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• x86 instruction encoding tables

  - by Cheery

  I'm in middle of rewriting my assembler. While at it I'm curious about implementing disassembly as well. I want to make it simple and compact, and there's concepts I can exploit while doing so. It is possible to determine rest of the x86 instruction encoding from opcode (maybe prefix bytes are required too, a bit). I know many people have written tables for doing it. I'm not interested about mnemonics but instruction encoding, because it is an actual hard problem there. For each opcode number I need to know: does this instruction contain modrm? how many immediate fields does this instruction have? what encoding does an immediate use? is the immediate in field an instruction pointer -relative address? what kind of registers does the modrm use for operand and register fields? sandpile.org has somewhat quite much what I'd need, but it's in format that isn't easy to parse. Before I start writing and validating those tables myself, I decided to write this question. Do you know about this kind of tables existing somewhere? In a form that doesn't require too much effort to parse.

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• Problems with MediaPlayer, raw resources, stop and start

  - by arakn0

  Hello everybody, I'm new in Android development and I have the next question/problem. I'm playing around with the MediaPlayer class to reproduce some sounds/music. I am playing raw resources (res/raw) and it looks kind of easy. To play a raw resource, the MediaPlayer has to be initialized like this: MediaPlayer mp = MediaPlayer.create(appContext, R.raw.song); mp.start(); Until here there is no problem. The sound is played, and everything works fine. My problem appears when I want to add more options to my application. Specifically when I add the "Stop" button/option. Basically, what I want to do is...when I press "Stop", the music stops. And when I press "Start", the song/sound starts over. (pretty basic!) To stop the media player, you only have to call stop(). But to play the sound again, the media player has to be reseted and prepared. mp.reset(); mp.setDataSource(params); mp.prepare(); The problem is that the method setDataSource() only accepts as params a file path, Content Provider URI, streaming media URL path, or File Descriptor. So, since this method doesn't accept a resource identifier, I don't know how to set the data source in order to call prepare(). In addition, I don't understand why you can't use a Resouce identifier to set the data source, but you can use a resource identifier when initializing the MediaPlayer. I guess that I'm missing something. I wonder if I am mixing concepts, and the method stop() doesn't have to be called in the "Stop" button. Any help? Thanks in advanced!!!

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• Abstract Base Class or Class?

  - by Mohit Deshpande

  For my semester project, my team and I are supposed to make a .jar file (library, not runnable) that contains a game development framework and demonstrate the concepts of OOP. Its supposed to be a FRAMEWORK and another team is supposed to use our framework and vice-versa. So I want to know how we should start. We thought of several approaches: 1. Start with a plain class public class Enemy { public Enemy(int x, int y, int health, int attack, ...) { ... } ... } public class UserDefinedClass extends Enemy { ... } 2. Start with an abstract class that user-defined enemies have to inherit abstract members public abstract class Enemy { public Enemy(int x, int y, int health, int attack, ...) { ... } public abstract void draw(); public abstract void destroy(); ... } public class UserDefinedClass extends Enemy { ... public void draw() { ... } public void destroy() { ... } } 3. Create a super ABC (Abstract Base Class) that ALL inherit from public abstract class VectorEntity { ... } public abstract class Enemy extends VectorEntity { ... } public class Player extends VectorEntity { ... } public class UserDefinedClass extends Enemy { ... } Which should I use? Or is there a better way?

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• What is a good starter-project in Perl?

  - by Vivin Paliath

  A buddy of mine wants to learn Perl. He asked me how to go about it. I told him: To learn Perl, you must first write Perl code. This was seconded by another buddy of mine who writes a lot of good Perl code. It's very zen, but not helpful. The problem is that this is exactly how I learnt to write Perl. At my very first job I had to implement something in Perl and I pretty much just jumped into it and waded and stumbled around until I figured it out. I was thinking that the best way for him to learn Perl would be to do a small project in Perl. The problem is, I can't think of anything that would be a good starter-project in Perl. For just basic learning and understanding concepts, I have recommended going to PerlMonks, to read Learning Perl, and also to look at Perl Best Practices. Aside from this, I think a good starter-project would be useful for him to get a grasp of the language. Any suggestions?

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• Learning about the low level

  - by Anoners

  I'm interested in learning more about the PC from a lower (machine) level. I graduated from a school which taught us concepts using the Java language which abstracted out that level almost completely. As a result I only learned a bit from the one required assembly language course. In order to cram in ASM and quite a few details about architecture, it was hard to get a very deep picture of what is going on there. At work I focus on unix socket programming in C, so i'm much closer to the hardware now, but I feel I should learn a bit more about what streams really are, how memory management and paging works, what goes on when you call "paint()" on a graphics buffer, etc. I missed out on a lot of this and i'm looking for a good resource to get me started. I've heard a lot about the "Pink Book" by Peter Norton (Programmer's Guide to the IBM PC, Programmer's Guide to inside the PC, etc). It seems like this is on the right track, however the original is quite out dated and the newer ones have had conflicting reviews, with many people saying to stay away from it. I'm not sure what the SO crowd thinks about this book or if they have some suggestions for similar books, online resources, etc that may be good primers for this sort of thing. Any suggestions would be appreciated.

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• Hiring a programmer: looking for the "right attitude"

  - by Totophil

  It's actually two questions in one: What is the right attitude for a programmer? How do you (or would you) look for one when interviewing or during hiring process? Please note this question is not about personality or traits of a candidate, it is about their attitude towards what they do for living. This is also not about reverse of programmers pet peeves. The question has been made community wiki, since I am interested in a good answer rather than reputation. I disagree that the question is purely subjective and just a matter of opinion: clearly some attitudes make a better programmer than others. Consecutively, there might quite possibly exist an attitude that is common to the most of the better programmers. Update: After some deliberation I came up with the following attitude measurement scales: identifies themselves with the job ? fully detached perceives code as a collection of concepts ? sees code as a sequence of steps thinks of creating software as an art ? takes 100% rational approach to design and development Answers that include some sort of a comment on the appropriateness of these scales are greatly appreciated. Definition of "attitude": a complex mental state involving beliefs and feelings and values and dispositions to act in certain ways; "he had the attitude that work was fun" The question came as a result of some reflection on the top voted answer to "How do you ensure code quality?" here on Stack Overflow.

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• Secure Password Storage and Transfer

  - by Andras Zoltan

  I'm developing a new user store for my organisation and am now tackling password storage. The concepts of salting, HMAC etc are all fine with me - and want to store the users' passwords either salted and hashed, HMAC hashed, or HMAC salted and hashed - not sure what the best way will be - but in theory it won't matter as it will be able to change over time if required. I want to have an XML & JSON service that can act as a Security Token Service for client-side apps. I've already developed one for another system, which requires that the client double-encrypts a clear-text password using SHA1 first and then HMACSHA1 using a 128 unique key (or nonce) supplied by the server for that session only. I'd like to repeat this technique for the new system - upgrading the algo to SHA256 (chosen since implementations are readily available for all aforementioned platforms - and it's much stronger than SHA1) - but there is a problem. If I'm storing the password as a salted hash in the user-store, the client will need to be sent that salt in order to construct the correct hash before being HMACd with the unique session key. This would completely go against the point of using a salt in the first place. Equally, if I don't use salt for password storage, but instead use HMAC, it's still the same problem. At the moment, the only solution I can see is to use naked SHA256 hashing for the password in the user store, so that I can then use this as a starting point on both the server and the client for a more secure salted/hmacd password transfer for the web service. This still leaves the user store vulnerable to a dictionary attack were it ever to be accessed; and however unlikely that might be - assuming it will never happen simply doesn't sit well with me. Greatly appreciate any input.

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• Help! I've learned jQuery... now I want to learn JavaScript

  - by Derek Adair

  I am a self-taught web developer/programmer. I started out about two years ago by learning how to make simple dynamic websites with HTML/CSS/PHP. Then I started dabbling with animation... Enter jQuery I've become quite proficient with jQuery over the last year and I've even started making my own plugins. I've spent most of my effort learning how to beautify websites with fancy effects and what not. Upon tackling my first full-blown application, I realized how under-developed my knowledge of JavaScript actually is. jQuery has allowed me to rely on its framework so heavily that I rarely use any interesting functions, techniques, or whatever that are 'native' to the JavaScript language. For example: I have a basic understanding of what a closure is... but I am unsure where this technique can actually benefit me. Although as I understand it, that's what my jQuery plugins do with (function ($){//plugin code here})(jQuery). I've seen many posts/blogs/whatever about memory leaks and circular references which is concerning. I'm frustrated because I can wrap my head around the basic concepts of what these are just by reading the articles, but I'm finding that the deeper I go the more I don't understand. The vocabulary alone is burdensome. Let alone how to actually use these techniques/functions/language features. I am trying to figure out what I don't know I'm looking to gather any advice, techniques, articles, books, videos, snippets, examples, potential pitfalls... really anything you have regarding application development with JavaScript/jQuery.

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• What is a good standard exercise to learn the OO features of a language?

  - by FarmBoy

  When I'm learning a new language, I often program some mathematical functions to get used to the control flow syntax. After that, I like to implement some sorting algorithms to get used to the array/list constructs. But I don't have a standard exercise for exploring the languages OO features. Does anyone have a stock exercise for this? A good answer would naturally lend to inheritance, polymorphism, etc., for a programmer already comfortable with these concepts. An ideal answer would be one that could be communicated in a few words, without ambiguity, in the way that "implement mergesort" is completely unambiguous. (As an example, answering "design a game" is so vague as to be useless.) Any ideas? EDIT: I have to remark that the results here are somewhat ironic. 10 upvotes and (originally) 5 favorites suggest that this is a question others are interested in. Yet the most upvoted answer is one that says there is no good answer. Oh well. I think I'll look at the textbook below, I've found games useful in the past for OO.

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• Sql Server Compact - Schema Management

  - by Richard B

  I've been searching for some time for a good solution to implement the idea of managing schema on a Sql Server Compact 3.5 db. I know of several ways of managing schema on Sql Express/std/enterprise, but Compact Edition doesn't support the necessary tools required to use the same methodology. Any suggestions/tips? I should expand this to say that it is for 100+ clients with wrapperware software. As the system changes, I need to publish update scripts alongside the new binaries to the client. I was looking for a decent method by which to publish this without having to just hand the client a script file and say "Run this in SSMSE". Most clients are not capable of doing such a beast. A buddy of mine disclosed a partial script on how to handle the SQL Server piece of my task, but never worked on Compact Edition... It looks like I'll be on my own for this. What I think that I've decided to do, and it's going to need a "geek week" to accomplish, is that I'm going to write some sort of tool much like how WiX and nAnt works, so that I can just write an overzealous Xml document to handle the work. If I think that it is worthwhile, I'll publish it on CodePlex and/or CodeProject because I've used both sites a bit to gain better understanding of concepts for jobs I've done in the past, and I think it is probably worthwhile to give back a little.

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• Generics with constraints hierarchy

  - by devoured elysium

  I am currently facing a very disturbing problem: interface IStateSpace<Position, Value> where Position : IPosition // <-- Problem starts here where Value : IValue // <-- and here as I don't { // know how to get away this // circular dependency! // Notice how I should be // defining generics parameters // here but I can't! Value GetStateAt(Position position); void SetStateAt(Position position, State state); } As you'll down here, both IPosition, IValue and IState depend on each other. How am I supposed to get away with this? I can't think of any other design that will circumvent this circular dependency and still describes exactly what I want to do! interface IState<StateSpace, Value> where StateSpace : IStateSpace where Value : IValue { StateSpace StateSpace { get; }; Value Value { get; set; } } interface IPosition { } interface IValue<State> where State : IState { State State { get; } } Basically I have a state space IStateSpace that has states IState inside. Their position in the state space is given by an IPosition. Each state then has one (or more) values IValue. I am simplifying the hierarchy, as it's a bit more complex than described. The idea of having this hierarchy defined with generics is to allow for different implementations of the same concepts (an IStateSpace will be implemented both as a matrix as an graph, etc). Would can I get away with this? How do you generally solve this kind of problems? Which kind of designs are used in these cases? Thanks

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• Adobe AIR non-Administrator application installation/upgrade on Windows

  - by bzlm

  Is there any way to allow non-Administrator users to install, upgrade or uninstall an Adobe AIR application on Windows? I've made an Adobe AIR application and packaged it as a .air package using the standard AIR mechanism for creating deployment packages. If a normal or Power user tries to install this AIR application, the Application Event Log shows an error saying administrative rights are required. And even if the user elevates during installation, administrative rights are still required for an upgrade using the automated AIR upgrade system (since an upgrade is essentially, behind the scenes, an uninstallation of a .msi package followed by an installation of another .msi package). Is there any way around this? What I've tried so far is: Using the Group Policy editor, setting Windows Installer to elevate during installations. Doesn't work, since AIR attempts a "for all users" installation. Specifying My Documents as the installation directory. Doesn't work, since AIR attempts a "for all users" installation. Giving the user Modify access to the Program Files folder where the application would usually reside. Doesn't work, since this isn't a file permissions issue. Making the user a Power User. Doesn't work, since AIR attempts a "for all users" installation. I'm guessing that both installing and upgrading would work fine for a user if the AIR installer would attempt to make an "only for me" application installation instead of a "for all users" installation, and the user was a Power User, and possibly the application was installed to My Documents I'm also guessing that this problem doesn't exist on OSX and Linux, since they have more intuitive concepts for per-user application installations.

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• Organizing code, logical layout of segmented files

  - by David H

  I have known enough about programming to get me in trouble for about 10 years now. I have no formal education, though I've read many books on the subject for various languages. The language I am primarily focused on now would be php, atleast for the scale of things I am doing now. I have used some OOP classes for a while, but never took the dive into understanding principals behind the scenes. I am still not at the level I would like to be expression-wise...however my recent reading into a book titled The OOP Thought Process has me wanting to advance my programming skills. With motivation from the new concepts, I have started with a new project that I've coded some re-usable classes that deal with user auth, user profiles, database interfacing, and some other stuff I use regularly on most projects. Now having split my typical garbled spaghetti bowl mess of code into somewhat organized files, I've come into some problems when it comes to making sure files are all included when they need to be, and how to logically divide the scripts up into classes, aswell as how segmented I should be making each class. I guess I have rambled on enough about much of nothing, but what I am really asking for is advise from people, or suggested reading that focuses not on specific functions and formats of code, but the logical layout of projects that are larger than just a hobby project. I want to learn how to do things proper, and while I am still learning in some areas, this is something that I have no clue about other than just being creative, and trial/error. Mostly error. Thanks for any replies. This place is great.

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• What are the most interesting equivalences arising from the Curry-Howard Isomorphism?

  - by Tom

  I came upon the Curry-Howard Isomorphism relatively late in my programming life, and perhaps this contributes to my being utterly fascinated by it. It implies that for every programming concept there exists a precise analogue in formal logic, and vice versa. Here's an "obvious" list of such analogies, off the top of my head: program/definition | proof type/declaration | proposition inhabited type | theorem function | implication function argument | hypothesis/antecedent function result | conclusion/consequent function application | modus ponens recursion | induction identity function | tautology non-terminating function | absurdity tuple | conjunction (and) disjoint union | exclusive disjunction (xor) parametric polymorphism | universal quantification So, to my question: what are some of the more interesting/obscure implications of this isomorphism? I'm no logician so I'm sure I've only scratched the surface with this list. For example, here are some programming notions for which I'm unaware of pithy names in logic: currying | "((a & b) => c) iff (a => (b => c))" scope | "known theory + hypotheses" And here are some logical concepts which I haven't quite pinned down in programming terms: primitive type? | axiom set of valid programs? | theory ? | disjunction (or)

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• Objective-C Simple Inheritance and OO Principles

  - by bleeckerj

  I have a subclass SubClass that inherits from baseclass BaseClass. BaseClass has an initializer, like so: -(id)init { self = [super init]; if(self) { [self commonInit]; } return self; } -(void)commonInit { self.goodStuff = [[NSMutableArray alloc]init]; } SubClass does its initializer, like so: -(id)init { self = [super init]; if(self) { [self commonInit]; } return self; } -(void)commonInit { self.extraGoodStuff = [[NSMutableArray alloc]init]; } Now, I've *never taken a proper Objective-C course, but I'm a programmer more from the Electrical Engineering side, so I make do. I've developed server-side applications mostly in Java though, so I may be seeing the OO world through Java principles. When SubClass is initialized, it calls the BaseClass init and my expectation would be — because inheritance to me implies that characteristics of a BaseClass pass through to SubClass — that the commonInit method in BaseClass would be called during BaseClass init. It is not. I can *sorta understand maybe-possibly-stretch-my-imagination why it wouldn't be. But, then — why wouldn't it be based on the principles of OOP? What does "self" represent if not the instance of the class of the running code? Okay, so — I'm not going to argue that what a well-developed edition of Objective-C is doing is wrong. So, then — what is the pattern I should be using in this case? I want SubClass to have two main bits — the goodStuff that BaseClass has as well as the extraGoodStuff that it deserves as well. Clearly, I've been using the wrong pattern in this type of situation. Am I meant to expose commonInit (which makes me wonder about encapsulation principles — why expose something that, in the Java world at least, would be considered "protected" and something that should only ever be called once for each instance)? I've run into a similar problem in the recent past and tried to muddle through it, but now — I'm really wondering if I've got my principles and concepts all straight in my head. Little help, please.

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• Why can't I create a database in an empty ASP MVC 2 project using Project->Add->New Item->SQL Server

  - by Dr Dork

  I'm diving head first into ASP MVC and am playing around with creating and manipulating a database. I did a search and found this tutorial for creating a database, however when I follow it, I get this error when trying to add a new database to my fresh, empty ASP MVC 2 project... A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) The only requirement the tutorial mentioned was SQL Server Express, but when I went to download it, it said it was already installed. I'm assuming it was part of the VS 2010 RC I installed and am running. So I don't know what else I need if I am missing something. This is all new to me, so I'm sure I'm missing something obvious here and after I'm done posting this question, I plan to do some more research into the topic of databases and how they work with ASP MVC. In the meantime, I was you could help me answer a couple high level questions... What am I missing/forgetting to do that is causing this error? Any suggestions for good resources/tutorials that focus on using databases with ASP MVC? I've done a lot of database programming in the past, so I'm familiar with the concepts of relational databases and the SQL language. I wish I could find a good resource for learning how to work with them in an ASP dev environment, as well as a good breakdown of all the related technologies used for working with them (i.e. LINQ to SQL). Thanks so much in advance for all your help! I'm going to start researching these questions right now.

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• Android Web App : Position:fixed broken?

  - by StevenGilligan

  Hi all, I'm in the process of developping a Web Application for mobiles. I went with web applications because to me it seems a winning situation having to develop one application that could run also on iPhone / Windows Mobile / Palm etc. I started testing today after a few days of doing concepts, ideas and designs and what I wanted to do was have a menu that sticks at the bottom of the page. Exactly like the menu on the bottom in this iPhone application screenshot : http://farm4.static.flickr.com/3094/2656904921_1c54e93b4f.jpg Using CSS, I though it would be really easy to do this. Only using position:fixed; bottom:0; would have done the trick but I have found it doesn't behave the same on mobile browsers I tried to split my page in 2 sections : 1 would be a scrollable div (for the content) and the other one would be the bottom menu. Scrollable divs also do not work on Android. I also tried using frames with no luck either. Does anyone know of any way to re-create a menu that would stick to the bottom of a page for mobile phones? Thank you, Steven

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• NSPopupButton bound to NSArrayController not updating

  - by BuzzB

  I've got an NSPopupButton bound to an NSArrayController. (Man, that was harder than I thought it would be!) I have an NSArrayController bound to an NSMutableArray via the NSArrayController's "Controller Content" binding. The "Content" and "Content Values" bindings of the NSPopupButton are bound to my NSArrayController, and "Selected Object" is bound to a member in my app delegate. It is working as I expect. Except, when I add items to the NSMutableArray that my NSArrayController is bound to they don't appear in the popup. I kind of expected this to work automagically... with the NSArrayController observing the NSMutableArray and updating the NSPopupButton as necessary. Clearly I am missing something. [Update] Ok, clearly I am adding items to my array in a way that the array controller can't see. I finally found this... https://developer.apple.com/library/mac/documentation/cocoa/conceptual/CocoaBindings/Concepts/Troubleshooting.html But I really don't understand what it means. Does anyone know of a simple example of the proper way to dynamically added items to a bound NSMutableArray when the "adder" has no idea that there is a UI element bound to the array? Any help would be greatly appreciated.

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• Should I learn VB.NET or C#?

  - by Ravi

  Background I have decided to do my graduation project (yet to start) in .NET. Regarding it, I am bit confused about: what language should I learn: VB.NET or C#? What I have learnt from those who know it that both VB.NET and C# have: The same concepts VB.NET is simpler as it is more like English statements but also C# is simple too if you already know C (Which I do know) Question So considering some factors, e.g. career point of view, newness, challenging and beneficial, etc., what language should I choose? Please help me out. And clearly do justify your answer (whatever reason you have.) References (Extra) A little information about what project I am doing: It is a database file system. Technologies I'll be using are SQL Server, WPF, etc. I just love the concept of Database file system.So those who want to know more about Database file system, here are the links DBFS (This one is really good.Serves as primary reference for me) Towards A Single Folder Filesystem stackoverflow-What is a database file system? UPDATE1 : After some really good explained answers (actually all are good at their place), I have finally decided to go with C# for myself. Thank you all. Still, you are requested to put your opinion (Once it is reopened,of course) UPDATE2 : Question reopened and made community wiki.Thank you all.

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• Mathematics for Computer Science Students

  - by Ender

  To cut a long story short, I am a CS student that has received no formal Post-16 Maths education for years. Right now even my Algebra is extremely rusty and I have a couple of months to shape up my skills. I've got a couple of video lectures in my bookmarks, consisting of: Pre-Calculus Algebra Calculus Probability Introduction to Statistics Differential Equations Linear Algebra My aim as of today is to be able to read the CLRS book Introduction to Algorithms and be able to follow the Mathematical notation in that, as well as being able to confidently read and back-up any arguments written in Mathematical notation. Aside from these video lectures, can anyone recommend any good books to help teach someone wishing to go from a low-foundation level to a more advanced level of Mathematics? Just as a note, I've taken a first-year module in Analytical Modelling, so I understand some of the basic concepts of Discrete Mathematics. EDIT: Just a note to those that are looking to learn Linear Algebra using the Video Lectures I have posted up. Peteris Krumins' Blog contains a run-through of these lecture notes as well as his own commentary and lecture notes, an invaluable resource for those looking to follow the lectures too.

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• Understanding Hibernate saveOrUpdate

  - by Stephano

  The books that I've read regarding hibernate are, at best, reference tomes. They very seldom have good code examples, so I tend to use online resources for those needs. However, I've always had a problem understanding the basic idea of hibernate persistence. I've read the books and understand the concepts, but in practice, I often see results that I don't understand. Perhaps you all can help, as you have in the past. Let's look at a simple example of a dog and a cat that are friends. This isn't a rare occurrence. It also has the benefit of being much more interesting than my business case. We want a function called "saveFriends" that takes a dog name and a cat name. We'll save the Dog and then the Cat. For this example to work, the cat is going to have a reference back to the dog. I understand this isn't an ideal example, but it's cute and works for our purposes. FriendService.java public int saveFriends(String dogName, String catName) { Dog fido = new Dog(); Cat felix = new Cat(); fido.name = dogName; fido = animalDao.saveDog(fido); felix.name = catName; [ex.A]felix.friend = fido; [ex.B]felix.friend = animalDao.getDogByName(dogName); animalDao.saveCat(felix); } AnimalDao.java (extends HibernateDaoSupport) public Dog saveDog(Dog dog) { getHibernateTemplate().saveOrUpdate(dog); return dog } public Cat saveCat(Cat cat) { getHibernateTemplate().saveOrUpdate(cat); return cat; } public Dog getDogByName(String name) { return (Dog) getHibernateTemplate().find("from Dog where name=?", name).get(0); } Now, assume for a minute that I would like to use either example A or example B to save my friend. Is one better than the other to use? I'll understand if neither of those examples work, but please explain why.

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• How do I get an overview and a methodology for programming in Python

  - by Peter Nielsen

  I've started to learn Python and programming from scratch. I have not programmed before so it's a new experience. I do seem to grasp most of the concepts, from variables to definitions and modules. I still need to learn a lot more about what the different libraries and modules do and also I lack knowledge on OOP and classes in Python. I see people who just program in Python like that's all they have ever done and I am still just coming to grips with it. Is there a way, some tools, a logical methodology that would give me an overview or a good hold of how to handle programming problems ? For instance, I'm trying to create a parser which we need at the office . I also need to create a spider that would collect links from various websites. Is there a formidable way of studying the various modules to see what is needed ? Or is it just nose to the grind stone and understand what the documentation says ? Sorry for the lengthy question..

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• Where and how to start on C# and .Net Framework ?

  - by Rachel

  Currently, I have been working as an PHP developer for approximately 1 year now and I want learn about C# and .Net Framework, I do not have any experience with .Net Framework and C# and also there is not firm basis as to why I am going for C# and .Net Framework vs Java or any other programming languages, this decision is mere on career point of view and job opportunities. So my question is about: Is my decision wise to go for C# and .Net Framework route after working for sometime as an PHP Developer ? What are the good resources which I can refer and learn from to get knowledge on C# and .NET Framework ? How should I go about learning on C# and .NET Framework ? What all technologies should I be learning OR have experience with to be considered as an C#/.Net Developer, I am mentioning some technologies, please add or suggest one, if am missing out any ? Technologies C#-THE LANGUAGE GUI APPLICATION DEVELOPMENT WINDOWS CONTROL LIBRARY DELEGATES DATA ACCESS WITH ADO.NET MULTI THREADING ASSEMBLIES WINDOWS SERVICES VB INTRODUCTION TO VISUAL STUDIO .NET WINDOWS CONTROL LIBRARY DATA ACCESS WITH ADO.NET ASP.NET WEB TECHNOLOGIES CONTROLS VALIDATION CONTROL STATE MANAGEMENT CACHING ASP.NET CONFIGURATION ADO.NET ASP.NET TRACING & SECURITY IN ASP.NET XMLPROGRAMMING WEB SERVICES CRYSTAL REPORTS SSRS (SQL Server Reporting Services) MS-Reports LINQ: NET Language-Integrated Query NET Language-Integrated Query LINQ to SQL: SQL Integration WCF: Windows Communication Foundation What Is Windows Communication Foundation? Fundamental Windows Communication Foundation Concepts Windows Communication Foundation Architecture WPF: Windows Presentation Foundation Getting Started (WPF) Application Development WPF Fundamentals What are your thoughts, suggestions on this and from Job and Market Perspective, what areas of C#/.Net Development should I put my focus on ? I know this is very subjective and long question but advice would be highly appeciated. Thanks.

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• Help needed in grokking password hashes and salts

  - by javafueled

  I've read a number of SO questions on this topic, but grokking the applied practice of storing a salted hash of a password eludes me. Let's start with some ground rules: a password, "foobar12" (we are not discussing the strength of the password). a language, Java 1.6 for this discussion a database, postgreSQL, MySQL, SQL Server, Oracle Several options are available to storing the password, but I want to think about one (1): Store the password hashed with random salt in the DB, one column Found on SO and elsewhere is the automatic fail of plaintext, MD5/SHA1, and dual-columns. The latter have pros and cons MD5/SHA1 is simple. MessageDigest in Java provides MD5, SHA1 (through SHA512 in modern implementations, certainly 1.6). Additionally, most RDBMSs listed provide methods for MD5 encryption functions on inserts, updates, etc. The problems become evident once one groks "rainbow tables" and MD5 collisions (and I've grokked these concepts). Dual-column solutions rest on the idea that the salt does not need to be secret (grok it). However, a second column introduces a complexity that might not be a luxury if you have a legacy system with one (1) column for the password and the cost of updating the table and the code could be too high. But it is storing the password hashed with a random salt in single DB column that I need to understand better, with practical application. I like this solution for a couple of reasons: a salt is expected and considers legacy boundaries. Here's where I get lost: if the salt is random and hashed with the password, how can the system ever match the password? I have theory on this, and as I type I might be grokking the concept: Given a random salt of 128 bytes and a password of 8 bytes ('foobar12'), it could be programmatically possible to remove the part of the hash that was the salt, by hashing a random 128 byte salt and getting the substring of the original hash that is the hashed password. Then re hashing to match using the hash algorithm...??? So... any takers on helping. :) Am I close?

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• How to transfer value from a DropDownList to a property of a serialized model object

  - by Richard77

  Hello, I'm testing some concepts in ASP.NET MVC multisteps (Style Wizards) with a small application which allow me to records organizations in a database. To make things easier, I've a class OrganizationFormModelView that contains an object of class Organization and a property called ParentOrgList of SelectList type. The only purpose of the selectList property is to be used by a DropDownList. I've also serialize OrganizationFormModelView to get the multisteps Wizard effect. In my first view (or first step), I use a dropdownlist helper to assign a value to one of the the Organization's property called ParentOrganization, which draws data from the ParentOrgList. ... <% = Html.DropDownList("Organization.ParentOrganization", Model.ParentOrgList)%> ... The first time the page loads, I'm able to make a choice. And, my choice is reflected in my object Model all along the wizard' steps(see Visual studio in debugging mode). But, when any time I'm redirected back to the first view (first step), I get the following error message: "The ViewData item with the key 'Organization.ParentOrganization' is of type 'System.String' but needs to be of type 'IEnumerable'." Thanks for helping

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