overriding

I am attempting to override a method declaration within an interface that extends another interface. Both of these interfaces use generics. According to the Java tutorials, this should be possible, but the example does not use generics. When I try to implement it, the compiler shows the following error (I've replaced names because some of the code is not my own.): myMethod(T) in InterfaceExtended clashes with myMethod(T) in Interface; both methods have the same erasure, but neither overrides the other. Code looks like this: public interface Interface<T> { public void myMethod(T x); } public

I needed a datecolumn with some custom behaviour, specifically I needed to be able to enter in a date or and age in the same field (with an age staying rendered as an age and a date staying rendered as a date) Eg. Entering "23" will leave "23" in the field as a valid value, or entering "22/1/88" will leave "22/1/88" as valid value. So I tried having a datecolumn with the editor defined like this (note the validate override): editor: { xtype: 'datefield', format: 'd/m/Y', validate: function(){ if(!this.value.match(SOME_REGEX){ if(!this.value.match(SOME_REGEX){ return false; } } return true; } }

I'm a bit confused to the, I guess concept, of the Dynamic/Static types of a reference variable and Dynamic Method Resolution in Java. Consider: public class Types { @Override public boolean equals(Object obj){ System.out.println("in class Types equals()"); return false;//Shut-up compiler! } public static void main(String[] args){ Object typ = new Types(); typ.equals("Hi");//can do this as String is a subclass of Object } } First: the reference variable typ is of type Types, isn't it?! So what is the reason behind typ having a Static Type Object and a Dynamic Type Types for method overriding?

This question already has answers here : Why is method overloading and overriding needed in java? [duplicate] (3 answers) Closed 5 years ago . Recently I was asked this question "why should one override a method? " I replied, if I have a class with 10 methods and I want to use all of its functionality except one method, then I will override that method to have my own functionality. Then the interviewer replied in that case why cant we write a new method with a different name and use that method instead. Yes this is also right. Now I am confused. What is the real objective in overriding a

I have a super class: public class SuperClass { public void dosomething() { firstMethod(); secondMethod(); } public void firstMethod() { System.out.println("Super first method"); } public void secondMethod() { System.out.println("Super second method"); } } A sub class: public class SubClass extends SuperClass { public void dosomething() { super.dosomething(); } public void firstMethod() { System.out.println("Sub first method"); } public void secondMethod() { System.out.println("Sub second method"); } } A test class： public static void main(String[] args) { SubClass sub = new SubClass(); sub