Removing square braces from a string in Java

Question

I want to remove square brackets for this one. I tried it but it gives same output.

String datetime = [Thu Sep 14 17:00:00 GMT+05:30 2017];
datetime=datetime.replaceAll("\\[", "").replaceAll("\\]","");

Where am I going wrong?

Answer 1

If you're already setting the datetime String on your own, why don't you just set it without square brackets? String datetime = "Thu Sep 14 17:00:00 GMT+05:30 2017";

And you're supposed to have a compiler error because your String datetime is not valid, because it has no double quotes.

On the other hand if you receive a data for datetime String from Java class Date then you can change the format of the data you're receiving with SimpleDateFormat.

If you do not know how to use SimpleDateFormat, check it out here

Here's some brief example of it and you can check full tutorial here:

public class GetCurrentDateTime {

private static final DateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
private static final DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");

public static void main(String[] args) {

    Date date = new Date();
    System.out.println(sdf.format(date));

    Calendar cal = Calendar.getInstance();
    System.out.println(sdf.format(cal.getTime()));

    LocalDateTime now = LocalDateTime.now();
    System.out.println(dtf.format(now));

    LocalDate localDate = LocalDate.now();
    System.out.println(DateTimeFormatter.ofPattern("yyy/MM/dd").format(localDate));

}

}

Answer 2

Don't replace brackets with nothing, match inside of brackets with regex, then replace whole string with inside part.

Like this

String datetime = "[Thu Sep 14 17:00:00 GMT+05:30 2017]";
datetime=datetime.replaceAll("\\[(.*)\\]", "$1");
System.out.println( datetime); // output is: Thu Sep 14 17:00:00 GMT+05:30 2017