java正則表達式驗證

public static void main(String[] args) {
            System.out.println(isContainEnglish("This is a piece of English"));
        }

 /**
         * 
         * @param str
         * @return true:是字母，false:含有非法字符
         */
public static boolean isContainEnglish(String str) {
            Pattern p = Pattern.compile("^[ A-Za-z]+$");
            Matcher m = p.matcher(str);
            if (m.find()) {
                return true;
            }
            return false;
        }