interface

问题 Here is the code: interface hi { public void meth1(); } abstract class Hullo { public abstract void meth1(); } public class Hello extends Hullo implements hi { public void meth1(){} } Question:The code compiles and everything. I wanted to know the meth1() in class Hello is overriding which meth1()? The ont in the interface or the one in the abstract class and why? 回答1: The answer is short: Both..... In fact, to be correct: You are overriding none of them, you are implementing them both, with

问题 The responsibility of the visibility of a method is relegated to the class that implements the interface. public interface IMyInterface { bool GetMyInfo(string request); } In C# set access modifier public, private or protected before the method GetMyInfo() generates the following error: The modifier 'private' is not valid for this item. Is there a reason you can not define the access modifier on a method or in an interface? (Question already asked in french here) 回答1: The interface defines a

问题 In my app, I have an activity that has two fragments in actionbar tabs navigation mode, just like the android developer site example. in my first fragment I have a listview (which has it's own adapter ) and each item of the listview has a button called +1. I want to refresh the second fragment that shows the items in listview in first fragment that their +1 button's clicked. I know i have to use interfaces. but I cant figure how to use them. where do I have to define the interface? how to use

问题 In my app, I have an activity that has two fragments in actionbar tabs navigation mode, just like the android developer site example. in my first fragment I have a listview (which has it's own adapter ) and each item of the listview has a button called +1. I want to refresh the second fragment that shows the items in listview in first fragment that their +1 button's clicked. I know i have to use interfaces. but I cant figure how to use them. where do I have to define the interface? how to use

问题 I have the following two interfaces: public interface IMembershipProvider { object Login(ILoginProviderParameters loginParameters); void SetAuthCookie(string userName, bool createPersistentCookie); } public interface IFacebookMembershipProvider : IMembershipProvider{} and an implimentation: public class FacebookMembershipProvider: IFacebookMembershipProvider { public object Login(ILoginProviderParameters loginParameters) { // Facebook login code is here } public void SetAuthCookie(string

问题 I have the following two interfaces: public interface IMembershipProvider { object Login(ILoginProviderParameters loginParameters); void SetAuthCookie(string userName, bool createPersistentCookie); } public interface IFacebookMembershipProvider : IMembershipProvider{} and an implimentation: public class FacebookMembershipProvider: IFacebookMembershipProvider { public object Login(ILoginProviderParameters loginParameters) { // Facebook login code is here } public void SetAuthCookie(string

问题 Consider this class hierarchy: Book extends Goods Book implements Taxable As we know, there is a relationship between a subclass and its superclass (is-a). Q: Is there any relationship like "is-a" between Book and Taxable ? GOOD Answers, but you said that "is-a" is also a relationship between Book and Taxable , but "is-a" is a relation between classes , and an interface is not a class! 回答1: Yes. The relationship is exactly the same Book is a Taxable too. EDIT An interface is an artifact that

问题 Can an EJB bean implement multiple user defined interfaces, except business interfaces (@Local, @Remote) or No-Interface view (@LocalBean)? For example define two interfaces UserInterface1 , UserInterface2 , with no annotation. Is this legal to implement: @Stateless public class MyBean implements UserInterface1, UserInterface2 { ... Then I have another confusion: @Stateless public class MyBean implements Runnable { ... //inside I won't try to manage thread } Is this legal or illegal, I found

问题 This question already has answers here : Closed 7 years ago . Possible Duplicate: What does it mean to “program to an interface”? I noticed that some people like to declare an object as one of the interfaces it implements even though, within the scope of the variable, it is not necessary to look at it as the interface , e.g. there is no external API that expect an interface. For example: Map<String, Object> someMap = new HashMap<String, Object>(); Or you can just do HashMap<String, Object>

问题 Say I need to rely on several implementations of a Spring bean. I have one AccountService interface and two implementations: DefaultAccountServiceImpl and SpecializedAccountServiceImpl . How is this possible (injecting one or the other implementation) in Spring? Which implementation will the following injection use? @Autowired private AccountService accountService; 回答1: Ad. 1: you can use @Qualifier annotation or autowire using @Resource as opposed to @Autowired which defaults to field name