So I have an array of 15 Flying Objects, The flyingObjects class consists of 1 variable (Price: Double) with its getters and setters. I also have an airplane class that extends FlyingObjects, a helicopter class that extends Airplane and quadrotor and multirotor class that extends helicopter. On the other side of the tree I have a UAV class that extends
Tag: polymorphism
Why doesn’t Java automatically access the overridden method?
Given two classes, a parent class and a child class: One has a method called greet(), which is private, and the other one defines a method with the same name, only that it is public. Now, as far as I know, the child’s greet() method doesn’t override the parent’s method, because it ‘hides’ it? (given the fact that private methods
Jackson subtypes – how to specify a default
I want to do something like this with subtypes. I have 3 different types of objects: value can either be a string or an object. The corresponding Java classes are I don’t mind having a discriminator inside Obj1 and Obj2, but there is no place for one when the value is just a string. Is there a way that I
Java Inheritance, instanceof, casting – how to accept a children object throught parent object?
I have three classes: (Parent) Animal, (Child) Bird & Monkey Monkey has weight & two pet Animals, which can be another Monkey, or bird Bird has weight & a name (weight, name) Together, they form a TREE, where leaf nodes are Bird, and non-leaf nodes are Monkeys (SEE VISUAL) While recursively traversing this tree to find a bird with a
Intellij cannot resolve method even though it is public (Java)
I have googled this a lot, invalidated the cache, and I can’t seem to find an answer. For background, this is a timetabling system using constraint solving. I have a custom class called Period with public methods getStart() and getEnd(). I also have an abstract class Constraint<V, D> and a subclass DemAvailConstratint<Demonstrator, Period>. It is in this subclass (and similarly
How to extract information from Java stack as individual data types and use in method call
I am trying to implement an undo feature by creating a stack of 2 subtypes. I have a stack of parent type UserEntry holding two child types Assign and RelEntry. Assign and RelEntry is both classes used to insert values (number and relationship) into a grid table. There is a method call to insert the values into the table as
Polymorphism – how to check if a superclass is a subclass?
This is my code: public class WriteReviewController { private OverviewActivity overviewActivity; private WriteReviewActivity writeReviewActivity; … public …
Jackson deserialization to concrete polymorphic class
I have following Jackson annotated classes (Kotlin) I try to deserialize JSON that does not contain type property but I provide concrete class so it should not matter I get Missing type id when trying to resolve subtype of … anyway. Is there a way how to tell Jackson to use the type provided in the deserialization and not to
java polymorphism aliasing issue
If there’s 3 classes. A, B and C. class B extends A and class C extends B. class A has equals method: class B has equals method: and class C has euals method: And the main has these code lines: I can’t understand why the equals method of class A is being executed. I know that overloaded methods are bonded
Polymorphism vs Strategy pattern
What is the difference between the Strategy pattern and Polymorphism in Java? I’m confused that whatever is achieved via Strategy Pattern is basically possible by polymorphism. Correct me if I’m wrong in this regard. Please, also provide me example to eradicate my confusion. Answer For me, the link from CKing post and the example in Wikipedia are clear enough, but