Checking if a value is numeric

[seanbee]

Hey guys I am new to Java and have to write a java program to convert an input file to another format for loading into the company's transaction processing system.

My question is how can I check to see if a field from the input file is numeric (similar to the vb function isNumeric()).

I figure that I could simply catch the exception NumberFormatException but I just want to know if it can be done without an exception having to be thrown.

Thanks in advance for you help

[ray326]

Use the get*(st, null) of the type you need, e.g. Integer num = Integer.getInteger(st, null). If the conversion fails then num == null.

[seanbee]

Thanks very much... great suggestion

[seanbee]

I actually found a better way to do it by using the isNaN function

[ray326]

Cool. I'm surprised it's general enough but if it works for you that's great.

[nspils]

Use the Scanner class to read your input stream. You can define your own tokenizer or use the default "whitespace". You can test the datatype of the next token and decide what to do based on the datatype, and it will "valueOf" the input to the correct datatype.