Search Results

Search found 12490 results on 500 pages for 'property injection'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 13/500 | < Previous Page | 9 10 11 12 13 14 15 16 17 18 19 20  | Next Page >

  • HTG Explains: How Hackers Take Over Web Sites with SQL Injection / DDoS

    - by Jason Faulkner
    Even if you’ve only loosely followed the events of the hacker groups Anonymous and LulzSec, you’ve probably heard about web sites and services being hacked, like the infamous Sony hacks. Have you ever wondered how they do it? There are a number of tools and techniques that these groups use, and while we’re not trying to give you a manual to do this yourself, it’s useful to understand what’s going on. Two of the attacks you consistently hear about them using are “(Distributed) Denial of Service” (DDoS) and “SQL Injections” (SQLI). Here’s how they work. Image by xkcd HTG Explains: How Hackers Take Over Web Sites with SQL Injection / DDoS Use Your Android Phone to Comparison Shop: 4 Scanner Apps Reviewed How to Run Android Apps on Your Desktop the Easy Way

    Read the article

  • Steps after SQL Injection detected

    - by Zukas
    I've come across SQL injection vulnerabilities on my companies ecommerce page. It was fairly poorly put together. I believe I have prevented future attempts however we are getting calls about fraudulent credit card charges on our site and others. This leads me to believe that someone was able to get a list of our credit card numbers. What doesn't make sense is that we don't store that information and we use Authorize.net for the transaction. If someone was able to get the CC#s, what should I do next? Inform ALL of our customers that someone broken into our system and stole their information? I have a feeling that will be bad for business.

    Read the article

  • SQL Injection: How it Works and How to Thwart it

    This is an extract from the book Tribal SQL. In this article, Kevin Feasel explains SQL injection attacks, how to defend against them, and how to keep your Chief Information Security Officer from appearing on the nightly news. NEW! The DBA Team in The Girl with the Backup TattooPina colada in the disk drives! How could any DBA do such a thing? And can the DBA Team undo the damage? Find out in Part 2 of their new series, 5 Worst Days in a DBA’s Life. Read the new article now.

    Read the article

  • What is the difference between Inversion of Control and Dependency injection in C++?

    - by rlbond
    I've been reading recently about DI and IoC in C++. I am a little confused (even after reading related questions here on SO) and was hoping for some clarification. It seems to me that being familiar with the STL and Boost leads to use of dependency injection quite a bit. For example, let's say I made a function that found the mean of a range of numbers: template <typename Iter> double mean(Iter first, Iter last) { double sum = 0; size_t number = 0; while (first != last) { sum += *(first++); ++number; } return sum/number; }; Is this dependency injection? Inversion of control? Neither? Let's look at another example. We have a class: class Dice { public: typedef boost::mt19937 Engine; Dice(int num_dice, Engine& rng) : n_(num_dice), eng_(rng) {} int roll() { int sum = 0; for (int i = 0; i < num_dice; ++i) sum += boost::uniform_int<>(1,6)(eng_); return sum; } private: Engine& eng_; int n_; }; This seems like dependency injection. But is it inversion of control? Also, if I'm missing something, can someone help me out?

    Read the article

  • Abstracting away the type of a property

    - by L. De Leo
    In Python luckily most of the times you don't have to write getters and setters to get access to class properties. That said sometimes you'll have to remember that a certain property is a list or whatnot and a property would save you there by abstracting the type and providing a setter to add something to such list for example rather than exposing the list directly. Where do you draw the line between exposing the type directly or wrapping its access in a property? What's the general "pythonic" advice?

    Read the article

  • Maintaining packages with code - Adding a property expression programmatically

    Every now and then I've come across scenarios where I need to update a lot of packages all in the same way. The usual scenario revolves around a group of packages all having been built off the same package template, and something needs to updated to keep up with new requirements, a new logging standard for example.You'd probably start by updating your template package, but then you need to address all your existing packages. Often this can run into the hundreds of packages and clearly that's not a job anyone wants to do by hand. I normally solve the problem by writing a simple console application that looks for files and patches any package it finds, and it is an example of this I'd thought I'd tidy up a bit and publish here. This sample will look at the package and find any top level Execute SQL Tasks, and change the SQL Statement property to use an expression. It is very simplistic working on top level tasks only, so nothing inside a Sequence Container or Loop will be checked but obviously the code could be extended for this if required. The code that actually sets the expression is shown below, the rest is just wrapper code to find the package and to find the task. /// <summary> /// The CreationName of the Tasks to target, e.g. Execute SQL Task /// </summary> private const string TargetTaskCreationName = "Microsoft.SqlServer.Dts.Tasks.ExecuteSQLTask.ExecuteSQLTask, Microsoft.SqlServer.SQLTask, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"; /// <summary> /// The name of the task property to target. /// </summary> private const string TargetPropertyName = "SqlStatementSource"; /// <summary> /// The property expression to set. /// </summary> private const string ExpressionToSet = "@[User::SQLQueryVariable]"; .... // Check if the task matches our target task type if (taskHost.CreationName == TargetTaskCreationName) { // Check for the target property if (taskHost.Properties.Contains(TargetPropertyName)) { // Get the property, check for an expression and set expression if not found DtsProperty property = taskHost.Properties[TargetPropertyName]; if (string.IsNullOrEmpty(property.GetExpression(taskHost))) { property.SetExpression(taskHost, ExpressionToSet); changeCount++; } } } This is a console application, so to specify which packages you want to target you have three options: Find all packages in the current folder, the default behaviour if no arguments are specified TaskExpressionPatcher.exe .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; } Find all packages in a specified folder, pass the folder as the argument TaskExpressionPatcher.exe C:\Projects\Alpha\Packages\ .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; } Find a specific package, pass the file path as the argument TaskExpressionPatcher.exe C:\Projects\Alpha\Packages\Package.dtsx The code was written against SQL Server 2005, but just change the reference to Microsoft.SQLServer.ManagedDTS to be the SQL Server 2008 version and it will work fine. If you get an error Microsoft.SqlServer.Dts.Runtime.DtsRuntimeException: The package failed to load due to error 0xC0011008… then check that the package is from the correct version of SSIS compared to the referenced assemblies, 2005 vs 2008 in other words. Download Sample Project TaskExpressionPatcher.zip (6 KB)

    Read the article

  • Get and Set property accessors are ‘actually’ methods

    - by nmarun
    Well, they are ‘special’ methods, but they indeed are methods. See the class below: 1: public class Person 2: { 3: private string _name; 4:  5: public string Name 6: { 7: get 8: { 9: return _name; 10: } 11: set 12: { 13: if (value == "aaa") 14: { 15: throw new ArgumentException("Invalid Name"); 16: } 17: _name = value; 18: } 19: } 20:  21: public void Save() 22: { 23: Console.WriteLine("Saving..."); 24: } 25: } Ok, so a class with a field, a property with the get and set accessors and a method. Now my calling code says: 1: static void Main() 2: { 3: try 4: { 5: Person person1 = new Person 6: { 7: Name = "aaa", 8: }; 9:  10: } 11: catch (Exception ex) 12: { 13: Console.WriteLine(ex.Message); 14: Console.WriteLine(ex.StackTrace); 15: Console.WriteLine("--------------------"); 16: } 17: } When the code is run, you’ll get the following exception message displayed: Now, you see the first line of the stack trace where it says that the exception was thrown in the method set_Name(String value). Wait a minute, we have not declared any method with that name in our Person class. Oh no, we actually have. When you create a property, this is what happens behind the screen. The CLR creates two methods for each get and set property accessor. Let’s look at the signature once again: set_Name(String value) This also tells you where the ‘value’ keyword comes from in our set property accessor. You’re actually wiring up a method parameter to a field. 1: set 2: { 3: if (value == "aaa") 4: { 5: throw new ArgumentException("Invalid Name"); 6: } 7: _name = value; 8: } Digging deeper on this, I ran the ILDasm tool and this is what I see: We see the ‘free’ constructor (named .ctor) that the compiler gives us, the _name field, the Name property and the Save method. We also see the get_Name and set_Name methods. In order to compare the Save and the set_Name methods, I double-clicked on the two methods and this is what I see: The ‘.method’ keyword tells that both Save and set_Name are both methods (no guessing there!). Seeing the set_Name method as a public method did kinda surprise me. So I said, why can’t I do a person1.set_Name(“abc”) since it is declared as public. This cannot be done because the get_Name and set_Name methods have an extra attribute called ‘specialname’. This attribute is used to identify an IL (Intermediate Language) token that can be treated with special care by the .net language. So the thumb-rule is that any method with the ‘specialname’ attribute cannot be generally called / invoked by the user (a simple test using intellisense proves this). Their functionality is exposed through other ways. In our case, this is done through the property itself. The same concept gets extended to constructors as well making them special methods too. These so-called ‘special’ methods can be identified through reflection. 1: static void ReflectOnPerson() 2: { 3: Type personType = typeof(Person); 4:  5: MethodInfo[] methods = personType.GetMethods(); 6:  7: for (int i = 0; i < methods.Length; i++) 8: { 9: Console.Write("Method: {0}", methods[i].Name); 10: // Determine whether or not each method is a special name. 11: if (methods[i].IsSpecialName) 12: { 13: Console.Write(" has 'SpecialName' attribute"); 14: } 15: Console.WriteLine(); 16: } 17: } Line 11 shows the ‘IsSpecialName’ boolean property. So a method with a ‘specialname’ attribute gets mapped to the IsSpecialName property. The output is displayed as: Wuhuuu! There they are.. our special guests / methods. Verdict: Getting to know the internals… helps!

    Read the article

  • Maintaining packages with code - Adding a property expression programmatically

    Every now and then I've come across scenarios where I need to update a lot of packages all in the same way. The usual scenario revolves around a group of packages all having been built off the same package template, and something needs to updated to keep up with new requirements, a new logging standard for example.You'd probably start by updating your template package, but then you need to address all your existing packages. Often this can run into the hundreds of packages and clearly that's not a job anyone wants to do by hand. I normally solve the problem by writing a simple console application that looks for files and patches any package it finds, and it is an example of this I'd thought I'd tidy up a bit and publish here. This sample will look at the package and find any top level Execute SQL Tasks, and change the SQL Statement property to use an expression. It is very simplistic working on top level tasks only, so nothing inside a Sequence Container or Loop will be checked but obviously the code could be extended for this if required. The code that actually sets the expression is shown below, the rest is just wrapper code to find the package and to find the task. /// <summary> /// The CreationName of the Tasks to target, e.g. Execute SQL Task /// </summary> private const string TargetTaskCreationName = "Microsoft.SqlServer.Dts.Tasks.ExecuteSQLTask.ExecuteSQLTask, Microsoft.SqlServer.SQLTask, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"; /// <summary> /// The name of the task property to target. /// </summary> private const string TargetPropertyName = "SqlStatementSource"; /// <summary> /// The property expression to set. /// </summary> private const string ExpressionToSet = "@[User::SQLQueryVariable]"; .... // Check if the task matches our target task type if (taskHost.CreationName == TargetTaskCreationName) { // Check for the target property if (taskHost.Properties.Contains(TargetPropertyName)) { // Get the property, check for an expression and set expression if not found DtsProperty property = taskHost.Properties[TargetPropertyName]; if (string.IsNullOrEmpty(property.GetExpression(taskHost))) { property.SetExpression(taskHost, ExpressionToSet); changeCount++; } } } This is a console application, so to specify which packages you want to target you have three options: Find all packages in the current folder, the default behaviour if no arguments are specified TaskExpressionPatcher.exe .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; } Find all packages in a specified folder, pass the folder as the argument TaskExpressionPatcher.exe C:\Projects\Alpha\Packages\ .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; } Find a specific package, pass the file path as the argument TaskExpressionPatcher.exe C:\Projects\Alpha\Packages\Package.dtsx The code was written against SQL Server 2005, but just change the reference to Microsoft.SQLServer.ManagedDTS to be the SQL Server 2008 version and it will work fine. If you get an error Microsoft.SqlServer.Dts.Runtime.DtsRuntimeException: The package failed to load due to error 0xC0011008… then check that the package is from the correct version of SSIS compared to the referenced assemblies, 2005 vs 2008 in other words. Download Sample Project TaskExpressionPatcher.zip (6 KB)

    Read the article

  • IOS Variable vs Property

    - by William Smith
    Just started diving into Objective-C and IOS development and was wondering when and the correct location I should be declaring variables/properties. The main piece of code i need explaining is below: Why and when should i be declaring variables inside the interface statement and why do they have the same variable with _ and then the same one as a property. And then in the implementation they do @synthesize tableView = _tableView (I understand what synthesize does) Thanks :-) @interface ViewController : UIViewController <UITableViewDataSource, UITableViewDelegate> { UITableView *_tableView; UIActivityIndicatorView *_activityIndicatorView; NSArray *_movies; } @property (nonatomic, retain) UITableView *tableView; @property (nonatomic, retain) UIActivityIndicatorView *activityIndicatorView; @property (nonatomic, retain) NSArray *movies;

    Read the article

  • Best alternative of Property file in Java

    - by Ranna
    Hey I an working on the product which is live at multiple portals. The product is developed in GWT, JAVA, Hibernate. My question is : Whether there is any alternative of using property file in java. My Requirement : For one property key there are multiple values in live portal for each different portal. Each time I change property file, I need to make the war again. The loading of any of the property should not be time-consuming. Any help or suggession would be apprecialble !!!

    Read the article

  • Dependency injection: what belongs in the constructor?

    - by Adam Backstrom
    I'm evaluating my current PHP practices in an effort to write more testable code. Generally speaking, I'm fishing for opinions on what types of actions belong in the constructor. Should I limit things to dependency injection? If I do have some data to populate, should that happen via a factory rather than as constructor arguments? (Here, I'm thinking about my User class that takes a user ID and populates user data from the database during construction, which obviously needs to change in some way.) I've heard it said that "initialization" methods are bad, but I'm sure that depends on what exactly is being done during initialization. At the risk of getting too specific, I'll also piggyback a more detailed example onto my question. For a previous project, I built a FormField class (which handled field value setting, validation, and output as HTML) and a Model class to contain these fields and do a bit of magic to ease working with fields. FormField had some prebuilt subclasses, e.g. FormText (<input type="text">) and FormSelect (<select>). Model would be subclassed so that a specific implementation (say, a Widget) had its own fields, such as a name and date of manufacture: class Widget extends Model { public function __construct( $data = null ) { $this->name = new FormField('length=20&label=Name:'); $this->manufactured = new FormDate; parent::__construct( $data ); // set above fields using incoming array } } Now, this does violate some rules that I have read, such as "avoid new in the constructor," but to my eyes this does not seem untestable. These are properties of the object, not some black box data generator reading from an external source. Unit tests would progressively build up to any test of Widget-specific functionality, so I could be confident that the underlying FormFields were working correctly during the Widget test. In theory I could provide the Model with a FieldFactory() which could supply custom field objects, but I don't believe I would gain anything from this approach. Is this a poor assumption?

    Read the article

  • Balancing dependency injection with public API design

    - by kolektiv
    I've been contemplating how to balance testable design using dependency injection with providing simple fixed public API. My dilemma is: people would want to do something like var server = new Server(){ ... } and not have to worry about creating the many dependencies and graph of dependencies that a Server(,,,,,,) may have. While developing, I don't worry too much, as I use an IoC/DI framework to handle all that (I'm not using the lifecycle management aspects of any container, which would complicate things further). Now, the dependencies are unlikely to be re-implemented. Componentisation in this case is almost purely for testability (and decent design!) rather than creating seams for extension, etc. People will 99.999% of the time wish to use a default configuration. So. I could hardcode the dependencies. Don't want to do that, we lose our testing! I could provide a default constructor with hard-coded dependencies and one which takes dependencies. That's... messy, and likely to be confusing, but viable. I could make the dependency receiving constructor internal and make my unit tests a friend assembly (assuming C#), which tidies the public API but leaves a nasty hidden trap lurking for maintenance. Having two constructors which are implicitly connected rather than explicitly would be bad design in general in my book. At the moment that's about the least evil I can think of. Opinions? Wisdom?

    Read the article

  • Call DB Stored Procedure using @NamedStoredProcedureQuery Injection

    - by anwilson
    Oracle Database Stored Procedure can be called from EJB business layer to perform complex DB specific operations. This approach will avoid overhead from frequent network hits which could impact end-user result. DB Stored Procedure can be invoked from EJB Session Bean business logic using org.eclipse.persistence.queries.StoredProcedureCall API. Using this approach requires more coding to handle the Session and Arguments of the Stored Procedure, thereby increasing effort on maintenance. EJB 3.0 introduces @NamedStoredProcedureQuery Injection to call Database Stored Procedure as NamedQueries. This blog will take you through the steps to call Oracle Database Stored Procedure using @NamedStoredProcedureQuery.EMP_SAL_INCREMENT procedure available in HR schema will be used in this sample.Create Entity from EMPLOYEES table.Add @NamedStoredProcedureQuery above @NamedQueries to Employees.java with definition as given below - @NamedStoredProcedureQuery(name="Employees.increaseEmpSal", procedureName = "EMP_SAL_INCREMENT", resultClass=void.class, resultSetMapping = "", returnsResultSet = false, parameters = { @StoredProcedureParameter(name = "EMP_ID", queryParameter = "EMPID"), @StoredProcedureParameter(name = "SAL_INCR", queryParameter = "SALINCR")} ) Observe how Stored Procedure's arguments are handled easily in  @NamedStoredProcedureQuery using @StoredProcedureParameter.Expose Entity Bean by creating a Session Facade.Business method need to be added to Session Bean to access the Stored Procedure exposed as NamedQuery. public void salaryRaise(Long empId, Long salIncrease) throws Exception { try{ Query query = em.createNamedQuery("Employees.increaseEmpSal"); query.setParameter("EMPID", empId); query.setParameter("SALINCR", salIncrease); query.executeUpdate(); } catch(Exception ex){ throw ex; } } Expose business method through Session Bean Remote Interface. void salaryRaise(Long empId, Long salIncrease) throws Exception; Session Bean Client is required to invoke the method exposed through remote interface.Call exposed method in Session Bean Client main method. final Context context = getInitialContext(); SessionEJB sessionEJB = (SessionEJB)context.lookup("Your-JNDI-lookup"); sessionEJB.salaryRaise(new Long(200), new Long(1000)); Deploy Session BeanRun Session Bean Client.Salary of Employee with Id 200 will be increased by 1000.

    Read the article

  • Are the ASP.net __EVENTTARGET and __EVENTARGUMENT susceptible to SQL injection?

    - by Schleichermann
    A security review was done against one of our ASP.net applications and returned in the test results was a SQL Injection Exposures considered to be a high risk item. The test that was performed passed a SQL statement as the value of the __EVENTTARGET and the __EVENTARGUMENT. I am wondering since these 2 values are ASP.net auto-generated hidden fields used for the Auto-Postback feature of the framework and hold information specific to the controls initiating the postback, is there really the potential for SQL injection if you are never manually calling and or pulling values out of these parameters in your code behind?

    Read the article

  • Are there any differences between SQL Server and MySQL when it comes to preventing SQL injection?

    - by Derek Adair
    I am used to developing in PHP/MySQL and have no experience developing with SQL Server. I've skimmed over the PHP MSSQL documentation and it looks similar to MySQLi in some of the methods I read about. For example, with MySQL I utilize the function mysql_real_excape_string(). Is there a similar function with PHP/SQL Server? What steps do I need to take in order to protect against SQL injection with SQL Server? What are the differences between SQL Server and MySQL pertaining to SQL injection prevention? also - is this post accurate? is the escape string character for SQL Server a single quote?

    Read the article

  • Are there any differences between MSSQL and MySQL when it comes to preventing SQL injection?

    - by Derek Adair
    I am used to developing in PHP/MySQL and have no experience developing with MSSQL. I've skimmed over the PHP MSSQL documentation and it looks similar to MySQLi in some of the methods I read about. For example, with MySQL I utilize the function mysql_real_excape_string(). Is there a similar function with PHP/MSSQL? What steps do I need to take in order to protect against SQL injection with MSSQL? What are the differences between MSSQL and MySQL pertaining to SQL injection prevention?

    Read the article

  • Is there any injection vunerability in the body of an email?

    - by Brett
    Hey guys..... AFAIK there is only a vulnerability within the HEADERS of an email when using user data correct? I am using the below function to sanitize my data, however I have some textarea fields on the page & hence these may contain linebreaks.. so was wondering if that user data is only going to be put in the body of the email, can it not bother with being sanitized - apart from stripping html of course? Here is the function: function is_injected($str) { $injections = array('(\n+)', '(\r+)', '(\t+)', '(%0A+)', '(%0D+)', '(%08+)', '(%09+)' ); $inject = join('|', $injections); $inject = "/$inject/i"; if (preg_match($inject,$str)) { return true; } else { return false; } } As a side note, surprised there wasn't currently a tag for mail-injection / email-injection. Thanks!

    Read the article

  • Dependency Injection Introduction

    - by MarkPearl
    I recently was going over a great book called “Dependency Injection in .Net” by Mark Seeman. So far I have really enjoyed the book and would recommend anyone looking to get into DI to give it a read. Today I thought I would blog about the first example Mark gives in his book to illustrate some of the benefits that DI provides. The ones he lists are Late binding Extensibility Parallel Development Maintainability Testability To illustrate some of these benefits he gives a HelloWorld example using DI that illustrates some of the basic principles. It goes something like this… class Program { static void Main(string[] args) { var writer = new ConsoleMessageWriter(); var salutation = new Salutation(writer); salutation.Exclaim(); Console.ReadLine(); } } public interface IMessageWriter { void Write(string message); } public class ConsoleMessageWriter : IMessageWriter { public void Write(string message) { Console.WriteLine(message); } } public class Salutation { private readonly IMessageWriter _writer; public Salutation(IMessageWriter writer) { _writer = writer; } public void Exclaim() { _writer.Write("Hello World"); } }   If you had asked me a few years ago if I had thought this was a good approach to solving the HelloWorld problem I would have resounded “No”. How could the above be better than the following…. class Program { static void Main(string[] args) { Console.WriteLine("Hello World"); Console.ReadLine(); } }  Today, my mind-set has changed because of the pain of past programs. So often we can look at a small snippet of code and make judgements when we need to keep in mind that we will most probably be implementing these patterns in projects with hundreds of thousands of lines of code and in projects that we have tests that we don’t want to break and that’s where the first solution outshines the latter. Let’s see if the first example achieves some of the outcomes that were listed as benefits of DI. Could I test the first solution easily? Yes… We could write something like the following using NUnit and RhinoMocks… [TestFixture] public class SalutationTests { [Test] public void ExclaimWillWriteCorrectMessageToMessageWriter() { var writerMock = MockRepository.GenerateMock<IMessageWriter>(); var sut = new Salutation(writerMock); sut.Exclaim(); writerMock.AssertWasCalled(x => x.Write("Hello World")); } }   This would test the existing code fine. Let’s say we then wanted to extend the original solution so that we had a secure message writer. We could write a class like the following… public class SecureMessageWriter : IMessageWriter { private readonly IMessageWriter _writer; private readonly string _secretPassword; public SecureMessageWriter(IMessageWriter writer, string secretPassword) { _writer = writer; _secretPassword = secretPassword; } public void Write(string message) { if (_secretPassword == "Mark") { _writer.Write(message); } else { _writer.Write("Unauthenticated"); } } }   And then extend our implementation of the program as follows… class Program { static void Main(string[] args) { var writer = new SecureMessageWriter(new ConsoleMessageWriter(), "Mark"); var salutation = new Salutation(writer); salutation.Exclaim(); Console.ReadLine(); } }   Our application has now been successfully extended and yet we did very little code change. In addition, our existing tests did not break and we would just need add tests for the extended functionality. Would this approach allow parallel development? Well, I am in two camps on parallel development but with some planning ahead of time it would allow for it as you would simply need to decide on the interface signature and could then have teams develop different sections programming to that interface. So,this was really just a quick intro to some of the basic concepts of DI that Mark introduces very successfully in his book. I am hoping to blog about this further as I continue through the book to list some of the more complex implementations of containers.

    Read the article

  • Property overwrite behaviour

    - by jeremyj
    I thought it worth sharing about property overwrite behaviour because i found it confusing at first in the hope of preventing some learning pain for the uninitiated with MSBuild :-)The confusion for me came because of the redundancy of using a Condition statement in a _project_ level property to test that a property has not been previously set. What i mean is that the following two statements are always identical in behaviour, regardless if the property has been supplied on the command line -  <PropertyGroup>    <PropA Condition=" '$(PropA)' == '' ">PropA set at project level</PropA>  </PropertyGroup>has the same behaviour regardless of command line override as -  <PropertyGroup>     <PropA>PropA set at project level</PropA>   </PropertyGroup>  i.e. the two above property declarations have the same result whether the property is overridden on the command line or not.To prove this experiment with the following .proj file -<?xml version="1.0" encoding="utf-8"?><Project ToolsVersion="4.0" >  <PropertyGroup>    <PropA Condition=" '$(PropA)' == '' ">PropA set at project level</PropA>  </PropertyGroup>  <Target Name="Target1">    <Message Text="PropA: $(PropA)"/>  </Target>  <Target Name="Target2">    <PropertyGroup>      <PropA>PropA set in Target2</PropA>    </PropertyGroup>    <Message Text="PropA: $(PropA)"/>  </Target>  <Target Name="Target3">    <PropertyGroup>      <PropA Condition=" '$(PropA)' == '' ">PropA set in Target3</PropA>    </PropertyGroup>    <Message Text="PropA: $(PropA)"/>  </Target>  <Target Name="Target4">    <PropertyGroup>      <PropA Condition=" '$(PropA)' != '' ">PropA set in Target4</PropA>    </PropertyGroup>    <Message Text="PropA: $(PropA)"/>  </Target></Project>Try invoking it using both of the following invocations and observe its output -1)>msbuild blog.proj /t:Target1;Target2;Target3;Target42)>msbuild blog.proj /t:Target1;Target2;Target3;Target4 "/p:PropA=PropA set on command line"Then try those two invocations with the following three variations of specifying PropA at the project level -1)  <PropertyGroup>     <PropA Condition=" '$(PropA)' == '' ">PropA set at project level</PropA>   </PropertyGroup> 2)   <PropertyGroup>     <PropA>PropA set at project level</PropA>   </PropertyGroup>3)  <PropertyGroup>     <PropA Condition=" '$(PropA)' != '' ">PropA set at project level</PropA>   </PropertyGroup>

    Read the article

  • Java Hibernate/C3P0 error: "Could not obtain connection metadata. An attempt by a client to checkout

    - by Allan
    I'm trying to get some code I was passed up and running. It appears to use the Hibernate framework. I've gotten past most of the errors tweaking the configuration, but this one has me dead stumped. It's trying to connect to two databases: gameapp and gamelog. Both exist. It seems to have issues connecting to gamelog, but none connecting to gameapp (later in the init, it connects to and loads other DBs just fine). Below, I've pasted the error and exception stack dump. I imaging there's something else in the configs, so I've also included the configuration file for that db. I know this is very vague, but I'm hoping some pro can see the stupid mistake I'm missing. <?xml version="1.0" encoding="GBK"?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://127.0.0.1:3306/gamelog</property> <property name="connection.username">root</property> <property name="connection.password"></property> <property name="connection.useUnicode">true</property> <property name="connection.characterEncoding">UTF-8</property> <property name="hibernate.jdbc.batch_size">100</property> <property name="jdbc.fetch_size">1</property> <property name="hbm2ddl.auto">none</property><!-- update --> <property name="connection.useUnicode">true</property> <property name="show_sql">true</property> <!-- c3p0-configuration --> <property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property> <property name="hibernate.c3p0.min_size">5</property> <property name="hibernate.c3p0.max_size">10</property> <property name="hibernate.c3p0.timeout">30</property> <property name="hibernate.c3p0.idle_test_period">30</property> <property name="hibernate.c3p0.max_statements">0</property> <property name="hibernate.c3p0.acquire_increment">5</property> </session-factory> </hibernate-configuration> Exception and stack trace: 2010-04-30 17:50:00,411 WARN [org.hibernate.cfg.SettingsFactory] - Could not obtain connection metadata java.sql.SQLException: An attempt by a client to checkout a Connection has timed out. at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106) at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:65) at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:527) at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128) at org.hibernate.connection.C3P0ConnectionProvider.getConnection(C3P0ConnectionProvider.java:35) at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:76) at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:1933) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1216) at com.database.hibernate.util.HibernateFactory.<init>(Unknown Source) at com.database.hibernate.util.HibernateUtil.<clinit>(Unknown Source) at com.server.databaseop.goodOp.GoodOpImpl.initBreedGoods(Unknown Source) at com.server.databaseop.goodOp.GoodOpImpl.access$000(Unknown Source) at com.server.databaseop.goodOp.GoodOpImpl$1.run(Unknown Source) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:351) at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:178) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:165) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:267) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) at java.lang.Thread.run(Thread.java:636) Caused by: com.mchange.v2.resourcepool.TimeoutException: A client timed out while waiting to acquire a resource from com.mchange.v2.resourcepool.BasicResourcePool@ca470 -- timeout at awaitAvailable() at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1317) at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557) at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477) at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525) ... 18 more

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 9 10 11 12 13 14 15 16 17 18 19 20  | Next Page >