polymorphism

问题 I am facing problem with hibernate's explicit polymorphism. I used the polymorphism annotation and set it to explicit, but with get() and collections in mapped classes i always get all subclasses. I see all subclasses with left join in the hibernate "show_sql" output. What's the problem? Do I understand the documentation wrong? Or is it a bug in hibernate 4? I haven't seen any example with hibernate 4 and polymorphism annotation. sessionFactory.getCurrentSession().get(Node.class, 111); //

问题 I am facing problem with hibernate's explicit polymorphism. I used the polymorphism annotation and set it to explicit, but with get() and collections in mapped classes i always get all subclasses. I see all subclasses with left join in the hibernate "show_sql" output. What's the problem? Do I understand the documentation wrong? Or is it a bug in hibernate 4? I haven't seen any example with hibernate 4 and polymorphism annotation. sessionFactory.getCurrentSession().get(Node.class, 111); //

问题 I have a superclass with the method: protected <E extends Enum<E>,T extends VO> void processarRelatorioComEstado(Date dataInicial, Date dataFinal, E estado) throws RelatorioException { throw new UnsupportedOperationException("method not overridden"); } and in one of its subclasses I want to do the following: @Override protected <E extends Enum<E>> DemonstrativoReceitaDespesasAnexo12Vo processarRelatorioComEstado(Date dataInicial, Date dataFinal, E estado) throws RelatorioException { //do

问题 class GrandParent { public virtual void Foo() { ... } } class Parent : GrandParent { public override void Foo() { base.Foo(); //Do additional work } } class Child : Parent { public override void Foo() { //How to skip Parent.Foo and just get to the GrandParent.Foo base? //Do additional work } } As the code above shows, how can I have the Child.Foo() make a call into GrandParent.Foo() instead of going into Parent.Foo()? base.Foo() takes me to the Parent class first. 回答1: Your design is wrong if

问题 Why don't we see C-like languages that allow for callables with polymorphism in the return type? I could see how the additional type inference would be a hurdle, but we have plenty of languages with full-fledged type inference systems (that work for varying levels of "work"). Edit: By return type polymorphism I mean overloading the function signature only in the return type. For example, C++ and Java only allow overloading in the type of the formal parameters, not in the return type. 回答1: If

问题 Consider the following basic case: Mapper.CreateMap<FromBase, ToBase>() .Include<FromD1, ToD1>() .Include<FromD2, ToD2>(); Mapper.CreateMap<FromD1, ToD1>() .ForMember( m => m.P0, a => a.MapFrom( x => x.Prop0 ) ) .ForMember( m => m.P1, a => a.MapFrom( x => x.Prop1 ) ); Mapper.CreateMap<FromD2, ToD2>() .ForMember( m => m.P0, a => a.MapFrom( x => x.Prop0 ) ) .ForMember( m => m.P2, a => a.MapFrom( x => x.Prop2 ) ); Mapper.AssertConfigurationIsValid(); FromBase[] froms = { new FromD1() { Prop0 =

问题 I'm interested to know if there is any viable way to contiguously store an array of polymorphic objects, such that virtual methods on a common base can be legally called (and would dispatch to the correct overridden method in a subclass). For example, considering the following classes: struct B { int common; int getCommon() { return common; } virtual int getVirtual() const = 0; } struct D1 : B { virtual int getVirtual final const { return 5 }; } struct D2 : B { int d2int; virtual int

问题 Closed . This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 5 years ago . I'm somewhat new to programming and I have a question about classes, inheritance, and polymorphism in C#. While learning about these topics, occasionally I'll come across code that looks something like this: Animal fluffy = new Cat(); // where Animal is a superclass of Cat*

问题 I just started developing some app in Java with spring-data-mongodb and came across some issue that I haven't been able to solve: Have a couple of document beans like this: @Document(collection="myBeanBar") public class BarImpl implements Bar { String id; Foo foo; // More fields and methods ... } @Docuemnt public class FooImpl implements Foo { String id; String someField; // some more fields and methods ... } And I have a repository class with a method that simply invokes a find similar to

问题 I've searched for a number of articles on refactoring a large switch statement. But they don't do what I want to do. The problem I'm going to to run in to is having a gigantic switch statement which calls a different method depending on two different values, lets say a type and a code . Currently, I would handle the situation like this: switch (type) { case Types.Type1: handleType1(code); break; case Types.Type2: handleType2(code); break; } void handleTypeN(code) { switch (code) { ... } }