Does java have a int.tryparse that doesn't throw an exception for bad data? [duplicate]

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.

Solution 1:

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:

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:

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;
}