Original analysis of the Inherits framework in the Java class library
Original analysis of the Inherits framework in the Java class library
In the Java library, the Inherits framework is a mechanism for implementing inheritance between classes.Inheritance is an important feature of object -oriented programming, allowing one class (subclass) to inherit the attributes and methods of another (parent).Inherits framework provides a flexible and scalable way to achieve this inheritance relationship.
In Java, all classes inherit from the Object class.Inherits framework uses keywords EXTENDS in the classes to specify which parent class that inherits the class.Sub -class can inherit the parent -class non -private members (attributes and methods), and can rewrite the parent class in the subclass.
The following is a simple example, which shows how to use the Inherits framework to achieve inheritance:
class Animal {
String sound = "Animal sound";
void makeSound() {
System.out.println(sound);
}
}
class Dog extends Animal {
String sound = "Woof";
void makeSound() {
System.out.println(sound);
}
}
public class Main {
public static void main(String[] args) {
Dog dog = new Dog();
dog.makesound (); // Output "woof"
}
}
In the above example, the Animal class is a parent class, and the DOG class is a subclass.The DOG class inherits the Makesound method of the Animal class and rewrite this method.In the main function, we created a DOG object and called the Makesound method to output "WOOF".
Using the Inherits framework can achieve more complex inheritance relationships, including multi -layer inheritance, interface inheritance, etc.By inheriting, subclasses can obtain the attributes and methods of parent class, and can add their own characteristics and behavior.
The principle of the Inherits framework is the processing of the inheritance of the compiler and virtual machine of Java.When the compiler compiles the Java code, it will check the inheritance relationship of the class and generate the byte code file that meets the inheritance rules.The virtual machine loaded the byte code file when runtime, and executes the corresponding method according to the inheritance relationship.
Summarize:
The Inherits framework is a mechanism for realizing inheritance in the Java library. The inheritance is achieved by using the keywords specified by the keyword EXTENDS.By inheriting, subclasses can obtain the attributes and methods of parent class, and can add their own characteristics and behavior.The principle of the Inherits framework is the processing of the inheritance relationship between the compiler and the virtual machine.
