Using JAXP for Transformations

More information and examples relating to the JAXP transformation API can be found in the example application found in the samples directory.

The types of object that can be supplied as stylesheet parameters are not defined in the JAXP specification: they are implementation-dependent. Saxon takes the Java object supplied, and converts it to an XPath value using the same rules as it applies for the return value from a Java extension function: for these rules, see Saxon Extensibility. If the resulting value is an atomic value, it is cast to the required type of the parameter as specified in the xsl:param declaration, using the XPath casting rules. If the value is non-atomic (for example, if it is a node, or a sequence of integers), then no conversion is attempted, instead, the value must match the required type as stated.

The JAXP TransformerFactory interface provides a configuration method setAttribute() for setting implementation-defined configuration parameters. The parameters supported by Saxon have names defined by constants in the class net.sf.saxon.FeatureKeys. The names of these properties and their meanings, are described in the table below.




A Boolean: true if the stylesheet allows external functions to be called. Default is true. The setting false is recommended in an environment where untrusted stylesheets may be executed. Setting this value to false also disables user-defined extension elements, together with the writing of multiple output files (xsl:result-document), all of which carry similar security risks.

It is also a good idea when executing untrusted stylesheets to use a URIResolver that monitors the use of the doc(), document(), and collection() functions to read external documents.


A user-written class implementing Saxon's CollationURIResolver interface. This is used to process any collation URIs found in the stylesheet, returning an object of class StringCollator that implements the requested collation.


A user-written class implementing Saxon's CollectionURIResolver interface. This is used to process any URIs used in calls to the collection() function. The CollectionURIResolver may either return a sequence of URIs (which are then resolved in the same way as URIs passed to the doc() function), or it may return a sequence of (typically document) nodes.


A Boolean. If run-time tracing of stylesheet execution is required, then the code must be compiled with tracing enabled. Default is false. (Switching tracing on at run-time is done by providing a TraceListener to the Controller object, which is Saxon's implementation of the JAXP Transformer.)


A Boolean. If true, the XML parser is requested to perform validation of source documents against their DTD. Default is false.


A Boolean. If true, default attribute values found in a schema or DTD are expanded (both on input and on output documents, if validation is requested). Default is true. It is always possible to switch this off for schema validation, but not all XML parsers allow it to be switched off in the case of DTD validation.


A Boolean. If true, line number information is retained for all source documents. This is accessible using the saxon:line-number() extension function. Default is false.


The full name of a class that implements the net.sf.saxon.output.Emitter interface; the class will be used to format the output of the xsl:message instruction.


Affects XQuery only. A user-written class implementing Saxon's ModuleURIResolver interface. This is used to process any URIs used in import module directives in XQuery.


A instance of class Indicates that the supplied NamePool should be used as the target (run-time) NamePool by all stylesheets compiled (using newTemplates()) after this call on setAttribute. Normally a single system-allocated NamePool is used for all stylesheets compiled while the Java VM remains loaded; this attribute allows user control over the allocation of NamePools. Note that source trees used as input to a transformation must be built using the same NamePool that is used when the stylesheet is compiled: this will happen automatically if the input to a transformation is supplied as a SAXSource or StreamSource but it is under user control if you build the source tree yourself.


An instance of the class OutputURIResolver; this object will be used to resolve URIs of secondary result documents specified in the href attribute of the xsl:result-document instruction


A Boolean. If true, calls on the doc() and document() functions, if their arguments are known at compile time, will be evaluated at compile time, and the resulting document will be stored as part of the Saxon Configuration and shared by all queries and transformations running within that Configuration. Useful for reference documents that have stable content and are used by many different queries and transformations. Default is false, which means each query or transformation will reload the document from disc.


A Boolean: true if the the standard URI resolver is to recognize query parameters included in the URI (for example, ?val=strict). Such parameters can then be used in URIs passed to the doc() or document() functions. For details of the query parameters available, see Source Documents


An Integer, 0, 1, or 2. Indicates the policy for handling dynamic errors that the XSLT specification defines as recoverable. 0 means recover silently; 1 means recover after signalling a warning to the ErrorListener; 2 means treat the error as fatal. An example of a recoverable error is when two template rules match the same node. These are available as constants in the Controller class: RECOVER_SILENTLY, RECOVER_WITH_WARNINGS, or DO_NOT_RECOVER


An instance of the class SchemaURIResolver; this object will be used to resolve URIs of schema documents referenced in xsl:import-schema declarations in XSLT, import schema in XQuery, references from one schema document to another using xs:include or xs:import, and references from an instance document to a schema using xsi:schemaLocation.


An Integer. One of the symbolic constants Validation.STRIP, Validation.PRESERVE, Validation.LAX, Validation.STRICT. Indicates whether and how schema validation should be applied to source documents.


The full name of a class that implements the org.xml.sax.XMLReader interface; the class will be used to parse source documents (that is, the principal source document plus any secondary source documents read using the document() function)


A string. One of the values "all", "none", or "ignorable". Indicates whether all whitespace, no whitespace, or whitespace in elements defined in a DTD or schema as having element-only content should be stripped from source documents. Default is "ignorable". This whitespace stripping is additional to any stripping done as a result of the xsl:strip-space declaration in the stylesheet.


The full name of a class that implements the org.xml.sax.XMLReader interface; the class will be used to parse stylesheet documents (that is, the principal stylesheet module plus any secondary source documents read using xsl:include or xsl:import)


A Boolean: true if basic timing information is to be output to the standard error output stream.


A Boolean. If true, Saxon will output (to the standard error output) progress information about its attempts to locate and disambiguate references to external Java extension functions. Useful for diagnistics if you are having trouble with user-written extension functions.


An instance of the class net.sf.saxon.trace.TraceListener. This object will be notified of significant events occurring during the transformation, for tracing or debugging purposes.


An Integer: Builder.STANDARD_TREE or Builder.TINY_TREE. Selects an implementation of the Saxon tree model. The default is Builder.TINY_TREE.


A Boolean. Indicates (if true) that errors occuring while validating a final result tree are to be treated as warnings rather than fatal errors. Although the XSLT specification states that validation errors are fatal, this switch can be useful during debugging because it enables the invalid output to be inspected. It will include comments showing where the validity errors were found. Applies to Saxon-SA only.


A Boolean. Indicates whether a warning message should be notified (to the ErrorListener) if running against a stylesheet that specifies version="1.0". This warning is output by default (because the W3C specification requires it), but it may be suppressed using this option.


A Boolean. Indicates whether source documents should have any XInclude directives expanded. Default is false. This relies on support in the underlying XML parser.


An integer. Indicates the version of XML that is used for validating names and determining which characters are allowed. Values are 10 for XML 1.0, and 11 for XML 1.1. Default is currently 1.0, but may change.

Saxon's implementation of the JAXP Transformer interface is the class net.sf.saxon.Controller. This provides a number of options beyond those available in the standard JAXP interface, for example the ability to set an output URI resolver for secondary output documents, and a method to set the initial mode before the transformation starts. You can access these methods by casting the Transformer to a Controller. The methods are described in the JavaDoc documentation supplied with the product.

When using the JAXP interface, you can set serialization properties using a java.util.Properties object. The names of the core XSLT 1.0 properties, such as method, encoding, and indent, are defined in the JAXP class javax.xml.transform.OutputKeys. Additional properties, including Saxon extensions and XSLT 2.0 extensions, have names defined by constants in the class net.sf.saxon.event.SaxonOutputKeys. The values of the properties are exactly as you would specify them in the xsl:output declaration.