Package org.apache.tools.ant.types

Class XMLCatalog

java.lang.Object
org.apache.tools.ant.ProjectComponent
org.apache.tools.ant.types.DataType
org.apache.tools.ant.types.XMLCatalog
All Implemented Interfaces:
Cloneable, URIResolver, EntityResolver
public class XMLCatalog extends DataType implements EntityResolver, URIResolver

This data type provides a catalog of resource locations (such as DTDs and XML entities), based on the OASIS "Open Catalog" standard. The catalog entries are used both for Entity resolution and URI resolution, in accordance with the EntityResolver and URIResolver interfaces as defined in the Java API for XML Processing Specification.

Resource locations can be specified either in-line or in external catalog file(s), or both. In order to use an external catalog file, the xml-commons resolver library ("resolver.jar") must be in your classpath. External catalog files may be either plain text format or XML format. If the xml-commons resolver library is not found in the classpath, external catalog files, specified in <catalogpath> paths, will be ignored and a warning will be logged. In this case, however, processing of inline entries will proceed normally.

Currently, only <dtd> and <entity> elements may be specified inline; these correspond to OASIS catalog entry types PUBLIC and URI respectively.

The following is a usage example:

 <xmlcatalog>
   <dtd publicId="" location="/path/to/file.jar"/>
   <dtd publicId="" location="/path/to/file2.jar"/>
   <entity publicId="" location="/path/to/file3.jar"/>
   <entity publicId="" location="/path/to/file4.jar"/>
   <catalogpath>
     <pathelement location="/etc/sgml/catalog"/>
   </catalogpath>
   <catalogfiles dir="/opt/catalogs/" includes="**\catalog.xml"/>
 </xmlcatalog>

Tasks wishing to use <xmlcatalog> must provide a method called createXMLCatalog which returns an instance of XMLCatalog. Nested DTD and entity definitions are handled by the XMLCatalog object and must be labeled dtd and entity respectively.

The following is a description of the resolution algorithm: entities/URIs/dtds are looked up in each of the following contexts, stopping when a valid and readable resource is found:

  1. In the local filesystem
  2. In the classpath
  3. Using the Apache xml-commons resolver (if it is available)
  4. In URL-space

See XMLValidateTask for an example of a task that has integrated support for XMLCatalogs.

Possible future extension could provide for additional OASIS entry types to be specified inline.

  • Field Details

    • APACHE_RESOLVER

      public static final String APACHE_RESOLVER
      The name of the bridge to the Apache xml-commons resolver class, used to determine whether resolver.jar is present in the classpath.
      See Also:

    • CATALOG_RESOLVER

      public static final String CATALOG_RESOLVER
      Resolver base class
      See Also:

  • Constructor Details

    • XMLCatalog

      public XMLCatalog()
      Default constructor

  • Method Details

    • createClasspath

      public Path createClasspath()
      Allows nested classpath elements. Not allowed if this catalog is itself a reference to another catalog -- that is, a catalog cannot both refer to another and contain elements or other attributes.
      Returns:
      a Path instance to be configured.

    • setClasspath

      public void setClasspath(Path classpath)
      Allows simple classpath string. Not allowed if this catalog is itself a reference to another catalog -- that is, a catalog cannot both refer to another and contain elements or other attributes.
      Parameters:
      classpath - the classpath to use to look up entities.

    • setClasspathRef

      public void setClasspathRef(Reference r)
      Allows classpath reference. Not allowed if this catalog is itself a reference to another catalog -- that is, a catalog cannot both refer to another and contain elements or other attributes.
      Parameters:
      r - an Ant reference containing a classpath.

    • createCatalogPath

      public Path createCatalogPath()
      Creates a nested <catalogpath> element. Not allowed if this catalog is itself a reference to another catalog -- that is, a catalog cannot both refer to another and contain elements or other attributes.
      Returns:
      a path to be configured as the catalog path.
      Throws:
      BuildException - if this is a reference and no nested elements are allowed.

    • setCatalogPathRef

      public void setCatalogPathRef(Reference r)
      Allows catalogpath reference. Not allowed if this catalog is itself a reference to another catalog -- that is, a catalog cannot both refer to another and contain elements or other attributes.
      Parameters:
      r - an Ant reference containing a classpath to be used as the catalog path.

    • getCatalogPath

      public Path getCatalogPath()
      Returns the catalog path in which to attempt to resolve DTDs.
      Returns:
      the catalog path

    • addDTD

      public void addDTD(ResourceLocation dtd) throws BuildException
      Creates the nested <dtd> element. Not allowed if this catalog is itself a reference to another catalog -- that is, a catalog cannot both refer to another and contain elements or other attributes.
      Parameters:
      dtd - the information about the PUBLIC resource mapping to be added to the catalog
      Throws:
      BuildException - if this is a reference and no nested elements are allowed.

    • addEntity

      public void addEntity(ResourceLocation entity) throws BuildException
      Creates the nested <entity> element. Not allowed if this catalog is itself a reference to another catalog -- that is, a catalog cannot both refer to another and contain elements or other attributes.
      Parameters:
      entity - the information about the URI resource mapping to be added to the catalog.
      Throws:
      BuildException - if this is a reference and no nested elements are allowed.

    • addConfiguredXMLCatalog

      public void addConfiguredXMLCatalog(XMLCatalog catalog)
      Loads a nested <xmlcatalog> into our definition. Not allowed if this catalog is itself a reference to another catalog -- that is, a catalog cannot both refer to another and contain elements or other attributes.
      Parameters:
      catalog - Nested XMLCatalog

    • setRefid

      public void setRefid(Reference r) throws BuildException
      Makes this instance in effect a reference to another XMLCatalog instance.

      You must not set another attribute or nest elements inside this element if you make it a reference. That is, a catalog cannot both refer to another and contain elements or attributes.

      Overrides:
      setRefid in class DataType
      Parameters:
      r - the reference to which this catalog instance is associated
      Throws:
      BuildException - if this instance already has been configured.

    • resolveEntity

      public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException
      Implements the EntityResolver.resolveEntity() interface method.
      Specified by:
      resolveEntity in interface EntityResolver
      Parameters:
      publicId - the public id to resolve.
      systemId - the system id to resolve.
      Returns:
      the resolved entity.
      Throws:
      SAXException - if there is a parsing problem.
      IOException - if there is an IO problem.
      See Also:

    • resolve

      public Source resolve(String href, String base) throws TransformerException
      Implements the URIResolver.resolve() interface method.
      Specified by:
      resolve in interface URIResolver
      Parameters:
      href - an href attribute.
      base - the base URI.
      Returns:
      a Source object, or null if href cannot be resolved.
      Throws:
      TransformerException - if an error occurs.
      See Also:

    • dieOnCircularReference

      protected void dieOnCircularReference(Stack<Object> stk, Project p) throws BuildException
      Description copied from class: DataType
      Check to see whether any DataType we hold references to is included in the Stack (which holds all DataType instances that directly or indirectly reference this instance, including this instance itself).

      If one is included, throw a BuildException created by circularReference.

      This implementation is appropriate only for a DataType that cannot hold other DataTypes as children.

      The general contract of this method is that it shouldn't do anything if DataType.checked is true and set it to true on exit.

      Overrides:
      dieOnCircularReference in class DataType
      Parameters:
      stk - the stack of references to check.
      p - the project to use to dereference the references.
      Throws:
      BuildException - on error.