String Encode and Decode

1. Mode : Select the target format to encode and decode the string.
   1. Base64 : Encode the string as Base64, or decode Base64 as a string.
   2. Hex : Encode a string as a Hex string, or decode a Hex string as a string.
   3. UrlEncode : Encode the string in UrlEncode format to meet the URL address format requirements. Or decode the UrlEncode string into a string.
   4. Html Entity Escape : Converts the HTML special characters in the input string to the corresponding HTML entity. Or convert HTML entities into corresponding characters.
   5. MD5 : Calculate the MD5 hash value of the input string, and the result is expressed as a hexadecimal string.
   6. Escape : Escape ',",\ in the input string to \',\",\\. Or remove the backslash of the escape character above.
2. Charset : Select the character set used for string - byte array conversion.
3. Download : Download the input content as a text file, and the file encoding is UTF-8.