Does java have a int tryparse that doesn t throw an exception for bad data

Question

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

User · Answer

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

User · Answer

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

User · Answer

No  You have to make your own like this     boolean tryParseInt String value           try              Integer parseInt value              return true            catch  NumberFormatException e               return false                     and you can use it like this     if  tryParseInt input          Integer parseInt input       We now know that it s safe to parse     EDIT  Based on the comment by  Erk   Something like follows should be better  public int tryParse String value  int defaultVal        try           return Integer parseInt value         catch  NumberFormatException e            return defaultVal            When you overload this with a single string parameter method  it would be even better  which will enable using with the default value being optional   public int tryParse String value        return tryParse value  0

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

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