How Do I convert very big String to number in Java

问题

Hi I have a big string like this :

"999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999"

I wish to convert this string to long. But I failed. I did:

Long.parseLong(longString);

But I'm getting an error:

java.lang.NumberFormatException: For input string: "99999999.......

Are there any way to avoid this?

回答1:

Use BigInteger class like this:

 BigInteger number = new BigInteger(longString);

回答2:

You need to use BigInteger. Long may not accommodate that big number.

Here is javadoc for BigInteger.

回答3:

you might use BigInteger rather than Long.

 BigInteger number = new BigInteger(longString);

Java BigInteger example

回答4:

long: Reference

use 8-byte to store values from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

As mention before answer, use BigInteger.

来源：https://stackoverflow.com/questions/12967201/how-do-i-convert-very-big-string-to-number-in-java