问在Java中，如何在不使用正则表达式情况下查找字符串的第一个字符是否为大写

EN

Character.isUpperCase(s.charAt(0))

Character.isUpperCase(s.codePointAt(0));

boolean isUpperCase = Character.isUpperCase("My String".charAt(0));

public class StartWithUpperCase{

        public static void main(String[] args){

            String str1 = ""; //StringIndexOfBoundException if 
                              //empty checking not handled
            String str2 = null; //NullPointerException if 
                                //null checking is not handled.
            String str3 = "Starts with upper case";
            String str4 = "starts with lower case";

            System.out.println(startWithUpperCase(str1)); //false
            System.out.println(startWithUpperCase(str2)); //false
            System.out.println(startWithUpperCase(str3)); //true
            System.out.println(startWithUpperCase(str4)); //false



        }

        public static boolean startWithUpperCase(String givenString){

            if(null == givenString || givenString.isEmpty() ) return false;
            else return (Character.isUpperCase( givenString.codePointAt(0) ) );
        }

    }