WHAT IS ABSTRACTION IN JAVA
- 2. Java abstraction or object-oriented programming is a way of separating the implementation of an interface and one of the five motifs, along with encapsulation, inheritance, polymorphism, class, and object abstraction.
- 3. it is achieved using Java the interface and the abstract class in Java. An interface or abstract class is something that is not concrete, something that is incomplete.
- 4. To use the interface or the abstract class, we need to extend and implement an abstract method with concrete behavior. An example of abstraction is to create an interface to denote common behavior without specifying Details on how this example behavior works.
- 5. An interface called Server is created that has the start () and stop () method. This is called the server abstraction because each server must have a way to start and stop and the details may be different. As I said earlier, the Abstraction in Java is implemented using abstract classes and interfaces, as discussed in the next section.
- 6. In truth, which is an abstraction in Java, the difference between abstraction and encapsulation is also a very popular Java interview because the strong capacity of OOPS is one of the main requirements for Java developers. Abstraction is also one of the concepts difficult to master. The programmer usually mixes different levels of abstraction that result in flexible code,
- 7. If you want to use it, you need to make it complete or concrete, extending it. A class is called concrete if it does not contain any abstract method and implements the entire abstract method inherited from the abstract class or interface implemented. By the way, Java has a concept of abstract classes, abstract method, but a variable can not be abstract in Java.
- 8. A popular example of an abstract class in Java is the ActionListener, which has an abstract method called actionPerformed (ActionEvent ae). This method is called when an ActionEvent is activated as when the JButton is clicked.
- 9. It is common in java to attach ActionListener with JButton by implementing the actionPerformed abstract method (ActionEvent a) using the anonymous class. An abstract method in Java does not have the body, it is just a statement. To use an abstract method, it is necessary to replace this method in the subclass. When you know that something needs to be there, you do not know exactly how it should be. For example.
- 10. When I'm creating a class called Vehicle, I know there must be methods like start () and stop (), but I do not know how this start and stop method should work, since each vehicle can have different start and stop mechanism and .. g some they can be initiated by kicking or some can be by pressing buttons.
- 11. If you know some behavior during the creation of a class and this would remain common to all subclasses, add it to an abstract class. An interface like the Runnable interface is a good example of Java abstraction that is used to abstract the tasks performed by multiple threads. Callable is another good summary of a task that can return value.