Search Results

Search found 31954 results on 1279 pages for 'dependency object'.

Page 12/1279 | < Previous Page | 8 9 10 11 12 13 14 15 16 17 18 19  | Next Page >

  • Why does stored procedure invalidate SQL Cache Dependency?

    - by Fabio Milheiro
    After many hours, I finally realize that I am working correctly with the Cache object in my ASP.NET application but my stored procedures stops it from working correctly. This stored procedure works correctly: CREATE PROCEDURE [dbo].[ListLanguages] @Page INT = 1, @ItemsPerPage INT = 10, @OrderBy NVARCHAR (100) = 'ID', @OrderDirection NVARCHAR(4) = 'DESC' AS BEGIN SELECT ID, [Name], Flag, IsDefault FROM dbo.Languages END But this (the one I wanted) doesn't: CREATE PROCEDURE [dbo].[ListLanguages] @Page INT = 1, @ItemsPerPage INT = 10, @OrderBy NVARCHAR (100) = 'ID', @OrderDirection NVARCHAR(4) = 'DESC', @TotalRecords INT OUTPUT AS BEGIN SET @TotalRecords = 10 EXEC('SELECT ID, Name, Flag, IsDefault FROM ( SELECT ROW_NUMBER() OVER (ORDER BY ' + @OrderBy + ' ' + @OrderDirection + ') as Row, ID, Name, Flag, IsDefault FROM dbo.Languages) results WHERE Row BETWEEN ((' + @Page + '-1)*' + @ItemsPerPage + '+1) AND (' + @Page + '*' + @ItemsPerPage + ')') END I gave the @TotalRecords parameter the value 10 so you can be sure that the problem is not from the COUNT(*) function which I know is not supported well. Also, when I run it from SQL Server Management Studio, it does exactly what it should do. In the ASP.NET application the results are retrieved correctly, only the cache is somehow unable to work! Can you please help? Maybe a hint I believe that the reason why the dependency HasChanged property is related to the fact that the column Row generated from the ROW_NUMBER is only temporary and, therefore, the SQL SERVER is not able to to say whether the results are changed or not. That's why HasChanged is always set to true. Does anyone know how to paginate results from SQL SERVER without using COUNT or ROW_NUMBER functions?

    Read the article

  • Using maven to distribute a swing application that can have each dependency individually tracked

    - by tms
    I'm moving my project to Maven and eventually OSGi. I currently distribute the project is a large Zip file with all the dependencies. Although my projects code is only 20% of the total package I have to redistribute all the dependency. With smaller independent modules this may be even less. Looking here on stack overflow it seems that to keep my current plan the maven-assembly-plugin should do the trick. I was considering having a base installer that would look at a XML manifest, then collect all the libraries that needed to be updated. This would mean that libraries that change occasionally would be downloaded less often. This also makes since for something like OSGi plugins (which could have independent release schedules). In essence I want my software to look and manage individual libraries, and download on demand (based on the manifest). I was wondering if there is a "maven way" of generating this Manifest and publishing all the libraries to a website? I believe the deploy life-cycle would do the second step. As an alternative, is there a OpenSource Java library that does this type of deployment? I don't want to embed Maven or something larger with the distributed code. The application is not for coders, the simpler the better, and the smaller the installer the better.

    Read the article

  • Dependency Injection into your Singleton

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

    Read the article

  • Dependency injection in constructors

    - by andre
    Hello everyone. I'm starting a new project and setting up the base to work on. A few questions have risen and I'll probably be asking quite a few in here, hopefully I'll find some answers. First step is to handle dependencies for objects. I've decided to go with the dependency injection design pattern, to which I'm somewhat new, to handle all of this for the application. When actually coding it I came across a problem. If a class has multiple dependencies and you want to pass on multiple dependencies via the constructor (so that they cannot be changed after you instantiate the object). How do you do it without passing an array of dependencies, using call_user_func_array(), eval() or Reflection? This is what i'm looking for: <?php class DI { public function getClass($classname) { if(!$this->pool[$classname]) { # Load dependencies $deps = $this->loadDependencies($classname); # Here is where the magic should happen $instance = new $classname($dep1, $dep2, $dep3); # Add to pool $this->pool[$classname] = $instance; return $instance; } else { return $this->pool[$classname]; } } } Again, I would like to avoid the most costly methods to call the class. Any other suggestions?

    Read the article

  • Serializing Configurations for a Dependency Injection / Inversion of Control

    - by Joshua Starner
    I've been researching Dependency Injection and Inversion of Control practices lately in an effort to improve the architecture of our application framework and I can't seem to find a good answer to this question. It's very likely that I have my terminology confused, mixed up, or that I'm just naive to the concept right now, so any links or clarification would be appreciated. Many examples of DI and IoC containers don't illustrate how the container will connect things together when you have a "library" of possible "plugins", or how to "serialize" a given configuration. (From what I've read about MEF, having multiple declarations of [Export] for the same type will not work if your object only requires 1 [Import]). Maybe that's a different pattern or I'm blinded by my current way of thinking. Here's some code for an example reference: public abstract class Engine { } public class FastEngine : Engine { } public class MediumEngine : Engine { } public class SlowEngine : Engine { } public class Car { public Car(Engine e) { engine = e; } private Engine engine; } This post talks about "Fine-grained context" where 2 instances of the same object need different implementations of the "Engine" class: http://stackoverflow.com/questions/2176833/ioc-resolve-vs-constructor-injection Is there a good framework that helps you configure or serialize a configuration to achieve something like this without hard coding it or hand-rolling the code to do this? public class Application { public void Go() { Car c1 = new Car(new FastEngine()); Car c2 = new Car(new SlowEngine()); } } Sample XML: <XML> <Cars> <Car name="c1" engine="FastEngine" /> <Car name="c2" engine="SlowEngine" /> </Cars> </XML>

    Read the article

  • Dependency Properties, change notification and setting values in the constructor

    - by stefan.at.wpf
    Hello, I have a clas with 3 dependency properties A,B,C. The values of these properties are set by the constructor and every time one of the properties A, B or C changes, the method recalculate() is called. Now during execution of the constructor these method is called 3 times, because the 3 properties A, B, C are changed. Hoewever this isn't necessary as the method recalculate() can't do anything really useful without all 3 properties set. So what's the best way for property change notification but circumventing this change notification in the constructor? I thought about adding the property changed notification in the constructor, but then each object of the DPChangeSample class would always add more and more change notifications. Thanks for any hint! class DPChangeSample : DependencyObject { public static DependencyProperty AProperty = DependencyProperty.Register("A", typeof(int), typeof(DPChangeSample), new PropertyMetadata(propertyChanged)); public static DependencyProperty BProperty = DependencyProperty.Register("B", typeof(int), typeof(DPChangeSample), new PropertyMetadata(propertyChanged)); public static DependencyProperty CProperty = DependencyProperty.Register("C", typeof(int), typeof(DPChangeSample), new PropertyMetadata(propertyChanged)); private static void propertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) { ((DPChangeSample)d).recalculate(); } private void recalculate() { // Using A, B, C do some cpu intensive caluclations } public DPChangeSample(int a, int b, int c) { SetValue(AProperty, a); SetValue(BProperty, b); SetValue(CProperty, c); } }

    Read the article

  • Spring Dependency Injecting an annotated Aspect

    Using Spring I've had some issues with doing a dependency injection on an annotated Aspect class. CacheService is injected upon the Spring context's startup, but when the weaving takes place, it says that the cacheService is null. So I am forced to relook up the spring context manually and get the bean from there. Is there another way of going about it? Here is an example of my Aspect: import org.apache.log4j.Logger; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import com.mzgubin.application.cache.CacheService; @Aspect public class CachingAdvice { private static Logger log = Logger.getLogger(CachingAdvice.class); private CacheService cacheService; @Around("execution(public *com.mzgubin.application.callMethod(..)) &&" + "args(params)") public Object addCachingToCreateXMLFromSite(ProceedingJoinPoint pjp, InterestingParams params) throws Throwable { log.debug("Weaving a method call to see if we should return something from the cache or create it from scratch by letting control flow move on"); Object result = null; if (getCacheService().objectExists(params))}{ result = getCacheService().getObject(params); } else { result = pjp.proceed(pjp.getArgs()); getCacheService().storeObject(params, result); } return result; } public CacheService getCacheService(){ return cacheService; } public void setCacheService(CacheService cacheService){ this.cacheService = cacheService; } }

    Read the article

  • Proper structure for dependency injection (using Guice)

    - by David B.
    I would like some suggestions and feedback on the best way to structure dependency injection for a system with the structure described below. I'm using Guice and thus would prefer solutions centered around it's annotation-based declarations, not XML-heavy Spring-style configuration. Consider a set of similar objects, Ball, Box, and Tube, each dependent on a Logger, supplied via the constructor. (This might not be important, but all four classes happen to be singletons --- of the application, not Gang-of-Four, variety.) A ToyChest class is responsible for creating and managing the three shape objects. ToyChest itself is not dependent on Logger, aside from creating the shape objects which are. The ToyChest class is instantiated as an application singleton in a Main class. I'm confused about the best way to construct the shapes in ToyChest. I either (1) need access to a Guice Injector instance already attached to a Module binding Logger to an implementation or (2) need to create a new Injector attached to the right Module. (1) is accomplished by adding an @Inject Injector injectorfield to ToyChest, but this feels weird because ToyChest doesn't actually have any direct dependencies --- only those of the children it instantiates. For (2), I'm not sure how to pass in the appropriate Module. Am I on the right track? Is there a better way to structure this? The answers to this question mention passing in a Provider instead of using the Injector directly, but I'm not sure how that is supposed to work. EDIT: Perhaps a more simple question is: when using Guice, where is the proper place to construct the shapes objects? ToyChest will do some configuration with them, but I suppose they could be constructed elsewhere. ToyChest (as the container managing them), and not Main, just seems to me like the appropriate place to construct them.

    Read the article

  • Global State and Singletons Dependency injection

    - by Manu
    this is a problem i face lot of times when i am designing a new app i'll use a sample problem to explain this think i am writing simple game.so i want to hold a list of players. i have few options.. 1.use a static field in some class private static ArrayList<Player> players = new ArrayList<Integer>(); public Player getPlayer(int i){ return players.get(i); } but this a global state 2.or i can use a singleton class PlayerList{ private PlayerList instance; private PlayerList(){...} public PlayerList getInstance() { if(instance==null){ ... } return instance; } } but this is bad because it's a singleton 3.Dependency injection class Game { private PlayerList playerList; public Game(PlayerList list) { this.list = list; } public PlayerList getPlayerList() { return playerList; } } this seems good but it's not, if any object outside Game need to look at PlayerList (which is the usual case) i have to use one of the above methods to make the Game class available globally. so I just add another layer to the problem. didn't actually solve anything. what is the optimum solution ? (currently i use Singleton approach)

    Read the article

  • Significant amount of the time, I can't think of a reason to have an object instead of a static class. Do objects have more benefits than I think?

    - by Prog
    I understand the concept of an object, and as a Java programmer I feel the OO paradigm comes rather naturally to me in practice. However recently I found myself thinking: Wait a second, what are actually the practical benefits of using an object over using a static class (with proper encapsulation and OO practices)? I could think of two benefits of using an object (both significant and powerful): Polymorphism: allows you to swap functionality dynamically and flexibly during runtime. Also allows to add new functionality 'parts' and alternatives to the system easily. For example if there's a Car class designed to work with Engine objects, and you want to add a new Engine to the system that the Car can use, you can create a new Engine subclass and simply pass an object of this class into the Car object, without having to change anything about Car. And you can decide to do so during runtime. Being able to 'pass functionality around': you can pass an object around the system dynamically. But are there any more advantages to objects over static classes? Often when I add new 'parts' to a system, I do so by creating a new class and instantiating objects from it. But recently when I stopped and thought about it, I realized that a static class would do just the same as an object, in a lot of the places where I normally use an object. For example, I'm working on adding a save/load-file mechanism to my app. With an object, the calling line of code will look like this: Thing thing = fileLoader.load(file); With a static class, it would look like this: Thing thing = FileLoader.load(file); What's the difference? Fairly often I just can't think of a reason to instantiate an object when a plain-old static-class would act just the same. But in OO systems, static classes are fairly rare. So I must be missing something. Are there any more advantages to objects other from the two that I listed? Please explain.

    Read the article

  • OOP concept: is it possible to update the class of an instantiated object?

    - by Federico
    I am trying to write a simple program that should allow a user to save and display sets of heterogeneous, but somehow related data. For clarity sake, I will use a representative example of vehicles. The program flow is like this: The program creates a Garage object, which is basically a class that can contain a list of vehicles objects Then the users creates Vehicles objects, these Vehicles each have a property, lets say License Plate Nr. Once created, the Vehicle object get added to a list within the Garage object --Later on--, the user can specify that a given Vehicle object is in fact a Car object or a Truck object (thus giving access to some specific attributes such as Number of seats for the Car, or Cargo weight for the truck) At first sight, this might look like an OOP textbook question involving a base class and inheritance, but the problem is more subtle because at the object creation time (and until the user decides to give more info), the computer doesn't know the exact Vehicle type. Hence my question: how would you proceed to implement this program flow? Is OOP the way to go? Just to give an initial answer, here is what I've came up until now. There is only one Vehicle class and the various properties/values are handled by the main program (not the class) through a dictionary. However, I'm pretty sure that there must be a more elegant solution (I'm developing using VB.net): Public Class Garage Public GarageAdress As String Private _ListGarageVehicles As New List(Of Vehicles) Public Sub AddVehicle(Vehicle As Vehicles) _ListGarageVehicles.Add(Vehicle) End Sub End Class Public Class Vehicles Public LicensePlateNumber As String Public Enum VehicleTypes Generic = 0 Car = 1 Truck = 2 End Enum Public VehicleType As VehicleTypes Public DictVehicleProperties As New Dictionary(Of String, String) End Class NOTE that in the example above the public/private modifiers do not necessarily reflect the original code

    Read the article

  • Jboss AS 7 - Dependency Injection

    - by Nic Willemse
    Im attempting to make use of dependency injection in Jboss AS 7 and im having huge difficulties. I have setup a EAR which contains both a EJB jar and a war. The war contains a richfaces web app. Im attempting to inject an EJB from the ejb jar into a faces managed bean with the code below : public class UserController { @EJB(mappedName="UserService") private UserFacadeService userService; public String getService(){ if(userService == null){ however when i deploy jboss puts the error in the console : rolled back with failure message {"Services with missing/unavailable dependencies" => ["jboss.deployment.subunit.\"GoodByeJohnEAR.ear\".\"GoodByeJohnWeb-1.0-SNAPSHOT.war\".component.\"managed-bean.za.co.gbj.UserController\".START missing [ jboss.naming.context.java.module.GoodByeJohnEAR.\"GoodByeJohnWeb-1.0-SNAPSHOT\".\"env/za.co.gbj.UserController/userService\" ]","jboss.deployment.subunit.\"GoodByeJohnEAR.ear\".\"GoodByeJohnWeb-1.0-SNAPSHOT.war\".jndiDependencyService missing [ jboss.naming.context.java.module.GoodByeJohnEAR.\"GoodByeJohnWeb-1.0-SNAPSHOT\".\"env/za.co.gbj.UserController/userService\" ]","jboss.naming.context.java.module.GoodByeJohnEAR.\"GoodByeJohnWeb-1.0-SNAPSHOT\".\"env/za.co.gbj.UserController/userService\".jboss.deployment.subunit.\"GoodByeJohnEAR.ear\".\"GoodByeJohnWeb-1.0-SNAPSHOT.war\".module.GoodByeJohnEAR.\"GoodByeJohnWeb-1.0-SNAPSHOT\".2 missing [ jboss.naming.context.java.module.GoodByeJohnEAR.\"GoodByeJohnWeb-1.0-SNAPSHOT\".env/UserService ]"]} 09:03:50,576 INFO [org.jboss.as.server.deployment] (MSC service thread 1-8) Starting deployment of "GoodByeJohnEAR.ear" 09:03:50,670 INFO [org.jboss.as.server.deployment] (MSC service thread 1-3) Starting deployment of "GoodByeJohnWeb-1.0-SNAPSHOT.war" 09:03:50,670 INFO [org.jboss.as.server.deployment] (MSC service thread 1-8) Starting deployment of "GoodByeJohnEJB-1.0-SNAPSHOT.jar" 09:03:51,367 WARN [org.jboss.as.server.deployment.service-loader] (MSC service thread 1-2) Encountered invalid class name "com.sun.faces.vendor.Tomcat6InjectionProvider:org.apache.catalina.util.DefaultAnnotationProcessor" for service type "com.sun.faces.spi.injectionprovider" 09:03:51,367 WARN [org.jboss.as.server.deployment.service-loader] (MSC service thread 1-2) Encountered invalid class name "com.sun.faces.vendor.Jetty6InjectionProvider:org.mortbay.jetty.plus.annotation.InjectionCollection" for service type "com.sun.faces.spi.injectionprovider" 09:03:51,375 INFO [org.jboss.as.ejb3.deployment.processors.EjbJndiBindingsDeploymentUnitProcessor] (MSC service thread 1-8) JNDI bindings for session bean named UserFacadeBean in deployment unit subdeployment "GoodByeJohnEJB-1.0-SNAPSHOT.jar" of deployment "GoodByeJohnEAR.ear" are as follows: java:global/GoodByeJohnEAR/GoodByeJohnEJB-1.0-SNAPSHOT/UserFacadeBean!za.co.gbj.UserFacadeService java:app/GoodByeJohnEJB-1.0-SNAPSHOT/UserFacadeBean!za.co.gbj.UserFacadeService java:module/UserFacadeBean!za.co.gbj.UserFacadeService java:global/GoodByeJohnEAR/GoodByeJohnEJB-1.0-SNAPSHOT/UserFacadeBean java:app/GoodByeJohnEJB-1.0-SNAPSHOT/UserFacadeBean java:module/UserFacadeBean 09:03:51,406 INFO [org.jboss.as.ejb3.deployment.processors.EjbJndiBindingsDeploymentUnitProcessor] (MSC service thread 1-4) JNDI bindings for session bean named UserFacadeBean in deployment unit subdeployment "GoodByeJohnWeb-1.0-SNAPSHOT.war" of deployment "GoodByeJohnEAR.ear" are as follows: java:global/GoodByeJohnEAR/GoodByeJohnWeb-1.0-SNAPSHOT/UserFacadeBean!za.co.gbj.UserFacadeService java:app/GoodByeJohnWeb-1.0-SNAPSHOT/UserFacadeBean!za.co.gbj.UserFacadeService java:module/UserFacadeBean!za.co.gbj.UserFacadeService java:global/GoodByeJohnEAR/GoodByeJohnWeb-1.0-SNAPSHOT/UserFacadeBean java:app/GoodByeJohnWeb-1.0-SNAPSHOT/UserFacadeBean java:module/UserFacadeBean 09:03:51,577 INFO [org.jboss.as.controller] (DeploymentScanner-threads - 1) Service status report New missing/unsatisfied dependencies: service jboss.naming.context.java.module.GoodByeJohnEAR."GoodByeJohnWeb-1.0-SNAPSHOT".env/UserService (missing) service jboss.naming.context.java.module.GoodByeJohnEAR."GoodByeJohnWeb-1.0-SNAPSHOT"."env/za.co.gbj.UserController/userService" (missing) Please assist!

    Read the article

  • Dependency Injection: I don't get where to start!

    - by Andy
    I have several articles about Dependency Injection, and I can see the benefits, especially when it comes to unit testing. The units can me loosely coupled, and mocking of dependencies can be made. The trouble is - I just don't get where to start. Consider this snippet below of (much edited for the purpose of this post) code that I have. I am instantiating a Plc object from the main form, and passing in a communications mode via the Connect method. In it's present form it becomes hard to test, because I can't isolate the Plc from the CommsChannel to unit test it. (Can I?) The class depends on using a CommsChannel object, but I am only passing in a mode that is used to create this channel within the Plc itself. To use dependancy injection, I should really pass in an already created CommsChannel (via an 'ICommsChannel' interface perhaps) to the Connect method, or maybe via the Plc constructor. Is that right? But then that would mean creating the CommsChannel in my main form first, and this doesn't seem right either, because it feels like everything will come back to the base layer of the main form, where everything begins. Somehow it feels like I am missing a crucial piece of the puzzle. Where do you start? You have to create an instance of something somewhere, but I'm struggling to understand where that should be. public class Plc() { public bool Connect(CommsMode commsMode) { bool success = false; // Create new comms channel. this._commsChannel = this.GetCommsChannel(commsMode); // Attempt connection success = this._commsChannel.Connect(); return this._connected; } private CommsChannel GetCommsChannel(CommsMode mode) { CommsChannel channel; switch (mode) { case CommsMode.RS232: channel = new SerialCommsChannel( SerialCommsSettings.Default.ComPort, SerialCommsSettings.Default.BaudRate, SerialCommsSettings.Default.DataBits, SerialCommsSettings.Default.Parity, SerialCommsSettings.Default.StopBits); break; case CommsMode.Tcp: channel = new TcpCommsChannel( TCPCommsSettings.Default.IP_Address, TCPCommsSettings.Default.Port); break; default: // Throw unknown comms channel exception. } return channel; } }

    Read the article

  • How can I use "Dependency Injection" in simple php functions, and should I bother?

    - by Tchalvak
    I hear people talking about dependency injection and the benefit of it all the time, but I don't really understand it. I'm wondering if it's a solution to the "I pass database connections as arguments all the time" problem. I tried reading wikipedia's entry on it, but the example is written in Java so I don't solidly understand the difference it is trying to make clear. ( http://en.wikipedia.org/wiki/Dependency_injection ). I read this dependency-injection-in-php article ( http://www.potstuck.com/2009/01/08/php-dependency-injection/ ), and it seems like the objective is to not pass dependencies to an object directly, but to cordon off the creation of an object along with the creation of it's dependencies. I'm not sure how to apply that in a using php functions context, though. Additionally, is the following Dependency Injection, and should I bother trying to do dependency injection in a functional context? Version 1: (the kind of code that I create, but don't like, every day) function get_data_from_database($database_connection){ $data = $database_connection->query('blah'); return $data; } Version 2: (don't have to pass a database connection, but perhaps not dependency injection?) function get_database_connection(){ static $db_connection; if($db_connection){ return $db_connection; } else { // create db_connection ... } } function get_data_from_database(){ $conn = get_database_connection(); $data = $conn->query('blah'); return $data; } $data = get_data_from_database(); Version 3: (the creation of the "object"/data is separate, and the database code is still, so perhaps this would count as dependency injection?) function factory_of_data_set(){ static $db_connection; $data_set = null; $db_connection = get_database_connection(); $data_set = $db_connection->query('blah'); return $data_set; } $data = factory_of_data_set(); Anyone have a good resource or just insight that makes the method and benefit -crystal- clear?

    Read the article

  • Save object using variable with object name

    - by FBE
    I'm wondering what an easy way is to save an object in R, using a variable objectName with the name of the object to be saved. I want this to easy save objects, with their name in the file name. I tried to use get, but I didn't manage to save the object with it's original object name. Example: If I have the object called "temp", which I want to save in the directory "dataDir". I put the name of the object in the variable "objectName". Attempt 1: objectName<-"temp" save(get(objectName), file=paste(dataDir, objectName, ".RData", sep="")) load(paste(dataDir, objectName, ".RData", sep="")) This didn't work, because R tries to save an object called get(objectName), instead of the result of this call. So I tried the following: Attempt 2: objectName<-"temp" object<-get(objectName) save(object, file=paste(dataDir, objectName, ".RData", sep="")) load(paste(dataDir, objectName, ".RData", sep="")) This obviously didn't work, because R saves the object with name "object", and not with name "temp". After loading I have a copy of "object", instead of "temp". (Yes, with the same contents...but that is not what I want :) ). So I thought it should be something with pointers. So tried the following: Attempt 3: objectName<-"temp" object<<-get(objectName) save(object, file=paste(dataDir, objectName, ".RData", sep="")) load(paste(dataDir, objectName, ".RData", sep="")) Same result as attempt 2. But I'm not sure I'm doing what I think I'm doing. What is the solution for this?

    Read the article

  • Dependency Injection: Jetty 7

    - by Malax
    Hi StackOverflow! My application requires several interface implementations which require a Jetty server to do their job. This is, however, not necessarily the case in every implementations of those interfaces so the Jetty server is only a dependency. Since it would be a huge amount of pain to wrap the entire jetty server with all its logging, connector and Handler configurations, I want to inject the server to those implementations with Spring. I decided that injecting the Server class is not a good idea because an implementation could stop the server even if its required at another location. Currently I inject empty HandlerList classes to those implementations and they register their handlers to avoid those problems. The Problem: Those handlers might interfere with other handlers for example: implementation one might register a handler for /foo and implementation two too... problem. Has anyone used Jetty in such an environment? And how could this problem be solved? My XML to clarify my problem: <bean id="jetty" class="org.eclipse.jetty.server.Server" destroy-method="stop"> <property name="connectors"> <list> <bean class="org.eclipse.jetty.server.bio.SocketConnector"> <property name="host" value="10.8.0.46" /> <property name="port" value="9999" /> </bean> </list> </property> <property name="handler"> <bean class="org.eclipse.jetty.server.handler.HandlerCollection"> <property name="handlers"> <list> <ref bean="jetty.handlerList" /> <bean class="org.eclipse.jetty.server.handler.RequestLogHandler"> <property name="requestLog"> <bean class="org.eclipse.jetty.server.NCSARequestLog"> <constructor-arg value="${jetty.logfile}" /> <property name="extended" value="false"/> </bean> </property> </bean> </list> </property> </bean> </property> <property name="sendServerVersion" value="false" /> </bean> <bean id="jetty.handlerList" class="org.eclipse.jetty.server.handler.HandlerList" /> If I require an empty HandlerList I use something like this where com.example.myapp.util.ioc.CreateHandlerListFactory is a org.springframework.beans.factory.FactoryBean which creates a new HandlerList within the given HandlerList. <constructor-arg> <bean class="com.example.myapp.util.ioc.CreateHandlerListFactory"> <constructor-arg ref="jetty.handlerList"/> </bean> </constructor-arg>

    Read the article

  • Is testability alone justification for dependency injection?

    - by fearofawhackplanet
    The advantages of DI, as far as I am aware, are: Reduced Dependencies More Reusable Code More Testable Code More Readable Code Say I have a repository, OrderRepository, which acts as a repository for an Order object generated through a Linq to Sql dbml. I can't make my orders repository generic as it performs mapping between the Linq Order entity and my own Order POCO domain class. Since the OrderRepository by necessity is dependent on a specific Linq to Sql DataContext, parameter passing of the DataContext can't really be said to make the code reuseable or reduce dependencies in any meaningful way. It also makes the code harder to read, as to instantiate the repository I now need to write new OrdersRepository(new MyLinqDataContext()) which additionally is contrary to the main purpose of the repository, that being to abstract/hide the existence of the DataContext from consuming code. So in general I think this would be a pretty horrible design, but it would give the benefit of facilitating unit testing. Is this enough justification? Or is there a third way? I'd be very interested in hearing opinions.

    Read the article

  • Dependency Injection Question - ASP.NET

    - by Paul
    I'm starting a web application that contains the following projects: Booking.Web Booking.Services Booking.DataObjects Booking.Data I'm using the repository pattern in my data project only. All services will be the same, no matter what happens. However, if a customer wants to use Access, it will use a different data repository than if the customer wants to use SQL Server. I have StructureMap, and want to be able to do the following: Web project is unaffected. It's a web forms application that will only know about the services project and the dataobjects project. When a service is called, it will use StructureMap (by looking up the bootstrapper.cs file) to see which data repository to use. An example of a services class is the error logging class: public class ErrorLog : IErrorLog { ILogging logger; public ErrorLog() { } public ErrorLog(ILogging logger) { this.logger = logger; } public void AddToLog(string errorMessage) { try { AddToDatabaseLog(errorMessage); } catch (Exception ex) { AddToFileLog(ex.Message); } finally { AddToFileLog(errorMessage); } } private void AddToDatabaseLog(string errorMessage) { ErrorObject error = new ErrorObject { ErrorDateTime = DateTime.Now, ErrorMessage = errorMessage }; logger.Insert(error); } private void AddToFileLog(string errorMessage) { // TODO: Take this value from the web.config instead of hard coding it TextWriter writer = new StreamWriter(@"E:\Work\Booking\Booking\Booking.Web\Logs\ErrorLog.txt", true); writer.WriteLine(DateTime.Now.ToString() + " ---------- " + errorMessage); writer.Close(); } } I want to be able to call this service from my web project, without defining which repository to use for the data access. My boostrapper.cs file in the services project is defined as: public class Bootstrapper { public static void ConfigureStructureMap() { ObjectFactory.Initialize(x => { x.AddRegistry(new ServiceRegistry()); } ); } public class ServiceRegistry : Registry { protected override void configure() { ForRequestedType<IErrorLog>().TheDefaultIsConcreteType<Booking.Services.Logging.ErrorLog>(); ForRequestedType<ILogging>().TheDefaultIsConcreteType<SqlServerLoggingProvider>(); } } } What else do I need to get this to work? When I defined a test, the ILogger object was null. Thanks,

    Read the article

  • Dependency Injection in ASP.NET Web API using Autofac

    - by shiju
    In this post, I will demonstrate how to use Dependency Injection in ASP.NET Web API using Autofac in an ASP.NET MVC 4 app. The new ASP.NET Web API is a great framework for building HTTP services. The Autofac IoC container provides the better integration with ASP.NET Web API for applying dependency injection. The NuGet package Autofac.WebApi provides the  Dependency Injection support for ASP.NET Web API services. Using Autofac in ASP.NET Web API The following command in the Package Manager console will install Autofac.WebApi package into your ASP.NET Web API application. PM > Install-Package Autofac.WebApi The following code block imports the necessary namespaces for using Autofact.WebApi using Autofac; using Autofac.Integration.WebApi; .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The following code in the Bootstrapper class configures the Autofac. 1: public static class Bootstrapper 2: { 3: public static void Run() 4: { 5: SetAutofacWebAPI(); 6: } 7: private static void SetAutofacWebAPI() 8: { 9: var configuration = GlobalConfiguration.Configuration; 10: var builder = new ContainerBuilder(); 11: // Configure the container 12: builder.ConfigureWebApi(configuration); 13: // Register API controllers using assembly scanning. 14: builder.RegisterApiControllers(Assembly.GetExecutingAssembly()); 15: builder.RegisterType<DefaultCommandBus>().As<ICommandBus>() 16: .InstancePerApiRequest(); 17: builder.RegisterType<UnitOfWork>().As<IUnitOfWork>() 18: .InstancePerApiRequest(); 19: builder.RegisterType<DatabaseFactory>().As<IDatabaseFactory>() 20: .InstancePerApiRequest(); 21: builder.RegisterAssemblyTypes(typeof(CategoryRepository) 22: .Assembly).Where(t => t.Name.EndsWith("Repository")) 23: .AsImplementedInterfaces().InstancePerApiRequest(); 24: var services = Assembly.Load("EFMVC.Domain"); 25: builder.RegisterAssemblyTypes(services) 26: .AsClosedTypesOf(typeof(ICommandHandler<>)) 27: .InstancePerApiRequest(); 28: builder.RegisterAssemblyTypes(services) 29: .AsClosedTypesOf(typeof(IValidationHandler<>)) 30: .InstancePerApiRequest(); 31: var container = builder.Build(); 32: // Set the WebApi dependency resolver. 33: var resolver = new AutofacWebApiDependencyResolver(container); 34: configuration.ServiceResolver.SetResolver(resolver); 35: } 36: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The RegisterApiControllers method will scan the given assembly and register the all ApiController classes. This method will look for types that derive from IHttpController with name convention end with “Controller”. The InstancePerApiRequest method specifies the life time of the component for once per API controller invocation. The GlobalConfiguration.Configuration provides a ServiceResolver class which can be use set dependency resolver for ASP.NET Web API. In our example, we are using AutofacWebApiDependencyResolver class provided by Autofac.WebApi to set the dependency resolver. The Run method of Bootstrapper class is calling from Application_Start method of Global.asax.cs. 1: protected void Application_Start() 2: { 3: AreaRegistration.RegisterAllAreas(); 4: RegisterGlobalFilters(GlobalFilters.Filters); 5: RegisterRoutes(RouteTable.Routes); 6: BundleTable.Bundles.RegisterTemplateBundles(); 7: //Call Autofac DI configurations 8: Bootstrapper.Run(); 9: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Autofac.Mvc4 The Autofac framework’s integration with ASP.NET MVC has updated for ASP.NET MVC 4. The NuGet package Autofac.Mvc4 provides the dependency injection support for ASP.NET MVC 4. There is not any syntax change between Autofac.Mvc3 and Autofac.Mvc4 Source Code I have updated my EFMVC app with Autofac.WebApi for applying dependency injection for it’s ASP.NET Web API services. EFMVC app also updated to Autofac.Mvc4 for it’s ASP.NET MVC 4 web app. The above code sample is taken from the EFMVC app. You can download the source code of EFMVC app from http://efmvc.codeplex.com/

    Read the article

  • Telerik Object reference not set to an instance of an object

    - by Duncan
    Hi, I have a main form which contains multiple worker threads. These threads raise events which update Telerik controls on the main form. The event handlers contain code which check if InvokeRequired and BeginInvoke where required. At random interval I am receiving the following exception, and have no idea on how where to find this? I was wondering if the following is understandable to anyone to point me in the right direction. Thanks in advance System.Reflection.TargetInvocationException was unhandled Message="Exception has been thrown by the target of an invocation." Source="mscorlib" StackTrace: at System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) at System.RuntimeMethodHandle.InvokeMethodFast(Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) at System.Delegate.DynamicInvokeImpl(Object[] args) at System.Windows.Forms.Control.InvokeMarshaledCallbackDo(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(Object obj) at System.Threading.ExecutionContext.runTryCode(Object userData) at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Windows.Forms.Control.InvokeMarshaledCallback(ThreadMethodEntry tme) at System.Windows.Forms.Control.InvokeMarshaledCallbacks() at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ScrollableControl.WndProc(Message& m) at Telerik.WinControls.RadControl.WndProc(Message& m) at Telerik.WinControls.UI.RadStatusStrip.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.Run(ApplicationContext context) at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun() at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel() at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine) at MyFX.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81 at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException: System.NullReferenceException Message="Object reference not set to an instance of an object." Source="Telerik.WinControls" StackTrace: at Telerik.WinControls.Layouts.ContextLayoutManager.LayoutQueue.RemoveOrphans(RadElement parent) at Telerik.WinControls.Layouts.ContextLayoutManager.LayoutQueue.Add(RadElement e) at Telerik.WinControls.RadElement.InvalidateArrange(Boolean recursive) at Telerik.WinControls.RadElement.InvalidateArrange() at Telerik.WinControls.RadElement.Measure(SizeF availableSize) at Telerik.WinControls.Layouts.ImageAndTextLayoutPanel.MeasureOverride(SizeF availableSize) at Telerik.WinControls.RadElement.MeasureCore(SizeF availableSize) at Telerik.WinControls.RadElement.Measure(SizeF availableSize) at Telerik.WinControls.Layouts.ContextLayoutManager.UpdateLayout() at Telerik.WinControls.Layouts.ContextLayoutManager.UpdateLayoutCallback(ILayoutManager manager)

    Read the article

  • Why did object-oriented paradigms take so long to go mainstream?

    - by Earlz
    I read this question and it got me thinking about another fairly recent thing. Object oriented languages. I'm not sure when the first one was created, but why did it take so long before they became mainstream? C became vastly popular, but didn't become the object-oriented C++ for years(decades?) later No mainstream language before the 90s was object oriented Object oriented really seemed to take off with Java and C++ around the same time Now, my question, why did this take so long? Why wasn't C originally conceived as an object-oriented language? Taking a very small subset of C++ wouldn't have affected the core language a whole lot, so why was this idea not popular until the 90s?

    Read the article

  • Explanation of the definition of interface inheritance as described in GoF book

    - by Geek
    I am reading the first chapter of the Gof book. Section 1.6 discusses about class vs interface inheritance: Class versus Interface Inheritance It's important to understand the difference between an object's class and its type. An object's class defines how the object is implemented.The class defines the object's internal state and the implementation of its operations.In contrast,an object's type only refers to its interface--the set of requests on which it can respond. An object can have many types, and objects of different classes can have the same type. Of course, there's a close relationship between class and type. Because a class defines the operations an object can perform, it also defines the object's type . When we say that an object is an instance of a class, we imply that the object supports the interface defined by the class. Languages like c++ and Eiffel use classes to specify both an object's type and its implementation. Smalltalk programs do not declare the types of variables; consequently,the compiler does not check that the types of objects assigned to a variable are subtypes of the variable's type. Sending a message requires checking that the class of the receiver implements the message, but it doesn't require checking that the receiver is an instance of a particular class. It's also important to understand the difference between class inheritance and interface inheritance (or subtyping). Class inheritance defines an object's implementation in terms of another object's implementation. In short, it's a mechanism for code and representation sharing. In contrast,interface inheritance(or subtyping) describes when an object can be used in place of another. I am familiar with the Java and JavaScript programming language and not really familiar with either C++ or Smalltalk or Eiffel as mentioned here. So I am trying to map the concepts discussed here to Java's way of doing classes, inheritance and interfaces. This is how I think of of these concepts in Java: In Java a class is always a blueprint for the objects it produces and what interface(as in "set of all possible requests that the object can respond to") an object of that class possess is defined during compilation stage only because the class of the object would have implemented those interfaces. The requests that an object of that class can respond to is the set of all the methods that are in the class(including those implemented for the interfaces that this class implements). My specific questions are: Am I right in saying that Java's way is more similar to C++ as described in the third paragraph. I do not understand what is meant by interface inheritance in the last paragraph. In Java interface inheritance is one interface extending from another interface. But I think the word interface has some other overloaded meaning here. Can some one provide an example in Java of what is meant by interface inheritance here so that I understand it better?

    Read the article

< Previous Page | 8 9 10 11 12 13 14 15 16 17 18 19  | Next Page >