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  • Can't decrypt after encrypting with blowfish Java

    - by user2030599
    Hello i'm new to Java and i have the following problem: i'm trying to encrypt the password of a user using the blowfish algorithm, but when i try to decrypt it back to check the authentication it fails to decrypt it for some reason. public static String encryptBlowFish(String to_encrypt, String salt){ String dbpassword = null; try{ SecretKeySpec skeySpec = new SecretKeySpec( salt.getBytes(), "Blowfish" ); // Instantiate the cipher. Cipher cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE, skeySpec); //byte[] encrypted = cipher.doFinal( URLEncoder.encode(data).getBytes() ); byte[] encrypted = cipher.doFinal( to_encrypt.getBytes() ); dbpassword = new String(encrypted); } catch (Exception e) { System.out.println("Exception while encrypting"); e.printStackTrace(); dbpassword = null; } finally { return dbpassword; } } public static String decryptBlowFish(String to_decrypt, String salt){ String dbpassword = null; try{ SecretKeySpec skeySpec = new SecretKeySpec( salt.getBytes(), "Blowfish" ); // Instantiate the cipher. Cipher cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding"); cipher.init(Cipher.DECRYPT_MODE, skeySpec); //byte[] encrypted = cipher.doFinal( URLEncoder.encode(data).getBytes() ); byte[] encrypted = cipher.doFinal( to_decrypt.getBytes() ); dbpassword = new String(encrypted); } catch (Exception e) { System.out.println("Exception while decrypting"); e.printStackTrace(); dbpassword = null; } finally { return dbpassword; } } When i call the decrypt function it gives me the following error: java.security.InvalidKeyException: Parameters missing Any ideas? Thank you

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  • Instance caching in Objective C

    - by zoul
    Hello! I want to cache the instances of a certain class. The class keeps a dictionary of all its instances and when somebody requests a new instance, the class tries to satisfy the request from the cache first. There is a small problem with memory management though: The dictionary cache retains the inserted objects, so that they never get deallocated. I do want them to get deallocated, so that I had to overload the release method and when the retain count drops to one, I can remove the instance from cache and let it get deallocated. This works, but I am not comfortable mucking around the release method and find the solution overly complicated. I thought I could use some hashing class that does not retain the objects it stores. Is there such? The idea is that when the last user of a certain instance releases it, the instance would automatically disappear from the cache. NSHashTable seems to be what I am looking for, but the documentation talks about “supporting weak relationships in a garbage-collected environment.” Does it also work without garbage collection? Clarification: I cannot afford to keep the instances in memory unless somebody really needs them, that is why I want to purge the instance from the cache when the last “real” user releases it. Better solution: This was on the iPhone, I wanted to cache some textures and on the other hand I wanted to free them from memory as soon as the last real holder released them. The easier way to code this is through another class (let’s call it TextureManager). This class manages the texture instances and caches them, so that subsequent calls for texture with the same name are served from the cache. There is no need to purge the cache immediately as the last user releases the texture. We can simply keep the texture cached in memory and when the device gets short on memory, we receive the low memory warning and can purge the cache. This is a better solution, because the caching stuff does not pollute the Texture class, we do not have to mess with release and there is even a higher chance for cache hits. The TextureManager can be abstracted into a ResourceManager, so that it can cache other data, not only textures.

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  • What exactly is a reentrant function?

    - by eSKay
    Most of the times, the definition of reentrance is quoted from Wikipedia: A computer program or routine is described as reentrant if it can be safely called again before its previous invocation has been completed (i.e it can be safely executed concurrently). To be reentrant, a computer program or routine: Must hold no static (or global) non-constant data. Must not return the address to static (or global) non-constant data. Must work only on the data provided to it by the caller. Must not rely on locks to singleton resources. Must not modify its own code (unless executing in its own unique thread storage) Must not call non-reentrant computer programs or routines. How is safely defined? If a program can be safely executed concurrently, does it always mean that it is reentrant? What exactly is the common thread between the six points mentioned that I should keep in mind while checking my code for reentrant capabilities? Also, Are all recursive functions reentrant? Are all thread-safe functions reentrant? Are all recursive and thread-safe functions reentrant? While writing this question, one thing comes to mind: Are the terms like reentrance and thread safety absolute at all i.e. do they have fixed concrete definations? For, if they are not, this question is not very meaningful. Thanks!

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  • Unique id of a column

    - by Kayes
    Hi. Does each column of a table in SQL Server have a unique id? I've looked into sys.columns and the column_id there is merely the order of the columns which changes if the order of the column is changed. I'd like to know if SQL Server maintains a unique id for each column as it does for each table and other objects. And if it does, how can I get that? Thanks.

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  • ASP.NET web control with the same ID

    - by user370401
    On an ASP.NET page, if the ASP.NET elements like <asp:Texbox ID="Textbox1"> appears in more than one place, are they the same Textbox object or are they different objects with the same name "Textbox1"? If the same, "why won't it cause any conflicts?" E.G. runat="server" Text='<%# Bind("Name") %' runat="server" Text='<%# Bind("Name") %' '

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  • Applying the Decorator Pattern to Forms

    - by devoured elysium
    I am trying to apply the Decorator Design Pattern to the following situation: I have 3 different kind of forms: Green, Yellow, Red. Now, each of those forms can have different set of attributes. They can have a minimize box disabled, a maximized box disabled and they can be always on top. I tried to model this the following way: Form <---------------------------------------FormDecorator /\ /\ |---------|-----------| |----------------------|-----------------| GreenForm YellowForm RedForm MinimizeButtonDisabled MaximizedButtonDisabled AlwaysOnTop Here is my GreenForm code: public class GreenForm : Form { public GreenForm() { this.BackColor = Color.GreenYellow; } public override sealed Color BackColor { get { return base.BackColor; } set { base.BackColor = value; } } } FormDecorator: public abstract class FormDecorator : Form { private Form _decoratorForm; protected FormDecorator(Form decoratorForm) { this._decoratorForm = decoratorForm; } } and finally NoMaximizeDecorator: public class NoMaximizeDecorator : FormDecorator { public NoMaximizeDecorator(Form decoratorForm) : base(decoratorForm) { this.MaximizeBox = false; } } So here is the running code: static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Application.Run(CreateForm()); } static Form CreateForm() { Form form = new GreenForm(); form = new NoMaximizeDecorator(form); form = new NoMinimizeDecorator(form); return form; } The problem is that I get a form that isn't green and that still allows me to maximize it. It is only taking in consideration the NoMinimizeDecorator form. I do comprehend why this happens but I'm having trouble understanding how to make this work with this Pattern. I know probably there are better ways of achieving what I want. I made this example as an attempt to apply the Decorator Pattern to something. Maybe this wasn't the best pattern I could have used(if one, at all) to this kind of scenario. Is there any other pattern more suitable than the Decorator to accomplish this? Am I doing something wrong when trying to implement the Decorator Pattern? Thanks

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  • ASP.Net:Best way to run scheduled tasks

    - by Niels Bosma
    Today we have built an console application for running scheduled tasks for our ASP.NET website. But I think this appoach is a bit error prone and difficult to maintain. How do you execute you scheduled task (in an windows/IIS/ASP.NET env.) Update: Examples of tasks: Sending email from an emial-queue in the database Removing utdated objects from the database Retreiving stats from google adwords and fill a table in the database.

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  • ahow can I resolve Django Error: str' object has no attribute 'autoescape'?

    - by Angelbit
    Hi have tried to create a inclusion tag on Django but don't work and return str' object has no attribute 'autoescape' this is the code of custom tag: from django import template from quotes.models import Quotes register = template.Library() def show_quote(): quote = Quotes.objects.values('quote', 'author').get(id=0) return {'quote': quote['quote']} register.inclusion_tag('quotes.html')(show_quote) EDIT: Quote class from django.db import models class Quotes(models.Model): quote = models.CharField(max_length=255) author = models.CharField(max_length=100) class Meta: db_table = 'quotes' quotes.html <blockquote id="quotes">{{ quote }}</blockquote>

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  • Can this extension method be improved?

    - by Newbie
    I have the following extension method public static class ListExtensions { public static IEnumerable<T> Search<T>(this ICollection<T> collection, string stringToSearch) { foreach (T t in collection) { Type k = t.GetType(); PropertyInfo pi = k.GetProperty("Name"); if (pi.GetValue(t, null).Equals(stringToSearch)) { yield return t; } } } } What it does is by using reflection, it finds the name property and then filteres the record from the collection based on the matching string. This method is being called as List<FactorClass> listFC = new List<FactorClass>(); listFC.Add(new FactorClass { Name = "BKP", FactorValue="Book to price",IsGlobal =false }); listFC.Add(new FactorClass { Name = "YLD", FactorValue = "Dividend yield", IsGlobal = false }); listFC.Add(new FactorClass { Name = "EPM", FactorValue = "emp", IsGlobal = false }); listFC.Add(new FactorClass { Name = "SE", FactorValue = "something else", IsGlobal = false }); List<FactorClass> listFC1 = listFC.Search("BKP").ToList(); It is working fine. But a closer look into the extension method will reveal that Type k = t.GetType(); PropertyInfo pi = k.GetProperty("Name"); is actually inside a foreach loop which is actually not needed. I think we can take it outside the loop. But how? PLease help. (C#3.0)

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  • PHP OOP singleton doesn't return object

    - by Misiur
    Weird trouble. I've used singleton multiple times but this particular case just doesn't want to work. Dump says that instance is null. define('ROOT', "/"); define('INC', 'includes/'); define('CLS', 'classes/'); require_once(CLS.'Core/Core.class.php'); $core = Core::getInstance(); var_dump($core->instance); $core->settings(INC.'config.php'); $core->go(); Core class class Core { static $instance; public $db; public $created = false; private function __construct() { $this->created = true; } static function getInstance() { if(!self::$instance) { self::$instance = new Core(); } else { return self::$instance; } } public function settings($path = null) { ... } public function go() { ... } } Error code Fatal error: Call to a member function settings() on a non-object in path It's possibly some stupid typo, but I don't have any errors in my editor. Thanks for the fast responses as always.

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  • How to replicate CoreData NSFetchedResultController with plain SQLite?

    - by jchatard
    I would like to replicate the notification sort of system provided with CoreData NSFetchedResultController which with really little enables us to update a tableView based on events such as Insert/Update/Delete of objects represented as Cells. I'm currently using SQLitePersistentObjects as a Database abstraction layer: http://code.google.com/p/sqlitepersistentobjects/ If you have any idea or something working or at least advices I'd be very happy! Thank you!

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  • Rhino Mocks - Do we really need stubs?

    - by Marcelo Oliveira
    If it's possible to change mock behaviour in Rhino Mocks using mock.Stub().Return(), why do we need Stubs anyway? What do we lose by always using MockRepository.GenerateMock()? One big benefit of using Mocks instead of Stubs is that we will be able to reuse the same instance among all the tests keeping them cleaner and straightforward. The moq framework works in a similar way... we don't have different objects for mocks and stubs. (please, don't answer with a link to Fowler's "Mocks aren't stubs" article)

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  • User defined literal arguments are not constexpr?

    - by Pubby
    I'm testing out user defined literals. I want to make _fac return the factorial of the number. Having it call a constexpr function works, however it doesn't let me do it with templates as the compiler complains that the arguments are not and cannot be constexpr. I'm confused by this - aren't literals constant expressions? The 5 in 5_fac is always a literal that can be evaluated during compile time, so why can't I use it as such? First method: constexpr int factorial_function(int x) { return (x > 0) ? x * factorial_function(x - 1) : 1; } constexpr int operator "" _fac(unsigned long long x) { return factorial_function(x); // this works } Second method: template <int N> struct factorial { static const unsigned int value = N * factorial<N - 1>::value; }; template <> struct factorial<0> { static const unsigned int value = 1; }; constexpr int operator "" _fac(unsigned long long x) { return factorial_template<x>::value; // doesn't work - x is not a constexpr }

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  • Schema to support dynamic properties

    - by Johan Fredrik Varen
    Hi people. I'm working on an editor that enables its users to create "object" definitions in real-time. A definition can contain zero or more properties. A property has a name a type. Once a definition is created, a user can create an object of that definition and set the property values of that object. So by the click of a mouse-button, the user should ie. be able to create a new definition called "Bicycle", and add the property "Size" of type "Numeric". Then another property called "Name" of type "Text", and then another property called "Price" of type "Numeric". Once that is done, the user should be able to create a couple of "Bicycle" objects and fill in the "Name" and "Price" property values of each bike. Now, I've seen this feature in several software products, so it must be a well-known concept. My problem started when I sat down and tried to come up with a DB schema to support this data structure, because I want the property values to be stored using the appropriate column types. Ie. a numeric property value is stored as, say, an INT in the database, and a textual property value is stored as VARCHAR. First, I need a table that will hold all my object definitions: Table obj_defs id | name | ---------------- 1 | "Bicycle" | 2 | "Book" | Then I need a table for holding what sort of properties each object definition should have: Table prop_defs id | obj_def_id | name | type | ------------------------------------ 1 | 1 | "Size" | ? | 2 | 1 | "Name" | ? | 3 | 1 | "Price" | ? | 4 | 2 | "Title" | ? | 5 | 2 | "Author" | ? | 6 | 2 | "ISBN" | ? | I would also need a table that holds each object: Table objects id | created | updated | ------------------------------ 1 | 2011-05-14 | 2011-06-15 | 2 | 2011-05-14 | 2011-06-15 | 3 | 2011-05-14 | 2011-06-15 | Finally, I need a table that will hold the actual property values of each object, and one solution is for this table to have one column for each possible value type, such as this: Table prop_vals id | prop_def_id | object_id | numeric | textual | boolean | ------------------------------------------------------------ 1 | 1 | 1 | 27 | | | 2 | 2 | 1 | | "Trek" | | 3 | 3 | 1 | 1249 | | | 4 | 1 | 2 | 26 | | | 5 | 2 | 2 | | "GT" | | 6 | 3 | 2 | 159 | | | 7 | 4 | 3 | | "It" | | 8 | 5 | 3 | | "King" | | 9 | 6 | 4 | 9 | | | If I implemented this schema, what would the "type" column of the prop_defs table hold? Integers that each map to a column name, varchars that simply hold the column name? Any other possibilities? Would a stored procedure help me out here in some way? And what would the SQL for fetching the "name" property of object 2 look like?

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  • What's faster to parse lots of data (5Mb): eval or json?

    - by AlfaTeK
    I want to get, via ajax, a collection of data objects and parse them into JS data. Currently I have 2 choices: - Server returns valid javascript code and then I eval it. - Server returns JSON object and then I eval the json object What is the fastest of these in Firefox? (I only care about the "parsing" performance, not server or data transfer)

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  • Why Enumerable.Range is faster than a direct yield loop?

    - by Morgan Cheng
    Below code is checking performance of three different ways to do same solution. public static void Main(string[] args) { // for loop { Stopwatch sw = Stopwatch.StartNew(); int accumulator = 0; for (int i = 1; i <= 100000000; ++i) { accumulator += i; } sw.Stop(); Console.WriteLine("time = {0}; result = {1}", sw.ElapsedMilliseconds, accumulator); } //Enumerable.Range { Stopwatch sw = Stopwatch.StartNew(); var ret = Enumerable.Range(1, 100000000).Aggregate(0, (accumulator, n) => accumulator + n); sw.Stop(); Console.WriteLine("time = {0}; result = {1}", sw.ElapsedMilliseconds, ret); } //self-made IEnumerable<int> { Stopwatch sw = Stopwatch.StartNew(); var ret = GetIntRange(1, 100000000).Aggregate(0, (accumulator, n) => accumulator + n); sw.Stop(); Console.WriteLine("time = {0}; result = {1}", sw.ElapsedMilliseconds, ret); } } private static IEnumerable<int> GetIntRange(int start, int count) { int end = start + count; for (int i = start; i < end; ++i) { yield return i; } } } The result is like this: time = 306; result = 987459712 time = 1301; result = 987459712 time = 2860; result = 987459712 It is not surprising that "for loop" is faster than the other two solutions, because Enumerable.Aggregate takes more method invocations. However, it really surprises that "Enumerable.Range" is faster than the "self-made IEnumerable". I thought that Enumerable.Range will take more overhead than the simple GetIntRange method. What is the possible reason for this?

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  • Checking ActiveRecord Associations in RSpec.

    - by alokswain
    I am learning how to write test cases using Rspec. I have a simple Post Comments Scaffold where a Post can have many Comments. I am testing this using Rspec. How should i go about checking for Post :has_many :comments. Should I stub Post.comments method and then check this with by returning a mock object of array of comment objects? Is testing for AR associations really required ?

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  • How can I pass in a params of Expression<Func<T, object>> to a method?

    - by Pure.Krome
    Hi folks, I have the following two methods :- public static IQueryable<T> IncludeAssociations<T>(this IQueryable<T> source, params string[] associations) { ... } public static IQueryable<T> IncludeAssociations<T>(this IQueryable<T> source, params Expression<Func<T, object>>[] expressions) { ... } Now, when I try and pass in a params of Expression<Func<T, object>>[], it always calls the first method (the string[]' and of course, that value isNULL`) Eg. Expression<Func<Order, object>> x1 = x => x.User; Expression<Func<Order, object>> x2 = x => x.User.Passport; var foo = _orderRepo .Find() .IncludeAssociations(new {x1, x2} ) .ToList(); Can anyone see what I've done wrong? Why is it thinking my params are a string? Can I force the type, of the 2x variables?

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  • Linq - How to collect Anonymous Type as Result for a Function

    - by GibboK
    I use c# 4 asp.net and EF 4. I'm precompiling a query, the result should be a collection of Anonymous Type. At the moment I use this code. public static readonly Func<CmsConnectionStringEntityDataModel, string, dynamic> queryContentsList = CompiledQuery.Compile<CmsConnectionStringEntityDataModel, string, dynamic> ( (ctx, TypeContent) => ctx.CmsContents.Where(c => c.TypeContent == TypeContent & c.IsPublished == true & c.IsDeleted == false) .Select(cnt => new { cnt.Title, cnt.TitleUrl, cnt.ContentId, cnt.TypeContent, cnt.Summary } ) .OrderByDescending(c => c.ContentId)); I suspect the RETURN for the FUNCTION Dynamic does not work properly and I get this error Sequence contains more than one element enter code here. I suppose I need to return for my function a Collection of Anonymous Types... Do you have any idea how to do it? What I'm doing wrong? Please post a sample of code thanks! Update: public class ConcTypeContents { public string Title { get; set; } public string TitleUrl { get; set; } public int ContentId { get; set; } public string TypeContent { get; set; } public string Summary { get; set; } } public static readonly Func<CmsConnectionStringEntityDataModel, string, ConcTypeContents> queryContentsList = CompiledQuery.Compile<CmsConnectionStringEntityDataModel, string, ConcTypeContents>( (ctx, TypeContent) => ctx.CmsContents.Where(c => c.TypeContent == TypeContent & c.IsPublished == true & c.IsDeleted == false) .Select(cnt => new ConcTypeContents { cnt.Title, cnt.TitleUrl, cnt.ContentId, cnt.TypeContent, cnt.Summary }).OrderByDescending(c => c.ContentId));

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  • Are these two functions the same?

    - by Ranhiru
    There is a function in the AES algorithm, to multiply a byte by 2 in Galois Field. This is the function given in a website private static byte gfmultby02(byte b) { if (b < 0x80) return (byte)(int)(b <<1); else return (byte)( (int)(b << 1) ^ (int)(0x1b) ); } This is the function i wrote. private static byte MulGF2(byte x) { if (x < 0x80) return (byte)(x << 1); else { return (byte)((x << 1) ^ 0x1b); } } What i need to know is, given any byte whether this will perform in the same manner. Actually I am worried about the extra conversion of to int and then again to byte. So far I have tested and it looks fine. Does the extra cast to int and then to byte make a difference?

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  • Passing a DataTable into a Stored Procedure. Is there a better way?

    - by punkouter
    Can A datatable somehow be passed into SQL Server 2005 or 2008 ? I know the standard way seesm to be passing XML to a SP. And a datatable can easily be converted to XML somehow to do that. What about passing a .NET object into a SP ? Is that possible ? I remember hearing about SQL and CLR working together in 2008 somehow but I never understood.. Maybe that means you can refer to .NET objects within a Stored Procedure ?

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  • Gaining access to jndi environment variables within a Tomcat LifecycleListener

    - by rmarimon
    I'm using a LifecycleListener in tomcat to initialize some objects required by contexts in my web server. Within LifecycleListener I would like to have access to GlobalNamingResources Environment variables to keep the configuration for the server inside the server.xml file. When trying various approaches I get the following error: javax.naming.NameNotFoundException: Name java:comp is not bound in this Context I'm assuming that the jndi is not initialized by this stage of the server startup process. Any ideas on how to tackle this?

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