Solved Java XML Parsing Error : Content is not allowed in prolog

No Beginning Tag:Content Is Not Allowed In Prolog

Content Is Not Allowed In Prolog

Prolog error is also shown when yhe XML header do not have a beginning tag “<” before thePseudo Attribute, firstquestion mark in the XML header as shown in the image. If the document in not proper UTF and there are invisible characters between the XML header, a prolog error can be shown.

AOnline Syntax Error Parsing XML Validator Toolcan be used to check the parsing errors and find invisible characters.

To Solve this Prolog error;

Copy either of the below code and replace it with the existing XML header;

<?xml version=”1.0″ encoding=”UTF-16″ standalone=”no”?>

or

<?xml version=”1.0″ encoding=”UTF-8″ ?>

Byte Order Markers

Byte order markers could be in the buffer. Before passing the buffer to the Parser do this.

String xml = “<?xml …”;
xml = xml.trim().replaceFirst(“^([\W]+)<“,”<“);

Clearing the white spaces between characters also helps in sorting out the issue. If the XML header has white space before it, you may encounter another error:The processing instruction target matching “[xX][mM][lL]” is not allowed as shown in the below image.

The processing instruction target matching “[xX][mM][lL]” is not allowed

Characters Before XML header:Content Is Not Allowed In Prolog

Characters Before XML header