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  • How Can I Find a List of All Exceptions That a Given Library Function Throws in Python?

    - by b14ck
    Sorry for the long title, but it seems most descriptive for my question. Basically, I'm having a difficult time finding exception information in the official python documentation. For example, in one program I'm currently writing, I'm using the shutil libary's move function: from shutil import move move('somefile.txt', '/tmp/somefile.txt') That works fine, as long as I have write access to /tmp/, there is enough diskspace, and if all other requirements are satisfied. However, when writing generic code, it is often difficult to guarantee those factors, so one usually uses exceptions: from shutil import move try: move('somefile.txt', '/tmp/somefile.txt') except: print 'Move failed for some reason.' I'd like to actually catch the appropriate exceptions thrown instead of just catching everything, but I simply can't find a list of exceptions thrown for most python modules. Is there a way for me to see which exceptions a given function can throw, and why? This way I can make appropriate cases for each exception, eg: from shutil import move try: move('somefile.txt', '/tmp/somefile.txt') except PermissionDenied: print 'No permission.' except DestinationDoesNotExist: print "/tmp/ doesn't exist" except NoDiskSpace: print 'No diskspace available.' Answer points go to whoever can either link me to some relevant documentation that I've somehow overlooked in the official docs, or provide a sure-fire way to figure out exactly which exceptions are thrown by which functions, and why. Thanks!

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  • How to define a batching routing service in WCF

    - by mattx
    I have designed a custom silverlight wcf channel that I want to leverage to selectively batch calls from the client to the server and possibly to cache on the client and short circuit calls. So far I'm just using this channel as a transport and sending the generic WCF messages that result to the WCF router service example here http://msdn.microsoft.com/en-us/magazine/cc500646.aspx?pr=blog to prototype this on the server side. So my scenario looks like this: IFooClient-MyTransportChannel-IRouterService-IFooService-Return I now need to be able to send more than one message per call through the router and carve them up and service them on the server side. Since this is just an experiment and I'm taking baby steps I will dispatch and service all the messages right away on the server side and return the batch of results. Immediately I noticed that simply making the router interface take Message[] instead of Message doesn't work due to serialization problems. I guess this makes sense. I'm not sure soap envelopes can contain other soap envelopes etc. Is there a simple way to take a collection of WCF Message objects and send them to a single method on a service where they can be split up and forwarded as appropriate? If not I'd love suggestions on how I should approach this. I want to have minimal work to do on the router service side so the goal should be to get as close to being able to "slice and forward" as possible.

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  • OSMF seek with Amazon Cloudfront

    - by giorrrgio
    I've written a little OSMF player that streams via RTMP from Amazon Cloudfront. There's a known issue, the mp3 duration is not correctly readed from metadata and thus the seek function is not working. I know there's a workaround implying the use of getStreamLength function of NetConnection, which I successfully implemented in a previous non-OSMF player, but now I don't know how and when to call it, in terms of OSMF Events and Traits. This code is not working: protected function initApp():void { //the pointer to the media var resource:URLResource = new URLResource( STREAMING_PATH ); // Create a mediafactory instance mediaFactory = new DefaultMediaFactory(); //creates and sets the MediaElement (generic) with a resource and path element = mediaFactory.createMediaElement( resource ); var loadTrait:NetStreamLoadTrait = element.getTrait(MediaTraitType.LOAD) as NetStreamLoadTrait; loadTrait.addEventListener(LoaderEvent.LOAD_STATE_CHANGE, _onLoaded); player = new MediaPlayer( element ); //Marker 5: Add MediaPlayer listeners for media size and current time change player.addEventListener( DisplayObjectEvent.MEDIA_SIZE_CHANGE, _onSizeChange ); player.addEventListener( TimeEvent.CURRENT_TIME_CHANGE, _onProgress ); initControlBar(); } private function onGetStreamLength(result:Object):void { Alert.show("The stream length is " + result + " seconds"); duration = Number(result); } private function _onLoaded(e:LoaderEvent):void { if (e.newState == LoadState.READY) { var loadTrait:NetStreamLoadTrait = player.media.getTrait(MediaTraitType.LOAD) as NetStreamLoadTrait; if (loadTrait && loadTrait.netStream) { var responder:Responder = new Responder(onGetStreamLength); loadTrait.connection.call("getStreamLength", responder, STREAMING_PATH); } } }

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  • How to specialize template for type derived from particular type

    - by relaxxx
    I have class World which manages creation of object... After creation it calls afterCreation method and I the created object is user-defined type derived from Entity (eg. MyEntity), I want to call addEntity. I the object was something else, I want to do nothing. addEntity must be called with appropriate T, because it generates unique IDs for every derived class etc. Here is my solution: template <int v> struct ToType { enum { value = v }; }; template <typename T> void World::afterCreation(T * t) { afterCreation(t, ToType<std::is_base_of<Entity, T>::value>()); } template <typename T> void World::afterCreation(T * t, ToType<true>) { addEntity(t); //here I cant pass Entity *, I need the real type, eg. MyEntity } template <typename T> void World::afterCreation(T * t, ToType<false>) { } My question is - Can in be done better way? How can I simulate following code without ToType or similar? template <typename T> void afterCreation(){/*generic impl*/} template <typename T where T is derived from Entity> void afterCreation(){/*some specific stuff*/} "specialize" in the title is only to describe my intention, no need to solve problem with template specialization

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  • Stupid newbie c++ two-dimensional array problem.

    - by paulson scott
    I've no idea if this is too newbie or generic for stackoverlflow. Apologies if that's the case, I don't intend to waste time. I've just started working through C++ Primer Plus and I've hit a little stump. This is probably super laughable but: for (int year = 0; year < YEARS; year++) { cout << "Year " << year + 1 << ":"; for (int month = 0; month < MONTHS; month++) { absoluteTotal = (yearlyTotal[year][year] += sales[year][month]); } cout << yearlyTotal[year][year] << endl; } cout << "The total number of books sold over a period of " << YEARS << " years is: " << absoluteTotal << endl; I wish to display the total of all 3 years. The rest of the code works fine: input is fine, individual yearly output is fine but I just can't get 3 years added together for one final total. I did have the total working at one point but I didn't have the individual totals working. I messed with it and reversed the situation. I've been messing with it for God knows how long. Any idea guys? Sorry if this isn't the place!

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  • I have problem using vesijama (Very Simple Java Mail)

    - by Huuhaacece
    Hi, i already read this tutorial from here and i have download all required libraries (Log4j, JavaMail API ,Activation framework) . But when i trying running this program i got this error log4j:WARN No appenders could be found for logger (org.codemonkey.vesijama.Mailer). org.codemonkey.vesijama.MailException: Generic error: Exception reading response log4j:WARN Please initialize the log4j system properly. this is the source code i use import javax.mail.Message.RecipientType; import org.codemonkey.vesijama.Email; import org.codemonkey.vesijama.MailException; import org.codemonkey.vesijama.Mailer; public class testSend { final Email email = new Email(); public testSend{ try{ email.setFromAddress("test", "[email protected]"); email.setSubject("hey"); email.addRecipient("hai", "[email protected]", RecipientType.TO); email.setText("We should meet up!"); email.setTextHTML("<b>We should meet up!</b>"); new Mailer("smtp.gmail.com", 465, "[email protected]", "XXXXXX").sendMail(email); } catch(MailException me) { System.out.println(me); } } } i have also trying using port 587. but i got same error .< btw , it say can add attachments what should i write if i want to attach .xls ( microsoft excel 2003) ? Thx B4.

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  • Is there a more elegant way to act on the first and last items in a foreach enumeration than count++

    - by Edward Tanguay
    Is there a more elegant way to act on the first and last items when iterating through a foreach loop than incrementing a separate counter and checking it each time? For instance, the following code outputs: >>> [line1], [line2], [line3], [line4] <<< which requires knowing when you are acting on the first and last item. Is there a more elegant way to do this now in C# 3 / C# 4? It seems like I could use .Last() or .First() or something like that. using System; using System.Collections.Generic; using System.Text; namespace TestForNext29343 { class Program { static void Main(string[] args) { StringBuilder sb = new StringBuilder(); List<string> lines = new List<string> { "line1", "line2", "line3", "line4" }; int index = 0; foreach (var line in lines) { if (index == 0) sb.Append(">>> "); sb.Append("[" + line + "]"); if (index < lines.Count - 1) sb.Append(", "); else sb.Append(" <<<"); index++; } Console.WriteLine(sb.ToString()); Console.ReadLine(); } } }

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  • Interpolating data points in Excel

    - by Niels Basjes
    Hi, I'm sure this is the kind of problem other have solved many times before. A group of people are going to do measurements (Home energy usage to be exact). All of them will do that at different times and in different intervals. So what I'll get from each person is a set of {date, value} pairs where there are dates missing in the set. What I need is a complete set of {date, value} pairs where for each date withing the range a value is known (either measured or calculated). I expect that a simple linear interpolation would suffice for this project. If I assume that it must be done in Excel. What is the best way to interpolate in such a dataset (so I have a value for every day) ? Thanks. NOTE: When these datasets are complete I'll determine the slope (i.e. usage per day) and from that we can start doing home-to-home comparisons. ADDITIONAL INFO After first few suggestions: I do not want to manually figure out where the holes are in my measurement set (too many incomplete measurement sets!!). I'm looking for something (existing) automatic to do that for me. So if my input is {2009-06-01, 10} {2009-06-03, 20} {2009-06-06, 110} Then I expect to automatically get {2009-06-01, 10} {2009-06-02, 15} {2009-06-03, 20} {2009-06-04, 50} {2009-06-05, 80} {2009-06-06, 110} Yes, I can write software that does this. I am just hoping that someone already has a "ready to run" software (Excel) feature for this (rather generic) problem.

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  • Why is Func<T> ambiguous with Func<IEnumerable<T>>?

    - by Matt Hamilton
    This one's got me flummoxed, so I thought I'd ask here in the hope that a C# guru can explain it to me. Why does this code generate an error? class Program { static void Main(string[] args) { Foo(X); // the error is on this line } static String X() { return "Test"; } static void Foo(Func<IEnumerable<String>> x) { } static void Foo(Func<String> x) { } } The error in question: Error 1 The call is ambiguous between the following methods or properties: 'ConsoleApplication1.Program.Foo(System.Func<System.Collections.Generic.IEnumerable<string>>)' and 'ConsoleApplication1.Program.Foo(System.Func<string>)' C:\Users\mabster\AppData\Local\Temporary Projects\ConsoleApplication1\Program.cs 12 13 ConsoleApplication1 It doesn't matter what type I use - if you replace the "String" declarations with "int" in that code you'll get the same sort of error. It's like the compiler can't tell the difference between Func<T> and Func<IEnumerable<T>>. Can someone shed some light on this?

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  • Permission denied to access property 'toString'

    - by Anders
    I'm trying to find a generic way of getting the name of Constructors. My goal is to create a Convention over configuration framework for KnockoutJS My idea is to iterate over all objects in the window and when I find the contructor i'm looking for then I can use the index to get the name of the contructor The code sofar (function() { constructors = {}; window.findConstructorName = function(instance) { var constructor = instance.constructor; var name = constructors[constructor]; if(name !== undefined) { return name; } var traversed = []; var nestedFind = function(root) { if(typeof root == "function" || traversed[root]) { return } traversed[root] = true; for(var index in root) { if(root[index] == constructor) { return index; } var found = nestedFind(root[index]); if(found !== undefined) { return found; } } } name = nestedFind(window); constructors[constructor] = name; return name; } })(); var MyApp = {}; MyApp.Foo = function() { }; var instance = new MyApp.Foo(); console.log(findConstructorName(instance)); The problem is that I get a Permission denied to access property 'toString' Exception, and i cant even try catch so see which object is causing the problem Fiddle http://jsfiddle.net/4ZwaV/

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  • CanCan polymorphic resource access problem

    - by Call 'naive' True
    Hi everybody, i don't quite understand how to restrict access to links in this particular case with CanCan. I always get "Edit" link displayed. So i believe the problem is in my incorrect definition of cancan methods(load_ and authorize_). I have CommentsController like that: class CommentsController < ApplicationController before_filter :authenticate_user! load_resource :instance_name => :commentable authorize_resource :article def index @commentable = find_commentable #loading our generic object end ...... private def find_commentable params.each { |name, value| if name =~ /(.+)_id$/ return $1.classify.constantize.includes(:comments => :karma).find(value) end } end end and i have in comments/index.html.erb following code that render file from other controller: <%= render :file => "#{get_commentable_partial_name(@commentable)}/show.html.erb", :collection => @commentable %> you can think about "#{get_commentable_partial_name(@commentable)}" like just "articles" in this case. Content of "articles/show.html.erb": <% if can? :update, @commentable %> <%= link_to 'Edit', edit_article_path(@commentable) %> | <% end %> my ability.rb: class Ability include CanCan::Ability def initialize(user) user ||= User.new # guest user if user.role? :admin can :manage, :all elsif user.role? :author can :read, [Article, Comment, Profile] can :update, Article, :user_id => user.id end end end relations with models is: class Comment < ActiveRecord::Base belongs_to :commentable, :polymorphic => true, :dependent => :destroy ... end class Article < ActiveRecord::Base has_many :comments, :as => :commentable, :dependent => :destroy ... end i have tried debug this issue like that user = User.first article = Article.first ability = Ability.new(user) ability.can?(:update, article) and i always get "= true" in ability check Note: user.role == author and article.user_id != user.id if you need more information please write thank's for your time && sorry for my english

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  • Adventures on Enterprise Library 5.0: Who moved my cheese (namespace)

    - by Junior Mayhé
    Jesus, Krishna, Budda! I've migrated to EntLib 5.0, but classes like ISymmetricCryptoProvider are not recognized anymore. Funny to say that Data, Logging and other blocks are working compiling fine. Here's the problematic class: using System; using System.Collections.Generic; using System.Text; using Microsoft.Practices.EnterpriseLibrary.Common.Configuration;//-->it's not working anymore using Microsoft.Practices.EnterpriseLibrary.Security.Cryptography;//-->it's not working anymore namespace MyClassLibrary.Security.EnterpriseLibrary { public sealed class Crypto { public static ISymmetricCryptoProvider MyProvider { get { //IConfigurationSource is not recognized either, neither SystemConfigurationSource IConfigurationSource cs = new SystemConfigurationSource(); SymmetricCryptoProviderFactory scpf = new SymmetricCryptoProviderFactory(cs); ISymmetricCryptoProvider p = scpf.CreateDefault(); return p; } } The references are fine on project too. I really don't know why this particular project it's causing too many trouble on VS2010! Older references were deleted, project was cleaned, rebuilt, but can't make it compile :-( The references are: Microsoft.Practices.EnterpriseLibrary.Common Microsoft.Practices.EnterpriseLibrary.Logging Microsoft.Practices.EnterpriseLibrary.Logging.Database Microsoft.Practices.EnterpriseLibrary.Security Microsoft.Practices.EnterpriseLibrary.Security.Cryptography Why some namespaces can be found while others can't?

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  • Serializable object in intent returning as String

    - by B_
    In my application, I am trying to pass a serializable object through an intent to another activity. The intent is not entirely created by me, it is created and passed through a search suggestion. In the content provider for the search suggestion, the object is created and placed in the SUGGEST_COLUMN_INTENT_EXTRA_DATA column of the MatrixCursor. However, when in the receiving activity I call getIntent().getSerializableExtra(SearchManager.EXTRA_DATA_KEY), the returned object is of type String and I cannot cast it into the original object class. I tried making a parcelable wrapper for my object that calls out.writeSerializable(...) and use that instead but the same thing happened. The string that is returned is like a generic Object toString(), i.e. com.foo.yak.MyAwesomeClass@4350058, so I'm assuming that toString() is being called somewhere where I have no control. Hopefully I'm just missing something simple. Thanks for the help! Edit: Some of my code This is in the content provider that acts as the search authority: //These are the search suggestion columns private static final String[] COLUMNS = { "_id", // mandatory column SearchManager.SUGGEST_COLUMN_TEXT_1, SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA }; //This places the serializable or parcelable object (and other info) into the search suggestion private Cursor getSuggestions(String query, String[] projection) { List<Widget> widgets = WidgetLoader.getMatches(query); MatrixCursor cursor = new MatrixCursor(COLUMNS); for (Widget w : widgets) { cursor.addRow(new Object[] { w.id w.name w.data //This is the MyAwesomeClass object I'm trying to pass }); } return cursor; } This is in the activity that receives the search suggestion: public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Object extra = getIntent().getSerializableExtra(SearchManager.EXTRA_DATA_KEY); //extra.getClass() returns String, when it should return MyAwesomeClass, so this next line throws a ClassCastException and causes a crash MyAwesomeClass mac = (MyAwesomeClass)extra; ... }

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  • Django filters - Using an AllValuesFilter (with a LinkWidget) on a ManyToManyField

    - by magnetix
    This is my first Stack Overflow question, so please let me know if I do anything wrong. I wish to create an AllValues filter on a ManyToMany field using the wonderful django-filters application. Basically, I want to create a filter that looks like it does in the Admin, so I also want to use the LinkWidget too. Unfortunately, I get an error (Invalid field name: 'operator') if I try this the standard way: # Models class Organisation(models.Model): name = models.CharField() ... class Sign(models.Model): name = models.CharField() operator = models.ManyToManyField('Organisation', blank=True) ... # Filter class SignFilter(LinkOrderFilterSet): operator = django_filters.AllValuesFilter(widget=django_filters.widgets.LinkWidget) class Meta: model = Sign fields = ['operator'] I got around this by creating my own filter with the many to many relationship hard coded: # Models class Organisation(models.Model): name = models.CharField() ... class Sign(models.Model): name = models.CharField() operator = models.ManyToManyField('Organisation', blank=True) ... # Filter class MyFilter(django_filters.ChoiceFilter): @property def field(self): cd = {} for row in self.model.objects.all(): orgs = row.operator.select_related().values() for org in orgs: cd[org['id']] = org['name'] choices = zip(cd.keys(), cd.values()) list.sort(choices, key=lambda x:(x[1], x[0])) self.extra['choices'] = choices return super(AllValuesFilter, self).field class SignFilter(LinkOrderFilterSet): operator = MyFilter(widget=django_filters.widgets.LinkWidget) I am new to Python and Django. Can someone think of a more generic/elegant way of doing this?

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  • Ways of breaking down SQL transactional/call data into reports -- 'square data'?

    - by RizwanK
    I've got a large database of call-traffic information (although the question could be answered with any generic data set.) For instance, a row contains : call endpoint server (endpoint_name) call endpoint status (sip_disconnect_reason) call destination (destination) call completed (duration) [duration 0 is completed] call account group (account_group) It's pretty easy to run SQL reports against the data, i.e. select count(*), endpoint_name from calls where duration0 group by endpoint_name select count(*),destination from calls where blah group by destination I've been calling this filtering or breakdown reports (I get the number of calls per carrier, etc.). Add another breakdown, and you've got two breakdowns, a la select count(*), endpoint_name, sip_disconnect_reason from calls where duration=0 group by endpoint_name, sip_disconnect_reason Of course, if you keep adding breakdowns, you end up making super-large reports and slicing your data so thin that you can't extract any trends from it. So my question is this : Is there a name for this sort of method of report writing? (I've heard words like squares, slicing and breakdown reports applied to them) --- I'm looking for a Python/Reporting toolkit that I can use to make these easier to generate for my end users. aside : Are there other ways of representing transactional data that might be useful rather than the above method? Thanks,

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  • Can we manipulate (subtract) the value of a property while template bidning?

    - by Subhen
    Hi, I am currently defining few grids as following: <Grid.RowDefinitions> <RowDefinition Height="{TemplateBinding Height-Height/5}"/> <RowDefinition Height="{TemplateBinding Height/15}"/> <RowDefinition Height="{TemplateBinding Height/20}"/> <RowDefinition Height="{TemplateBinding Height/6}"/> </Grid.RowDefinitions> While the division works fine , the subtraction isn't yielding the output. Ialso tried like following: <RowDefinition Height="{TemplateBinding Height-(Height/5)}"/> Still no result. Any suggestions plz. Thanks, Subhen ** Update ** Now In My XAML I tried implementing the IvalueConverter like : <RowDefinition Height="{TemplateBinding Height, Converter={StaticResource heightConverter}}"/> Added the reference as <local:medieElementHeight x:Key="heightConverter"/> In side generic.cs I have coded as following: public class medieElementHeight : IValueConverter { public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { //customVideoControl objVdeoCntrl=new customVideoControl(); double custoMediaElementHeight = (double)value;//objVdeoCntrl.customMediaPlayer.Height; double mediaElementHeight = custoMediaElementHeight - (custoMediaElementHeight / 5); return mediaElementHeight; } #region IValueConverter Members object IValueConverter.ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) { throw new NotImplementedException(); } #endregion } But getting the exception Unknown Element Height in the element RowDefination.

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  • ssh & script problem

    - by Nishanth
    I am having a strange problem while doing ssh. I am not sure where the term Unmatched ` is coming from. What I need to do is run script that logs information of what I am doing on the terminal to text file. After ssh - Sun Microsystems Inc. SunOS 5.8 Generic Patch October 2001 This is /etc/motd, last updated 3 Feb 2003. To learn about the UCS system and other aspects of computing at UL-Lafayette visit our home page http://helpdesk.louisiana.edu/ . For more information about system use, contact the Help Desk, Stephens Hall, Room 201, 482-5516 (x25516), during normal UL office hours; or send e-mail to [email protected]. ATTENTION: Unsecure Telnet and FTP will be turned off soon. Please make arrange to use ssh or sftp. Putty(telnet) and WinSCP(ftp) would be a good replacement. Unmatched ` d13.ucs.louisiana.edu% bash bash-2.04$ script -a myInformation.txt Script started, file is myInformation.txt Unmatched ` d13.ucs.louisiana.edu% When I tried to start the script with name myInformation.txt, you can see the message I am getting - Script started, file is myInformation.txt. But again I am getting that message Unmatched ` and is coming out of bash, as you can notice. What is the problem ? Any insights suggested would be very great. Note: file with name myInformation.txt is being created but nothing goes in to it. As I have even tried running certain commands like ls and then exited the script with ctrl+d. But when I open the file, nothing is there.

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  • How to enumerate word document using office interop API?

    - by Shekhar
    Hello everyone, I want to traverse through all the elements of an word document one by one and according to type of element (header, sentence, table,image,textbox, shape, etc.) I want to process that element. I tried to search any enumerator or object which can represent elements of document in office interop API but failed to find any. API offers sentences, paragraphs, shapes collections but doesnt provide generic object which can point to next element. For example : <header of document> <plain text sentences> <table with many rows,columns> <text box> <image> <footer> (Please imagine it as a word document) So, now I want some enumerator which will first give me <header of document>, then on next iteration give me <plain text sentences>, then <table with many rows,columns> and so on. Does anyone knows how we can achieve this? Is it possible? I am using C#, visual studio 2005 and Word 2003. Thanks a lot

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  • Referencing not-yet-defined variables - Java

    - by user2537337
    Because I'm tired of solving math problems, I decided to try something more engaging with my very rusty (and even without the rust, very basic) Java skills. I landed on a super-simple people simulator, and thus far have been having a grand time working through the various steps of getting it to function. Currently, it generates an array of people-class objects and runs a for loop to cycle through a set of actions that alter the relationships between them, which I have stored in a 2d integer array. When it ends, I go look at how much they all hate each other. Fun stuff. Trouble has arisen, however, because I would like the program to clearly print what action is happening when it happens. I thought the best way to do this would be to add a string, description, to my "action" class (which stores variables for the actor, reactor, and the amount the relationship changes). This works to a degree, in that I can print a generic message ("A fight has occurred!") with no problem. However, ideally I would like it to be a little more specific ("Person A has thrown a rock at Person B's head!"). This latter goal is proving more difficult: attempting to construct an action with a description string that references actor and reactor gets me a big old error, "Cannot reference field before it is defined." Which makes perfect sense. I believe I'm not quite in programmer mode, because the only other way I can think to do this is an unwieldy switch statement that negates the need for each action to have its own nicely-packaged description. And there must be a neater way. I am not looking for examples of code, only a push in the direction of the right concept to handle this.

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  • Alternatives to static methods on interfaces for enforcing consistency

    - by jayshao
    In Java, I'd like to be able to define marker interfaces, that forced implementations to provide static methods. For example, for simple text-serialization/deserialization I'd like to be able to define an interface that looked something like this: public interface TextTransformable<T>{ public static T fromText(String text); public String toText(); Since interfaces in Java can't contain static methods though (as noted in a number of other posts/threads: here, here, and here this code doesn't work. What I'm looking for however is some reasonable paradigm to express the same intent, namely symmetric methods, one of which is static, and enforced by the compiler. Right now the best we can come up with is some kind of static factory object or generic factory, neither of which is really satisfactory. Note: in our case our primary use-case is we have many, many "value-object" types - enums, or other objects that have a limited number of values, typically carry no state beyond their value, and which we parse/de-parse thousands of time a second, so actually do care about reusing instances (like Float, Integer, etc.) and its impact on memory consumption/g.c. Any thoughts?

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  • Handling Corrupted JPEGs in C#

    - by ddango
    We have a process that pulls images from a remote server. Most of the time, we're good to go, the images are valid, we don't timeout, etc. However, every once and awhile we see this error similar to this: Unhandled Exception: System.Runtime.InteropServices.ExternalException: A generic error occurred in GDI+. at System.Drawing.Image.Save(Stream stream, ImageCodecInfo encoder, EncoderPa rameters encoderParams) at ConsoleApplication1.Program.Main(String[] args) in C:\images\ConsoleApplic ation1\ConsoleApplication1\Program.cs:line 24 After not being able to reproduce it locally, we looked closer at the image, and realized that there were artifacts, making us suspect corruption. Created an ugly little unit test with only the image in question, and was unable to reproduce the error on Windows 7 as was expected. But after running our unit test on Windows Server 2008, we see this error every time. Is there a way to specify non-strictness for jpegs when writing them? Some sort of check/fix we can use? Unit test snippet: var r = ReadFile("C:\\images\\ConsoleApplication1\\test.jpg"); using (var imgStream = new MemoryStream(r)) { using (var ms = new MemoryStream()) { var guid = Guid.NewGuid(); var fileName = "C:\\images\\ConsoleApplication1\\t" + guid + ".jpg"; Image.FromStream(imgStream).Save(ms, ImageFormat.Jpeg); using (FileStream fs = File.Create(fileName)) { fs.Write(ms.GetBuffer(), 0, ms.GetBuffer().Length); } } }

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  • How can I edit an incoming text message (sms) as it arrives in windows mobile 6 using managed code

    - by x86shadow
    I want to make an application for pocket PCs to send and receive Encrypted text messages. I have already made an application that gets special text messages ( starting with !farenc! ) and I know how to Encrypt/Decrypt the messages as well. The problem is that I don't know how to edit a text message after it's arrived (for decryption). See code below for more info. using System; using System.Linq; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; using Microsoft.WindowsMobile; using Microsoft.WindowsMobile.PocketOutlook; using Microsoft.WindowsMobile.PocketOutlook.MessageInterception; namespace SMSDECRYPT { public partial class Form1 : Form { MessageInterceptor _SMSCatcher = new MessageInterceptor(InterceptionAction.Notify, true); MessageCondition _SMSFilter = new MessageCondition(); public Form1() { InitializeComponent(); _SMSFilter.Property = MessageProperty.Body; _SMSFilter.ComparisonType = MessagePropertyComparisonType.StartsWith; _SMSFilter.CaseSensitive = true; _SMSFilter.ComparisonValue = "!farenc!"; _SMSCatcher.MessageCondition = _SMSFilter; _SMSCatcher.MessageReceived += new MessageInterceptorEventHandler(_SMSCatcher_MessageReceived); } private void Form1_Load(object sender, EventArgs e) { //... } void _SMSCatcher_MessageReceived(object sender, MessageInterceptorEventArgs e) { SmsMessage mySMS = (SmsMessage)e.Message; string sms = mySMS.Body.ToString(); sms = sms.Substring(8); //Decryption //... //Update the received message and replace it with the decrypted text //!!!HELP!!! } } }

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  • How to implement a network protocol?

    - by gotch4
    Here is a generic question. I'm not in search of the best answer, I'd just like you to express your favourite practices. I want to implement a network protocol in Java (but this is a rather general question, I faced the same issues in C++), this is not the first time, as I have done this before. But I think I am missing a good way to implement it. In fact usually it's all about exchanging text messages and some byte buffers between hosts, storing the status and wait until the next message comes. The problem is that I usually end up with a bunch of switch and more or less complex if statements that react to different statuses / messages. The whole thing usually gets complicated and hard to mantain. Not to mention that sometimes what comes out has some "blind spot", I mean statuses of the protocol that have not been covered and that behave in a unpredictable way. I tried to write down some state machine classes, that take care of checking start and end statuses for each action in more or less smart ways. This makes programming the protocol very complicated as I have to write lines and lines of code to cover every possible situation. What I'd like is something like a good pattern, or a best practice that is used in programming complex protocols, easy to mantain and to extend and very readable. What are your suggestions?

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  • What do I name classes whose only purpose is to act as a structure?

    - by Sergio Tapia
    For example, take my Actor class: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Drawing; namespace FreeIMDB { class Actor { public string Name { get; set; } public Image Portrait { get; set; } public DateTime DateOfBirth { get; set; } public List<string> ActingRoles { get; set; } public List<string> WritingRoles { get; set; } public List<string> ProducingRoles { get; set; } public List<string> DirectingRoles { get; set; } } } This class will only be used to stuff information into it, and allow other developers to get their values. What are these types of classes officially called? What is the correct nomenclature?

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  • How do I access Dictionary items?

    - by salvationishere
    I am developing a C# VS2008 / SQL Server website app and am new to the Dictionary class. Can you please advise on best method of accomplishing this? Here is a code snippet: SqlConnection conn2 = new SqlConnection(connString); SqlCommand cmd = conn2.CreateCommand(); cmd.CommandText = "dbo.AppendDataCT"; cmd.CommandType = CommandType.StoredProcedure; cmd.Connection = conn2; SqlParameter p1, p2, p3; foreach (string s in dt.Rows[1].ItemArray) { DataRow dr = dt.Rows[1]; // second row p1 = cmd.Parameters.AddWithValue((string)dic[0], (string)dr[0]); p1.SqlDbType = SqlDbType.VarChar; p2 = cmd.Parameters.AddWithValue((string)dic[1], (string)dr[1]); p2.SqlDbType = SqlDbType.VarChar; p3 = cmd.Parameters.AddWithValue((string)dic[2], (string)dr[2]); p3.SqlDbType = SqlDbType.VarChar; } but this is giving me compiler error: The best overloaded method match for 'System.Collections.Generic.Dictionary<string,string>.this[string]' has some invalid arguments I just want to access each value from "dic" and load into these SQL parameters. How do I do this? Do I have to enter the key? The keys are named "col1", "col2", etc., so not the most user-friendly. Any other tips? Thanks!

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