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• Problem running java code through command line

  - by kunjaan

  I have a simple Class package chapter10; public class CompilationTest { public static void main(String[] args) { System.out.println("HELLO WORLD"); } } The path is Test\src\chapter10\CompilationTest.java I successfully compiled the code into the same folder and now I have Test\src\chapter10\CompilationTest.class However when I try to run from the same folder it I get this error >java CompilationTest Exception in thread "main" java.lang.NoClassDefFoundError: CompilationTest (wrong name: chapter10/CompilationTest) at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(Unknown Source) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.access$000(Unknown Source) 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) Could not find the main class: CompilationTest. Program will exit. When I run using >java chapter10/PropertiesTest Exception in thread "main" java.lang.NoClassDefFoundError: chapter10/PropertiesTest Caused by: java.lang.ClassNotFoundException: chapter10.PropertiesTest 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) Could not find the main class: chapter10/PropertiesTest. Program will exit.

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• Spring - How do you set Enum keys in a Map with annotations

  - by al nik

  Hi all, I've an Enum class public enum MyEnum{ ABC; } than my 'Mick' class has this property private Map<MyEnum, OtherObj> myMap; I've this spring xml configuration. <util:map id="myMap"> <entry key="ABC" value-ref="myObj" /> </util:map> <bean id="mick" class="com.x.Mick"> <property name="myMap" ref="myMap" /> </bean> and this is fine. I'd like to replace this xml configuration with Spring annotations. Do you have any idea on how to autowire the map? The problem here is that if I switch from xml config to the @Autowired annotation (on the myMap attribute of the Mick class) Spring is throwing this exception nested exception is org.springframework.beans.FatalBeanException: Key type [class com.MyEnum] of map [java.util.Map] must be assignable to [java.lang.String] Spring is no more able to recognize the string ABC as a MyEnum.ABC object. Any idea? Thanks

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• Grafting LINQ onto C# 2 library

  - by P Daddy

  I'm writing a data access layer. It will have C# 2 and C# 3 clients, so I'm compiling against the 2.0 framework. Although encouraging the use of stored procedures, I'm still trying to provide a fairly complete ability to perform ad-hoc queries. I have this working fairly well, already. For the convenience of C# 3 clients, I'm trying to provide as much compatibility with LINQ query syntax as I can. Jon Skeet noticed that LINQ query expressions are duck typed, so I don't have to have an IQueryable and IQueryProvider (or IEnumerable<T>) to use them. I just have to provide methods with the correct signatures. So I got Select, Where, OrderBy, OrderByDescending, ThenBy, and ThenByDescending working. Where I need help are with Join and GroupJoin. I've got them working, but only for one join. A brief compilable example of what I have is this: // .NET 2.0 doesn't define the Func<...> delegates, so let's define some workalikes delegate TResult FakeFunc<T, TResult>(T arg); delegate TResult FakeFunc<T1, T2, TResult>(T1 arg1, T2 arg2); abstract class Projection{ public static Condition operator==(Projection a, Projection b){ return new EqualsCondition(a, b); } public static Condition operator!=(Projection a, Projection b){ throw new NotImplementedException(); } } class ColumnProjection : Projection{ readonly Table table; readonly string columnName; public ColumnProjection(Table table, string columnName){ this.table = table; this.columnName = columnName; } } abstract class Condition{} class EqualsCondition : Condition{ readonly Projection a; readonly Projection b; public EqualsCondition(Projection a, Projection b){ this.a = a; this.b = b; } } class TableView{ readonly Table table; readonly Projection[] projections; public TableView(Table table, Projection[] projections){ this.table = table; this.projections = projections; } } class Table{ public Projection this[string columnName]{ get{return new ColumnProjection(this, columnName);} } public TableView Select(params Projection[] projections){ return new TableView(this, projections); } public TableView Select(FakeFunc<Table, Projection[]> projections){ return new TableView(this, projections(this)); } public Table Join(Table other, Condition condition){ return new JoinedTable(this, other, condition); } public TableView Join(Table inner, FakeFunc<Table, Projection> outerKeySelector, FakeFunc<Table, Projection> innerKeySelector, FakeFunc<Table, Table, Projection[]> resultSelector){ Table join = new JoinedTable(this, inner, new EqualsCondition(outerKeySelector(this), innerKeySelector(inner))); return join.Select(resultSelector(this, inner)); } } class JoinedTable : Table{ readonly Table left; readonly Table right; readonly Condition condition; public JoinedTable(Table left, Table right, Condition condition){ this.left = left; this.right = right; this.condition = condition; } } This allows me to use a fairly decent syntax in C# 2: Table table1 = new Table(); Table table2 = new Table(); TableView result = table1 .Join(table2, table1["ID"] == table2["ID"]) .Select(table1["ID"], table2["Description"]); But an even nicer syntax in C# 3: TableView result = from t1 in table1 join t2 in table2 on t1["ID"] equals t2["ID"] select new[]{t1["ID"], t2["Description"]}; This works well and gives me identical results to the first case. The problem is if I want to join in a third table. TableView result = from t1 in table1 join t2 in table2 on t1["ID"] equals t2["ID"] join t3 in table3 on t1["ID"] equals t3["ID"] select new[]{t1["ID"], t2["Description"], t3["Foo"]}; Now I get an error (Cannot implicitly convert type 'AnonymousType#1' to 'Projection[]'), presumably because the second join is trying to join the third table to an anonymous type containing the first two tables. This anonymous type, of course, doesn't have a Join method. Any hints on how I can do this?

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• NHibernate Mapping and Querying Where Tables are Related But No Foreign Key Constraint

  - by IanT8

  I'm fairly new to NHibernate, and I need to ask a couple of questions relating to a very frequent scenario. The following simplified example illustrates the problem. I have two tables named Equipment and Users. Users is a set of system administrators. Equipment is a set of machinery. Tables: Users table has UserId int and LoginName nvarchar(64). Equipment table has EquipId int, EquipType nvarchar(64), UpdatedBy int. Behavior: System administrators can make changes to Equipment, and when they do, the UpdatedBy field of Equipment is "normally" set to their User Id. Users can be deleted at any time. New Equipment items have an UpdatedBy value of null. There's no foreign key constraint on Equipment.UpdatedBy which means: Equipment.UpdatedBy can be null. Equipment.UpdatedBy value can be = existing User.UserId value Equipment.UpdatedBy value can be = non-existent User.UserId value To find Equipment and who last updated the Equipment, I might query like this: select E.EquipId, E.EquipName, U.UserId, U.LoginName from Equipment E left outer join Users U on. E.UpdatedBy = U.UserId Simple enough. So how to do that in NHibernate? My mappings might be as follows: <?xml version="1.0" encoding="utf-8"?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="Data" assembly="Data"> <class name="User" table="Users"> <id name="Id" column="UserId" unsaved-value="0"> <generator class="native" /> </id> <property name="LoginName" unique="true" not-null="true" /> </class> <class name="Equipment" table="Equipment"> <id name="Id" column="EquipId" type="int" unsaved-value="0"> <generator class="native" /> </id> <property name="EquipType" /> <many-to-one name="UpdatedBy" class="User" column="UpdatedBy" /> </class> </hibernate-mapping> So how do I get all items of equipment and who updated them? using (ISession session = sessionManager.OpenSession()) { List<Data.Equipment> equipList = session .CreateCriteria<Data.Equipment>() // Do I need to SetFetchmode or specify that I // want to join onto User here? If so how? .List<Data.Equipment>(); foreach (Data.Equipment item in equipList) { Debug.WriteLine("\nEquip Id: " + item.Id); Debug.WriteLine("Equip Type: " + item.EquipType); if (item.UpdatedBy.Country != null) Debug.WriteLine("Updated By: " + item.UpdatedBy.LoginName); else Debug.WriteLine("Updated by: Nobody"); } } When Equipment.UpdatedBy = 3 and there is no Users.UserId = 3, the above fail I also have a feeling that the generated SQL is a select all from Equipment followed by many select columns from Users where UserId = n whereas I'd expected NHibernate to left join as per my plain ordinary SQL and do one hit. If I can tell NHibernate to do the query in one hit, how do I do that? Time is of the essence on my project, so any help you could provide is gratefully received. If you're speculating about how NHibernate might work in this scenario, please say you're not absolutely sure. Many thanks.

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• What to pass to UserType, BlobType.setPreparedStatement session parameter

  - by dlots

  http://blog.xebia.com/2009/11/09/understanding-and-writing-hibernate-user-types/ I am attempting to defined a customer serialization UserType that mimics, the XStreamUserType referenced and provided here: http://code.google.com/p/aphillips/source/browse/commons-hibernate-usertype/trunk/src/main/java/com/qrmedia/commons/persistence/hibernate/usertype/XStreamableUserType.java My serializer outputs a bytearray that should presumably written to a Blob. I was going to do: public class CustomSerUserType extends DirtyCheckableUserType { protected SerA ser=F.g(SerA.class); public Class<Object> returnedClass() { return Object.class; } public int[] sqlTypes() { return new int[] {Types.BLOB}; } public Object nullSafeGet(ResultSet resultSet,String[] names,Object owner) throws HibernateException,SQLException { if() } public void nullSafeSet(PreparedStatement preparedStatement,Object value,int index) throws HibernateException,SQLException { BlobType.nullSafeSet(preparedStatement,ser.ser(value),index); } } Unfortunetly, the BlobType.nullSafeSet method requires the session. So how does one define a UserType that gets access to a servlet requests session? EDIT: There is a discussion of the issue here and it doesn't appear there is a solution: Best way to implement a Hibernate UserType after deprecations?

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• JAXB marshals XML differently to OutputStream vs. StringWriter

  - by Andy

  I apologize if this has been answered, but the search terms I have been using (i.e. JAXB @XmlAttribute condensed or JAXB XML marshal to String different results) aren't coming up with anything. I am using JAXB to un/marshal objects annotated with @XmlElement and @XmlAttribute annotations. I have a formatter class which provides two methods -- one wraps the marshal method and accepts the object to marshal and an OutputStream, the other just accepts the object and returns the XML output as a String. Unfortunately, these methods do not provide the same output for the same objects. When marshaling to a file, simple object fields internally marked with @XmlAttribute are printed as: <element value="VALUE"></element> while when marshaling to a String, they are: <element value="VALUE"/> I would prefer the second format for both cases, but I am curious as to how to control the difference, and would settle for them being the same regardless. I even created one static marshaller that both methods use to eliminate different instance values. The formatting code follows: /** Marker interface for classes which are listed in jaxb.index */ public interface Marshalable {} /** Local exception class */ public class XMLMarshalException extends BaseException {} /** Class which un/marshals objects to XML */ public class XmlFormatter { private static Marshaller marshaller = null; private static Unmarshaller unmarshaller = null; static { try { JAXBContext context = JAXBContext.newInstance("path.to.package"); marshaller = context.createMarshaller(); marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8"); unmarshaller = context.createUnmarshaller(); } catch (JAXBException e) { throw new RuntimeException("There was a problem creating a JAXBContext object for formatting the object to XML."); } } public void marshal(Marshalable obj, OutputStream os) throws XMLMarshalException { try { marshaller.marshal(obj, os); } catch (JAXBException jaxbe) { throw new XMLMarshalException(jaxbe); } } public String marshalToString(Marshalable obj) throws XMLMarshalException { try { StringWriter sw = new StringWriter(); marshaller.marshal(obj, sw); } catch (JAXBException jaxbe) { throw new XMLMarshalException(jaxbe); } } } /** Example data */ @XmlType @XmlAccessorType(XmlAccessType.FIELD) public class Data { @XmlAttribute(name = value) private String internalString; } /** Example POJO */ @XmlType @XmlRootElement(namespace = "project/schema") @XmlAccessorType(XmlAccessType.FIELD) public class Container implements Marshalable { @XmlElement(required = false, nillable = true) private int number; @XmlElement(required = false, nillable = true) private String word; @XmlElement(required = false, nillable = true) private Data data; } The result of calling marshal(container, new FileOutputStream("output.xml")) and marshalToString(container) are as follows: Output to file <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <ns2:container xmlns:ns2="project/schema"> <number>1</number> <word>stackoverflow</word> <data value="This is internal"></data> </ns2:container> and Output to String <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <ns2:container xmlns:ns2="project/schema"> <number>1</number> <word>stackoverflow</word> <data value="This is internal"/> </ns2:container>

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• PostSharp when using DataContractSerializer?

  - by Dan Bryant

  I have an Aspect that implements INotifyPropertyChanged on a class. The aspect includes the following: [OnLocationSetValueAdvice, MethodPointcut("SelectProperties")] public void OnPropertySet(LocationInterceptionArgs args) { var currentValue = args.GetCurrentValue(); bool alreadyEqual = (currentValue == args.Value); // Call the setter args.ProceedSetValue(); // Invoke method OnPropertyChanged (ours, the base one, or the overridden one). if (!alreadyEqual) OnPropertyChangedMethod.Invoke(args.Location.Name); } This works fine when I instantiate the class normally, but I run into problems when I deserialize the class using a DataContractSerializer. This bypasses the constructor, which I'm guessing interferes with the way that PostSharp sets itself up. This ends up causing a NullReferenceException in an intercepted property setter, but before it has called the custom OnPropertySet, so I'm guessing it interferes with setting up the LocationInterceptionArgs. Has anyone else encountered this problem? Is there a way I can work around it? I did some more research and discovered I can fix the issue by doing this: [OnDeserializing] private void OnDeserializing(StreamingContext context) { AspectUtilities.InitializeCurrentAspects(); } I thought, okay, that's not too bad, so I tried to do this in my Aspect: private IEnumerable<MethodInfo> SelectDeserializing(Type type) { return type.GetMethods(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public).Where( t => t.IsDefined(typeof (OnDeserializingAttribute), false)); } [OnMethodEntryAdvice, MethodPointcut("SelectDeserializing")] public void OnMethodEntry(MethodExecutionArgs args) { AspectUtilities.InitializeCurrentAspects(); } Unfortunately, even though it intercepts the method properly, it doesn't work. I'm thinking the call to InitializeCurrentAspects isn't getting transformed properly, since it's now inside the Aspect rather than directly inside the aspect-enhanced class. Is there a way I can cleanly automate this so that I don't have to worry about calling this on every class that I want to have the Aspect?

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• Is this way of storing typed objects in memory good?

  - by Pindatjuh

  This is an "is this okay, or can it be done better" question. Topic: Storing typed objects in memory. Background information: I'm building a compiler for the x86-32 platform for my language. My goal includes typed objects. Idea: Every primitive is a semi-class (it can be used as if it was a normal class, but it's stored more compact). Every class is represented by primitives and some meta-data (containing class-properties, inheritance stuff, etc.). The meta-data is complex: it doesn't use fields but instead context-switches. For primitives, the meta-data is very small, compared to a "real" class, which is alot bigger. This enables another idea that "primitives are objects", in my language, which I found nessecairy. Example: If I have an array of 32 booleans, then the pure content of this array is exactly 4 byte (32 bits of booleans). The meta-data will contain flags that the type is an array of booleans, which contains 32 entries. The meta-data is very compacted, on bit-level: using a sort of "packing" mechanism, which is read by a FSM at runtime, when doing inspection of the type (like when passing the object to methods for checking, etc.) For instance (read from left to right, top to bottom, remember vertical possition when going to the right, and check nearest column header for meaning of switch): Primitive? Array? Type-Meta 1 Byte? || Size (1 byte) 1 1 [...] 1 [...] done 0 2 Bytes? || Size (2 bytes) 1 [...] done || Size (4 bytes) 0 [...] done Integer? 1 Byte? 2 Bytes? 0 1 0 1 done 1 done 0 done Boolean? Byte? 0 1 0 done 1 done More-Primitives 0 .... Class-Stuff (Huge) 0 ... (After reaching done the data is inserted. || = byte alignement. [...] is variable sized. ... is not described here, for simplicity. And let's call them cost-based-data-structures.) For an array of 32 booleans containing all true values, the memory for this type would be (read top-down): 1 Primitive 1 Array 1 ArrayType: Primitive 0 Not-Array 0 Not-Integer 1 Boolean 0 Not-Byte (thus bit) 1 Integer Size: 1 Byte 00100000 Array size 11111111 11111111 11111111 11111111 Data Thus, 8 bytes represent 32 booleans in an array: 11100101 00100000 11111111 11111111 11111111 11111111 Is this okay, or can it be done better?

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• Unit testing in python?

  - by yossi.ittach

  Hey - I'm new to python , and I'm having a hard time grasping the concept of Unit testing in python. I'm coming from Java - so unit testing makes sense because - well , there you actually have a unit - A Class. But a Python class is not necessarily the same as a Java class , and the way I use Python - as a scripting language - is more functional then OOP - So what do you "unit test" in Python ? A flow? Thanks!

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• How do I correctly use Unity to pass a ConnectionString to my repository classes?

  - by GenericTypeTea

  I've literally just started using the Unity Application Blocks Dependency Injection library from Microsoft, and I've come unstuck. This is my IoC class that'll handle the instantiation of my concrete classes to their interface types (so I don't have to keep called Resolve on the IoC container each time I want a repository in my controller): public class IoC { public static void Intialise(UnityConfigurationSection section, string connectionString) { _connectionString = connectionString; _container = new UnityContainer(); section.Configure(_container); } private static IUnityContainer _container; private static string _connectionString; public static IMovementRepository MovementRepository { get { return _container.Resolve<IMovementRepository>(); } } } So, the idea is that from my Controller, I can just do the following: _repository = IoC.MovementRepository; I am currently getting the error: Exception is: InvalidOperationException - The type String cannot be constructed. You must configure the container to supply this value. Now, I'm assuming this is because my mapped concrete implementation requires a single string parameter for its constructor. The concrete class is as follows: public sealed class MovementRepository : Repository, IMovementRepository { public MovementRepository(string connectionString) : base(connectionString) { } } Which inherits from: public abstract class Repository { public Repository(string connectionString) { _connectionString = connectionString; } public virtual string ConnectionString { get { return _connectionString; } } private readonly string _connectionString; } Now, am I doing this the correct way? Should I not have a constructor in my concrete implementation of a loosely coupled type? I.e. should I remove the constructor and just make the ConnectionString property a Get/Set so I can do the following: public static IMovementRepository MovementRepository { get { return _container.Resolve<IMovementRepository>( new ParameterOverrides { { "ConnectionString", _connectionString } }.OnType<IMovementRepository>() ); } } So, I basically wish to know how to get my connection string to my concrete type in the correct way that matches the IoC rules and keeps my Controller and concrete repositories loosely coupled so I can easily change the DataSource at a later date.

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• Groovy: How to access objects with Id tag?

  - by skifan0

  Hello, I have the following Groovy+SwingBuilder code. In one panel I generate checkboxes and in another panel I want to access the values of the checkboxes. The code looks basically likes this: def optionsmap = [ foo : "value_foo", bar : "value_bar"] SwingBuilder.build() { frame(title:'demo1', size:[400,700], visible:true, defaultCloseOperation:WC.EXIT_ON_CLOSE) { gridLayout(rows: 1, cols: 2) panel(id:'optionPanel', constraints:java.awt.BorderLayout.CENTER) { gridLayout(rows: 5, cols: 1) myGroup = buttonGroup(); for (entry in optionsmap) { checkBox(id: entry.key, text: entry.value ) } } panel(constraints:java.awt.BorderLayout.WEST) { button ('Show values', actionPerformed: { for (entry in optionsmap) { println (entry.key as Class).text } }) } } } optionsmap is a map with (id, text) pairs that can be extended. When I press "show values" I get an error message: org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object 'foo' with class 'java.lang.String' to class 'java.lang.Class' How could I access the checkboxes for my action in the second panel by using the checkbox ids from optionsmap? Thank you if you can help

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• Django model manager didn't work with related object when I do aggregated query

  - by Satoru.Logic

  Hi, all. I'm having trouble doing an aggregation query on a many-to-many related field. Let's begin with my models: class SortedTagManager(models.Manager): use_for_related_fields = True def get_query_set(self): orig_query_set = super(SortedTagManager, self).get_query_set() # FIXME `used` is wrongly counted return orig_query_set.distinct().annotate( used=models.Count('users')).order_by('-used') class Tag(models.Model): content = models.CharField(max_length=32, unique=True) creator = models.ForeignKey(User, related_name='tags_i_created') users = models.ManyToManyField(User, through='TaggedNote', related_name='tags_i_used') objects_sorted_by_used = SortedTagManager() class TaggedNote(models.Model): """Association table of both (Tag , Note) and (Tag, User)""" note = models.ForeignKey(Note) # Note is what's tagged in my app tag = models.ForeignKey(Tag) tagged_by = models.ForeignKey(User) class Meta: unique_together = (('note', 'tag'),) However, the value of the aggregated field used is only correct when the model is queried directly: for t in Tag.objects.all(): print t.used # this works correctly for t in user.tags_i_used.all(): print t.used #prints n^2 when it should give n Would you please tell me what's wrong with it? Thanks in advance.

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• Scheduling a recurring alarm/event

  - by martinjd

  I have a class that extends Application. In the class I make a call to AlarmManager and pass in an intent. As scheduled my EventReceiver class, that extends BroadcastReceiver, processes the call in the onReceive method. How would I call the intent again from the onReceive method to schedule another event?

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• Casting a non-generic type to a generic one

  - by John Sheehan

  I've got this class: class Foo { public string Name { get; set; } } And this class class Foo<T> : Foo { public T Data { get; set; } } Here's what I want to do: public Foo<T> GetSome() { Foo foo = GetFoo(); Foo<T> foot = (Foo<T>)foo; foot.Data = GetData<T>(); return foot; } What's the easiest way to convert Foo to Foo<T>? I can't cast directly InvalidCastException) and I don't want to copy each property manually (in my actual use case, there's more than one property) if I don't have to. Is a user-defined type conversion the way to go?

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• How to query collections in NHibernate

  - by user305813

  Hi, I have a class: public class User { public virtual int Id { get; set; } public virtual string Name { get; set; } public virtual IDictionary<string, string> Attributes { get; set; } } and a mapping file: <class name="User" table="Users"> <id name="Id"> <generator class="hilo"/> </id> <property name="Name"/> <map name="Attributes" table="UserAttributes"> <key column="UserId"/> <index column="AttributeName" type="System.String"/> <element column="Attributevalue" type="System.String"/> </map> </class> So now I can add many attributes and values to a User. How can I query those attributes so I can get ie. Get all the users where attributename is "Age" and attribute value is "20" ? I don't want to do this in foreach because I may have millions of users each having its unique attributes. Please help

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• How to catch the exception in initialization list?

  - by skydoor

  Hi I have a question about how to catch the exception in the initialization list. For example, we have a class Foo derived from Bar class Foo { public: Foo(int i) {throw 0; } } class Bar : public Foo{ public: Bar() : Foo(1) {} }

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• RoR associations through or not through?

  - by showFocus

  I have four models that are related to one another, the way I have it setup at the moment is I have to select a county, region and country when entering a new city. class Country < ActiveRecord::Base has_many :regions has_many :counties has_many :cities end class Region < ActiveRecord::Base has_one :country has_many :counties has_many :cities end class County < ActiveRecord::Base has_one :country has_one :region has_many :cities end class City < ActiveRecord::Base has_one :country has_one :region has_one :county end Would it be better to use the :through symbol in the association? So I could say the city: has_one :country, :through => :region Not sure if this is correct, I have read how :through works but I'm not sure if this is the best solution. I am a newbie and while I'm not struggling with the syntax and how things work, it would be good to get opinions on best practices and the way things should be done from some rails wizards! Thanks in advance.

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• Qt - Calling widget parent's slots

  - by bullettime

  I wrote a small program to test accessing a widget parent's slot. Basically, it has two classes: Widget: namespace Ui { class Widget; } class Widget : public QWidget { Q_OBJECT public: Widget(QWidget *parent = 0); ~Widget(); QLabel *newlabel; QString foo; public slots: void changeLabel(); private: Ui::Widget *ui; }; Widget::Widget(QWidget *parent) : QWidget(parent), ui(new Ui::Widget) { ui->setupUi(this); customWidget *cwidget = new customWidget(); newlabel = new QLabel("text"); foo = "hello world"; this->ui->formLayout->addWidget(newlabel); this->ui->formLayout->addWidget(cwidget); connect(this->ui->pushButton,SIGNAL(clicked()),cwidget,SLOT(callParentSlot())); connect(this->ui->pb,SIGNAL(clicked()),this,SLOT(changeLabel())); } void Widget::changeLabel(){ newlabel->setText(this->foo); } and customWidget: class customWidget : public QWidget { Q_OBJECT public: customWidget(); QPushButton *customPB; public slots: void callParentSlot(); }; customWidget::customWidget() { customPB = new QPushButton("customPB"); QHBoxLayout *hboxl = new QHBoxLayout(); hboxl->addWidget(customPB); this->setLayout(hboxl); connect(this->customPB,SIGNAL(clicked()),this,SLOT(callParentSlot())); } void customWidget::callParentSlot(){ ((Widget*)this->parentWidget())->changeLabel(); } in the main function, I simply created an instance of Widget, and called show() on it. This Widget instance has a label, a QString, an instance of customWidget class, and two buttons (inside the ui class, pushButton and pb). One of the buttons calls a slot in its own class called changeLabel(), that, as the name suggests, changes the label to whatever is set in the QString contained in it. I made that just to check that changeLabel() worked. This button is working fine. The other button calls a slot in the customWidget instance, named callParentSlot(), that in turn tries to call the changeLabel() slot in its parent. Since in this case I know that its parent is in fact an instance of Widget, I cast the return value of parentWidget() to Widget*. This button crashes the program. I made a button within customWidget to try to call customWidget's parent slot as well, but it also crashes the program. I followed what was on this question. What am I missing?

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• django internationlisation

  - by ha22109

  Hello I need to have multiple language support of my django admin application.I can create the messege files.But how can i change the text of my models.The heading ,fields etc .I m only able to change the static elements which are there in my template. here is example of my class class Mymodel(model.Models): id=models.IntegerField(primary_key=true) name=models.CharField(max_length=200) group=models.CharField(max_length=200) class Meta: managed=False verbose_name_plural='My admin' db_table='my_admin' one more question.In my home page it is showing my verbose name 'My admin' which i mentioned.But when i go to list page it shows me the class name 'mymodel'.Why so.Can i changed that to

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• Django: Inherit Permssions from abstract models?

  - by lazerscience

  Is it possible to inherit permissions from an abstract model in Django? I can not really find anything about that. For me this doesn't work! class PublishBase(models.Model): class Meta: abstract = True get_latest_by = 'created' permissions = (('change_foreign_items', "Can change other user's items"),) EDIT: Not working means it fails silently. Permission is not created, as it wouldn't exist on the models inheriting from this class.

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• Rails transaction: save data in multiple models.

  - by smotchkkiss

  my models class Auction belongs_to :item belongs_to :user, :foreign_key => :current_winner_id has_many :auction_bids end class User has_many :auction_bids end class AuctionBid belongs_to :user end current usage An item is displayed on the page, the user enters an amount and clicks bid. Controller code might look something like this: class MyController def bid @ab = AuctionBid.new(params[:auction_bid]) @ab.user = current_user if @ab.save render :json => {:response => 'YAY!'} else render :json => {:response => 'FAIL!'} end end end desired functionality This works great so far! However, I need to ensure a couple other things happen. @ab.auction.bid_count needs to be incremented by one. @ab.user.bid_count needs to be incremented by one @ab.auction.current_winner_id needs to be set to @ab.user_id That is, the User and the Auction associated with the AuctionBid need values updated as well in order for the AuctionBid#save to return true.

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• Background settings for a JDesktopPane

  - by EricR

  I'm using a self-made DesktopPaneUI for a JDesktopPane, I've written the proper methods for the class, and I'm running into trouble. When I resize the JDesktopPane, the background image doesn't resize with the frame. The image appears to be clipped at the size it was when the window initially opened. I'm giving it an image larger than the window, and I'm still having this problem. Here's my method call inside the constructor of my desktopUI class. super(); this.background = javax.imageio.ImageIO.read(new File(fileName)); Is there a way I can change my main class where I set the UI, or the myDesktopPaneUI class such that the background still fills the window when the JDesktopPane changes size? setUI(new myDesktopPaneUI("media/bg.jpg"));

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• Learning Hibernate: too many connections

  - by stivlo

  I'm trying to learn Hibernate and I wrote the simplest Person Entity and I was trying to insert 2000 of them. I know I'm using deprecated methods, I will try to figure out what are the new ones later. First, here is the class Person: @Entity public class Person { private int id; private String name; @Id @GeneratedValue(strategy = GenerationType.TABLE, generator = "person") @TableGenerator(name = "person", table = "sequences", allocationSize = 1) public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } } Then I wrote a small App class that insert 2000 entities with a loop: public class App { private static AnnotationConfiguration config; public static void insertPerson() { SessionFactory factory = config.buildSessionFactory(); Session session = factory.getCurrentSession(); session.beginTransaction(); Person aPerson = new Person(); aPerson.setName("John"); session.save(aPerson); session.getTransaction().commit(); } public static void main(String[] args) { config = new AnnotationConfiguration(); config.addAnnotatedClass(Person.class); config.configure("hibernate.cfg.xml"); //is the default already new SchemaExport(config).create(true, true); //print and execute for (int i = 0; i < 2000; i++) { insertPerson(); } } } What I get after a while is: Exception in thread "main" org.hibernate.exception.JDBCConnectionException: Cannot open connection Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Too many connections Now I know that probably if I put the transaction outside the loop it would work, but mine was a test to see what happens when executing multiple transactions. And since there is only one open at each time, it should work. I tried to add session.close() after the commit, but I got Exception in thread "main" org.hibernate.SessionException: Session was already closed So how to solve the problem?

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• How does Fluent NHibernate support the Import Entity

  - by Bender

  I want to create a strongly type object from a fluent NHibernate query. If I were using HQL and NHibernate I belive I would need: the class for the output Namespace Model Public Class namecount Public Overridable Property lastname() as string ... Public Overridable Property lastnamecount() as integer ... Public Sub New(lastname as string, count as integer) ... End Class End Namespace an .hbm.xml file <?xml ...> <hibernate-mapping ...> <import class="model.namecount,model"> </hibernate-mapping> and of course the query _session.createquery("select new namecount(lastname, count(lastname)) ...") (The above is a paraphrased example taken from one of the 2008 SummerofNHibernate videos) I cannot find any examples of how to do this with fluent (even in C#), is it possible? If it isn't is there a VB example of how to mix Fluent and .hbm.xml

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• BigInteger or not BigInteger?

  - by Alon

  In Java, most of the primitive types are signed (one bit is used to represent the +/-), and therefore when I am exceed the limits of this type, I can get many strange things, like negative numbers. In the BigInteger class, I have no limits and there are some helpful functions there but it is pretty depressing to convert your beautiful code to work with the BigInteger class, specially when primitive operators don't work there and you must use functions from this class. I was wondering if you had this problem, and if you have any better solution than the BigInteger class? Thank you.

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