Search Results

Search found 1261 results on 51 pages for 'trivial'.

Page 18/51 | < Previous Page | 14 15 16 17 18 19 20 21 22 23 24 25  | Next Page >

• Oracle as a Service in the Cloud

  - by Jason Williamson

  This should really be a Tweet, but I guess I'm writing a bit more. In theme of data migration and legacy modernization, I am seeing more and more of a push to consolidate data sources, especially from non-oracle to oracle in an effort to save dollars. From a modernization perspective, this fits in quite well. We are able to migrate things like Terradata, Sybase and DB2 and put that all into an Oracle database and then provide that as a OaaS (Oracle as a Service) Cloud offering. This seems to be a growing trend, and not unlike the cool RDS Amazon Database cloud being built on Oracle as well. We again find ourselves back in the similar theme of migration, however. The target technology sounds like a winner (COBOL to Java/SOA...DB2/Datacom/Adabas to Oracle) but the age-old problem of how to get there still persists. It it not trivial to migrate large amounts of pre-relational or "devolved" relational data. To do this, we again must revert back to a tight roadmap to migration and leverage the growing tools and services that we have. I'm working on a couple of new sections and chapters for a book that Tom and Prakash and I are writing around Database Migration and Consolidation. I'll share some snipits shortly.

  Read the article

• How can I pass an external instance to the constructor of an object that's being created using the default XNA XML content loader?

  - by Michael

  I'm trying to understand how to use the XNA XML content importer to instantiate non-trivial objects that are more than a collection of basic properties (e.g., a class that inherits from DrawableGameObject or GameObject and requires other things to be passed into its constructor). Is it possible to pass existing external instances (e.g., an instance of the current Game) to the constructor of an object that's being created using the default XNA XML content loader? For example, imagine that I have the following class, inheriting from DrawableGameComponent: public class Character : DrawableGameComponent { public string Name { get; set; } public Character(Game game) : base(game) { } public override void Update(GameTime gameTime) { } public override void Draw(GameTime gameTime) { } } If I had a simple class that did not need other parameters in its constructor (i.e., the Game instance), then I could simply use this XML: <XnaContent> <Asset Type="MyNamespace.Character"> <Name>John Doe</Name> </Asset> </XnaContent> ...and then create an instance of Character using this code: var character = Content.Load<Character>("MyXmlAssetName"); But that won't work because I need to pass the need to pass the Game into the constructor. What's the best way to handle this situation? Is there a way to pass in things like the current Game using the default XNA XML content loader? Do I need to write my own XML loader? (If so, how?) Is there a better object-oriented design that I should be using for my classes? Note: Although I used Game in this example, I'm really just asking how to pass any type of existing instance to my constructors. (For example, I'm using the Farseer Physics Engine, and some of my classes also need a reference to the Farseer World object too.) Thanks in advance.

  Read the article

• How To Use the Restore Partition to Break Into a Mac Running OS X Lion

  - by Justin Garrison

  It’s trivial to break into a Mac using an OS X boot disk, but new Macs use a restore partition for OS installations. Here’s how you can use that partition to reset a user password and break into a Mac. All laptops that come with OS X 10.7 “Lion” or laptops that were upgraded to Lion have a restore partition for easy OS recovery. This easy-to-use recovery partition also opens up hackers to break into your Mac without needing any additional tools. To reset a user password on a Mac with Lion you first need to restart the computer and hold the Command+R (?+R) keys. When the gray Apple logo shows up on the screen you can release the keys. Your computer should automatically boot into the recovery partition. Start by selecting your language and then go to Utilities -> Terminal in the menu. How to Sync Your Media Across Your Entire House with XBMC How to Own Your Own Website (Even If You Can’t Build One) Pt 2 How to Own Your Own Website (Even If You Can’t Build One) Pt 1

  Read the article

• Reformatting and version control

  - by l0b0

  Code formatting matters. Even indentation matters. And consistency is more important than minor improvements. But projects usually don't have a clear, complete, verifiable and enforced style guide from day 1, and major improvements may arrive any day. Maybe you find that SELECT id, name, address FROM persons JOIN addresses ON persons.id = addresses.person_id; could be better written as / is better written than SELECT persons.id, persons.name, addresses.address FROM persons JOIN addresses ON persons.id = addresses.person_id; while working on adding more columns to the query. Maybe this is the most complex of all four queries in your code, or a trivial query among thousands. No matter how difficult the transition, you decide it's worth it. But how do you track code changes across major formatting changes? You could just give up and say "this is the point where we start again", or you could reformat all queries in the entire repository history. If you're using a distributed version control system like Git you can revert to the first commit ever, and reformat your way from there to the current state. But it's a lot of work, and everyone else would have to pause work (or be prepared for the mother of all merges) while it's going on. Is there a better way to change history which gives the best of all results: Same style in all commits Minimal merge work ? To clarify, this is not about best practices when starting the project, but rather what should be done when a large refactoring has been deemed a Good Thing™ but you still want a traceable history? Never rewriting history is great if it's the only way to ensure that your versions always work the same, but what about the developer benefits of a clean rewrite? Especially if you have ways (tests, syntax definitions or an identical binary after compilation) to ensure that the rewritten version works exactly the same way as the original?

  Read the article

• How to represent a graph with multiple edges allowed between nodes and edges that can selectively disappear

  - by Pops

  I'm trying to figure out what sort of data structure to use for modeling some hypothetical, idealized network usage. In my scenario, a number of users who are hostile to each other are all trying to form networks of computers where all potential connections are known. The computers that one user needs to connect may not be the same as the ones another user needs to connect, though; user 1 might need to connect computers A, B and D while user 2 might need to connect computers B, C and E. Image generated with the help of NCTM Graph Creator I think the core of this is going to be an undirected cyclic graph, with nodes representing computers and edges representing Ethernet cables. However, due to the nature of the scenario, there are a few uncommon features that rule out adjacency lists and adjacency matrices (at least, without non-trivial modifications): edges can become restricted-use; that is, if one user acquires a given network connection, no other user may use that connection in the example, the green user cannot possibly connect to computer A, but the red user has connected B to E despite not having a direct link between them in some cases, a given pair of nodes will be connected by more than one edge in the example, there are two independent cables running from D to E, so the green and blue users were both able to connect those machines directly; however, red can no longer make such a connection if two computers are connected by more than one cable, each user may own no more than one of those cables I'll need to do several operations on this graph, such as: determining whether any particular pair of computers is connected for a given user identifying the optimal path for a given user to connect target computers identifying the highest-latency computer connection for a given user (i.e. longest path without branching) My first thought was to simply create a collection of all of the edges, but that's terrible for searching. The best thing I can think to do now is to modify an adjacency list so that each item in the list contains not only the edge length but also its cost and current owner. Is this a sensible approach? Assuming space is not a concern, would it be reasonable to create multiple copies of the graph (one for each user) rather than a single graph?

  Read the article

• Displaying Datamatrix in application error screen

  - by DaveNay

  Quite often we will get a report from a user in the field saying there was an error in our application. Frequently this leads to the typical round of "What was the error?" "I don't know, it was just an error." We of course log these faults to the log files, and we can even enable detailed debug logs, but this involves the end user changing a setting in the configuration file and then finding the correct files and then emailing them to us. As I'm sure you can all imagine, there are plenty of pitfalls and alligators in this methodology. Recently a couple of people have used their cell phone to email me a "screen capture" of the fault, and while this helps, we still have to scrutinize the image to find the exact fault, and if enabled, the stack trace. So this evening, I had the brilliant idea (IMHO) to encode the fault into a Datamatrix barcode image and then encourage users to send me a picture from their cell phone. I can then decode the datamatrix and get a parse-able error message! Our core technology is machine vision, so the decoding of the datamatrix image would be trivial, I just need to find a method of generating the actual image to display in the fault handler. Thoughts?

  Read the article

• RetinaPad Enables Retina Display for iPhone Apps on the iPad

  - by Jason Fitzpatrick

  RetinaPad is an iPad application that actives the Retina Display resolution on iPhone applications to increase the clarity on the iPad. It’s a feature that should be built-in but is currently only available for jailbroken iPads. The premise is simple. Currently iPads lack support for the Retina Display level resolution that iPhone apps are capable of if displaying. RetinaPad allows you to stop using the ugly and blocky simple doubling available on the iPad and start accessing the higher resolution Retina Display mode for iPhone applications on the iPad. It’s such a trivial thing that it’s outright shameful Apple doesn’t include it by default. You should have to jailbreak your device to unlock functionality that should be there right from the factory. Check out the demo video below to see it in action: Fire up your jailbroken iPad, launch Cydia and search for RetinaPad. Retina Pad is $2.99, iPad only. How to Enable Google Chrome’s Secret Gold IconHTG Explains: What’s the Difference Between the Windows 7 HomeGroups and XP-style Networking?Internet Explorer 9 Released: Here’s What You Need To Know

  Read the article

• Does it make sense to write tests for legacy code when there is no time for a complete refactoring?

  - by is4

  I usually try to follow the advice of the book Working Effectively with Legacy Code. I break dependencies, move parts of the code to @VisibleForTesting public static methods and to new classes to make the code (or at least some part of it) testable. And I write tests to make sure that I don't break anything when I'm modifying or adding new functions. A colleague says that I shouldn't do this. His reasoning: The original code might not work properly in the first place. And writing tests for it makes future fixes and modifications harder since devs have to understand and modify the tests too. If it's GUI code with some logic (~12 lines, 2-3 if/else block, for example), a test isn't worth the trouble since the code is too trivial to begin with. Similar bad patterns could exist in other parts of the codebase, too (which I haven't seen yet, I'm rather new); it will be easier to clean them all up in one big refactoring. Extracting out logic could undermine this future possibility. Should I avoid extracting out testable parts and writing tests if we don't have time for complete refactoring? Is there any disadvantage to this that I should consider?

  Read the article

• FP for simulation and modelling

  - by heaptobesquare

  I'm about to start a simulation/modelling project. I already know that OOP is used for this kind of projects. However, studying Haskell made me consider using the FP paradigm for modelling a system of components. Let me elaborate: Let's say I have a component of type A, characterised by a set of data (a parameter like temperature or pressure,a PDE and some boundary conditions,etc.) and a component of type B, characterised by a different set of data(different or same parameter, different PDE and boundary conditions). Let's also assume that the functions/methods that are going to be applied on each component are the same (a Galerkin method for example). If I were to use an OOP approach, I would create two objects that would encapsulate each type's data, the methods for solving the PDE(inheritance would be used here for code reuse) and the solution to the PDE. On the other hand, if I were to use an FP approach, each component would be broken down to data parts and the functions that would act upon the data in order to get the solution for the PDE. This approach seems simpler to me assuming that linear operations on data would be trivial and that the parameters are constant. What if the parameters are not constant(for example, temperature increases suddenly and therefore cannot be immutable)? In OOP, the object's (mutable) state can be used. I know that Haskell has Monads for that. To conclude, would implementing the FP approach be actually simpler,less time consuming and easier to manage (add a different type of component or new method to solve the pde) compared to the OOP one? I come from a C++/Fortran background, plus I'm not a professional programmer, so correct me on anything that I've got wrong.

  Read the article

• Displaying Datamatrix in application error screen

  - by DaveNay

  Quite often we will get a report from a user in the field saying there was an error in our application. Frequently this leads to the typical round of "What was the error?" "I don't know, it was just an error." We of course log these faults to the log files, and we can even enable detailed debug logs, but this involves the end user changing a setting in the configuration file and then finding the correct files and then emailing them to us. As I'm sure you can all imagine, there are plenty of pitfalls and alligators in this methodology. Recently a couple of people have used their cell phone to email me a "screen capture" of the fault, and while this helps, we still have to scrutinize the image to find the exact fault, and if enabled, the stack trace. So this evening, I had the brilliant idea (IMHO) to encode the fault into a Datamatrix barcode image and then encourage users to send me a picture from their cell phone. I can then decode the datamatrix and get a parse-able error message! Our core technology is machine vision, so the decoding of the datamatrix image would be trivial, I just need to find a method of generating the actual image to display in the fault handler. Thoughts?

  Read the article

• What is an appropriate language for expressing initial stages of algorithm refinement?

  - by hydroparadise

  First, this is not a homework assignment, but you can treat it as such ;). I found the following question in the published paper The Camel Has Two Humps. I was not a CS major going to college (I majored in MIS/Management), but I have a job where I find myself coding quite often. For a non-trivial programming problem, which one of the following is an appropriate language for expressing the initial stages of algorithm refinement? (a) A high-level programming language. (b) English. (c) Byte code. (d) The native machine code for the processor on which the program will run. (e) Structured English (pseudocode). What I do know is that you usually want to start your design implementation by writing down pseuducode and then moving/writing in the desired technology (because we all do that, right?) But I never thought about it in terms of refinement. I mean, if you were the original designer, then you might have access to the original pseudocode. But realisticly, when I have to maintain/refactor/refine somebody elses code, I just keep trucking with the language it currently resides in. Anybody have a definitive answer to this? As a side note, I did a quick scan of the paper as I havn't read every single detail. It presents various score statistics, can't find where the answers are with the paper.

  Read the article

• Suggestion: ALLFILES option for RESTORE

  - by Greg Low

  The default action when performing a backup is to append to the backup file yet the default action when restoring a backup is to restore just the first file.I constantly come across customer situations where they are puzzled that they seem to have lost data after they have completed a restore. Invariably, it's just that they haven't restored all the backups contained within a single OS file. This happens most commonly with log backups but also happens when they have not restored the most recent database backup file.It is not trivial to achieve this within simple T-SQL scripts, when the number of backup files within the OS file is unknown. It really should be.I'd like to see a FILES=ALLFILES option on the RESTORE command. For RESTORE DATABASE, it should restore the most recent database backup plus any subsequent log files. For RESTORE LOG (which is the most important missing option), it should just restore all relevant log backups that are contained.If you agree, you know what to do: please vote:  https://connect.microsoft.com/SQLServer/feedback/details/769204/option-to-restore-all-backups-files-within-a-media-setAlternately, how would you write a T-SQL command to restore all log backups within a single OS file where the number of files is unknown? Would love to hear creative solutions because all the ones that I think of are pretty messy and need dynamic SQL. 

  Read the article

• How to start Sharepoint Development - Resources wanted [closed]

  - by user1249641

  I'm a apprentice for software development here in good ol' Germany and I've been doing fairly well with c#, asp.net mvc, entity framework and LINQ so far. My superiors want me to focus solely on our intranet development and Sharepoint development. They don't provide me with any resources to start. No books, no co-workers with actual webpart-dev-experience, seminars and the likes. There for it's do it on your own or die. I bought a book and started working through it on my virtual machine messing with the infrastructure and everything i can get a grip on. My main problem however stays the actual development. I have managed to write 2 webparts which can be used as a rudimentary ticket system(using WSP Builder and SP2007). But there it stops. Are there any comprehensive step by step tutorials or blogs out there, like the asp.net tutorials on www.asp.net which take you by the hand go over each step with you? Starting with the basic classes, going over custom css implementation, Jquery/Javascript ajax and async calls? No matter how trivial, I appreciate every help and hint you can give.

  Read the article

• Is it okay to use a language that isn't supported by your company for some tasks?

  - by systempuntoout

  I work for a company that supports several languages: COBOL, VB6, C# and Java. I use those languages for my primary work, but I often find myself to coding some minor programs (e.g. scripts) in Python because I found it to be the best tool for that type of task. For example: An analyst gives me a complex CSV file to populate some DB tables, so I would use Python to parse it and create a DB script. What's the problem? The main problem I see is that a few parts of these quick & dirty scripts are slowly gaining importance and: My company does not support Python They're not version controlled (I back them up in another way) My coworkers do not know Python The analysts have even started referencing them in email ("launch the script that exports..."), so they are needed more often than I initially thought. I should add that these scripts are just utilities that are not part of the main project; they simply help to get trivial tasks done in less time. For my own small tasks they help a lot. In short, if I were a lottery winner to be in a accident, my coworkers would need to keep the project alive without those scripts; they would spend more time in fixing CSV errors by hand for example. Is this a common scenario? Am I doing something wrong? What should I do?

  Read the article

• Which hard disk drive is which?

  - by djeikyb

  I want to know which hard disk drive corresponds to which device path. It's trivial to match the hard disk stats (brand, size) with the dev path, but I want more. I want to know which drive is which inside my case. What's a good way to go about getting this info? Rules: I am a lazy bum. I don't want to tear apart my server to remove all the drives, then add back one by one. A reboot is acceptable. The drives are inconveniently scrunched together in the case. All label information is hidden. The case can be opened. Most disks are SATA, so theoretically hot swappable. Unplugging cables is fair game. Bonus: For a cli only solution. I'll award answer to the best/easiest gui or cli answer, and give a bounty to the next-best answer of the other kind. Or maybe the other way around, because the bounty is worth more points.

  Read the article

• How can I get a gnome environment in my VNC session?

  - by adante

  When I start VNC I have an empty desktop without the ability to manage windows or start apps etc). I'd like to have a desktop environment to be able to basic desktop things (someone asked me why I wanted this - I can't really say except that I would like my computer to be useful). My focus at the moment is basically having a working environment with as little time/effort expenditure as possible, as opposed to spending a full-time week learning the most trivial and arcane details of x, vnc, gnome or whatever passes for the current desktop architecture standard of the hour. What command or series of hoops do I have to jump to to achieve this? I have tried running gnome-session but it looks like it is attempting to run compiz and fails spectacularly. I've also tried running metacity but this simply gives me a titlebars to my windows (this is great! But I'd also like the taskbar and other stuff). I considered trying to start gnome-session in a way that it uses metacity instead of compiz. But I don't know how to do this. Tutorials on the net exist for changing to metacity - once you already have compiz running. Not so useful if compiz does not run.

  Read the article

• Solutions for "Maintenance Mode"

  - by Ka Lyse

  Given a web application running across 10+ servers, what techniques have you put in place for doing things like altering the state of your website so that you can implement certain features. For instance, you might want to: Restrict Logins/Disable Certain Features Turn Site to "Read Only" Turn Site to Single "Maintenance Mode" page. Doing any of the above is pretty trivial. You can throw a particular "flag" in an .ini file, or add a row/value to a site_options table in your database and just read that value and do the appropriate thing. But these solutions have their problems. Disadvantages/Problems For instance, if you use a file for your application, and you want to switch off a certain feature temporarily, then you need to update this file on all servers. So then you might want to look at running something like ZooKeeper, but you are probably overcomplicating things. So then, you might decide that you want to store these "feature" flags in a database. But then you are obviously adding unncessary queries to each page request. So you think to yourself, that you will throw memcached in to the mix and just cache the query. Then you just retrieve all of your "Features" from memcached and add a 2ms~ latency to your application on every page. So to get around this, you decide to use a two tier-cache system, whereby you use an inmemory cache on each machine, (like Apc/Redis etc). This would work, but then it gets complicated, because you would have to set the key/hash life to perhaps 60 seconds, so that when you purge/invalidate the memcached object storing your "Features" result, your on machine cache is prompt enough to get the the new states. What suggestions might you have? Keeping in mind that optimization/efficiency is the priority here.

  Read the article

• Is there a proven concept to website reverse certificate authentication?

  - by Tom

  We're looking at exposing some of our internal application data externally via a website. The actual details of the website aren't that interesting, it'll be built using ASP.NET/IIS etc, that might be relevant. With this, I'm essentially I'm looking for a mechanism to authenticate users viewing my website. This sounds trivial, a username/password is typically fine, but I want more. Now I've read plenty about SSL/x.509 to realise that the CA determines that we're alright, and that the user can trust us. But I want to trust the user, I want the user to be rejected if they don't have the correct credentials. I've seen a system for online banking whereby the bank issues a certificate which gets installed on the users' computer (it was actually smartcard based). If the website can't discover/utilise the key-pair then you are immediately rejected! This is brutal, but necessary. Is there a mechanism where I can do the following: Generate a certificate for a user Issue the certificate for them to install, it can be installed on 1 machine If their certificate is not accessible, they are denied all access A standard username/password scheme is then used after that SSL employed using their certificate once they're "in" This really must already exist, please point me in the right direction! Thanks for your help :)

  Read the article

• Problems with 3D transformation - (SharpDX)

  - by Morphex

  First of all , I have been trying to get this right for a couple of day already, I have read so much info and still fail miserably to understand this. So I am going to tell you that even though I have done fairly amount of research myself, I failed to implement it. I must say miserably I am trying to create a generic camera class for a game engine of sorts - for research purposes only - the thing is I have no idea how to go about it. I have read about quaternions and matrices, but when it comes to the actual implementation I suck at it. Sharpdx has already Matrices and QUaternions implemented. SO no big deal on the map behind it. How in the world would I go about creating a camera? I have seen so many camera examples and still can't make one that works as expected. I would like to implement diferent types too (Orbital, 6DoF, FPS). So what is need for a camera? UP, Forward and Right vectors I read they are needed, also a quaternion for rotations, and View and Projection matrices. I understand that a FPS camera for instance only rotates around the World Y and the Right Axis of the camera. the 6DoF rotates always around their own axis, and the orbital is just translating for set distance and making it look always at a fixed target point. The concepts are there, now implementing this is not trivial for me. Can anyone point me on what am I missing, what I got wrong? I would really enjoy if you could give a tutorial, some piece of code, or just plain explanation of the concepts. Thank you for readin, a frustrated coder.

  Read the article

• Random generation of interesting puzzle levels?

  - by monsterfarm

  I'm making a Sokoban-like game i.e. there's a grid that has some crates on it you can push and you have to get the crates on crosses to win the level (although I'm going to add some extra elements to it). Are there any general algorithms or reading material I can look at for how I could go about generating interesting (as in, not trivial to solve) levels for this style of game? I'm aware that random level generators exist for Sokoban but I'm having trouble finding the algorithm descriptions. I'm interested in making a game where the machine can generate lots of levels for me, sorted by difficulty. I'm even willing to constrain the rules of the game to make the level generation easier (e.g. I'll probably limit the grid size to about 7x7). I suspect there are some general ways to do level generation here as I've seen e.g. Traffic Jam-like games (where you have to move blocks around the free some block) with 1000s of levels where each one has a unique solution. One idea I had was to generate a random map in its final state (i.e. where all crates are on top of their crosses) and then the computer would pull (instead of push) these crates around to create a level. The nice property here is that we know the level is solvable. However, I'd need some heuristics to ensure the level was interesting.

  Read the article

• Implementing Explosions

  - by Xkynar

  I want to add explosions to my 2D game, but im having a hard time with the architecture. Several game elements might be responsible for explosions, like, lets say, explosive barrels and bullets (and there might be chain reactions with close barrels). The only options i can come up with are: 1 - Having an array of explosions and treat them as a game element as important as any other Pros: Having a single array which is updated and drawn with all the other game element arrays makes it more organized and simple to update, and the explosive barrels at a first glance would be easy to create, simply by passing the explosion array as a pointer to each explosive barrel constructor Cons: It might be hard for the bullets to add an explosion to the vector, since bullets are shot by a Weapon class which is located in every mob, so lets say, if i create a new enemy and add it to the enemy array, that enemy will have a weapon and functions to be able to use it, and if i want the weapon (rocket launcher in this case) to have access to the explosions array to be able to add a new one, id have to pass the explosion array as a pointer to the enemy, which would then pass it to the weapon, which would pass it to the bullets (ugly chain). Another problem I can think of is a little more weird: If im checking the collisions between explosions and barrels (so i create a chain reaction) and i detect an explosion colliding with a barrel, if i add a new explosion while im iterating the explosions java will trow an exception. So this is kinda annoying, i cant iterate through the explosions and add a new explosion, i must do it in another way... The other way which isnt really well thought yet is to just add an explosive component to every element that might explode so that when it dies, it explodes or something, but i dont have good ways on implementing this theory either Honestly i dont like either the solutions so id like to know how is it usually done by actual game developers, sorry if my problem seems trivial and dumb.

  Read the article

• TDD - How to start really thinking TDD?

  - by user74825

  I have been reading about Agile, XP methodologies and TDDs. I have been in projects which states it needs to do TDD, but most of the tests are somehow integration tests or during the course of project TDD is forgotten in effort to finish codes faster. So, as far as my case goes, I have written unit tests, but I find myself going to start writing code first instead of writing a test. I feel there's a thought / design / paradigm change which is actually huge. So, though one really believes in TDD, you actually end up going back old style because of time pressure / project deliverables. I have few classes where I have pure unit tested code, but I can't seem to continue with the process, when mocks come into picture. Also, I see at times : "isn't it too trivial to write a test for it" syndrome. How do you guys think I should handle this?

  Read the article

• Single Table Per Class Hierarchy with an abstract superclass using Hibernate Annotations

  - by Andy Hull

  I have a simple class hierarchy, similar to the following: @Entity @Table(name="animal") @Inheritance(strategy=InheritanceType.SINGLE_TABLE) @DiscriminatorColumn(name="animal_type", discriminatorType=DiscriminatorType.STRING) public abstract class Animal { } @Entity @DiscriminatorValue("cat") public class Cat extends Animal { } @Entity @DiscriminatorValue("dog") public class Dog extends Animal { } When I query "from Animal" I get this exception: "org.hibernate.InstantiationException: Cannot instantiate abstract class or interface: Animal" If I make Animal concrete, and add a dummy discriminator... such as @DiscriminatorValue("animal")... my query returns my cats and dogs as instances of Animals. I remember this being trivial with HBM based mappings but I think I'm missing something when using annotations. Can anyone help? Thanks!

  Read the article

• Fancy dynamic list in Android: TableLayout vs ListView

  - by Ralkie

  There is a requirement to have not-so-trivial dynamic list, each record of which consists of several columns (texts, buttons). It should look something like: Text11 Text12 Button1 Button2 Text21 Text22 Button1 Button2 ... At first obvious way to accomplish that seemed to be TableLayout. I was expecting to have layout/styling data specified in res/layout/*.xml and to populate it with some dataset from java code (as with ListView, for which its possible to specify TextView of item in *.xml and bind it to some array using ArrayAdapter). But after playing for a while, all I found to be possible is fully populating TableLayout programatically. Still, creating TableRow by TableRow and setting layout attributes directly in java code doesn't seem elegant enough. So the questions are: Am I at the right path? Is TableLayout really best View to accomplish that? Maybe it's more appropriate to extend ListView or something else to meet such requirements? Is it possible to have TableLayout/TableRow template specified in *.xml and data bound to this template in java side?

  Read the article

• Perl, waitpid() exit code returning wrong value?

  - by Mike

  Consder this trivial example of fork()ing then waiting for a child to die in Perl #!/usr/bin/perl use strict; use warnings; if (fork() == 0) { exit(1); } waitpid(-1,0); print $?; $perl test.pl 256 I suspect the values of are being shifted upwards because when I do exit(2) in the child, the output becomes 512 I can't seem to find this documented in perl's waitpid. Is this a bug on my system or am I doing something wrong? (btw, my OS is solaris 10)

  Read the article

< Previous Page | 14 15 16 17 18 19 20 21 22 23 24 25  | Next Page >