JSON - simple get an Integer instead of Long

问题

How to get an Integer instead of Long from JSON?

I want to read JSON in my Java program, but when I get a JSON value which is a number, my parser returns a number of type Long.

I want to get an Integer. I tried to cast the long to an integer, but java throws a ClassCastException (java.lang.Long cannot be cast to java.lang.Integer).

I tried several things, such as first converting the long to a string, and then converting with Integer.parseInt(); but also that doesn't work.

I am using json-simple

Edit:

I still can't get it working. Here is an example: jsonItem.get("amount"); // returns an Object

I can do this:

(long)jsonItem.get("amount");

But not this:

(int)jsonItem.get("amount");

I also can't convert it with

Integer newInt = new Integer(jsonItem.get("amount"));

or

Integer newInt = new Integer((long)jsonItem.get("amount"));

回答1:

Please understand that Long and Integer are object classes, while long and int are primitive data types. You can freely cast between the latter (with possible loss of high-order bits), but you must do an actual conversion between the former.

Integer newInt = new Integer(oldLong.intValue());

来源：https://stackoverflow.com/questions/20869138/json-simple-get-an-integer-instead-of-long