在java.util.Date类型中插入特殊字符

Question

In this invprbm.setFollowUpDate() is java.util.Date type.
If the given value is empty, I have to set followUpDate as special characters - - , eg:

SimpleDateFormat formatter = new SimpleDateFormat("- -");
invprbm.setFollowUpDate(formatter.parse("- -"));

In this scenario I am getting a value like Thu Jan 01 00:00:00 IST 1970 instead of the expected - - .

Answer 1

You seem to be asking how you should parse an "empty" date that you have denoted by the string "- -". And the simple answer is that you don't parse it!

Instead do something like this:

SimpleDateFormat formatter = new SimpleDateFormat("dd-MMM-yy"); // or whatever
if (str.equals("- -")) {
    invprbm.setFollowupDate(null);
} else {
    invprbm.setFollowUpDate(formatter.parse(str));
}

And if you actually want to go from a Date to a String, you do it something like this:

if (date == null) {
    invprbm.setFollowupDate("- -");
} else {
    invprbm.setFollowUpDate(formatter.format(date));
}

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The problem with your current approach is that SimpleDateFormat is not designed to cope with null Dates. It can't parse a string to produce a null Date object, and it can't format a null Date object.

What your current code is actually doing is specifying a format that doesn't tell the parser how to extract any components of a date / time from the input string. The parse method is returning a Date object whose getTime() value is zero. This is not unreasonable, since what you are trying to do falls outside of the javadoc specification for the SimpleDateFormat class.