Java Integer.parseInt() Not Working for Large Numbers

Question

I have the following simple piece of code which is intended to detect that a given IPv4 address indeed only has numeric values (that is after the dots have been stripped):

import edu.gcc.processing.exceptions.net.IPAddressNumericException;

//Get the IP address
  String address = "239.255.255.255";

//Check to see if this is a number      
  try {
    String IPNumbers = address.replace(".", "");
    Integer.parseInt(IPNumbers);            
  } catch (NumberFormatException e) {
    System.out.print(e.getMessage());
  }

For some reason, the NumberFormatException is fired, and I get this error:

For input string: "239255255255"

Could someone please help me understand this? The parseInt() method works on smaller numbers, such as 127001.

Thank you for your time.

Solution 1

try using Long.parseLong(IPNumbers)

Solution 2

Why not use a regular expression, or break it down into its components by using split(".")?

There are other limitations besides needing to consist solely of digits. For example:

666.666.666.666

This will parse just fine, but is an... unlikely IP.

Breaking it up into its parts lets you determine (a) that it has four parts, and (b) that each part actually makes sense in the context of an IP address.

You could also use an InetAddress implementation, or InetAddressValidator from Apache Commons.

Solution 3

For very large integers you may want to use the BigInteger class (or BigDecimal), as the values may exceed the limits of Integer.

Integer Limits:

Minimum : -2147483648
Maximum :  2147483647

Using BigInteger:

string s = "239255255255";
BigInteger yourNumber = new BigInteger(s);

Solution 4

Range of an Integer is -2,147,483,648 to 2,147,483,647, the number you have above mentioned is not included in these range, so use long , the range of long primitive type is in between -9,223,372,036,854,775,808 and 9,223,372,036,854,775,807.

So for your case its better to use Long.parseLong() function to convert such large number to long type.

Solution 5

239255255255 is too big to be held by an Integer. Try using a BigInteger or a BigDecimal.

View more solutions

Comments

[Rion Williams]

Also - a very unfortunate one :)

[Oliver Spryn]

hmm... What method can I use to convert the string to an integer?

[Rion Williams]

There is also a BigDecimal class if you need one, I'll include the necessary documentation in an edit.

[Steve Kuo]

239255255255 is not an integer. See docs.oracle.com/javase/6/docs/api/java/lang/…

[Oliver Spryn]

That's exactly what I needed. Thanks!

[Rion Williams]

@spryno724, An integer will be unable to hold that large of a value, you will have to use BigInteger to store it.

[Robin]

+1 for actually suggesting that the approach of just checking whether it is a number is insufficient, and that switching to a long will not solve this