Java中组合的用法_Java中组合模式的应用

interface Flyable {
    void fly();
}

class Wings implements Flyable {
    @Override
    public void fly() {
        System.out.println("Using wings to fly.");
    }
}

class Jetpack implements Flyable {
    @Override
    public void fly() {
        System.out.println("Using a jetpack to fly!");
    }
}

class Dog {
    private Flyable flyable;

    public Dog(Flyable flyable) {
        this.flyable = flyable;
    }

    public void setFlyable(Flyable flyable) {
        this.flyable = flyable;
    }

    public void fly() {
        if (flyable != null) {
            flyable.fly();
        } else {
            System.out.println("This dog cannot fly.");
        }
    }
}

public class Main {
    public static void main(String[] args) {
        Dog dogWithWings = new Dog(new Wings());
        dogWithWings.fly(); // Output: Using wings to fly.

        Dog dogWithJetpack = new Dog(new Jetpack());
        dogWithJetpack.fly(); // Output: Using a jetpack to fly!

        Dog dogWithoutWings = new Dog(null);
        dogWithoutWings.fly(); // Output: This dog cannot fly.
    }
}

import java.util.ArrayList;
import java.util.List;

interface FileSystemComponent {
    String getName();
    long getSize();
    void display();
}

class File implements FileSystemComponent {
    private String name;
    private long size;

    public File(String name, long size) {
        this.name = name;
        this.size = size;
    }

    @Override
    public String getName() {
        return name;
    }

    @Override
    public long getSize() {
        return size;
    }

    @Override
    public void display() {
        System.out.println("File: " + name + ", Size: " + size + " bytes");
    }
}

class Directory implements FileSystemComponent {
    private String name;
    private List<FileSystemComponent> children = new ArrayList<>();

    public Directory(String name) {
        this.name = name;
    }

    public void addComponent(FileSystemComponent component) {
        children.add(component);
    }

    public void removeComponent(FileSystemComponent component) {
        children.remove(component);
    }

    @Override
    public String getName() {
        return name;
    }

    @Override
    public long getSize() {
        long totalSize = 0;
        for (FileSystemComponent child : children) {
            totalSize += child.getSize();
        }
        return totalSize;
    }

    @Override
    public void display() {
        System.out.println("Directory: " + name);
        for (FileSystemComponent child : children) {
            child.display();
        }
    }
}

public class Main {
    public static void main(String[] args) {
        Directory root = new Directory("Root");
        File file1 = new File("document.txt", 1024);
        Directory subDirectory = new Directory("SubDir");
        File file2 = new File("image.jpg", 2048);

        subDirectory.addComponent(file2);
        root.addComponent(file1);
        root.addComponent(subDirectory);

        root.display();
        System.out.println("Total size of root directory: " + root.getSize() + " bytes");
    }
}