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• How to fix this java.lang.LinkageError?

  - by Péter Török

  I am trying to configure a custom layout class to Log4J as described in my previous post. The class uses java.util.regex.Matcher to identify potential credit card numbers in log messages. It works perfectly in unit tests (I can also programmatically configure a logger to use it and produce the expected output). However when I try to deploy it with our app in JBoss, I get the following error: --- MBEANS THAT ARE THE ROOT CAUSE OF THE PROBLEM --- ObjectName: jboss.web.deployment:war=MyWebApp-2010_02-SNAPSHOT.war,id=476602902 State: FAILED Reason: java.lang.LinkageError: java/util/regex/Matcher I couldn't even find any info on this form of the error - typically LinkageError seems to show up with a "loader constrain violation" message, like in here. Technical details: we use JBoss 4.2, Java 5, Log4J 1.2.12. We deploy our app in an .ear, which contains (among others) the above mentioned .war file, and the custom layout class in a separate jar file. We override the default settings in jboss-log4J.xml with our own log4j.properties located in a different folder, which is added to the classpath at startup, and is provided via Carbon. I can only guess: are two different Matcher class versions loaded from somewhere, or is Matcher loaded by two different classloaders when it is used from the jar and the war? What does this error message mean, and how can I fix it?

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• Java OutOfMemoryError message changes when trying to create Arrays of different sizes

  - by Gordon

  In the question by DKSRathore How to simulate the Out Of memory : Requested array size exceeds VM limit some odd behavior was noted when creating an arrays. When creating an array of size Integer.MAX_VALUE an exception with the error java.lang.OutOfMemoryError Requested array size exceeds VM limit was thrown. However when an array was created with a size less than the max but still above the virtual machine memory limit the error message read java.lang.OutOfMemoryError: Java heap space. Testing further I managed to narrow down where the error messages changes. long[] l = new long[2147483645]; exceptions message reads - Requested array size exceeds VM limit long[] l = new long[2147483644]; exceptions message reads - Java heap space errors I increased my virtual machine memory and still produced the same result. Has anyone any idea why this happens? Some extra info: Integer.MAX_VALUE = 2147483647. Edit: Here's the code I used to find the value, might be helpful. int max = Integer.MAX_VALUE; boolean done = false; while (!done) { try { max--; // Throws an error long[] l = new long[max]; // Exit if an error is no longer thrown done = true; } catch (OutOfMemoryError e) { if (!e.getMessage().contains("Requested array size exceeds VM limit")) { System.out.println("Message changes at " + max); done = true; } } }

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• Simple typemap example in swig java

  - by celil

  I am trying to wrap a native C++ library using swig, and I am stuck at trying to convert time_t in C, to long in Java. I have successfully used swig with python, but so far I am unable to get the above typemap to work in Java. In python it looks like this %typemap(in) time_t { if (PyLong_Check($input)) $1 = (time_t) PyLong_AsLong($input); else if (PyInt_Check($input)) $1 = (time_t) PyInt_AsLong($input); else if (PyFloat_Check($input)) $1 = (time_t) PyFloat_AsDouble($input); else { PyErr_SetString(PyExc_TypeError,"Expected a large number"); return NULL; } } %typemap(out) time_t { $result = PyLong_FromLong((long)$1); } I guess the in map from Java to C would be: %typemap(in) time_t { $1 = (time_t) $input; } How would I complete the out map from C to Java? %typemap(out) time_t ??? Would I need typemaps like the ones below? %typemap(jni) %typemap(jtype) %typemap(jstype) I need this in order to wrap C functions like this: time_t manipulate_time (time_t dt);

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• Which Java library for Binary Decision Diagrams?

  - by reprogrammer

  A Binary Decision Diagram (BDD) is a data structure to represent boolean functions. I'd like use this data structure in a Java program. My search for Java based BDD libraries resulted into the following packages. Java Decision Diagram Libraries JavaBDD JDD If you know of any other BDD libraries available for Java programs, please let me know so that I add it to the list above. If you have used any of these libraries, please tell me about your experience with the library. In particular, I'd like you to compare the available libraries along the following dimensions. Quality. Is the library mature and reasonably bug free? Performance. How do you evaluate the performance of the library? Support. Could you easily get support whenever you encountered a problem with the library? Was the library well documented? Ease of use. Was the API well designed? Could you install and use the library quickly and easily? Please mention the version of the library that you are evaluating.

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• Does this inheritance design belong in the database?

  - by Berryl

  === CLARIFICATION ==== The 'answers' older than March are not answers to the question in this post! Hello In my domain I need to track allocations of time spent on Activities by resources. There are two general types of Activities of interest - ones base on a Project and ones based on an Account. The notion of Project and Account have other features totally unrelated to both each other and capturing allocations of time, and each is modeled as a table in the database. For a given Allocation of time however, it makes sense to not care whether the allocation was made to either a Project or an Account, so an ActivityBase class abstracts away the difference. An ActivityBase is either a ProjectActivity or an AccountingActivity (object model is below). Back to the database though, there is no direct value in having tables for ProjectActivity and AccountingActivity. BUT the Allocation table needs to store something in the column for it's ActivityBase. Should that something be the Id of the Project / Account or a reference to tables for ProjectActivity / Accounting? How would the mapping look? === Current Db Mapping (Fluent) ==== Below is how the mapping currently looks: public class ActivityBaseMap : IAutoMappingOverride<ActivityBase> { public void Override(AutoMapping<ActivityBase> mapping) { //mapping.IgnoreProperty(x => x.BusinessId); //mapping.IgnoreProperty(x => x.Description); //mapping.IgnoreProperty(x => x.TotalTime); mapping.IgnoreProperty(x => x.UniqueId); } } public class AccountingActivityMap : SubclassMap<AccountingActivity> { public void Override(AutoMapping<AccountingActivity> mapping) { mapping.References(x => x.Account); } } public class ProjectActivityMap : SubclassMap<ProjectActivity> { public void Override(AutoMapping<ProjectActivity> mapping) { mapping.References(x => x.Project); } } There are two odd smells here. Firstly, the inheritance chain adds nothing in the way of properties - it simply adapts Projects and Accounts into a common interface so that either can be used in an Allocation. Secondly, the properties in the ActivityBase interface are redundant to keep in the db, since that information is available in Projects and Accounts. Cheers, Berryl ==== Domain ===== public class Allocation : Entity { ... public virtual ActivityBase Activity { get; private set; } ... } public abstract class ActivityBase : Entity { public virtual string BusinessId { get; protected set; } public virtual string Description { get; protected set; } public virtual ICollection<Allocation> Allocations { get { return _allocations.Values; } } public virtual TimeQuantity TotalTime { get { return TimeQuantity.Hours(Allocations.Sum(x => x.TimeSpent.Amount)); } } } public class ProjectActivity : ActivityBase { public virtual Project Project { get; private set; } public ProjectActivity(Project project) { BusinessId = project.Code.ToString(); Description = project.Description; Project = project; } }

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• Simple Java Applet not loading in FireFox / Safari on MacOS

  - by Sleepless

  Hello all, I'm probably missing something very basic here. I'm trying to get my first applet to run inside a local HTML page in Firefox 3.6 on Mac OS 10.5.8. Here's the applet's code: package SimpleApplet; import java.applet.Applet; import java.awt.*; public class MyApplet extends Applet { private static final long serialVersionUID = 1L; public void init() { } public void stop() { } public void paint(Graphics g) { g.drawString("Tweedle-Dee!",20,40); } } Here's the HTML page: <html> <body> Here's the applet: <br/> <applet code="MyApplet.class" width="300" height="150"> </applet> </body> </html> Both files (.class and .html) are in the same folder on my local machine. Now when I load the .html file into Firefox, a rectangle with a red X gets displayed. The applet works when started from Eclipse (using JRE 1.5 BTW). Also, it's not a general problem with my browser, as several pages with applets (e.g. http://java.sun.com/applets/jdk/1.4/demo/applets/Blink/example1.html) work. This is also difficult to troubleshoot because there is no output at all on the Java console... Any suggestions are appreciated!

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• Is factory method proper design for my problem?

  - by metdos

  Hello Everyone, here is my problem and I'm considering to use factory method in C++, what are your opinions ? There are a Base Class and a lot of Subclasses. I need to transfer objects on network via TCP. I will create objects in first side, and using this object I will create a byte array TCP message, and send it to other side. On the other side I will decompose TCP message, I will create object and I will add this object to a polymorphic queue.

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• UnsupportedEncodingException thrown when using Resin and Grails

  - by knorv

  I've encountered a strange problem in a Grails webapp running under Grails: java.io.UnsupportedEncodingException is thrown quite frequently due to various unknown encoding strings (such as "ISO8859_10", "ISO-8859-10"), and the strange thing is that this is done entirely within the Resin and Grails code. That is - no custom code is involved when the exception is thrown. I'm not sure if it is Grails or the servlet container's code that should handle the exception. But I'd assume that the exception should be handled somewhere and not bubble up all the way to stderr. This is the exception in full: java.io.UnsupportedEncodingException: ISO-8859-10 at com.caucho.vfs.i18n.JDKWriter$OutputStreamEncodingWriter.<init>(JDKWriter.java:112) at com.caucho.vfs.i18n.JDKWriter.create(JDKWriter.java:79) at com.caucho.vfs.Encoding.getWriteEncoding(Encoding.java:231) at com.caucho.server.connection.ToByteResponseStream.setEncoding(ToByteResponseStream.java:137) at com.caucho.server.connection.AbstractHttpResponse.setLocale(AbstractHttpResponse.java:1683) at com.caucho.server.connection.HttpServletResponseImpl.setLocale(HttpServletResponseImpl.java: 115) at javax.servlet.ServletResponseWrapper.setLocale(ServletResponseWrapper.java:139) at javax.servlet.ServletResponseWrapper.setLocale(ServletResponseWrapper.java:139) at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1035) at org.codehaus.groovy.grails.web.servlet.GrailsDispatcherServlet.doDispatch(GrailsDispatcherServlet.java:290) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:716) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:647) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:552) at javax.servlet.http.HttpServlet.service(HttpServlet.java:114) My questions: Should the exception be handled? If so, is it the responsibility of the servlet container (Resin) or the web framework (Grails)? How would you go about solving this? (I'd rather not having the exception log cluttered with exceptions that I can do nothing about.)

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• Following Domain Driven Design with MVVM/WPF

  - by msfanboy

  Hello, I have plain POCOs here and as INotifyPropertyChanged is a Interface for the Views need its implemented in the ViewModel not the Model. Now I want to show validation errors in the View beside every textbox the user typed in data. I do not want to implemented the IDataErrorInfo interface in my Models because lets assume I am not allowed to touch them as they come from another Service/Supplier. I do not want to put my IsCustomerFirstNameLenthValid Method into the Model because I could not have access to it or I just dont want to pollute my Models with interface`s having nothing to do there! How can I validate my naked POCO`s in the ViewModel and forward the results to the View by showing validation errors ?

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• Problems when data save on database by Hibernate

  - by alex

  Hi; I'm trying do save data to database by help of Hibernate , in Java. But when i run codes , i had lot of problems. Can anyone help me about that? Thanks... My code: package org.ultimania.model; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; public class Test { public static void main(String[] args) { Session session = null; SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory(); session = sessionFactory.openSession(); Transaction transaction = session.getTransaction(); BusinessCard card = new BusinessCard(); card.setId(1); card.setName("Özgür"); card.setDescription("Aciklama"); try{ transaction.begin(); session.save(card); transaction.commit(); } catch(Exception e){ e.printStackTrace(); } finally{ session.close(); } } } Problems : SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. Exception in thread "main" java.lang.NoClassDefFoundError: org/slf4j/impl/StaticLoggerBinder at org.slf4j.LoggerFactory.getSingleton(LoggerFactory.java:223) at org.slf4j.LoggerFactory.bind(LoggerFactory.java:120) at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:111) at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:269) at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:242) at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:255) at org.hibernate.cfg.Configuration.(Configuration.java:152) at org.ultimania.model.Test.main(Test.java:14) Caused by: java.lang.ClassNotFoundException: org.slf4j.impl.StaticLoggerBinder at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... 8 more

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• Tag, comment, rating, etc. database design

  - by Efe Kaptan

  I want to implement modules such as comment, rating, tag, etc. to my entities. What I thought was: comments_table - comment_id, comment_text entity1 - entitity1_id, entity1_text entity2 - entitity2_id, entity2_text entity1_comments - entity1_id, comment_id entity2_comments - entity2_id, comment_id .... Is this approach correct?

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• Database design for heavy timed data logging

  - by user293995

  Hi, I have an application where I receive each data 40.000 rows. I have 5 million rows to handle (500 Mb MySQL 5.0 database). Actually, thoses rows are stored in the same table = slow to update, hard to backup, ... Which king of scheme is used in such application to allow long term accessibility to the datas without problems with too big tables, easy backup, fast read / write ? Is postgresql better than mysql for such purpose ? Thanks in advance BEst regards

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• Facebook database design?

  - by Marin

  I have always wondered how Facebook designed the friend <- user relation. I figure the user table is something like this: user_email PK user_id PK password I figure the table with user's data (sex, age etc connected via user email I would assume). How does it connect all the friends to this user? Something like this? user_id friend_id_1 friend_id_2 friend_id_3 friend_id_N Probably not. Because the number of users is unknown and will expand.

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• Beyond core java

  - by Paul

  Coming to the end of the first year of my CS degree, we've done some Java but just the core stuff; manipulating strings and arrays, inheritance, implementing logic etc. I visit this website daily and I see so much stuff that is beyond me; using frameworks; managing databases etc. It makes me feel like I've just learned the syntax of Java, and there is so much more to do with it. My question is though, how do I get there? I don't think I'm advanced enough to join an open source project, which seems to be suggested often (though I'd love to) and I've looked at other similar questions on here (like this one) but even then I don't think that'd work for me.. firstly, could somebody try give me some commonly used frameworks etc and how and what they are used for? Where would be a good place to start? How did you get started in using the things you do? Or perhaps you think I'm going down the wrong route. Should I learn another language, and just wait until the moment occurs where it's clear what I should be doing? I'm only in the first year of my degree, so far we've lightly covered Haskell and Java, and I've done a little HTML and CSS in my free time. I know that next year we cover python, so perhaps I should just wait till then and see if I prefer that? I feel like I also risk learning something in depth and then never using it... I suppose I'm also asking for personal experiences; was there a point where you felt you'd exceeded the basic grasp of a language (does not necessarily have to be Java related) and reach a more "advanced" level? I guess I'll put subjective tag on this, but really I just want to know how to get beyond the basic understanding of a language.

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• MongoDB Schema Design - Real-time Chat

  - by Nick

  I'm starting a project which I think will be particularly suited to MongoDB due to the speed and scalability it affords. The module I'm currently interested in is to do with real-time chat. If I was to do this in a traditional RDBMS I'd split it out into: Channel (A channel has many users) User (A user has one channel but many messages) Message (A message has a user) The the purpose of this use case, I'd like to assume that there will be typically 5 channels active at one time, each handling at most 5 messages per second. Specific queries that need to be fast: Fetch new messages (based on an bookmark, time stamp maybe, or an incrementing counter?) Post a message to a channel Verify that a user can post in a channel Bearing in mind that the document limit with MongoDB is 4mb, how would you go about designing the schema? What would yours look like? Are there any gotchas I should watch out for?

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• How should I design my MYSQL table/s?

  - by yaya3

  I built a really basic php/mysql site for an architect that uses one 'projects' table. The website showcases various projects that he has worked on. Each project contained one piece of text and one series of images. Original projects table (create syntax): CREATE TABLE `projects` ( `project_id` int(11) NOT NULL auto_increment, `project_name` text, `project_text` text, `image_filenames` text, `image_folder` text, `project_pdf` text, PRIMARY KEY (`project_id`) ) ENGINE=MyISAM AUTO_INCREMENT=8 DEFAULT CHARSET=latin1; The client now requires the following, and I'm not sure how to handle the expansions in my DB. My suspicion is that I will need an additional table. Each project now have 'pages'. Pages either contain... One image One "piece" of text One image and one piece of text. Each page could use one of three layouts. As each project does not currently have more than 4 pieces of text (a very risky assumption) I have expanded the original table to accommodate everything. New projects table attempt (create syntax): CREATE TABLE `projects` ( `project_id` int(11) NOT NULL AUTO_INCREMENT, `project_name` text, `project_pdf` text, `project_image_folder` text, `project_img_filenames` text, `pages_with_text` text, `pages_without_img` text, `pages_layout_type` text, `pages_title` text, `page_text_a` text, `page_text_b` text, `page_text_c` text, `page_text_d` text, PRIMARY KEY (`project_id`) ) ENGINE=MyISAM AUTO_INCREMENT=8 DEFAULT CHARSET=latin1; In trying to learn more about MYSQL table structuring I have just read an intro to normalization and A Simple Guide to Five Normal Forms in Relational Database Theory. I'm going to keep reading! Thanks in advance

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• DB Design Question

  - by hazimdikenli

  I am designing an Org Chart, model is almost ready and simplified a bit for clarity here. OrgUnit (OrgUnitId, Name, ReportsToOrgUnitId, ...) OrgUnitJobs (OrgUnitJobId, OrgUnitId, JobName, ReportsToOrgUnitJobId, ... ,IsJobGroup) Employee (EmployeeId, ........) OrgUnitJobEmployee (OrgUnitJobId, EmployeeId, AssignedDate, .....,) so I want to know every OrgUnit's ManagerEmployee (should have one), and Employees can have more than one job, but one of them has to be the main job, so I know whats his manager and other stuff. This is going to support a little workflow behind the scnese, so that is why it is not a very simple Org chart Model. so what would you do, would you add properties like (IsManager property to OrgUnitJobs model) or add ManagerOrgUnitJobId to OrgUnitModel. and why? Likewise, for employees would you add IsPrimaryJob property to OrgUnitJobEmployee model, or add PrimaryJobId to Employee Model.

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• Understanding Domain Driven Design

  - by Nihilist

  Hi I have been trying to understand DDD for few weeks now. Its very confusing. I dont understand how I organise my projects. I have lot of questions on UnitOfWork, Repository, Associations and the list goes on... Lets take a simple example. Album and Tracks. Album: AlbumId, Name, ListOf Tracks Tracks: TrackId, Name Question1: Should i expose Tracks as a IList/IEnumerabe property on Album ? If that how do i add an album ? OR should i expose a ReadOnlyCollection of Tracks and expose a AddTrack method? Question2: How do i load Tracks for Album [assuming lazy loading]? should the getter check for null and then use a repository to load the tracks if need be? Question3: How do we organise the assemblies. Like what does each assembly have? Model.dll - does it only have the domain entities? Where do the repositories go? Interfaces and implementations both. Can i define IAlbumRepository in Model.dll? Infrastructure.dll : what shold this have? Question4: Where is unit of work defined? How do repository and unit of work communicate? [ or should they ] for example. if i need to add multiple tracks to album, again should this be defined as AddTrack on Album OR should there a method in the repository? Regardless of where the method is, how do I implement unit of work here? Question5: Should the UI use Infrastructure..dll or should there be ServiceLayer? Do my quesitons make sense? Regards

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• MANIFEST.MF issue

  - by dhananjay

  hi I have created a jar inside this folder: '/usr/local/bin/niidle.jar' in eclipse. And I have another jar inside /usr/local/bin/niidle.jar. In my niidle.jar file,there is one 'lib' folder and in that 'lib' folder,there is another jar file 'hector-0.6.0-17.jar'. I have added this 'hector-0.6.0-17.jar' file in MANIFEST.MF as follows: Manifest-Version: 1.0 Main-Class: com.ensarm.niidle.web.scraper.NiidleScrapeManager Class-Path: hector-0.6.0-17.jar But when I run this using command: >>java -jar /usr/local/bin/niidle.jar arguments... It is not working.. It is showing error message:- Exception in thread "main" java.lang.NoClassDefFoundError: me/prettyprint/hector/api/Serializer at com.ensarm.niidle.web.scraper.NiidleScrapeManager.main(NiidleScrapeManager.java:21) Caused by: java.lang.ClassNotFoundException: me.prettyprint.hector.api.Serializer at java.net.URLClassLoader$1.run(URLClassLoader.java:200) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:307) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:252) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) ... 1 more What is the problem,Please tell me solution for this Exception...

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• How do i get a more recent version of Java on my Mac than is showing up in software update?

  - by Bec

  I need at least Java 1.6 to run a program that someone else in my lab wrote On the Java website it tells me to update Java via apple's software update function, i've run this a few times but it only got up to Java 1.5.0_24 and it now says no more updates are available for my computer Is there another way to update Java on a Mac? Is my operating system maybe to old for Java 1.6? i'm not sure what i'm running exactly, and i can't find a list of what mac operating systems run what versions of Java because the java site just suggests using Mac's software update.

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• Schema-less design guidelines for Google App Engine Datastore and other NoSQL DBs

  - by jamesaharvey

  Coming from a relational database background, as I'm sure many others are, I'm looking for some solid guidelines for setting up / designing my datastore on Google App Engine. Are there any good rules of thumb people have for setting up these kinds of schema-less data stores? I understand some of the basics such as denormalizing since you can't do joins, but I was wondering what other recommendations people had. The particular simple example I am working with concerns storing searches and their results. For example I have the following 2 models defined in my Google App Engine app using Python: class Search(db.Model): who = db.StringProperty() what = db.StringProperty() where = db.StringProperty() createDate = db.DateTimeProperty(auto_now_add=True) class SearchResult(db.Model): title = db.StringProperty() content = db.StringProperty() who = db.StringProperty() what = db.StringProperty() where = db.StringProperty() createDate = db.DateTimeProperty(auto_now_add=True) I'm duplicating a bunch of properties between the models for the sake of denormalization since I can't join Search and SearchResult together. Does this make sense? Or should I store a search ID in the SearchResult model and effectively 'join' the 2 models in code when I retrieve them from the datastore? Please keep in mind that this is a simple example. Both models will have a lot more properties and the way I'm approaching this right now, I would put any property I put in the Search model in the SearchResult model as well.

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• Efficient data structure design

  - by Sway

  Hi there, I need to match a series of user inputed words against a large dictionary of words (to ensure the entered value exists). So if the user entered: "orange" it should match an entry "orange' in the dictionary. Now the catch is that the user can also enter a wildcard or series of wildcard characters like say "or__ge" which would also match "orange" The key requirements are: * this should be as fast as possible. * use the smallest amount of memory to achieve it. If the size of the word list was small I could use a string containing all the words and use regular expressions. however given that the word list could contain potentially hundreds of thousands of enteries I'm assuming this wouldn't work. So is some sort of 'tree' be the way to go for this...? Any thoughts or suggestions on this would be totally appreciated! Thanks in advance, Matt

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• Partial Classes - are they bad design?

  - by dferraro

  Hello, I'm wondering why the 'partial class' concept even exists in .NET. I'm working on an application and we are reading a (actually very good) book relavant to the development platform we are implementing at work. In the book he provides a large code base /wrapper around the platform API and explains how he developed it as he teaches different topics about the platform development. Anyway, long story short - he uses partial classes, all over the place, as a way to fake multiple inheritence in C# (IMO). Why he didnt just split the classes up into multiple ones and use composition is beyond me. He will have 3 'partial class' files to make up his base class, each w/ 3-500 lines of code... And does this several times in his API. Do you find this justifiable? If it were me, I'd have followed the S.R.P. and created multiple classes to handle different required behaviors, then create a base class that has instances of these classes as members (e.g. composition). Why did MS even put partial class into the framework?? They removed the ability to expand/collapse all code at each scope level in C# (this was allowed in C++) because it was obviously just allowing bad habits - partial class is IMO the same thing. I guess my quetion is: Can you explain to me when there would be a legitimate reason to ever use a partial class? I do not mean this to be a rant / war thread. I'm honeslty looking to learn something here. Thanks

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• How do I normalise this database design?

  - by Ian Roke

  I am creating a rowing reporting and statistics system for a client where I have a structure at the moment similar to the following: ----------------------------------------------------------------------------- | ID | Team | Coaches | Rowers | Event | Position | Time | ----------------------------------------------------------------------------- | 18 | TeamName | CoachName1 | RowerName1 | EventName | 1 | 01:32:34 | | | | CoachName2 | RowerName2 | | | | | | | | RowerName3 | | | | | | | | RowerName4 | | | | ----------------------------------------------------------------------------- This is an example row of data but I would like to expand this out to a Rowers table and Coaches table and so on but I don't know how best to then link that back to the Entries table which is what this is. Has anybody got any words of wisdom they could share with me? Update A Team can have any number of Coaches and Rowers, a Rower can be in many Teams (Team A, B, C etc) and a Team can have many Coaches.

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• UI Design, incase of numerous situations

  - by The King

  Hi... I'm creating a web form, where in there are around 12-15 Input Fields... You can have a look at the screen and The request is such that depending on the data the user selects in the Gridview and the DropDown list, the appropriate Textboxes and CheckBoxes needs to be displayed. Some times the conditions are very direct, like when the DDL value is "ABC", get only paid amount from the user. Sometime they are so complex like... IF DDL is "DEF" and Selected GPMS value is between 1000-2000, calculate the values of allowed, paid etc (using some formula) and the focus should be directed to Page No Field, leaving the other fields open incase user wants to edit... There are around 10-15 conditions like this. As this was done through agile, conditions were being added as and when, and wherever it feels appropriate (DDL on change Event, GridView on selecting change event etc... etc..) After completion, now I see the code has become a big chuck, is growing unmanageably... Now, I'm planning to clear this... From you experience, what you think is the best way to handle this. There is a possibility to add more conditions like this in future... Please let me know, incase you need more information. I'm currently developing this app in C# .Net WindowsForms Edit: Currently there are only three items (The Datagrid, the DDL, the OverrideAmt CheckBox) that change the way other fields behave... Almost all of the conditions will fall between the two situations I mentioned... Mostly they belong to "Enabling/Disabling".. "Setting of Values"... and "Changing Focus" or any combination of these.

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