/**
 * @Author: gaoshang
 * @Description:
 * @Date: 2019/7/19
 */
public class EmojiUtil {

 /**
  * 將文本中的表情轉為十六進制
  * <p>
  *
  * @param input
  * @return
  */
 public static String parseFromAliases(String input) {
  if (input == null) {
   return input;
  }

  return stringToUnicode(input);
 }

 /**
  * 將文本中的十六進制轉為表情
  * <p>
  *
  * @param input
  * @return
  */
 public static String parseToAliases(String input) {
  if (input == null) {
   return input;
  }

  return unicodeToString(input);
 }

 /**
  * 字符串轉unicode
  *
  * @param str
  * @return
  */
 public static String stringToUnicode(String str) {
  StringBuilder sb = new StringBuilder();
  StringBuilder cacheSB = new StringBuilder();
  char[] c = str.toCharArray();
  for (int i = 0; i < c.length; i++) {
   if (!isEmojiCharacter(c[i])) {
    if (cacheSB.length() > 0) {
     sb.append("\\u").append(cacheSB);
     cacheSB.delete(0, cacheSB.length());
    }

    sb.append("\\u").append("[").append(Integer.toHexString(c[i])).append("]");
   } else {
    if (c[i] == '[' || c[i] == '\\' || c[i] == ']') {
     if (cacheSB.length() > 0) {
      sb.append("\\u").append(cacheSB);
      cacheSB.delete(0, cacheSB.length());
     }
     sb.append("\\u").append(c[i]);
    } else {
     cacheSB.append(c[i]);
    }
   }
  }
  if (cacheSB.length() > 0) {
   if (sb.length() > 0) {
    sb.append("\\u");
   }
   sb.append(cacheSB);
  }
  return sb.toString();
 }

 /**
  * unicode轉字符串
  *
  * @param unicode
  * @return
  */
 public static String unicodeToString(String unicode) {
  StringBuilder sb = new StringBuilder();
  String[] hex = unicode.split("\\\\u");
  for (int i = 0; i < hex.length; i++) {
   if (hex[i].indexOf("[") == 0 && hex[i].indexOf("]") == hex[i].length() - 1) {
    try {
     int index = Integer.parseInt(hex[i].substring(1, hex[i].length() - 1), 16);
     sb.append((char) index);
    } catch (NumberFormatException e) {
     sb.append(hex[i]);
    }
   } else {
    sb.append(hex[i]);
   }
  }
  return sb.toString();
 }

 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));
 }

}