Baseelements xml error bom6/3/2023 A text file beginning with the bytes FE FF suggests that the file is encoded in big-endian UTF-16, while a text file beginning with FF FE suggests that the file is encoded in little-endian UTF-16. The BOM character is, simply, the Unicode codepoint U+FEFF ZERO WIDTH NO-BREAK SPACE, encoded in the current encoding. This use of the BOM character is called a "Unicode signature". Therefore, placing an encoded BOM at the start of a text stream can indicate that the text is Unicode and identify the encoding scheme used. The byte sequence of the BOM differs per Unicode encoding (including ones outside the Unicode standard such as UTF-7, see table below), and none of the sequences is likely to appear at the start of text streams stored in other encodings. Generally the receiving computer will swap the bytes to its own endianness, if necessary, and would no longer need the BOM for processing. Hence, the process accessing the text can examine these first few bytes to determine the endianness, without requiring some contract or metadata outside of the text stream itself. The BOM is encoded in the same scheme as the rest of the document and becomes a noncharacter Unicode code point if its bytes are swapped. For the 16- and 32-bit representations, a computer receiving text from arbitrary sources needs to know which byte order the integers are encoded in. Unicode can be encoded in units of 8-bit, 16-bit, or 32-bit integers. Its presence interferes with the use of UTF-8 by software that does not expect non-ASCII bytes at the start of a file but that could otherwise handle the text stream. Which Unicode character encoding is used.īOM use is optional.The fact that the text stream's encoding is Unicode, to a high level of confidence.The byte order, or endianness, of the text stream in the cases of 16-bit and 32-bit encodings.The byte order mark ( BOM) is a particular usage of the special Unicode character, U+FEFF ZERO WIDTH NO-BREAK SPACE, whose appearance as a magic number at the start of a text stream can signal several things to a program reading the text: For the name of U+FEFF in Unicode and the alternative usage as a zero-width non-breaking space, see Word joiner. For the program used in X-ray absorption spectroscopy, see FEFF (software). For the airport in Central African Republic with the airport code FEFF, see Bangui M'Poko International Airport. 'A' could be represented by A ), so it isn't necessarily a requirement to avoid data loss."FEFF" redirects here. That said, XML allows the representation of any Unicode character via escape entities (e.g. I advocate encoding as Unicode wherever possible (see also the 10 Commandments of Unicode). If you are strict about this, parsers should be able to interpret your documents correctly. Always make sure that the XML declaration ( ) matches the encoding used to write the document. Detection of encoding in XML is relatively straightforward if the encoding is specified in the declaration. When it comes to BOMs and XML, they are optional (see also the Unicode BOM FAQ). ( More on encoding the BOM using Java here.) Since U+FEFF isn't in most encodings, it is not possible for this BOM codepoint to be encoded by them. This can be expressed as a Java char literal using '' (Java char values are implicitly UTF-16). These are the variously encoded forms of the Unicode codepoint U+FEFF. The byte order mark is likely to be one of these byte sequences: UTF-8 BOM: ef bb bf
0 Comments
Leave a Reply. |