How to determine whether a string is English in java

public class ChineseAndEnglish {

    // GENERAL_PUNCTUATION 判断中文的"号

    // CJK_SYMBOLS_AND_PUNCTUATION 判断中文的。号

    // HALFWIDTH_AND_FULLWIDTH_FORMS 判断中文的，号

  /**

   * 是否是中文

   * @param c

   * @return

   */

   public static boolean isChinese(char c) {

        Character.UnicodeBlock ub = Character.UnicodeBlock.of(c);

        if (ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS

                || ub == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS

                || ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A

                || ub == Character.UnicodeBlock.GENERAL_PUNCTUATION

                || ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION

                || ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS) {

            return true;

        }

        return false;

    }

  /**

   * 是否是英文

   * @param c

   * @return

   */

   public static boolean isEnglish(String charaString){

      return charaString.matches("^[a-zA-Z]*");

    }

  public static boolean isChinese(String str){

      String regEx = "[\\u4e00-\\u9fa5]+";

      Pattern p = Pattern.compile(regEx);

      Matcher m = p.matcher(str);

     if(m.find())

       return true;

     else

       return false;

   }

    public static void main(String[] args) {

 System.out.println(isChinese('员'));

System.out.println(isChinese('s'));

 System.out.println(isEnglish("程序员之家"));

System.out.println(isEnglish("robert"));

        System.out.println(isChinese("

程序员论坛"));

    }