java-将评论内容过滤特殊表情emoj符号，保存到mysql中

正常操作评论，保存时，若评论内容含有特殊表情符号，后台将报错如下：

Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_general_ci,COERCIBLE) for operation '='; nested exception is java.sql.SQLException: Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_general_ci,COERCIBLE) for operation '='

后来查阅资料，找到方法将其评论内容中特殊符号过滤掉，然后保存。废话不多说，直接上代码：

 /**
      * 检测是否有emoji字符
      * @param source
      * @return 一旦含有就抛出
      */
     public static boolean containsEmoji(String source) {
         if (StringUtils.isBlank(source)) {
             return false;
         }

         int len = source.length();

         for (int i = 0; i < len; i++) {
             char codePoint = source.charAt(i);

             if (isEmojiCharacter(codePoint)) {
                 //do nothing，判断到了这里表明，确认有表情字符
                 return true;
             }
         }

         return false;
     }

     private static boolean isEmojiCharacter(char codePoint) {
         return (codePoint == 0x0) ||
                 (codePoint == 0x9) ||
                 (codePoint == 0xA) ||
                 (codePoint == 0xD) ||
                 ((codePoint >= 0x20) && (codePoint <= 0xD7FF)) ||
                 ((codePoint >= 0xE000) && (codePoint <= 0xFFFD)) ||
                 ((codePoint >= 0x10000) && (codePoint <= 0x10FFFF));
     }

     /**
      * 过滤emoji 或者 其他非文字类型的字符
      * @param source
      * @return
      */
     public static String filterEmoji(String source) {

         if (!containsEmoji(source)) {
             return source;//如果不包含，直接返回
         }
         //到这里铁定包含
         StringBuilder buf = null;

         int len = source.length();

         for (int i = 0; i < len; i++) {
             char codePoint = source.charAt(i);

             if (isEmojiCharacter(codePoint)) {
                 if (buf == null) {
                     buf = new StringBuilder(source.length());
                 }

                 buf.append(codePoint);
             } else {
             }
         }

         if (buf == null) {
             return source;//如果没有找到 emoji表情，则返回源字符串
         } else {
             if (buf.length() == len) {//这里的意义在于尽可能少的toString，因为会重新生成字符串
                 buf = null;
                 return source;
             } else {
                 return buf.toString();
             }
         }

     }

Java Code