在Java代码中获取语法错误：无法从Object转换为int

Question

I keep getting the syntactic error in Java code:

 Cannot cast from Object to int.

The problem code is like this:

int a = (int)obj;//obj is of Object type

But I have always been using this trick around, and only get the error recently.

My question:

1. Is this a real syntactic error?
2. Is there any configuration that can hide such syntactic error?.

Answer 1

Object to int is two steps - first you need to convert the Object to an Integer , then you need to convert the Integer to an int .

Fortunately auto-boxing will handle the second conversion for you, but you still need to explicitly make the first conversion:

 int a = (Integer)obj;

Answer 2

您不能将对象强制转换为基本类型，您需要强制转换为Integer ：

Integer a = (Integer)obj;