I’ve declared a table that has the mother class type and i’ve filled it with many objects that have the extended classe type, everything looks fine and the table is successfully filled, the problem is when i’m trying to access to the table values i cannot ( in the exemple i’m trying to…
Tag: inheritance
Spring implements to kinds of Repository interface
I’m trying to study Spring more specific Spring Data but i have a question about the use of interface Repository and its derivatives classes and i asking you help for clarify them. For example i see this code example extends CrudRepository but i see the using of extends keyword but no implements. why ? …
Java: make static methods of one class mirror instance methods of another class
I have a POJO like this: As an alternative to Java reflection (which is quite slow in general), I would like to define a class with static methods like this: which enforces the creation/deprecation of a static method every time the Foo class is updated. For example, if the field bar2 is deleted in FooStatic, …
How to show that a Catch block for the Parent-exception will handle subclasses as well
I have met this problem. I have created a class CatHandler, with 3 inner classes (ExceptionAlpha extends Exception, ExceptionBeta extends ExceptionAlpha, ExceptionGammer extends ExceptionBeta). These three exception subclasses are empty; they contain no code. All code should be written in CatHandler. Now the …
An issue with Generic type parameters and Inheritance
Couldn’t concretize the title, sorry for that. For example, we have a Parent class and a Child class: And a class that can contain Parent’s child in its field called a: Let’s create an instance of that class and try to assign a value to a: So far, so good. But let’s say we want to move…
Unable to inherit in OpenAPI 3 using allOf in java
Please find the schemas in my contract yaml file : While using swagger 2, the generated class Foo extends Bar. But after using openAPI 3 Foo isn’t extending Bar when using allOf. All it is doing is copying all the properties of Bar to Foo class. Although now that Foo class will contain all the propertie…
Inheritance, setters and getters (Game Class Output)
How am I supposed to decrease its armor first and next the health? I want not to print the negative of armor, and I want to print if the armor gets 0, the health should be the next to decrease. For Instance in Testing Class, I use wizard and cast a spell to fireball 3 times to knight. Since knight
Duplicate code across enums .. is there an approach to centralize common code in these enums?
I have the following 3 enum’s in my project, which are all very similar. Since each enum has at least 2 common fields i.e key and code, is there any way that I can make the common: constructors getters field declarations shared to all of my enums? Without having to declare inside each one. I know no ext…
NoArgsConstructor and AllArgsConstructor annotation on Child class for parent constructors
Hello to the overflow community, I am struggling on an inheritance problem with Lombok. I’m trying to add both annotation @AllArgsConstructor and @NoArgsConstructor on a child class in order to use the parent lombok constructors but got the error “Duplicate method Child()”. Parent class: Chi…
Abstract Classes & Methods In Java
I am working on a Java exercise where a parent class is abstract, and the subclasses override the isSimilar method. This method should take a device parameter. In the Server subclass, this method should compare the Brand, Operating System, and Available Services. In the NetworkDevice subclass, this method sho…