First method accept a string, and will return true if the first letter of that string is found in the range [A-Z]. Second method is a test method.

stringtest

    /**
     * Check first character of a String is a letter [A-Z]. If first character is letter, return true otherwise return false.
     *
     * @param value input value as String
     * @return return true if the first character is in the Range [A-Z]
     */
    private boolean isFirstCharacterLetter(String value){
        if (value == null || value.isEmpty()){
            return false;
        }

        String input = value.trim();
        if (input.isEmpty()){
            return false;
        }

        return Character.isLetter(input.charAt(0));
    }
    
    
        @Test
    public void firstCharacterLetterTest(){
        boolean result = isFirstCharacterLetter("Sharif");
        Assert.assertEquals(result, true);

        /*Input is null*/
        result = isFirstCharacterLetter(null);
        Assert.assertEquals(result, false);

        /*Input is only number*/
        result = isFirstCharacterLetter("122");
        Assert.assertEquals(result, false);

        /*Input is empty*/
        result = isFirstCharacterLetter(" ");
        Assert.assertEquals(result, false);
    }