The CatalogFeatures holds a collection of features and properties.

[1] There is no System property for the features that marked as "N/A".

[2] The value shall be exactly as listed in this table, case-sensitive. Any unspecified value will result in IllegalArgumentException.

[3] The Catalog specification defined complex rules on the prefer attribute. Although the prefer can be public or system, the specification actually made system the preferred option, that is, no matter the option, a system entry is always used if found. Public entries are only considered if the prefer is public and system entries are not found. It is therefore recommended that the prefer attribute be set as public (which is the default).

[4] Although non-standard attributes in the OASIS Catalog specification, defer and resolve are recognized by the Java Catalog API the same as the prefer as being an attribute in the catalog entry of the main catalog. Note that only the attributes specified for the catalog entry of the main Catalog file will be used.

[5] If the intention is to share an entire catalog store, it may be desirable to set the property javax.xml.catalog.defer to false to allow the entire catalog to be pre-loaded.

Scope and Order

Properties that are specified as attributes in the catalog file for the catalog and group entries shall take preference over any of the other settings. For example, if a prefer attribute is set in the catalog file as in <catalog prefer="public">, any other input for the "prefer" property is not necessary or will be ignored.

Properties set through the Catalog API override those that may have been set by system properties and/or in jaxp.properties. In case of multiple interfaces, the latest in a procedure shall take preference. For CatalogFeatures.Feature.FILES, this means that the URI(s) specified through the methods of the CatalogManager will override any that may have been entered through the CatalogFeatures.Builder.

System properties when set shall override those in jaxp.properties.

The jaxp.properties file is typically in the conf directory of the Java installation. The file is read only once by the JAXP implementation and its values are then cached for future use. If the file does not exist when the first attempt is made to read from it, no further attempts are made to check for its existence. It is not possible to change the value of any properties in jaxp.properties after it has been read.

A CatalogFeatures instance can be created through its builder as illustrated in the following sample code:

CatalogFeatures f = CatalogFeatures.builder()
                        .with(Feature.FILES, "file:///etc/xml/catalog")
                        .with(Feature.PREFER, "public")
                        .with(Feature.DEFER, "true")
                        .with(Feature.RESOLVE, "ignore")
                        .build();

JAXP XML Processor Support

SAXParserFactory spf = SAXParserFactory.newInstance();
      spf.setFeature(XMLConstants.USE_CATALOG, true); [1]
      SAXParser parser = spf.newSAXParser();
      parser.setProperty(CatalogFeatures.Feature.FILES.getPropertyName(), "file:///etc/xml/catalog");

[1] Note that this statement is not required since the default value of USE_CATALOG is true.

The JAXP Processors' support for Catalog depends on both the USE_CATALOG feature and the existence of valid Catalog file(s). A JAXP processor will use the Catalog only when the feature is true and valid Catalog file(s) are specified through the javax.xml.catalog.files property. It will make no attempt to use the Catalog if either USE_CATALOG is set to false, or there is no Catalog file specified.

The JAXP processors will observe the default settings of the CatalogFeatures. The processors, for example, will report an Exception by default when no matching entry is found since the default value of the javax.xml.catalog.resolve property is strict.

The JAXP processors give preference to user-specified custom resolvers. If such a resolver is registered, it will be used over the CatalogResolver. If it returns null however, the processors will continue resolving with the CatalogResolver. If it returns an empty source, no attempt will be made by the CatalogResolver.

The Catalog support is available for any process in the JAXP library that supports a resolver. The following table lists all such processes.

Processes with Catalog Support

The following DTD reference:
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

   Can be resolved using the following Catalog entry:
   <public publicId="-//W3C//DTD XHTML 1.0 Strict//EN" uri="catalog/xhtml1-strict.dtd"/>
   or
   <systemSuffix systemIdSuffix="html1-strict.dtd" uri="catalog/xhtml1-strict.dtd"/>

The following XInclude element:
   <xi:include href="http://openjdk.java.net/xml/disclaimer.xml"/>

   can be resolved using a URI entry:
   <uri name="http://openjdk.java.net/xml/disclaimer.xml" uri="file:///pathto/local/disclaimer.xml"/>
   or
   <uriSuffix uriSuffix="disclaimer.xml" uri="file:///pathto/local/disclaimer.xml"/>

The following import element:
    <xsd:import namespace="http://openjdk.java.net/xsd/XSDImport_person"
                schemaLocation="http://openjdk.java.net/xsd/XSDImport_person.xsd"/>

   can be resolved using a URI entry:
   <uri name="http://openjdk.java.net/xsd/XSDImport_person.xsd" uri="file:///pathto/local/XSDImport_person.xsd"/>
   or
   <uriSuffix uriSuffix="XSDImport_person.xsd" uri="file:///pathto/local/XSDImport_person.xsd"/>
   or
   <uriSuffix uriSuffix="http://openjdk.java.net/xsd/XSDImport_person" uri="file:///pathto/local/XSDImport_person.xsd"/>

The following include element:
   <xsd:include schemaLocation="http://openjdk.java.net/xsd/XSDInclude_person.xsd"/>

   can be resolved using a URI entry:
   <uri name="http://openjdk.java.net/xsd/XSDInclude_person.xsd" uri="file:///pathto/local/XSDInclude_person.xsd"/>
   or
   <uriSuffix uriSuffix="XSDInclude_person.xsd" uri="file:///pathto/local/XSDInclude_person.xsd"/>

The following include element:
   <xsl:include href="http://openjdk.java.net/xsl/include.xsl"/>

   can be resolved using a URI entry:
   <uri name="http://openjdk.java.net/xsl/include.xsl" uri="file:///pathto/local/include.xsl"/>
   or
   <uriSuffix uriSuffix="include.xsl" uri="file:///pathto/local/include.xsl"/>

The document in the following element:
   <xsl:variable name="dummy" select="document('http://openjdk.java.net/xsl/list.xml')"/>

   can be resolved using a URI entry:
   <uri name="http://openjdk.java.net/xsl/list.xml" uri="file:///pathto/local/list.xml"/>
   or
   <uriSuffix uriSuffix="list.xml" uri="file:///pathto/local/list.xml"/>