/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.regex.*;
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String str = "mongodb://localhost:27017/admin?replicaSet=rs";
		System.out.println(str.replaceAll("mongodb://([^/]*).*", "$1")); 
 
        Pattern ptrn = Pattern.compile("(?<=//)[^/]*");
        Matcher matcher = ptrn.matcher(str);
        while (matcher.find()) {
          System.out.println(matcher.group());
        }
 
	}
}

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