Question

I have a EditText field in android. The password should contain minimum 4 characters and maximum 20 characters without spaces at the start or in the middle. Example blankspaceRaghu and RaghublankspaceRaghu should not be alllowed.

Pass= password.getText().toString();    

Pattern p= Pattern.compile("[^\\S]+[a-z,A-Z]+");

Matcher m = p.matcher(Pass);

Answer 1

Updated – Spaces are allowed at the end….

Pass= password.getText().toString();    
Pattern p= Pattern.compile("((?!\\s)\\A)(\\s|(?<!\\s)\\S){4,20}\\Z");
Matcher m = p.matcher(Pass);

This matches

• Match start of string as long as it is not followed by a space
• Match 4 to 20 occurrences of either a space or a non space provided it is not prefixed by a space
• Match end of string