Java结构相当于Javascript中的对象/接口

发布于 2025-01-14 06:32:24 字数 746 浏览 3 评论 0 原文

我需要从方法返回 2 种类型的值。
一个是Integer，另一个是List。

尝试使用

Map<String, Object> test = new HashMap<>();

// save the data
test.put("myList", list);
test.put("counter", 12); 

// And read later like
Integer counter = test.get("counter");
List<someClass> myList = test.get("myList");

，但转换总是在 Eclipse/声纳中引发警告/错误。

因此，我尝试实现一个接口only以获得具有我需要的属性类型的对象。

private interface theList {
  List<someCLass> myList;
  Integer counter;
}

但我不认为这就是java中接口的使用。我不想在任何类中实现方法或扩展此接口。

我需要的是有一种类型的元素，我可以在其中存储我需要的任何类型的信息并稍后读取它，就像我们在 javascript 中处理对象一样。
我只是不想为此创建另一个类或文件。

我可以使用什么结构？

原文

I need to return from a method 2 types of values.
One is an Integer and the other is a List<someClass>.

Tried using

Map<String, Object> test = new HashMap<>();

// save the data
test.put("myList", list);
test.put("counter", 12); 

// And read later like
Integer counter = test.get("counter");
List<someClass> myList = test.get("myList");

but the casts always fire warnings/errors in Eclipse/sonar.

So I tried to implement an interface only to have an object with the attributes type that I need.

private interface theList {
  List<someCLass> myList;
  Integer counter;
}

But I don't think this is the use of interfaces in java. I don't want to implement methods or extend this interface in any class.

What I need is to have a type of element where I can store any type of information I need and read it later, just like we do with objects in javascript.
I just don't want to create another class or file for this.

What structure could I use?

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你怎么这么可爱啊 2025-01-21 06:32:24

使用元组从方法返回多个值。元组只是一系列对象，它们不一定以任何方式相互关联。

简单实现的示例：

public class Tuple<K, V> {
    private final K first;
    private final V second;

    public Tuple(K first, V second){
        this.first = first;
        this.second = second;
    }

    public K getFirst() {
        return first;
    }

    public V getSecond() {
        return second;
    }
}

public Tuple<Integer, List<SomeClass>> method() {
    return new Tuple<>(1, new ArrayList<SomeClass>());
}

元组的良好实现是配对或 ImmutablePair 。
Spring元组可能有用实现和文档。

Use Tuples for returning multiple values from the method. A tuple is just a sequence of objects that do not necessarily relate to each other in any way.

Example of simple implementation:

public class Tuple<K, V> {
    private final K first;
    private final V second;

    public Tuple(K first, V second){
        this.first = first;
        this.second = second;
    }

    public K getFirst() {
        return first;
    }

    public V getSecond() {
        return second;
    }
}

public Tuple<Integer, List<SomeClass>> method() {
    return new Tuple<>(1, new ArrayList<SomeClass>());
}

The good implementation of tuples is Pair or ImmutablePair in Apache Commons Lang.
Probably can be useful Spring Tuples implementation and documentation.