如何在java中使用观察者模式来检测Java列表中的变化？

public interface Observer {
    void update();
}

public class ListObserver implements Observer {
    private List<Object> list;

    public ListObserver(List<Object> list) {
        this.list = list;
    }

    @Override
    public void update() {
        // 列表发生变化时执行的操作
        // 可以在这里对列表进行处理或执行其他逻辑
        System.out.println("List has changed: " + list);
    }
}

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

public class ObservableList {
    private List<Object> list;
    private List<Observer> observers;

    public ObservableList() {
        list = new ArrayList<>();
        observers = new ArrayList<>();
    }

    public void add(Object item) {
        list.add(item);
        notifyObservers();
    }

    public void remove(Object item) {
        list.remove(item);
        notifyObservers();
    }

    public void addObserver(Observer observer) {
        observers.add(observer);
    }

    public void removeObserver(Observer observer) {
        observers.remove(observer);
    }

    private void notifyObservers() {
        for (Observer observer : observers) {
            observer.update();
        }
    }
}

public class Main {
    public static void main(String[] args) {
        // 创建观察者
        Observer observer = new ListObserver(list);

        // 创建被观察者
        ObservableList observableList = new ObservableList();
        observableList.addObserver(observer);

        // 修改列表
        observableList.add("Item 1");
        observableList.add("Item 2");

        // 移除观察者
        observableList.removeObserver(observer);
    }
}