Controlling parsing of source documents
Saxon does not include its own XML parser. By default:
SaxonJ uses the default SAX parser provided as part of the JDK. With the Oracle JDK, this is a variant of the Apache Xerces parser customized by Oracle.
SaxonCS uses the
An error reported by the XML parser is generally fatal. It is not possible to process ill-formed XML.
With SaxonJ, there are several ways you can cause a different XML parser to be used:
-yoptions on the command line can be used to specify the class name of a SAX parser, which Saxon will load in preference to the default SAX parser. The
-xoption is used for source XML documents, the
-yoption for schemas and stylesheets. The equivalent options can be set programmatically or by using the configuration file.
By default Saxon uses the
SAXParserFactorymechanism to load a parser. This can be configured by setting the system property
javax.xml.parsers.SAXParserFactory, by means of the file
lib/jaxp.propertiesin the JRE directory, or by adding another parser to the
The source for parsing can be supplied in the form of a
SAXSourceobject, which has an
XMLReaderproperty containing the parser instance to be used.
For a document read using the
document()functions, the parser (XMLReader) to be used can be specified using the query parameter
?parser=full.class.namein the document URI -- but only if the
StandardURIResolveris used, and the feature is enabled by calling
Configuration.setParameterizedURIResolver()or by setting
Transformcommand lines. For example,
parser=org.ccil.cowan.tagsoup.Parsercauses John Cowan's TagSoup parser for HTML to be used.
Saxonica traditionally recommended use of the Xerces parser from Apache in preference to the version bundled in the JDK, which was known to have some serious bugs. However, the version bundled in Java 8 appears to be more reliable.
By default, Saxon invokes the parser in non-validating mode (that is, without requested DTD
validation). Note however, that the parser still needs to read the DTD if one is present,
because it may contain entity definitions that need to be expanded. DTD validation can be
-dtd:on on the command line, or equivalent API or configuration
Saxon never asks the XML parser to perform schema validation. If schema validation is
required it should be requested using the command line options
-val:lax, or their API equivalents. Saxon will then use its own schema
processor to validate the document as it emerges from the XML parser. Schema processing is
done in parallel with parsing, by use of a SAX-like pipeline.