overriding

I am having trouble getting the onPostExecute() method to call when running an AsyncTask . When I try to set up my class extending AsyncTask in which the onPostExecute() is overridden I get the following build error. 'The method onPostExecute() of type AsyncTaskExampleActivity must override or implement a supertype method' I have tried getting rid of the @Override annotation. This gets rid of the build error but the method still does not execute. If any one would be so kind as to point out what I'm overlooking I would greatly appreciated it. Code: package com.asynctaskexample; import android

Is it possible to override methids for db.Model in Google App Engine? I want to declare beforeSave, afterSave methods, etc.. to create automatic tagging system. I know there are hooks, but it seems to me a wrong way to solve this issue :) Thanks! jbochi Yes, it's possible to override these methods. Have a look at this blog post by Nick Johnson .The hooked model class looks this: class HookedModel(db.Model): def before_put(self): pass def after_put(self): pass def put(self, **kwargs): self.before_put() super(HookedModel, self).put(**kwargs) self.after_put() Read the blog to see how to handle

EDIT: This question was marked as a duplicate of this one , but see the addendum near the end of this answer to see what that question doesn't ask, and what the answer doesn't answer. I'm working on a web app that uses Bootstrap 3. I have a basic 3-layer override architecture, where 1) Bootstrap's _variables.scss contains the core variables, 2) _app-variables.scss contains the base app variables that override Bootstrap's _variables.scss, and 3) _client-variables.scss contains client-specific customizations that override _app-variables.scss. Either #2 or #3 (or both) can be blank files. So here

Can anybody tell the working of overriding and hiding in terms of memory and references. class A { public virtual void Test1() { //Impl 1} public virtual void Test2() { //Impl 2} } class B : A { public override void Test1() { //Impl 3} public new void Test2() { Impl 4} } static Main() { A aa=new B() //This will give memory to B aa.Test1(); //What happens in terms of memory when this executes aa.Test2(); //-----------------------SAME------------------------ } Here memory is with class B but in the second statement aa.Test2 class A's method will be called. Why is it? If B has memory then B's

I have an abstract class that has a generic method and I want to override the generic method by substituting specific types for the generic parameter. So in pseudo-code I have the following: public abstract class GetAndParse { public SomeClass var; public abstract <T extends AnotherClass> void getAndParse(T... args); } public class Implementor extends GetAndParse { // some field declarations // some method declarations @Override public <SpecificClass> void getAndParse(SpecificClass... args) { // method body making use of args } } But for some reason I'm not allowed to do this? Am I making some

This code works perfectly. The method test() works for both interfaces. What is exactly going on under the hood? And how is this feature useful in practical scenario? interface A { void test(); } interface B { void test(); } class C implements A, B { public void test() { System.out.println("abc"); } } A a = new C(); a.test(); B b = new C(); b.test(); Because it's an interface there is no harm done. You're basically using a blueprint for your C class by implementing A and B . Both A and B say that C should implement a method called test() Your C class implements that method, so the interfaces

Suppose I have a base class with unimplemented methods as follows: class Polygon(): def __init__(self): pass def perimeter(self): pass def area(self): pass Now, let's say one of my colleagues uses the Polygon class to create a subclass as follows: import math class Circle(Polygon): def __init__(self, radius): self.radius = radius def perimeter(self): return 2 * math.pi * self.radius (H/Sh)e has forgotten to implement the area() method. How can I force the subclass to implement the parent's area() method? this could be your parent class: class Polygon(): def __init__(self): raise

Consider the following code: class Base(object): @classmethod def do(cls, a): print cls, a class Derived(Base): @classmethod def do(cls, a): print 'In derived!' # Base.do(cls, a) -- can't pass `cls` Base.do(a) if __name__ == '__main__': d = Derived() d.do('hello') > $ python play.py > In derived! > <class '__main__.Base'> msg From Derived.do , how do I call Base.do ? I would normally use super or even the base class name directly if this is a normal object method, but apparently I can't find a way to call the classmethod in the base class. In the above example, Base.do(a) prints Base class