didn't take long before this class became bloated with the virtually unlimited types of data to be validated. What I'm doing now is using decorators to separate the different types of data into their own classes and call them only when needed leaving generic validations (i.e. isAlphaNumeric()) in the base class: class Validation { private $errorList = array(); public function isAlphaNumeric($string, $field, $msg = '') { if (!preg_match('/^[a-z\d]+$/i', $string)) { $this->errorList[$field] = $msg; } } // more generic methods here public function setError($field, $msg = '') { $this->errorList[$field] = $msg; } public function hasErrors() { return count($this->errorList); } } class ValidationCreditCard { protected $validate; public function __construct(Validation $validate) { $this->validate = $validate; } public function creditCard($cardNumber, $field, $msg = '') { // Do validation // ... // if there is an error $this->validate->setError($field, $msg); } // more methods here } /* Client code */ $validate = new Validation(); $validate->isAlphaNumeric($fieldvalue, $fieldname, 'Please only use letters and numbers for your street address'); $validateCC = new ValidationCreditCard($validate); $validateCC->creditCard($fieldvalue2, $fieldname2, 'Please enter a valid credit card number'); if ($validate->hasErrors()) { // Handle as appropriate } Am I on the right track? Or did I just complicate data validation more then I needed to?

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