String to Int in java - Likely bad data, need to avoid exceptions

Question

Seeing as Java doesn't have nullable types, nor does it have a TryParse(), how do you handle input validation without throwing an exceptions?

The usual way:

String userdata = /*value from gui*/ int val; try {    val = Integer.parseInt(userdata); } catch (NumberFormatException nfe) {    // bad data - set to sentinel    val = Integer.MIN_VALUE; } 

I could use a regex to check if it's parseable, but that seems like a lot of overhead as well.

What's the best practice for handling this situation?

EDIT: Rationale: There's been a lot of talk on SO about exception handling, and the general attitude is that exceptions should be used for unexpected scenarios only. However, I think bad user input is EXPECTED, not rare. Yes, it really is an academic point.

Further Edits:

Some of the answers demonstrate exactly what is wrong with SO. You ignore the question being asked, and answer another question that has nothing to do with it. The question isn't asking about transition between layers. The question isn't asking what to return if the number is un-parseable. For all you know, val = Integer.MIN_VALUE; is exactly the right option for the application that this completely context free code snippet was take from.

Answer 1

I asked if there were open source utility libraries that had methods to do this parsing for you and the answer is yes!

From Apache Commons Lang you can use NumberUtils.toInt:

// returns defaultValue if the string cannot be parsed. int i = org.apache.commons.lang.math.NumberUtils.toInt(s, defaultValue); 

From Google Guava you can use Ints.tryParse:

// returns null if the string cannot be parsed // Will throw a NullPointerException if the string is null Integer i = com.google.common.primitives.Ints.tryParse(s); 

There is no need to write your own methods to parse numbers without throwing exceptions.