anonymous-class

问题 I'm trying to call a method, setPostal(String post) I made from an anonymous class, but for some reason the compiler doesnt even recognize it in main. Any reason why this is? Part of my code (address is an inner class of Student): Student public class Student implements Gradeable, Cloneable { String name; int id; Address address; public Student() { name = "unknown"; address = new Address(); } public Student(String name, int id, Integer... option) { this.name = name; this.id = id; if (option

问题 In java, an interface contains only the method type, name and parameters. The actual implementation is done in a class that implements it. Given this, how is it possible to create an instance of a interface and use it as if it were a class object? There are many such interfaces, such as org.w3c.dom.Node. This is the code that I am using: DocumentBuilderFactory fty = DocumentBuilderFactory.newInstance(); fty.setNamespaceAware(true); DocumentBuilder builder = fty.newDocumentBuilder();

问题 In java, an interface contains only the method type, name and parameters. The actual implementation is done in a class that implements it. Given this, how is it possible to create an instance of a interface and use it as if it were a class object? There are many such interfaces, such as org.w3c.dom.Node. This is the code that I am using: DocumentBuilderFactory fty = DocumentBuilderFactory.newInstance(); fty.setNamespaceAware(true); DocumentBuilder builder = fty.newDocumentBuilder();

问题 I have a requirement in which 28 threads have to complete some functionality. I have created these threads as in anonymous inner classes like : Thread t=new Thread(new Runnable(){public void run() {//code }} ); t.start(); Now I want that the further execution should start after all these threads have finished there work. Note : I am confused about join() method as it makes my threads run sequentially. So can anyone suggest me how can I make main thread run once these threads are done with

问题 I have a requirement in which 28 threads have to complete some functionality. I have created these threads as in anonymous inner classes like : Thread t=new Thread(new Runnable(){public void run() {//code }} ); t.start(); Now I want that the further execution should start after all these threads have finished there work. Note : I am confused about join() method as it makes my threads run sequentially. So can anyone suggest me how can I make main thread run once these threads are done with

问题 I'm still not satisfied with explanation regarding anonymous class and final field. There were tons of questions trying to explain obvious problem but I have not found answers for all my questions :-) Suppose following code: public void method(final int i, int j) { final int z = 6; final int x = j; int k = 5; new Runnable() { public void run() { System.out.print(i); System.out.print(x); System.out.print(z); System.out.print(k); } }; } It's not possible to compile this code because of "unfinal

问题 Although I'm not currently planning to serialize anything, I give all serializable outer classes, as well as static nested classes a SerialVersionUID , because that is the proper way to do it. However, I've read here that Serialization of inner classes (i.e., nested classes that are not static member classes), including local and anonymous classes, is strongly discouraged for several reasons. ... So my question is: Should I give inner and anonymous classes a SerialVersionUID each, or should I

问题 Although I'm not currently planning to serialize anything, I give all serializable outer classes, as well as static nested classes a SerialVersionUID , because that is the proper way to do it. However, I've read here that Serialization of inner classes (i.e., nested classes that are not static member classes), including local and anonymous classes, is strongly discouraged for several reasons. ... So my question is: Should I give inner and anonymous classes a SerialVersionUID each, or should I

问题 a can only be final here. Why? How can I reassign a in onClick() method without keeping it as private member? private void f(Button b, final int a){ b.addClickHandler(new ClickHandler() { @Override public void onClick(ClickEvent event) { int b = a*5; } }); } How can I return the 5 * a when it clicked? I mean, private void f(Button b, final int a){ b.addClickHandler(new ClickHandler() { @Override public void onClick(ClickEvent event) { int b = a*5; return b; // but return type is void } }); }

问题 I have a class and a factory function that creates new anonymous class objects extending that class. However, the anonymous class objects all have a method in which there are references to other objects. In my full program, I need this to create and combine parsers, but I've stripped down the code here. class Base{ public Base run(){ return null; } static Base factory(final Base n){ return new Base(){ public Base run(){ return n; } }; } } public class CircularReferences{ public static void