Tag: abstract-class

Is instantiating an instance of an abstract class a runtime or compilation error?

From my understanding, no objects are instantiated in compilation time. Hence, the error should be classified as a run time error when the instance of the abstract object is created in runtime. Am I correct or will such an error be picked up by the compiler before runtime? Answer The work of compiler basically boils down to accepting your java

abstractor method with object return type in java

I’m new at oop ,I want to pass object parameter of an abstract method but it gives me error, can anyone explain it to me and help me fix the error . Thanks for your help. Answer You cannot change the abstract method signature. You have created an entirely new method unrelated to the method you wanted to override. Use

How to properly unwrap an optional in Java?

I am learning the basics of Java and I am exploring Optionals and abstract classes so I came across the following issue, I have this code import java.util.Optional; public abstract class Animal { …

Abstract class with Gson serialization/deserialization

I am expecting to get from a json a LinkedList. The pojos look like this: @Data @Builder public class Request { private String id; private List parameters; } @…

abstraction can be done without inheritance? java

Is abstraction possible without inheritance? This is my code Please note above, how i: did not extend the class “what” from abstract class “whatever” and yet the code runs perfectly with no errors Did not declare class “what” as abstract (since it’s not declaring the other two methods disp2() and disp3()) I am very confused. Please help. Answer There is

Java override abstract generic method

I have the following code public abstract class Event { public void fire(Object… args) { // tell the event handler that if there are free resources it should call // …