Interpretation of the constructed framework of the Java Library

Interpretation In Java programming, the class library is a set of predefined classes and methods, which provides the implementation of various common functions.The structural framework technology of the class library is a methodology that is used to design and implement the reusable, scalable class libraries.This article will interpret the technical principles of the structure framework of the Java library and provide the corresponding Java code example. The purpose of the constructing framework technology is to define the structure and organizational methods of the class library, so that developers can use existing code to build new applications.The main principles of this methodology include abstraction, interfaces, inheritance, and polymorphism. Abstract is one of the core concepts of constructing framework technology.Through abstraction, we can define the basic concepts and general behaviors in the class library.For example, for a graphical library, we can define an abstract "graphic" class, which contains the calculation area and the method of drawing graphics.Through abstraction, we can extract the common parts in order to reuse in actual applications. The interface is another important concept in the structural framework technology.The interface defines the agreement between the class library and the external world.By defining the interface, we can standardize the use of the class library and restrict the direct access to the internal implementation of the library.For example, in the graphical library, we can define an "drawable" interface, which contains a drawing method.Other classes only need to implement this interface, and the graphic library can be used to draw operations. Inheritance is a mechanism of structural framework technology. Through it, it can create new classes on the basis of existing classes.By inheriting, the new class can inherit existing attributes and methods, and can be further expanded and customized.For example, for the graphical library, we can derive specific graphic classes, such as circular, rectangles, and triangles. These classes can inherit the basic "graphic" classes and expand according to their own needs. Polymorphism is a characteristic of constructing framework technology. It allows different objects to respond differently to the same method.In Java, rewriting and method re -loading by method to achieve polymorphism.For graphic libraries, different graphic objects can be drawn with the same drawing method, but the actual drawing effect is different. Below is a simple Java code example, demonstrating the application of the structure framework technology: // Define abstract graphic classes abstract class Shape { abstract void draw(); } // Definition can be drawn interface interface Drawable { void draw(); } // round category class Circle extends Shape implements Drawable { @Override void draw() { System.out.println("Drawing circle"); } } // rectangle class Rectangle extends Shape implements Drawable { @Override void draw() { System.out.println("Drawing rectangle"); } } public class Main { public static void main(String[] args) { Shape circle = new Circle(); Shape rectangle = new Rectangle(); circle.draw(); // 输出：Drawing circle rectangle.draw(); // 输出：Drawing rectangle } } The above code defines an abstract graphical class `shape` and a drawable interface` drawable`.The category of `circle` and` RECTANGLE "inherited the` Shape` class and implemented the `Drawable` interface.In the `Main` method of the` Main` class, we created a circular object and a rectangular object, and was drawn by their `Draw` method.Due to the polymorphism characteristics, whether through the inheritance of the `Shape` class or the implementation of the` Drawable` interface, we can all use the same `Draw` method for graphics. By constructing framework technology, we can design reused and scalable class libraries, and use these class libraries to build a variety of different applications.The core principles of constructing framework technology are to achieve universal and flexibility of class libraries through abstraction, interface, inheritance, and polymorphism.Such libraries can greatly improve development efficiency and promote the maintenance and scalability of software.