Regarding format date/time in java
I have two datetime formats,
'dd-mm-yyyy'
and'dd-mm-yyyy hh:MM:ss'
in my application. The input value may be a string in any of above forms.
I want to store this date value in database. So, first I format it with SimpleDateFormatter
. But how can I check that input string is of type 1 or of type 2?
If input date time type is in form of (2) and I format datetime with formatter 'dd-mm-yyyy'
then it returns null
.
Whatever input type - it must be converted according to inp开发者_Python百科ut. In short, how can I check input datetime format?
i want to store this date value in data base. So, first i formate it with SimpleDateFormatter , but how can i check that input string is type of 1 or type of 2.
It sounds like you want to parse the value - you shouldn't be storing it in the database as a string. (Parsing is converting from a string to the natural data type, e.g. Date
. Formatting is converting from a value to a string.)
You can just try parsing the value using DateFormat.parse
, and catching the exception thrown if the text is invalid - but you should be aware that your format strings are wrong. 'M' is for month-of-year, and 'm' is for minutes, not the other way round. You also probably want the 24 hour clock (H), not the 12 hour clock (h), so you want:
dd-MM-yyyy
dd-MM-yyyy HH:mm:ss
Finally, I'd strongly advise you to use Joda Time instead of the built-in date/time classes. Joda Time is a much better API. (For example, the formatters in Joda Time are thread-safe, unlike those in the JRE...)
Firstly, your data format is screwed up - you have minutes (mm
) and months (MM
) around the wrong way. ie your formats should be:
"dd-MM-yyyy"
"dd-MM-yyyy HH:mm:ss"
Next, rather than being too smart about it, you can simply try each format and see what works:
public static Date parseDate(String input) {
String[] formats = { "dd-MM-yyyy", "dd-MM-yyyy HH:mm:ss" }; // Add more as you like
for (String format : formats) {
try {
return new SimpleDateFormat(format).parse(input);
}
catch (ParseException e) {
// Ignore and continue
}
}
throw new IllegalArgumentException("Could not parse date from " + input);
}
There are many possibilities to distinguish the two formats. An easy one is to check the length of the input string.
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