Search Results

Search found 4077 results on 164 pages for 'throw'.

Page 99/164 | < Previous Page | 95 96 97 98 99 100 101 102 103 104 105 106  | Next Page >

• What does the Spring framework do? Should I use it? Why or why not?

  - by sangfroid

  So, I'm starting a brand-new project in Java, and am considering using Spring. Why am I considering Spring? Because lots of people tell me I should use Spring! Seriously, any time I've tried to get people to explain what exactly Spring is or what it does, they can never give me a straight answer. I've checked the intros on the SpringSource site, and they're either really complicated or really tutorial-focused, and none of them give me a good idea of why I should be using it, or how it will make my life easier. Sometimes people throw around the term "dependency injection", which just confuses me even more, because I think I have a different understanding of what that term means. Anyway, here's a little about my background and my app : Been developing in Java for a while, doing back-end web development. Yes, I do a ton of unit testing. To facilitate this, I typically make (at least) two versions of a method : one that uses instance variables, and one that only uses variables that are passed in to the method. The one that uses instance variables calls the other one, supplying the instance variables. When it comes time to unit test, I use Mockito to mock up the objects and then make calls to the method that doesn't use instance variables. This is what I've always understood "dependency injection" to be. My app is pretty simple, from a CS perspective. Small project, 1-2 developers to start with. Mostly CRUD-type operations with a a bunch of search thrown in. Basically a bunch of RESTful web services, plus a web front-end and then eventually some mobile clients. I'm thinking of doing the front-end in straight HTML/CSS/JS/JQuery, so no real plans to use JSP. Using Hibernate as an ORM, and Jersey to implement the webservices. I've already started coding, and am really eager to get a demo out there that I can shop around and see if anyone wants to invest. So obviously time is of the essence. I understand Spring has quite the learning curve, plus it looks like it necessitates a whole bunch of XML configuration, which I typically try to avoid like the plague. But if it can make my life easier and (especially) if make it can make development and testing faster, I'm willing to bite the bullet and learn Spring. So please. Educate me. Should I use Spring? Why or why not?

  Read the article

• How to suggest using an ORM instead of stored procedures?

  - by Wayne M

  I work at a company that only uses stored procedures for all data access, which makes it very annoying to keep our local databases in sync as every commit we have to run new procs. I have used some basic ORMs in the past and I find the experience much better and cleaner. I'd like to suggest to the development manager and rest of the team that we look into using an ORM Of some kind for future development (the rest of the team are only familiar with stored procedures and have never used anything else). The current architecture is .NET 3.5 written like .NET 1.1, with "god classes" that use a strange implementation of ActiveRecord and return untyped DataSets which are looped over in code-behind files - the classes work something like this: class Foo { public bool LoadFoo() { bool blnResult = false; if (this.FooID == 0) { throw new Exception("FooID must be set before calling this method."); } DataSet ds = // ... call to Sproc if (ds.Tables[0].Rows.Count > 0) { foo.FooName = ds.Tables[0].Rows[0]["FooName"].ToString(); // other properties set blnResult = true; } return blnResult; } } // Consumer Foo foo = new Foo(); foo.FooID = 1234; foo.LoadFoo(); // do stuff with foo... There is pretty much no application of any design patterns. There are no tests whatsoever (nobody else knows how to write unit tests, and testing is done through manually loading up the website and poking around). Looking through our database we have: 199 tables, 13 views, a whopping 926 stored procedures and 93 functions. About 30 or so tables are used for batch jobs or external things, the remainder are used in our core application. Is it even worth pursuing a different approach in this scenario? I'm talking about moving forward only since we aren't allowed to refactor the existing code since "it works" so we cannot change the existing classes to use an ORM, but I don't know how often we add brand new modules instead of adding to/fixing current modules so I'm not sure if an ORM is the right approach (too much invested in stored procedures and DataSets). If it is the right choice, how should I present the case for using one? Off the top of my head the only benefits I can think of is having cleaner code (although it might not be, since the current architecture isn't built with ORMs in mind so we would basically be jury-rigging ORMs on to future modules but the old ones would still be using the DataSets) and less hassle to have to remember what procedure scripts have been run and which need to be run, etc. but that's it, and I don't know how compelling an argument that would be. Maintainability is another concern but one that nobody except me seems to be concerned about.

  Read the article

• What if I can't make my unit test fail in "Red, Green, Refactor" of TDD?

  - by Joshua Harris

  So let's say that I have a test: @Test public void MoveY_MoveZero_DoesNotMove() { Point p = new Point(50.0, 50.0); p.MoveY(0.0); Assert.assertAreEqual(50.0, p.Y); } This test then causes me to create the class Point: public class Point { double X; double Y; public void MoveY(double yDisplace) { throw new NotYetImplementedException(); } } Ok. It fails. Good. Then I remove the exception and I get green. Great, but of course I need to test if it changes value. So I write a test that calls p.MoveY(10.0) and checks if p.Y is equal to 60.0. It fails, so then I change the function to look like so: public void MoveY(double yDisplace) { Y += yDisplace; } Great, now I have green again and I can move on. I've tested not moving and moving in the positive direction, so naturally I should test a negative value. The only problem with this test is that if I wrote the test correctly, then it doesn't fail at first. That means that I didn't fit the principle of "Red, Green, Refactor." Of course, This is a first-world problem of TDD, but getting a fail at first is helpful in that it shows that your test can fail. Otherwise this seemingly innocent test that is just passing for incorrect reasons could fail later because it was written wrong. That might not be a problem if it happened 5 minutes later, but what if it happens to the poor-sap that inheirited your code two years later. What he knows is that MoveY does not work with negative values because that is what the test is telling him. But, it really could work and just be a bug in the test. I don't think that would happen in this particular case because the code sample is so simple, but if it were a large complicated system that might not be the case. It seems crazy to say that I want to fail my tests, but that is an important step in TDD, for good reasons.

  Read the article

• How do you handle objects that need custom behavior, and need to exist as an entity in the database?

  - by Scott Whitlock

  For a simple example, assume your application sends out notifications to users when various events happen. So in the database I might have the following tables: TABLE Event EventId uniqueidentifier EventName varchar TABLE User UserId uniqueidentifier Name varchar TABLE EventSubscription EventUserId EventId UserId The events themselves are generated by the program. So there are hard-coded points in the application where an event instance is generated, and it needs to notify all the subscribed users. So, the application itself doesn't edit the Event table, except during initial installation, and during an update where a new Event might be created. At some point, when an event is generated, the application needs to lookup the Event and get a list of Users. What's the best way to link the event in the source code to the event in the database? Option 1: Store the EventName in the program as a fixed constant, and look it up by name. Option 2: Store the EventId in the program as a static Guid, and look it up by ID. Extra Credit In other similar circumstances I may want to include custom behavior with the event type. That is, I'll want subclasses of my Event entity class with different behaviors, and when I lookup an event, I want it to return an instance of my subclass. For instance: class Event { public Guid Id { get; } public Guid EventName { get; } public ReadOnlyCollection<EventSubscription> EventSubscriptions { get; } public void NotifySubscribers() { foreach(var eventSubscription in EventSubscriptions) { eventSubscription.Notify(); } this.OnSubscribersNotified(); } public virtual void OnSubscribersNotified() {} } class WakingEvent : Event { private readonly IWaker waker; public WakingEvent(IWaker waker) { if(waker == null) throw new ArgumentNullException("waker"); this.waker = waker; } public override void OnSubscribersNotified() { this.waker.Wake(); base.OnSubscribersNotified(); } } So, that means I need to map WakingEvent to whatever key I'm using to look it up in the database. Let's say that's the EventId. Where do I store this relationship? Does it go in the event repository class? Should the WakingEvent know declare its own ID in a static member or method? ...and then, is this all backwards? If all events have a subclass, then instead of retrieving events by ID, should I be asking my repository for the WakingEvent like this: public T GetEvent<T>() where T : Event { ... // what goes here? ... } I can't be the first one to tackle this. What's the best practice?

  Read the article

• Loading levels from .txt or .XML for XNA

  - by Dave Voyles

  I'm attemptin to add multiple levels to my pong game. I'd like to simply exchange a few elements with each level, nothing crazy. Just the background texture, the color of the AI paddle (the one on the right side), and the music. It seems that the best way to go about this is by utilizing the StreamReader to read and write the files from XML. If there is a better, or more efficient alternative way then I'm all for it. In looking over the XNA Starter Platformer Kit provided by MS it seems that they've done it in this manner as well. I'm perplexed by a few things, however, namely parts within the Level class which aren't commented. /// <summary> /// Iterates over every tile in the structure file and loads its /// appearance and behavior. This method also validates that the /// file is well-formed with a player start point, exit, etc. /// </summary> /// <param name="fileStream"> /// A stream containing the tile data. /// </param> private void LoadTiles(Stream fileStream) { // Load the level and ensure all of the lines are the same length. int width; List<string> lines = new List<string>(); using (StreamReader reader = new StreamReader(fileStream)) { string line = reader.ReadLine(); width = line.Length; while (line != null) { lines.Add(line); if (line.Length != width) throw new Exception(String.Format("The length of line {0} is different from all preceeding lines.", lines.Count)); line = reader.ReadLine(); } } What does width = line.Length mean exactly? I mean I know how it reads the line, but what difference does it make if one line is longer than any of the others? Finally, their levels are simply text files that look like this: .................... .................... .................... .................... .................... .................... .................... .........GGG........ .........###........ .................... ....GGG.......GGG... ....###.......###... .................... .1................X. #################### It can't be that easy..... Can it?

  Read the article

• VS2010 Launch Presentations

  Last week I was in Vegas to present at the DevConnections / VS2010 Launch event.  The show was well-attended and everybody I spoke to agreed it was educational and enjoyable.  My three talks were all on Wednesday, 14 April 2010, including one at 8am for which I was impressed to see a large turnout in attendance.   Pragmatic ASP.NET Tips, Tricks, and Tools My first session was on tips, tricks, and tools for ASP.NET developers.  This is a talk Ive given in past years, but which I refine every time.  I usually like to have a full session to devote to tools, and a separate talk just for Tips and Tricks, but for this show I was only given the one 75-minute slot, so I had to cut some materials to make things fit.  The talk went well, all the demos work, and the attendees seemed to enjoy it, and I like giving it, so hopefully I can continue to present on this topic in future DevConnections shows. Download the ASP.NET Tips, Tricks, and Tools slides and demos.   Whats New in ASP.NET MVC 2 My second talk of the day followed immediately after the Tips and Tricks talk, and was a brand new talk for me.  I have to throw out a thank-you to Phil for letting me see his MIX slide deck before he gave his talk, as that was a big help.  The official whats new document online is also worth checking out if youre interested in this subject.  Download the Whats New in ASP.NET MVC 2 slides and demos.   SOLIDify Your ASP.NET MVC 2 Application Just because youre using a ASP.NET MVC doesnt mean your code cant still end up being a big ball of mud.  This session describes a number of principles of software design that can help ensure applications remain loosely-coupled and malleable even as they age and increase in features and complexity.  This was my last talk of the day and did have one minor demo failure involving a database constraint.  Ive given this talk many times before, and in this case I had to fit it into a 60-minute timeslot, so Im not sure I had quite enough time to drive home all of the concepts to everyone in the audience.  That said, I did hear a number of positive comments on how the talk went, so thats encouraging. Download the SOLIDify Your ASP.NET MVC 2 Application slides and demos.   In my sessions, I promised to have these posted by the end of the weekend theyre going up at 10pm Sunday night (my time) 2 hours to spare!  Enjoy! Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

  Read the article

• Hadoop, NOSQL, and the Relational Model

  - by Phil Factor

  (Guest Editorial for the IT Pro/SysAdmin Newsletter)Whereas Relational Databases fit the world of commerce like a glove, it is useless to pretend that they are a perfect fit for all human endeavours. Although, with SQL Server, we’ve made great strides with indexing text, in processing spatial data and processing markup, there is still a problem in dealing efficiently with large volumes of ephemeral semi-structured data. Key-value stores such as Cassandra, Project Voldemort, and Riak are of great value for ephemeral data, and seem of equal value as a data-feed that provides aggregations to an RDBMS. However, the Document databases such as MongoDB and CouchDB are ideal for semi-structured data for which no fixed schema exists; analytics and logging are obvious examples. NoSQL products, such as MongoDB, tackle the semi-structured data problem with panache. MongoDB is designed with a simple document-oriented data model that scales horizontally across multiple servers. It doesn’t impose a schema, and relies on the application to enforce the data structure. This is another take on the old ‘EAV’ problem (where you don’t know in advance all the attributes of a particular entity) It uses a clever replica set design that allows automatic failover, and uses journaling for data durability. It allows indexing and ad-hoc querying. However, for SQL Server users, the obvious choice for handling semi-structured data is Apache Hadoop. There will soon be an ODBC Driver for Apache Hive .and an Add-in for Excel. Additionally, there are now two Hadoop-based connectors for SQL Server; the Apache Hadoop connector for SQL Server 2008 R2, and the SQL Server Parallel Data Warehouse (PDW) connector. We can connect to Hadoop process the semi-structured data and then store it in SQL Server. For one steeped in the culture of Relational SQL Databases, I might be expected to throw up my hands in the air in a gesture of contempt for a technology that was, judging by the overblown journalism on the subject, about to make my own profession as archaic as the Saggar makers bottom knocker (a potter’s assistant who helped the saggar maker to make the bottom of the saggar by placing clay in a metal hoop and bashing it). However, on the contrary, I find that I'm delighted with the advances made by the NoSQL databases in the past few years. Having the flow of ideas from the NoSQL providers will knock any trace of complacency out of the providers of Relational Databases and inspire them into back-fitting some features, such as horizontal scaling, with sharding and automatic failover into SQL-based RDBMSs. It will do the breed a power of good to benefit from all this lateral thinking.

  Read the article

• Inline template efficiency

  - by Darryl Gove

  I like inline templates, and use them quite extensively. Whenever I write code with them I'm always careful to check the disassembly to see that the resulting output is efficient. Here's a potential cause of inefficiency. Suppose we want to use the mis-named Leading Zero Detect (LZD) instruction on T4 (this instruction does a count of the number of leading zero bits in an integer register - so it should really be called leading zero count). So we put together an inline template called lzd.il looking like: .inline lzd lzd %o0,%o0 .end And we throw together some code that uses it: int lzd(int); int a; int c=0; int main() { for(a=0; a<1000; a++) { c=lzd(c); } return 0; } We compile the code with some amount of optimisation, and look at the resulting code: $ cc -O -xtarget=T4 -S lzd.c lzd.il $ more lzd.s .L77000018: /* 0x001c 11 */ lzd %o0,%o0 /* 0x0020 9 */ ld [%i1],%i3 /* 0x0024 11 */ st %o0,[%i2] /* 0x0028 9 */ add %i3,1,%i0 /* 0x002c */ cmp %i0,999 /* 0x0030 */ ble,pt %icc,.L77000018 /* 0x0034 */ st %i0,[%i1] What is surprising is that we're seeing a number of loads and stores in the code. Everything could be held in registers, so why is this happening? The problem is that the code is only inlined at the code generation stage - when the actual instructions are generated. Earlier compiler phases see a function call. The called functions can do all kinds of nastiness to global variables (like 'a' in this code) so we need to load them from memory after the function call, and store them to memory before the function call. Fortunately we can use a #pragma directive to tell the compiler that the routine lzd() has no side effects - meaning that it does not read or write to memory. The directive to do that is #pragma no_side_effect(<routine name), and it needs to be placed after the declaration of the function. The new code looks like: int lzd(int); #pragma no_side_effect(lzd) int a; int c=0; int main() { for(a=0; a<1000; a++) { c=lzd(c); } return 0; } Now the loop looks much neater: /* 0x0014 10 */ add %i1,1,%i1 ! 11 ! { ! 12 ! c=lzd(c); /* 0x0018 12 */ lzd %o0,%o0 /* 0x001c 10 */ cmp %i1,999 /* 0x0020 */ ble,pt %icc,.L77000018 /* 0x0024 */ nop

  Read the article

• Drawing 2D Grid in 3D View - Need help with method

  - by Deukalion

  I'm trying to draw a simple 2D grid for an editor, to able to navigate more clearly around the 3D space, but I can't render it: Grid2D class, creates a grid of a certain size at a location and should just draw lines. public class Grid2D : IShape { private VertexPositionColor[] _vertices; private Vector2 _size; private Vector3 _location; private int _faces; public Grid2D(Vector2 size, Vector3 location, Color color) { float x = 0, y = 0; if (size.X < 1f) { size.X = 1f; } if (size.Y < 1f) { size.Y = 1f; } _size = size; _location = location; List<VertexPositionColor> vertices = new List<VertexPositionColor>(); _faces = 0; for (y = -size.Y; y <= size.Y; y++) { vertices.Add(new VertexPositionColor(location + new Vector3(-size.X, y, 0), color)); vertices.Add(new VertexPositionColor(location + new Vector3(size.X, y, 0), color)); _faces++; } for (x = -size.X; x <= size.X; x++) { vertices.Add(new VertexPositionColor(location + new Vector3(x, -size.Y, 0), color)); vertices.Add(new VertexPositionColor(location + new Vector3(x, size.Y, 0), color)); _faces++; } _vertices = vertices.ToArray(); } public void Render(GraphicsDevice device) { device.DrawUserPrimitives<VertexPositionColor>(PrimitiveType.LineList, _vertices, 0, _faces); } } Like this: +----+----+----+----+ | | | | | +----+----+----+----+ | | | | | +----+----+----+----+ | | | | | +----+----+----+----+ | | | | | +----+----+----+----+ Anyone knows what I'm doing wrong? If I add a Shape without texture, it's set automatically to VertexColorEnabled and TextureEnabled = false. This is how I render it: foreach (RenderObject render in _renderObjects) { render.Effect.Projection = projection; render.Effect.View = view; render.Effect.World = world; foreach (EffectPass pass in render.Effect.CurrentTechnique.Passes) { pass.Apply(); try { // Could be a Grid2D render.Shape.Render(_device); } catch { throw; } } } Exception is thrown: The current vertex shader declaration does not include all the elements required by the current Vertex Shader. Normal0 is missing. Simply put, I can't figure out how to draw a few lines. I want to draw them one at a time and I guess that's the problem I haven't figured out, and even when I tried rendering vertices[i], vertices[i+1] and primitiveCount = 1, vertices = 2, and so on it didn't work either. Any suggestions?

  Read the article

• On the art of self-promotion

  - by Tony Davis

  I attended Brent Ozar's Building the Fastest SQL Servers session at Tech Ed last week, and found myself engulfed in a 'perfect storm' of excellent technical and presentational skills coupled with an astute awareness of the value of promoting one's work. I spend a lot of time at such events talking to developers and DBAs about the value of blogging and writing articles, and my impression is that some could benefit from a touch less modesty and a little more self-promotion. I sense a reticence in many would-be writers. Is what I have to say important enough? Haven't far more qualified and established commentators, MVPs and so on, already said it? While it's a good idea to pick reasonably fresh and interesting topics, it's more important not to let such fears lead to writer's block. In the eyes of any future employer, your published writing is an extension of your resume. They will not care that a certain MVP knows how to solve problem x, but they will be very interested to see that you have tackled that same problem, and solved it in your own way, and described the process in your own voice. In your current job, your writing is one of the ways you can express to your peers, and to the organization as a whole, the value of what you contribute. Many Developers and DBAs seem to rely on the idea that their work will speak for itself, and that their skill shines out from it. Unfortunately, this isn't always true. Many Development DBAs, for example, will be painfully aware of the massive effort involved in tuning and adding resilience to rapidly developed applications. However, others in the organization who are unaware of what's involved in getting an application that is 'done' ready for production may dismiss such efforts as fussiness or conservatism. At the dark end of the development cycle, chickens come home to roost, but their droppings tend to land on those trying to clear up the mess. My advice is this: next time you fix a bug or improve the resilience or performance of a database or application, make sure that you use team meetings, informal discussions and so on to ensure that people understand what the problem was and what you had to do to fix it. Use your blog to describe, generally, the process you adopted, the resources you used and the insights that came from your work. Encourage your colleagues to do the same. By spreading the art of self-promotion to everyone involved in an IT project, we get a better idea of the extent of the work and the value of the contribution of all the team members. As always, we'd love to hear what you think. This very week, Simple-talk launches its new blogging platform. If any of this has moved you to 'throw your hat into the ring', drop us a mail at [email protected]. Cheers, Tony.

  Read the article

• How to avoid the exception “Substitution controls cannot be used in cached User Controls or cached M

  - by DigiMortal

  Recently I wrote example about using user controls with donut caching. Because cache substitutions are not allowed inside partially cached controls you may get the error Substitution controls cannot be used in cached User Controls or cached Master Pages when breaking this rule. In this posting I will introduce some strategies that help to avoid this error. How Substitution control checks its location? Substitution control uses the following check in its OnPreRender method. protected internal override void OnPreRender(EventArgs e) {     base.OnPreRender(e);     for (Control control = this.Parent; control != null;          control = control.Parent)     {         if (control is BasePartialCachingControl)         {             throw new HttpException(SR.GetString("Substitution_CannotBeInCachedControl"));         }     } } It traverses all the control tree up to top from its parent to find at least one control that is partially cached. If such control is found then exception is thrown. Reusing the functionality If you want to do something by yourself if your control may cause exception mentioned before you can use the same code. I modified the previously shown code to be method that can be easily moved to user controls base class if you have some. If you don’t you can use it in controls where you need this check. protected bool IsInsidePartialCachingControl() {     for (Control control = Parent; control != null;         control = control.Parent)         if (control is BasePartialCachingControl)             return true;       return false; } Now it is up to you how to handle the situation where your control with substitutions is child of some partially cache control. You can add here also some debug level output so you can see exactly what controls in control hierarchy are cached and cause problems.

  Read the article

• Creating an object that is ready to be used & unset properties - with IoC

  - by GetFuzzy

  I have a question regarding the specifics of object creation and the usage of properties. A best practice is to put all the properties into a state such that the object is useful when its created. Object constructors help ensure that required dependencies are created. I've found myself following a pattern lately, and then questioning its appropriateness. The pattern looks like this... public class ThingProcesser { public List<Thing> CalculatedThings { get; set; } public ThingProcesser() { CalculatedThings = new List<Thing>(); } public double FindCertainThing() { CheckForException(); foreach (var thing in CalculatedThings) { //do some stuff with things... } } public double FindOtherThing() { CheckForException(); foreach (var thing in CalculatedThings) { //do some stuff with things... } } private void CheckForException() { if (CalculatedThings.Count < 2) throw new InvalidOperationException("Calculated things must have more than 2 items"); } } The list of items is not being changed, just looked through by the methods. There are several methods on the class, and to avoid having to pass the list of things to each function as a method parameter, I set it once on the class. While this works, does it violate the principle of least astonishment? Since starting to use IoC I find myself not sticking things into the constructor, to avoid having to use a factory pattern. For example, I can argue with myself and say well the ThingProcessor really needs a List to work, so the object should be constructed like this. public class ThingProcesser { public List<Thing> CalculatedThings { get; set; } public ThingProcesser(List<Thing> calculatedThings) { CalculatedThings = calculatedThings; } } However, if I did this, it would complicate things for IoC, and this scenario hardly seems appropriate for something like the factory pattern. So in summary, are there some good guidelines for when something should be part of the object state, vs. passed as a method parameter? When using IoC, is the factory pattern the best way to deal with objects that need created with state? If something has to be passed to multiple methods in a class, does that render it a good candidate to be part of the objects state?

  Read the article

• Understanding exceptional cases

  - by Justin

  I've been studying the use of exceptions in various php projects (such as Doctrine and Zend Framework). Exceptions seem to be thrown when unordinary input/state occurs. A perfect example is Doctrine throwing an exception when you try to use a invalid query string. I think the creators of the doctrine api understood that first, you can't query data by using an invalid DQL statement, and a developer should immediately be warned that an error has occurred, rather then letting execution continue with the possibility of an error code going un-checked. I also bet that this simplifies reading the code. I can't think of a situation where you would want to use an invalid DQL statement, except unit testing. Since this is true, it's better to avoid plaguing a bunch of code with null/error checks and use exceptions. I've read in books that exceptions shouldn't be thrown when validating dating user input. I've seen examples where of where the guideline is broken. One example is the Zend framework. If supplying an invalid controller or action name, an exception is thrown. Unlike doctrine, the user has more direct control over this sort of input. I know you can configure an error controller and set up a 404 message or what have you, but I'm curious why they have used an exception in this scenario? I guess you can argue the Zend Framework does not know how to continue processing the quest. One last example Is I wrote a function to return some html based on a given resource type. This resource type is hard-coded and sent when a user interacts with a web site (such as clicking a button to display the form to input data). I don't expect users to be mucking around with the request type. Under normal operating conditions, the resource type should be valid. To clean up some logic, I was going to throw an exception if a particular form wasn't found. This is mainly to find the correct form associated with a resource type so proper validation can occur. Does this sound like a valid use case for an exception? Right now it's pretty trivial, but I do plan to implement a restful consumer and re-using a function to map resources to their validation services would be very useful. I can then catch the exception and based on the consumer, return an error message suitable for the request type...

  Read the article

• Best Advice Ever: Learn By Helping Others

  - by Argenis

  I remember when back in 2001 my friend and former SQL Server MVP Carlos Eduardo Rojas was busy earning his MVP street-cred in the NNTP forums, aka Newsgroups. I always thought he was playing the Sheriff trying to put some order in a Wild Wild West town by trying to understand what these people were asking. He spent a lot of time doing this stuff – and I thought it was just plain crazy. After all, he was doing it for free. What was he gaining from all of that work? It was not until the advent of Twitter and #SQLHelp that I realized the real gain behind helping others. Forget about the glory and the laurels of others thanking you (and thinking you’re the best thing ever – ha!), or whatever award with whatever three letter acronym might be given to you. It’s about what you learn in the process of helping others. See, when you teach something, it’s usually at a fixed date and time, and on a specific topic. But helping others with their issues or general questions is something that goes on 24x7, on whatever topic under the sun. Just go look at sites like DBA.StackExchange.com, or the SQLServerCentral forums. It’s questions coming in literally non-stop from all corners or the world. And yet a lot of people are willing to help you, regardless of who you are, where you come from, or what time of day it is. And in my case, this process of helping others usually leads to me learning something new. Especially in those cases where the question isn’t really something I’m good at. The delicate part comes when you’re ready to give an answer, but you’re not sure. Often times I’ll try to validate with Internet searches and what have you. Often times I’ll throw in a question mark at the end of the answer, so as not to look authoritative, but rather suggestive. But as time passes by, you get more and more comfortable with that topic. And that’s the real gain.  I have done this for many years now on #SQLHelp, which is my preferred vehicle for providing assistance. I cannot tell you how much I’ve learned from it. By helping others, by watching others help. It’s all knowledge and experience you gain…and you might not be getting all that in your day job today. Such thing, my dear reader, is invaluable. It’s what will differentiate yours amongst a pack of resumes. It’s what will get you places. Take it from me - a guy who, like you, knew nothing about SQL Server.

  Read the article

• Our own Daily WTF

  - by Dennis Vroegop

  Originally posted on: http://geekswithblogs.net/dvroegop/archive/2014/08/20/our-own-daily-wtf.aspxIf you're a developer, you've probably heard of the website the DailyWTF. If you haven't, head on over to http://www.thedailywtf.com and read. And laugh. I'll wait. Read it? Good. If you're a bit like me probably you've been wondering how on earth some people ever get hired as a software engineer. Most of the stories there seem to weird to be true: no developer would write software like that right? And then you run into a little nugget of code one of your co-workers wrote. And then you realize: "Hey, it happens everywhere!" Look at this piece of art I found in our codebase recently: public static decimal ToDecimal(this string input) {     System.Globalization.CultureInfo cultureInfo = System.Globalization.CultureInfo.InstalledUICulture;     var numberFormatInfo = (System.Globalization.NumberFormatInfo)cultureInfo.NumberFormat.Clone();     int dotIndex = input.IndexOf(".");     int commaIndex = input.IndexOf(",");     if (dotIndex > commaIndex)         numberFormatInfo.NumberDecimalSeparator = ".";     else if (commaIndex > dotIndex)         numberFormatInfo.NumberDecimalSeparator = ",";     decimal result;     if (decimal.TryParse(input, System.Globalization.NumberStyles.Float, numberFormatInfo, out result))         return result;     else         throw new Exception(string.Format("Invalid input for decimal parsing: {0}. Decimal separator: {1}.", input, numberFormatInfo.NumberDecimalSeparator)); }  Me and a collegue have been looking long and hard at this and what we concluded was the following: Apparently, we don't trust our users to be able to correctly set the culture in Windows. Users aren't able to determine if they should tell Windows to use a decimal point or a comma to display numbers. So what we've done here is make sure that whatever the user enters, we'll translate that into whatever the user WANTS to enter instead of what he actually did. So if you set your locale to US, since you're a US citizen, but you want to enter the number 12.34 in the Dutch style (because, you know, the Dutch are way cooler with numbers) so you enter 12,34 we will understand this and respect your wishes! Of course, if you change your mind and in the next input field you decide to use the decimal dot again, that's fine with us as well. We will do the hard work. Now, I am all for smart software. Software that can handle all sorts of input the user can think of. But this feels a little uhm, I don't know.. wrong.. Or am I too old fashioned?

  Read the article

• Entity Framework 5, separating business logic from model - Repository?

  - by bnice7

  I am working on my first public-facing web application and I’m using MVC 4 for the presentation layer and EF 5 for the DAL. The database structure is locked, and there are moderate differences between how the user inputs data and how the database itself gets populated. I have done a ton of reading on the repository pattern (which I have never used) but most of my research is pushing me away from using it since it supposedly creates an unnecessary level of abstraction for the latest versions of EF since repositories and unit-of-work are already built-in. My initial approach is to simply create a separate set of classes for my business objects in the BLL that can act as an intermediary between my Controllers and the DAL. Here’s an example class: public class MyBuilding { public int Id { get; private set; } public string Name { get; set; } public string Notes { get; set; } private readonly Entities _context = new Entities(); // Is this thread safe? private static readonly int UserId = WebSecurity.GetCurrentUser().UserId; public IEnumerable<MyBuilding> GetList() { IEnumerable<MyBuilding> buildingList = from p in _context.BuildingInfo where p.Building.UserProfile.UserId == UserId select new MyBuilding {Id = p.BuildingId, Name = p.BuildingName, Notes = p.Building.Notes}; return buildingList; } public void Create() { var b = new Building {UserId = UserId, Notes = this.Notes}; _context.Building.Add(b); _context.SaveChanges(); // Set the building ID this.Id = b.BuildingId; // Seed 1-to-1 tables with reference the new building _context.BuildingInfo.Add(new BuildingInfo {Building = b}); _context.GeneralInfo.Add(new GeneralInfo {Building = b}); _context.LocationInfo.Add(new LocationInfo {Building = b}); _context.SaveChanges(); } public static MyBuilding Find(int id) { using (var context = new Entities()) // Is this OK to do in a static method? { var b = context.Building.FirstOrDefault(p => p.BuildingId == id && p.UserId == UserId); if (b == null) throw new Exception("Error: Building not found or user does not have access."); return new MyBuilding {Id = b.BuildingId, Name = b.BuildingInfo.BuildingName, Notes = b.Notes}; } } } My primary concern: Is the way I am instantiating my DbContext as a private property thread-safe, and is it safe to have a static method that instantiates a separate DbContext? Or am I approaching this all wrong? I am not opposed to learning up on the repository pattern if I am taking the total wrong approach here.

  Read the article

• "Whole-team" C++ features?

  - by Blaisorblade

  In C++, features like exceptions impact your whole program: you can either disable them in your whole program, or you need to deal with them throughout your code. As a famous article on C++ Report puts it: Counter-intuitively, the hard part of coding exceptions is not the explicit throws and catches. The really hard part of using exceptions is to write all the intervening code in such a way that an arbitrary exception can propagate from its throw site to its handler, arriving safely and without damaging other parts of the program along the way. Since even new throws exceptions, every function needs to provide basic exception safety — unless it only calls functions which guarantee throwing no exception — unless you disable exceptions altogether in your whole project. Hence, exceptions are a "whole-program" or "whole-team" feature, since they must be understood by everybody in a team using them. But not all C++ features are like that, as far as I know. A possible example is that if I don't get templates but I do not use them, I will still be able to write correct C++ — or will I not?. I can even call sort on an array of integers and enjoy its amazing speed advantage wrt. C's qsort (because no function pointer is called), without risking bugs — or not? It seems templates are not "whole-team". Are there other C++ features which impact code not directly using them, and are hence "whole-team"? I am especially interested in features not present in C. Update: I'm especially looking for features where there's no language-enforced sign you need to be aware of them. The first answer I got mentioned const-correctness, which is also whole-team, hence everybody needs to learn about it; however, AFAICS it will impact you only if you call a function which is marked const, and the compiler will prevent you from calling it on non-const objects, so you get something to google for. With exceptions, you don't even get that; moreover, they're always used as soon as you use new, hence exceptions are more "insidious". Since I can't phrase this as objectively, though, I will appreciate any whole-team feature. Appendix: Why this question is objective (if you wonder) C++ is a complex language, so many projects or coding guides try to select "simple" C++ features, and many people try to include or exclude some ones according to mostly subjective criteria. Questions about that get rightfully closed regularly here on SO. Above, instead, I defined (as precisely as possible) what a "whole-team" language feature is, provide an example (exceptions), together with extensive supporting evidence in the literature about C++, and ask for whole-team features in C++ beyond exceptions. Whether you should use "whole-team" features, or whether that's a relevant concept, might be subjective — but that only means the importance of this question is subjective, like always.

  Read the article

• Using extension methods to decrease the surface area of a C# interface

  - by brian_ritchie

  An interface defines a contract to be implemented by one or more classes.  One of the keys to a well-designed interface is defining a very specific range of functionality. The profile of the interface should be limited to a single purpose & should have the minimum methods required to implement this functionality.  Keeping the interface tight will keep those implementing the interface from getting lazy & not implementing it properly.  I've seen too many overly broad interfaces that aren't fully implemented by developers.  Instead, they just throw a NotImplementedException for the method they didn't implement. One way to help with this issue, is by using extension methods to move overloaded method definitions outside of the interface. Consider the following example: .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; } 1: public interface IFileTransfer 2: { 3: void SendFile(Stream stream, Uri destination); 4: } 5:   6: public static class IFileTransferExtension 7: { 8: public static void SendFile(this IFileTransfer transfer, 9: string Filename, Uri destination) 10: { 11: using (var fs = File.OpenRead(Filename)) 12: { 13: transfer.SendFile(fs, destination); 14: } 15: } 16: } 17:   18: public static class TestIFileTransfer 19: { 20: static void Main() 21: { 22: IFileTransfer transfer = new FTPFileTransfer("user", "pass"); 23: transfer.SendFile(filename, new Uri("ftp://ftp.test.com")); 24: } 25: } In this example, you may have a number of overloads that uses different mechanisms for specifying the source file. The great part is, you don't need to implement these methods on each of your derived classes.  This gives you a better interface and better code reuse.

  Read the article

• Customizable Method Bodies in NetBeans IDE 7.3

  - by Geertjan

  In NetBeans IDE 7.3, bodies of newly created methods can now be customized in Tools/Templates/Java/Code Snippets, see below: The content of the first of the two above, "Generated Method Body", is like this: <#-- A built-in Freemarker template (see http://freemarker.sourceforge.net) used for filling the body of methods generated by the IDE. When editing the template, the following predefined variables, that will be then expanded into the corresponding values, could be used together with Java expressions and comments: ${method_return_type}       a return type of a created method ${default_return_value}     a value returned by the method by default ${method_name}              name of the created method ${class_name}               qualified name of the enclosing class ${simple_class_name}        simple name of the enclosing class --> throw new java.lang.UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. The second one, "Overriden Methody Body", is as follows: <#-- A built-in Freemarker template (see http://freemarker.sourceforge.net) used for filling the body of overridden methods generated by the IDE. When editing the template, the following predefined variables, that will be then expanded into the corresponding values, could be used together with Java expressions and comments: ${super_method_call}        a super method call ${method_return_type}       a return type of a created method ${default_return_value}     a value returned by the method by default ${method_name}              name of the created method ${class_name}               qualified name of the enclosing class ${simple_class_name}        simple name of the enclosing class --> <#if method_return_type?? && method_return_type != "void"> return ${super_method_call}; //To change body of generated methods, choose Tools | Templates. <#else> ${super_method_call}; //To change body of generated methods, choose Tools | Templates. </#if>

  Read the article

• Access to message queuing system is denied MSMQ?

  - by user1401694

  My problem is a little confusing. I have 2 servers (Windows Server 2008 R2) with MSMQ installed and I want to use Server B to consume a MessageQueue on Server A. When I try to Receive it always throws a message error: "Access to message queuing system is denied.". IP between them. Server A: 172.31.23.130 Server B: 172.31.23.195 FormatName:Direct=TCP:172.31.23.195\private$\queuesource (It's working for Sends) I can ping each server from the other; The firewall is disabled; The "queuesource" has Full Control to "Everyone", "Anonymous Logon", "Network", "Network Services"; Journal is disabled; Authentication is ok; The queue is Transactional. My code in .Net C# is basically like this: MessageQueue _sourceQueue = new MessageQueue(); _sourceQueue.Path = "FormatName:Direct=TCP:172.31.23.195\private$\queuesource"; _sourceQueue.Receive(); // << here throw an exception. Actually I'm using the Private Queue only to avoid Active Directory's problems. For example, if the server DNS fail all network fail. I don't know what do anymore.

  Read the article

• HD Tune warning for "Reallocated Event Count" with a new/unused drive. How serious is that?

  - by Developer Art

  I've just looked at the health status of my old 2,5 inch 500 Gb Fujitsu drive with a popular "HD Tune" utility. It shows a warning for the "Reallocated Event Count" property. How serious is that? The thing is that the drive is practically new. I pulled it out of a new laptop over a year ago and never used it since. Right now it only has 53 "Power On" hours which sounds about right since I only had it running a few evenings overnight before switching it for something more performant. Does this warning indicate that the drive is likely to fail some time in the future? I'm somewhat perplexed since the drive is effectively unused. What is more, I have arranged with somebody to buy off this drive since I don't really need. It is 12,5 mm thick (with 3 plates) meaning it doesn't fit into an external enclosure which makes it quite useless to me. Can I give away the drive without having it on my conscience or better cancel the deal? In other words, can the drive be used safely for years to come or better throw it away? I'm running a sector test now to see if there are any real problems. Will post the results as soon as they're available.

  Read the article

• ADODB DB2 DSN using IBMDADB2 provider

  - by Eli Sand

  I have a very bizarre issue with trying to establish a working connection to an IBM DB2 server from Classic ASP using ADODB. On my development server I am running IIS and have a local instance of DB2 running. When I create a system DSN on this server and try to connect to it with ADODB, I have to specify Provider=IBMDADB2; in my connection along with the DSN name - failure to include the provider and my connection won't work. On my production server(s), I have one running IIS and a second system running an instance of DB2. When I create a system DSN on the production IIS server and try to connect to it with ADODB, I cannot specify the provider, otherwise it throws an uncatchable error in an external module (I assume it's referring to the DB2 module) if I try to do anything past get a connection (oddly, opening the connection itself doesn't throw an error - but if I run a query it does). If I remove the Provider=IBMDADB2; from the connection string (thus I just have DSN=some_name), it works fine. On both systems I can verify through the ODBC connection manager that the DSN's work and can connect to the databases, and on both systems I have made sure to set the correct (only) instance of DB2 as the default. Can anyone tell me why I have to have different connection strings for the development and production servers? I would like to be able to use the same connection string for both environments if at all possible. If that means either specifying a provider for both, or for neither I don't care which - I would just like to know what's going on and how to fix it.

  Read the article

• Intel 1.83 Mac Mini upgraded to 1.5 gig for Snow Leopard

  - by Paula

  Even though I've upgraded countless video cards, RAM, harddrives, motherboards in PCs... this will be my first mac mini RAM upgrade. I've watched the classic "putty knife" video. (Absurd method... but I guess it's what I'm stuck with.) I have a 1.83 Intel-based Mac Mini from 2007-2008, with 1 gig of RAM. (Two 512 sticks) Can I install 1 gig + 512 ? (Or do I have to throw away my existing sticks and buy two 1 gig sticks?) This old machine is rarely used... so I want to spend the absolute minimum on this RAM upgrade. We ONLY use it to run xCode... nothing more. But wanted to increase the RAM so we can install Snow Leopard. I have no idea how many pins the memory has. I printed out over FORTY pages of specs about this machine from "About this Mac"... but didn't find what I needed. Does this sound right: DDR2 SDRAM (but no mention of SO-DIMM) 667MHZ (but don't know if I can use faster also) Pin count: Unknown Computer model number: Unknown (But I "think" it's an MB138/A) PC2 RAM (unknown... not mentioned) 5300 (unknown... not mentioned) Mfg date: (unknown... not mentioned) Number of slots: (unknown... not mentioned) Laptop or desktop RAM: (unknown... not mentioned)

  Read the article

• How can I recover data from a dmg that cannot mount?

  - by Benjamin Lee

  I backed up a hard drive in a dmg, then reformatted the hard drive. (I had deleted the efi partition before which was preventing me from reinstalling the operation system). When I tried use the restore function in disk utility it gave an input/output error. I get this error with anything I do to the image including mounting, converting, attaching, verifying, scanning, and getting info through hdiutil imageinfo. I have run all of these with hdiutil and the -noverify, -nomount, and -ignorebadchecksums flags. When I copy the image onto another disk/partition I get a different error: something like "No filesystem". I cannot repair the image with disk utility or asr, which both throw the I/O error. When I put the -verbose flag on the command I actually get a different error: "hdiutil: attach failed - No child processes". I have output from both the -verbose and -debug flags but it is fairly long so I had to attach a link to avoid the 3000 character limit. No recovery system can get the data because it is both compressed and unmountable. How can I get the data back, and what has gone wrong? -debug -verbose

  Read the article

• pros and cons with server management gui tools to manage linux web servers

  - by ajsie

  i have stumbled upon these GUI tools that could help you manage your linux server through a web interface. ebox, webmin, ispconfig, zivios, ispcp, plesk, cpanel etc. i wonder what the pros and cons are with these solutions. a lot of people is saying that they are not as good as using pure command line (ssh) to manage your server. but i think thats yet another "linux are for advanced users" talk. i agree that a lot of things may only be done with the command line by editing directly in the configuration files. but i don't really want to do that every time and for everything. especially basic configurations these could manage. its like not having phpmyadmin for managing mysql. it would be a pain in the ass right? so if one wants to throw up a web server serving a php site oneself developed and wants all the usual stuff up and running (mysql, phpmyadmin, svn, webdav etc) is these tools the right way to go? and for more advanced features, one just use the terminal like old days. is this a smart way of managing a linux server? and which one would you choose? have you used any of these and could share your thoughts about them?

  Read the article

< Previous Page | 95 96 97 98 99 100 101 102 103 104 105 106  | Next Page >