java - 在 Java 中定义类型转换

Question

我想在 Java 中定义从任意类型转换为原始数据类型的类型。是否可以定义从一种任意类型到另一种任意类型的转换？

public class Foo{
    //methods, constructor etc for this class
    ...
    //make it possible to cast an object of type Foo to an integer 
}
//example of how an object of type foo would be cast to an integer
public class Bar(){
    public static void main(String[] args){
        Foo foo1 = new Foo();
        int int1 = (int)foo1;
        System.out.println(int1+"");
    }
}

Answer 1

不能强制转换，但可以提供转换函数:

public class Foo{
    //methods, constructor etc for this class
    ...
    public int toInt(){
        //convert to an int.
    }    
}

然后栏变成:

public class Bar(){
    public static void main(String[] args){
        Foo foo1 = new Foo();
        int int1 = foo1.toInt();
        System.out.println(int1+"");
    }
}