为什么我用这个Integer.parseInt（x，y）得到一个NumberFormatException？

Question

My code is simply:

int idec = Integer.parseInt(value, 16);

When I enter as value "01dae610", I correctly get "31122960". When I enter as value "d149e510", I get a java.lang.NumberFormatException. The correct value is: "3511280912".

I have no clue why this is. Can someone help?

Answer 1

Because that is outside the range of an int . Use a long / Long instead.

Answer 2

int is signed in Java - so the maximum value is 2 ³¹ - 1.

If you use Long.parseLong(value, 16) you'll get your desired value. You can then cast back to int if you're happy to get the right bit pattern, but interpreted as a negative value instead.

Answer 3

Simply because it's the outside the range of int . You should use the long data type instead.

Answer 4

Integer.MAX_VALUE is 2147483647, which is lower than the value you are expecting. So this string doesn't represent anything which can be parsed into an int . Hence the exception.

Answer 5

From here :

The int data type is a 32-bit signed two's complement integer. It has a minimum value of -2,147,483,648 and a maximum value of 2,147,483,647 (inclusive).

3,511,280,912 > 2,147,483,647, which explains the NumberFormatException .

However, you could use a long . From that same page:

The long data type is a 64-bit signed two's complement integer. It has a minimum value of -9,223,372,036,854,775,808 and a maximum value of 9,223,372,036,854,775,807 (inclusive).