inner-classes

问题 I have the following: public class A extends B { static class C { Object field1; int field2; boolean field3; } } I cannot get the C class via reflection! I've tried the following: -keep class com.path.to._class.A$** {*;} -keep class com.path.to._class.A$* {*;} -keep class com.path.to._class.A$C {*;} -keep class com.path.to._class.A$C { <fields>; } -keep class com.path.to._class.A$C { Object field1; int field2; boolean field3; } None of the above worked. Am I doing something completely wrong

问题 This question already has answers here : Cannot refer to a non-final variable inside an inner class defined in a different method (20 answers) Closed 5 years ago . I am trying to implement an inner class within a loop, and have come into an interesting situation. The internal class has methods, however, when I try and access the variable, Netbeans gives me a compiler error and tells me to make the int final. As the int is a looping variable, it can not be final. I have tried creating new

问题 Named local classes are very rarely used, usually local classes are anonymous. Does anybody know why the code below generates a compiler warning? public class Stuff<E> { Iterator<E> foo() { class InIterator implements Iterator<E> { @Override public boolean hasNext() { return false; } @Override public E next() { return null; } @Override public void remove() { } } return new InIterator(); } } The warning is in new InIterator() and it says [unchecked] unchecked conversion found : InIterator

问题 Named local classes are very rarely used, usually local classes are anonymous. Does anybody know why the code below generates a compiler warning? public class Stuff<E> { Iterator<E> foo() { class InIterator implements Iterator<E> { @Override public boolean hasNext() { return false; } @Override public E next() { return null; } @Override public void remove() { } } return new InIterator(); } } The warning is in new InIterator() and it says [unchecked] unchecked conversion found : InIterator

问题 I've just read through the chapter on method-local inner classes in the SCJP book, and I'm really struggling to think of any practical use for them. I've always been under the impression, that methods should be as small and specific to their task as possible (Orthogonality IIRC), so introducing even the simplest inner class would create heft and unwieldy methods. Can anyone suggest a good practical usage for method local inner classes? So far it feels as if I might have to understand them

问题 I wonder is there a way to reach the code using aspect in "//do something" part? Thanks in advance. Turan. public class Test { private class InnerTest { public InnerTest() { JButton j = new JButton("button"); j.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { //do something } }); } } } 回答1: You can use the within or withincode pointcuts to match the containing class, and the cflow pointcut to match the execution of the addActionListener() method, then

问题 The following source code is brought from: Understanding partial specialization of inherited nested class templates #include <type_traits> struct Base { template<class U, class _ = void> struct Inner: std::true_type {}; template<class _> struct Inner<char, _>: std::false_type {}; }; struct Derived : Base { }; template<class _> struct Derived::Inner<int, _>: std::false_type {}; I had an issue about specializing inherited class, so I googled, and find out the question above. The source code in

问题 I know that an inner class has access to everything in the outer class (because it's a member of that class) but what about the other way around? Does the outer class have access to private variables and methods within an inner class? I've seen articles mentioning that inner classes should be private so that they are accessible only to the outer class. What does that do to the accessibility of that inner class? What is best practices in dealing with access levels when it comes to your inner

问题 I'll write an header file,and it's very long.Since it will be too complicated,i don't want to put inner class definition in root class.I mean how can i make a class inner without writing it in root class. class outer { } class inner { } If i can use like that, The header file will be clearer i think. 回答1: Like this: // foo.hpp class Foo { public: class Inner; Foo(); void bar(); Inner zoo(); }; // foo_inner.hpp #include "foo.hpp" class Foo::Inner { void func(); }; Then, in the implementation:

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 last year . What's the best practise(design and performance wise) for anonymous classes and static inner classes? Personally I would like to think that static inner classes provide better encapsulation and should give better performance as they dont have access to finalized variables