NumberFormatException from DateFormat.parse() ???

[David Duran]

I'm getting this exception thrown sometimes, unfortunately I don't know the exact value that's getting passed to the parse method because the code is in a production environment. The calling code is pretty much:

public Date convert(String str)
{
   SimpleDateFormat sdf = new SimpleDateFormat(SOME_PATTERN);
   return sdf.parse(str);
}

According to the javadoc, parse() throws only ParseException yet strangely whatever argument is being passed to parse() is causing a NumberFormatException with the following message below.
Passing "" directly to parse() results in the appropriate ParseException: Exception in thread "main" java.text.ParseException: Unparseable date: ""
However, I don't know how to replicate the exception below. Any ideas?
java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Long.parseLong(Long.java:344)
at java.lang.Long.parseLong(Long.java:381)
at java.text.DigitList.getLong(DigitList.java:150)
at java.text.DecimalFormat.parse(DecimalFormat.java:1067)
at java.text.SimpleDateFormat.subParse(SimpleDateFormat.java:1381)
at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1159)
at java.text.DateFormat.parse(DateFormat.java:332)

[Tom Angioletti]

The exception gives exact line numbers, so we could take a look in the source code for the Java API. What version of Java are you running?

[David Duran]

1.4.1_01

[Tom Angioletti]

Well I followed the stack trace from Long to DigitList but then got lost in DecimalFormat. It looks like the decimalAt field in DigitList must be 0 when Long.parseLong is called, but I don't know why.
I also noted that this area of the code was modified in Java 1.4.2. Maybe an upgrade would correct the problem or shed more light on it.
Sorry I'm not more help.

[David Duran]

I've put in some logging to catch the exception and log the input. I'll post it if I find out.
Thanks for the input guys.