我创建的类可以进行自动装箱吗？

问题描述

有没有办法为我创建的类使用自动装箱？例如，我有 Number 的子类。

  public class UnsignedInteger扩展数字{
 int n; 
 
 public UnsignedInteger（int n）{
 if（n> = 0）
 this.n = n; 
 else 
抛出新的IllegalArgumentException（仅支持正整数）; 
} 
} 
  

现在， UnsignedInteger i =新的UnsignedInteger（88）; 工作得很好，但有没有办法进行编译： UnsignedInteger i = 88; ？它不适合我。提前致谢！

解决方案

简而言之，没有。没有办法让它编译。

Java只定义了一组有限的预定义拳击转换。

来自：

此外，有人可能会考虑重载 = 运算符来执行此转换，但是在Java中不支持运算符重载，这与C ++不同，这是可能的。

所以你的转换不可能用Java。

Is there any way to use autoboxing for the classes I create? For example, I have this subclass of Number.

public class UnsignedInteger extends Number {
    int n;

    public UnsignedInteger(int n) {
        if(n >= 0)
            this.n = n;
        else
            throw new IllegalArgumentException("Only positive integers are supported");
    }
}

Now, UnsignedInteger i = new UnsignedInteger(88); works perfectly fine, but is there any way to make this compile : UnsignedInteger i = 88;? It won't for me. Thanks in advance!

解决方案

In short, no. There's no way to get that to compile.

Java only defines a limited set of pre-defined boxing conversions.

From the JLS, section 5.1.7:

Additionally, one might think of overloading the = operator to perform this conversion, but operator overloading is not supported in Java, unlike in C++, where this would be possible.

So your conversion is not possible in Java.

这篇关于我创建的类可以进行自动装箱吗？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！