Question

I have a String in this format:

mydb://<user>:<password>@<host>:27017

And I would like to use Java regexp in order to extract the <user> and <password> strings from the String. What would be the best way doing so?

EDIT:

I would like to be able to use this regexp in the String’s replace method so that I’m left only with the relevant user and password Strings

Answer 1

You can use this regex (Pattern)

Pattern p = Pattern.compile("^mydb://([^:]+):([^@]+)@[^:]+:\\d+$");

And then capture group #1 and #2 will have your user and password respectively.

Code:

String str = "mydb://foo:bar@localhost:27017"; 
Pattern p = Pattern.compile("^mydb://([^:]+):([^@]+)@[^:]+:\\d+$");
Matcher matcher = p.matcher(str);
if (matcher.find())
    System.out.println("User: " + matcher.group(1) + ", Password: "
                        + matcher.group(2));

OUTPUT:

User: foo, Password: bar

EDIT: Based on your comments: if you want to use String methods then:

String regex = "^mydb://([^:]+):([^@]+)@[^:]+:\\d+$";
String user = str.replaceAll(regex, "$1");
String pass = str.replaceAll(regex, "$2")