Visitor Pattern

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已于 2024-03-28 14:48:22 修改 · 1.1k 阅读

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#访问者模式

于 2024-03-28 13:22:38 首次发布

访问者模式是一种行为设计模式，能将算法与操作的对象分离，使得在不修改对象结构的情况下，可以为现有对象结构添加新的操作。此模式在处理复杂对象结构且需要对不同类型的对象执行多种操作时特别有用。文章通过一个Java实现的例子详细解释了访问者模式的工作原理。

The Visitor pattern is a behavioral design pattern that allows you to separate algorithms from the objects on which they operate. It enables you to add new operations to existing object structures without modifying those structures. This pattern is particularly useful when you have a complex object structure with different types of objects and you need to perform various operations on these objects.

Here's an example of the Visitor pattern implemented in Java:

// Visitor interface
interface Visitor {
    void visit(Circle circle);
    void visit(Rectangle rectangle);
}

// Concrete visitor implementation
class AreaVisitor implements Visitor {
    @Override
    public void visit(Circle circle) {
        double area = Math.PI * circle.getRadius() * circle.getRadius();
        System.out.println("Area of Circle is: " + area);
    }

    @Override
    public void visit(Rectangle rectangle) {
        double area = rectangle.getWidth() * rectangle.getHeight();