When the cause of the error is that the content contains low-order non-printing characters, the processing method is filtering.
There are two reasons for including characters: first, the content contains xml predetermined entities, such as ""marking the end, and CDATA internal content is ignored by the parser; Second, the content contains low-order non-printing characters, which will cause an error when parsing: ""(hexadecimal value 0x 1D) is an invalid character.