Does java have a int.tryparse that doesn't throw an exception for bad data?
JavaJava Problem Overview
> Possible Duplicate:
> Java: Good way to encapsulate Integer.parseInt()
> how to convert a string to float and avoid using try/catch in java?
C# has Int.TryParse: Int32.TryParse Method (String, Int32%)
The great thing with this method is that it doesn't throw an exception for bad data.
In java, Integer.parseInt("abc")
will throw an exception, and in cases where this may happen a lot performance will suffer.
Is there a way around this somehow for those cases where performance is an issue?
The only other way I can think of is to run the input against an regex, but I have to test to see what is faster.
Java Solutions
Solution 1 - Java
No. You have to make your own like this:
public int tryParseInt(String value, int defaultVal) { try { return Integer.parseInt(value); } catch (NumberFormatException e) { return defaultVal; } }
...or
public Integer parseIntOrNull(String value) { try { return Integer.parseInt(value); } catch (NumberFormatException e) { return null; } }
Solution 2 - Java
Apache Commons has an IntegerValidator class which appears to do what you want. Java provides no in-built method for doing this.
See here for the groupid/artifactid.
Code sample: (slightly verbose to show functionality clearly)
private boolean valueIsAndInt(String value) {
boolean returnValue = true;
if (null == new org.apache.commons.validator.routines.IntegerValidator().validate(value)) {
returnValue = false;
}
return returnValue;
}
Solution 3 - Java
Edit -- just saw your comment about the performance problems associated with a potentially bad piece of input data. I don't know offhand how try/catch on parseInt compares to a regex. I would guess, based on very little hard knowledge, that regexes are not hugely performant, compared to try/catch, in Java.
Anyway, I'd just do this:
public Integer tryParse(Object obj) {
Integer retVal;
try {
retVal = Integer.parseInt((String) obj);
} catch (NumberFormatException nfe) {
retVal = 0; // or null if that is your preference
}
return retVal;
}