Strip date from String with junk data - Java

Question

I need to know if there is anyway to strip the date alone from text like below using java. I am trying to find something more generic, but couldn't get any help, As the input varies.

Some example inputs:

This time is  Apr.19,2021 Cheers

or

19-04-2021 Cheers

or

This time is  19-APR-2021

I have seen some code which works for trailing junk characters but couldn't find anything if the date is in between the string and if it varies to different formats.

Answer 1

We could use String#replaceAll here for a regex one-liner approach:

String[] inputs = new String[] {
    "This time is  Apr.19,2021 Cheers",
    "19-04-2021 Cheers",
    "This time is  19-APR-2021",
    "Hello 2021-19-Apr World"
};
for (String input : inputs) {
    String date = input.replaceAll(".*(?<!\\S)(\\S*\\b\\d{4}\\b\\S*).*", "$1");
    System.out.println(date);
}

This prints:

Apr.19,2021
19-04-2021
19-APR-2021
2021-19-Apr

Answer 2

如果您假设“日期”是任何以 4 位“单词”结尾的字母/数字/点/逗号/破折号字符，请匹配并替换为空白以将其删除

str = str.replaceAll("\\b[A-Za-z0-9.,-]+\\b\\d{4}\\b", "");