如何在用户控制台输入的可观察列表上执行操作？

Question

我创建了一个列表，用于观察用户控制台输入触发的更改，假设用户输入了一个字符串，那么该字符串应该在观察列表中订阅。

Answer 1

你应该像这样创建一个自定义列表：

public class CustomList<T> extends ArrayList<T> {
    public static void main(String[] args) {
        CustomList<String> customList = new CustomList<>();
        customList.add("First Adding");
    }
    public boolean add(T t) {
        boolean b = super.add(t);
        System.out.println("you just add :" + t.toString());
        return b;
    }
}

如果你想有很多自定义事件，你可以这样做：

public class CustomList<T> extends ArrayList<T> {
    public static void main(String[] args) {
        CustomList<String> customList = new CustomList<>(new EventCustomList<String>() {
            public void remove(String s) {
                System.out.println("you just remove :" + s);
            }
            public void add(String s) {
                System.out.println("you just add :" + s);
            }
        });
        customList.add("First Adding");
    }
    private EventCustomList event;
    public CustomList (EventCustomList<T> event) {
        this.event = event;
    }
    public boolean add(T t) {
        boolean b = super.add(t);
        event.add(t);
        return b;
    }
    public T remove(int index) {
        T t = super.remove(index);
        remove(index);
        return t;
    }
    public interface EventCustomList<T> {
        void add(T t);
        void remove(T t);
    }
}

或者你可以使用BackedList喜欢这个话题How to add listener on ArrayList in java

public static void main(String[] args) {        
    BackedList<String> list = new BackedList();
    list.addListener(new BackedListListener<String>(){
        @Override
        public void setOnChanged(ListChangeEvent<String> event) {
            if (event.wasAdded()) {
                event.getChangeList().forEach(e->{
                   // do whatever you need to do                        
                    System.out.println("added: " + e);
                });
            }
            if (event.wasRemoved()) {

                // do whatever you need to dl
                event.getChangeList().forEach(e->{System.out.println(e + " was removed");});
            }
        }
    });