Search Results

Search found 45150 results on 1806 pages for 'class'.

Page 86/1806 | < Previous Page | 82 83 84 85 86 87 88 89 90 91 92 93  | Next Page >

  • Java: is Exception class thread-safe?

    - by Vilius Normantas
    As I understand, Java's Exception class is certainly not immutable (methods like initCause and setStackTrace give some clues about that). So is it at least thread-safe? Suppose one of my classes has a field like this: private final Exception myException; Can I safely expose this field to multiple threads? I'm not willing to discuss concrete cases where and why this situation could occur. My question is more about the principle: can I tell that a class which exposes field of Exception type is thread-safe? Another example: class CustomException extends Exception { ... } Is this class thread-safe?

    Read the article

  • Custom class object in Initialization list

    - by Michael
    I have a class Bar: class Bar { public: Bar(void); ~Bar(void); }; And a class Foo that gets a reference to Bar object as a constructor parameter and needs to save it in a private member bar_ : class Foo { private: Bar& bar_; public: Foo(Bar& bar) : bar_(bar) {} ~Foo(void) {} }; This doesn't compile : overloaded member function not found in 'Parser' missing type specifier - int assumed. Note: C++ does not support default-int Now i suspect couple of things that i need to assure, the second error is for Bar& bar_; declaration in Foo. Do i need to use an explicit constructor when declaring bar_ ? I am interested in learning how the compiler works regarding this matter, so a detailed explanation would be highly appreciated. Thanks.

    Read the article

  • Obtaining reference to Class instance by string name - VB.NET

    - by Jeff Williams
    Is it possible using Reflection or some other method to obtain a reference to a specific class instance from the name of that class instance? For example the framework for the applications i develop heavily uses public class instances such as: Public bMyreference as MyReference = new MyReference Then throughout the application bMyReference is used by custom controls and code. One of the properties of the custom controls is the "FieldName" which references a Property in these class instances (bMyReference.MyField) as a string. What i would like to be able to do is analyze this string "bMyReference.MyField" and then refer back to the actual Instance/Property. In VB6 I would use an EVAL or something simular to convert the string to an actual object but this obviously doesn't work in VB.net What I'm picturing is something like this Dim FieldName as String = MyControl.FieldName ' sets FielName to bMyReference.MyField Dim FieldObject() as String = FieldName.Split(".") ' Split into the Object / Property Dim myInstance as Object = ......... ' Obtain a reference to the Instance and set as myInstance Dim myProperty = myInstance.GetType().GetProperty(FieldObject(1))

    Read the article

  • using AsyncTask class for parallel operationand displaying a progress bar

    - by Kumar
    I am displaying a progress bar using Async task class and simulatneously in parallel operation , i want to retrieve a string array from a function of another class that takes some time to return the string array. The problem is that when i place the function call in doing backgroung function of AsyncTask class , it gives an error in Doing Background and gives the message as cant change the UI in doing Background .. Therefore , i placed the function call in post Execute method of Asynctask class . It doesnot give an error but after the progress bar has reached 100% , then the screen goes black and takes some time to start the new activity. How can i display the progress bar and make the function call simultaneously.??plz help , m in distress here is the code package com.integrated.mpr; import android.app.Activity; import android.app.ProgressDialog; import android.content.Intent; import android.os.AsyncTask; import android.os.Bundle; import android.os.Handler; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class Progess extends Activity implements OnClickListener{ static String[] display = new String[Choose.n]; Button bprogress; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.progress); bprogress = (Button) findViewById(R.id.bProgress); bprogress.setOnClickListener(this); } @Override public void onClick(View v) { // TODO Auto-generated method stub switch(v.getId()){ case R.id.bProgress: String x ="abc"; new loadSomeStuff().execute(x); break; } } public class loadSomeStuff extends AsyncTask<String , Integer , String>{ ProgressDialog dialog; protected void onPreExecute(){ dialog = new ProgressDialog(Progess.this); dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL); dialog.setMax(100); dialog.show(); } @Override protected String doInBackground(String... arg0) { // TODO Auto-generated method stub for(int i = 0 ;i<40;i++){ publishProgress(5); try { Thread.sleep(1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } dialog.dismiss(); String y ="abc"; return y; } protected void onProgressUpdate(Integer...progress){ dialog.incrementProgressBy(progress[0]); } protected void onPostExecute(String result){ display = new Logic().finaldata(); Intent openList = new Intent("com.integrated.mpr.SENSITIVELIST"); startActivity(openList); } } }

    Read the article

  • PDO using singleton stored as class properity

    - by Misiur
    Hi again. OOP drives me crazy. I can't move PDO to work. Here's my DB class: class DB extends PDO { public function &instance($dsn, $username = null, $password = null, $driver_options = array()) { static $instance = null; if($instance === null) { try { $instance = new self($dsn, $username, $password, $driver_options); } catch(PDOException $e) { throw new DBException($e->getMessage()); } } return $instance; } } It's okay when i do something like this: try { $db = new DB(DB_TYPE.':host='.DB_HOST.';dbname='.DB_NAME, DB_USER, DB_PASS); } catch(DBException $e) { echo $e->getMessage(); } But this: try { $db = DB::instance(DB_TYPE.':host='.DB_HOST.';dbname='.DB_NAME, DB_USER, DB_PASS); } catch(DBException $e) { echo $e->getMessage(); } Does nothing. I mean, even when I use wrong password/username, I don't get any exception. Second thing - I have class which is "heart" of my site: class Core { static private $instance; public $db; public function __construct() { if(!self::$instance) { $this->db = DB::instance(DB_TYPE.':hpost='.DB_HOST.';dbname='.DB_NAME, DB_USER, DB_PASS); } return self::$instance; } private function __clone() { } } I've tried to use "new DB" inside class, but this: $r = $core->db->query("SELECT * FROM me_config"); print_r($r->fetch()); Return nothing. $sql = "SELECT * FROM me_config"; print_r($core->db->query($sql)); I get: PDOStatement Object ( [queryString] => SELECT * FROM me_config ) I'm really confused, what am I doing wrong?

    Read the article

  • How to update GUI thread/class from worker thread/class?

    - by user315182
    First question here so hello everyone. The requirement I'm working on is a small test application that communicates with an external device over a serial port. The communication can take a long time, and the device can return all sorts of errors. The device is nicely abstracted in its own class that the GUI thread starts to run in its own thread and has the usual open/close/read data/write data basic functions. The GUI is also pretty simple - choose COM port, open, close, show data read or errors from device, allow modification and write back etc. The question is simply how to update the GUI from the device class? There are several distinct types of data the device deals with so I need a relatively generic bridge between the GUI form/thread class and the working device class/thread. In the GUI to device direction everything works fine with [Begin]Invoke calls for open/close/read/write etc. on various GUI generated events. I've read the thread here (How to update GUI from another thread in C#?) where the assumption is made that the GUI and worker thread are in the same class. Google searches throw up how to create a delegate or how to create the classic background worker but that's not at all what I need, although they may be part of the solution. So, is there a simple but generic structure that can be used? My level of C# is moderate and I've been programming all my working life, given a clue I'll figure it out (and post back)... Thanks in advance for any help.

    Read the article

  • Append json data to html class name

    - by user2898514
    I have a problem with my json code. I want to append each json value comes from a key to be appended to an html class name which matches the key of json data. here's my Live demo if you see the result in the life demo. it's only appending the last record. is it possible to make it show all records in order? json var json = '[{"castle":"big","commercial":"large","common":"sergio","cultural":"2009"},' + '{"castle":"big2","commercial":"large2","common":"sergio2","cultural":"20092"}]'; html <div class="castle"></div> <div class="commercial"></div> <div class="common"></div> <div class="cultural"></div> javascript var data = $.parseJSON(json); $.each(data, function(l,v) { $.each(v, function(k,o) { $('.'+k).attr('id', k+o); console.log($('#'+k+o).attr('id')); $('#'+k+o).text(o); }); }); for more illustration... I want the result in the live demo to look like this big large sergio 2009, big2 large2 sergio2 20092

    Read the article

  • Encapsulating user input of data for a class (C++)

    - by Dr. Monkey
    For an assignment I've made a simple C++ program that uses a superclass (Student) and two subclasses (CourseStudent and ResearchStudent) to store a list of students and print out their details, with different details shown for the two different types of students (using overriding of the display() method from Student). My question is about how the program collects input from the user of things like the student name, ID number, unit and fee information (for a course student) and research information (for research students): My implementation has the prompting for user input and the collecting of that input handled within the classes themselves. The reasoning behind this was that each class knows what kind of input it needs, so it makes sense to me to have it know how to ask for it (given an ostream through which to ask and an istream to collect the input from). My lecturer says that the prompting and input should all be handled in the main program, which seems to me somewhat messier, and would make it trickier to extend the program to handle different types of students. I am considering, as a compromise, to make a helper class that handles the prompting and collection of user input for each type of Student, which could then be called on by the main program. The advantage of this would be that the student classes don't have as much in them (so they're cleaner), but also they can be bundled with the helper classes if the input functionality is required. This also means more classes of Student could be added without having to make major changes to the main program, as long as helper classes are provided for these new classes. Also the helper class could be swapped for an alternative language version without having to make any changes to the class itself. What are the major advantages and disadvantages of the three different options for user input (fully encapsulated, helper class or in the main program)?

    Read the article

  • Question regarding common class

    - by Rocky Singh
    I have following two classes: public class A : System.Web.UI.WebControls.Button { public virtual string X { get { object obj = ViewState["X"]; if (obj != null) return (string)obj; return null; } set { ViewState["X"] = value; } } protected override void OnLoad(EventArgs e) { X=2; } } and public class B : System.Web.UI.WebControls.TextBox { public virtual string X { get { object obj = ViewState["X"]; if (obj != null) return (string)obj; return null; } set { ViewState["X"] = value; } } protected override void OnLoad(EventArgs e) { X=2; } } As you must be seeing the class A and B have exactly the same code , my question is how can I make a common class for it and use these two classes.

    Read the article

  • creative way for implementing Data object with its corresponding business logic class in java

    - by ekeren
    I have a class that need to be serialized (for both persistentcy and client-server communication) for simplicity's sake let's call the classes Business a BusinessData and I prefix for their Interfaces. All the getter and setter are delegated from Business class to BusinessData class. I thought about implementing IBusinessData interface that will contain all the getter and setters and IBusiness interface that will extend it. I can either make Business extend BuisnessData so I will not need to implement all getter and setter delegates, or make some abstract class ForwardingBusinessData that will only delegate getter and setters. Any of the above option I lose my hierarchy freedom, do any of you have any creative solutions for this problem... I also reviewed DAO pattern: http://java.sun.com/blueprints/patterns/DAO.html

    Read the article

  • Base class with abstract subclasses in C# ?

    - by Nick Brooks
    public abstract class Request { public class Parameters { //Threre are no members here //But there should be in inherited classes } public Request() { parameters = new Parameters(); } public Parameters parameters; } Two questions: How do I make it so I can add stuff to the constructor but the original constructor will still be executed? How do I make it so the subclasses can add members to the Parameters class?

    Read the article

  • selenium cannot find element with class in IE

    - by Rob
    I'm using selenium_client with cucumber, webrat + IE As you'd expect, Firefox works fine. I've tried the following: selenium.is_visible("css=#flash .flash_notice") selenium.is_visible("xpath=//*[@id='flash']/*[@class='flash_notice]") selenium.is_visible("xpath=//*[@id='flash']/*[contains(@class,'flash_notice]')") both cannot find the element. I think it must be something to do with IE, looking closer at the html selenium returns from IE... It looks like this: <UL id=flash> <LI className=flash_notice>Deleted</LI> </UL> Notice IE returns the class attribute as className, is this confusing selenium? How can I get round this so that I can use the same statement for selenium using IE and Firefox Just to confuse us even more, this example works, confirming its something to do with checking the class attribute selenium.is_visible("xpath=//*[@id='flash']/*[. =\'Deleted\']")

    Read the article

  • StructureMap - Injecting a dependency into a base class?

    - by David
    In my domain I have a handful of "processor" classes which hold the bulk of the business logic. Using StructureMap with default conventions, I inject repositories into those classes for their various IO (databases, file system, etc.). For example: public interface IHelloWorldProcessor { string HelloWorld(); } public class HelloWorldProcessor : IHelloWorldProcessor { private IDBRepository _dbRepository; public HelloWorldProcessor(IDBRepository dbRepository) { _dbRepository = dbrepository; } public string HelloWorld(){ return _dbRepository.GetHelloWorld(); } } Now, there are some repositories that I'd like to be available to all processors, so I made a base class like this: public class BaseProcessor { protected ICommonRepository _commonRepository; public BaseProcessor(ICommonRepository commonRepository) { _commonRepository = commonRepository; } } But when my other processors inherit from it, I get a compiler error on each one saying that there's no constructor for BaseProcessor which takes zero arguments. Is there a way to do what I'm trying to do here? That is, to have common dependencies injected into a base class that my other classes can use without having to write the injections into each one?

    Read the article

  • Adding business logic to a domain class using a getter style method name

    - by Richard Paul
    I'm attempting to add a method to a grails domain class, e.g. class Item { String name String getReversedName() { name.reverse() } } When I attempt to load the application using grails console I get the following error: Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory':Invocation of init method failed; nested exception is org.hibernate.PropertyNotFoundException: Could not find a setter for property reversedName in class Item ... 18 more It looks like Hibernate is interpreting getReversedName() as a getter for a property, however in this case it is a derived field and hence should not be persisted. Obviously in my actual code the business logic I'm exposing is more complex but it isn't relevant to this question. I want to be able to call item.reversedName in my code/gsps. How can I provide property (getter) access to a method in a Grails domain class without Grails attempting to map it with Hibernate?

    Read the article

  • How can i use 'log' inside a src/groovy/ class

    - by firnnauriel
    I'm encountering this error: groovy.lang.MissingPropertyException: No such property: log for class: org.utils.MyClass Here's the content of the class: package org.utils class MyClass { int organizationCount = 0 public int getOrganizationCount(){ log.debug "There are ${organizationCount} organization(s) found." return organizationCount } } Do i need to add an import statement? What do i need to add? Note that the class is located in src/groovy/org/utils. I know that the 'log' variable is accessible in controllers, services, etc. Not sure in 'src' classes. Thanks.

    Read the article

  • How to remove class Conditionally ?

    - by Wazdesign
    $("li").hoverIntent({ sensitivity: 3, interval: 200, over: addOver, timeout: 500, out: removeOver }); function addOver(){ $(this).addClass('over').children('a:first').addClass('active');} function removeOver(){ $(this).removeClass('over').children('a:first').removeClass('active');} alert ('version 2 menu'); }); On mouseout I want to remove class of " li a" if it already dont have class. I want to remove the class of the children.

    Read the article

  • Create generic class instance throws TypeLoadException

    - by Elisa
    My TestLayer class has the namespace: "BLL.Infrastructure.TestLayer" and is inside the assembly: "BLL" public class LayerFactory<T, U> { public static IBaseLayer<T, U> Get() { var obj = Activator.CreateInstance("BLL", "BLL.Infrastructure.TestLayer", new object[] { (IBaseLayer<T, U>)null }); } } When I run the code the Activator throws an TypeLoadException with no more details Thats the concrete class it should create: GenericBaseLayer implements the IBaseLayer. public class TestLayer<T, U> : GenericBaseLayer<MyRequest, MyInfo.ActionType> { public TestLayer(IBaseLayer<MyRequest, MyInfo.ActionType> layer) : base(layer) { } } What do I wrong?

    Read the article

  • Choosing a design pattern for a class that might change it's internal attributes

    - by the_drow
    I have a class that holds arbitrary state and it's defined like this: class AbstractFoo { }; template <class StatePolicy> class Foo : public StatePolicy, public AbstractFoo { }; The state policy contains only protected attributes that represent the state. The state might be the same for multiple behaviors and they can be replaced at runtime. All Foo objects have the same interface to abstract the state itself and to enable storing Foo objects in containers. I would like to find the least verbose and the most maintainable way to express this.

    Read the article

  • Question of using static_cast on "this" pointer in a derived object to base class

    - by Johnyy
    Hi, this is an example taken from Effective C++ 3ed, it says that if the static_cast is used this way, the base part of the object is copied, and the call is invoked from that part. I wanted to understand what is happening under the hood, will anyone help? class Window { // base class public: virtual void onResize() { } // base onResize impl }; class SpecialWindow: public Window { // derived class public: virtual void onResize() { // derived onResize impl; static_cast<Window>(*this).onResize(); // cast *this to Window, // then call its onResize; // this doesn't work! // do SpecialWindow- } // specific stuff };

    Read the article

  • Overriding the admin Media class

    - by shacker
    Given an admin media class that sets up a rich text editor, like: class TutorialAdmin(admin.ModelAdmin): fields... class Media: js = ['/paths/to/tinymce.js',] I would like the ability to selectively override js depending on a field value in the model it references. I've added a "use_editor" boolean to the Tutorial model. The question is, how can I detect whether the current instance has that bool set? I'd like to end up with something like: class Media: if self.use_editor: js = ['/path/to/tinymce.js',] else: js = '' Ideas? Thanks.

    Read the article

  • Python: Is there a way to reflectivly list all attributes of a class

    - by hhafez
    Given a class such as def MyClass text = "hello" number = 123 Is there a way in python to inspect MyClass an determine that it has the two attributes text and number. I can not use something like inspect.getSource(object) because the class I am to get it's attributes for are generate using SWIG (so they are hidden in .so :) ). So I am really looking for something equivalant to Java's [Class.getDeclardFields][1] Any help would be appreciated, otherwise I'll have to solve this problem with SWIG + JAVA instead of SWIG + Python.

    Read the article

  • Dispose a Web Service Proxy class?

    - by Matt
    When you create and use a Web Service proxy class in the ASP.Net framework, the class ultimately inherits from Component, which implements IDisposable. I have never seen one example online where people dispose of a web proxy class, but was wondering if it really needs to be done. When I call only one method, I normally wrap it in a using statement, but if I have a need to call it several times throughout the page, I might end up using the same instance, and just wondered what the ramifications are of not disposing it.

    Read the article

  • how to pass a variable value from one class to another

    - by Arunabha
    I have two packages one is com.firstBooks.series.db.parser which have a java file XMLParser.java, I have another package com.firstBooks.series79 which have a class called AppMain.NW I want to send the value of a variable called _xmlFileName frm AppMain class to the xmlFile variable in XMLParser class, I am posting the code for both the class, kindly help me. package com.firstBooks.series.db.parser; import java.io.IOException; import java.io.InputStream; import java.util.Vector; import net.rim.device.api.xml.parsers.DocumentBuilder; import net.rim.device.api.xml.parsers.DocumentBuilderFactory; import net.rim.device.api.xml.parsers.ParserConfigurationException; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.NodeList; import org.xml.sax.SAXException; import com.firstBooks.series.db.Question; public class XMLParser { private Document document; public static Vector questionList; public static String xmlFile; public XMLParser() { questionList = new Vector(); } public void parseXMl() throws SAXException, IOException, ParserConfigurationException { // Build a document based on the XML file. DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); InputStream inputStream = getClass().getResourceAsStream(xmlFile); document = builder.parse(inputStream); } public void parseDocument() { Element element = document.getDocumentElement(); NodeList nl = element.getElementsByTagName("question"); if (nl != null && nl.getLength() > 0) { for (int i = 0; i < nl.getLength(); i++) { Element ele = (Element) nl.item(i); Question question = getQuestions(ele); questionList.addElement(question); } } } private Question getQuestions(Element element) { String title = getTextValue(element, "title"); String choice1 = getTextValue(element, "choice1"); String choice2 = getTextValue(element, "choice2"); String choice3 = getTextValue(element, "choice3"); String choice4 = getTextValue(element, "choice4"); String answer = getTextValue(element, "answer"); String rationale = getTextValue(element, "rationale"); Question Questions = new Question(title, choice1, choice2, choice3, choice4, answer, rationale); return Questions; } private String getTextValue(Element ele, String tagName) { String textVal = null; NodeList nl = ele.getElementsByTagName(tagName); if (nl != null && nl.getLength() > 0) { Element el = (Element) nl.item(0); textVal = el.getFirstChild().getNodeValue(); } return textVal; } } Nw the code for AppMain class //#preprocess package com.firstBooks.series79; import net.rim.device.api.ui.UiApplication; import com.firstBooks.series.ui.screens.HomeScreen; public class AppMain extends UiApplication { public static String _xmlFileName; public static boolean _Lite; public static int _totalNumofQuestions; public static void initialize(){ //#ifndef FULL /* //#endif _xmlFileName = "/res/Series79_FULL.xml"; _totalNumofQuestions = 50; _Lite = false; //#ifndef FULL */ //#endif //#ifndef LITE /* //#endif _xmlFileName = "/res/Series79_LITE.xml"; _totalNumofQuestions = 10; _Lite = true; //#ifndef LITE */ //#endif } private AppMain() { initialize(); pushScreen(new HomeScreen()); } public static void main(String args[]) { new AppMain().enterEventDispatcher(); } }

    Read the article

  • executing a class in remote jvm

    - by redzedi
    Hi All, I have a small test class that i want to run on a particular jvm that's already up and running (basically it's an web application running on Tomcat) . The reason i want to do this is i want to execute a small test class (with the main method and all) within that jvm so that i get the same environment (loaded and initialized classes) for my test class. Is it possible to indicate that ,say through a jvm parameter, that it should not initialize a new vm to execute my class but instead go and execute on the remote vm and show me the result here, on my console. So the local jvm acts as a kind of thin proxy ? I am not aware in case there are some tools that should make this possible ... also heard somewhere that java 6 jvm comes with an option like this , is that true ?? Please help me. Thanks,

    Read the article

< Previous Page | 82 83 84 85 86 87 88 89 90 91 92 93  | Next Page >