# Package javax.xml.catalog

package javax.xml.catalog
Provides the classes for implementing XML Catalogs OASIS Standard V1.1, 7 October 2005.

The Catalog API defines a standard solution for resolving external resources referenced by XML documents. It is fully supported by the XML Processors allowing application developers to configure a catalog through an XML processor or system property or the configuration file to take advantage of the feature.

The XML Catalog API defines the following interfaces:

- `Catalog` -- The `Catalog` interface represents an entity catalog as defined by the Catalog standard. A `Catalog` object is immutable. Once created, it can be used to find matches in a `system`, `public` or `uri` entry. A custom resolver implementation may find it useful for locating local resources through a catalog.
- `CatalogFeatures` -- The `CatalogFeatures` class holds all of the features and properties the Catalog API supports, including `javax.xml.catalog.files`, `javax.xml.catalog.defer`, `javax.xml.catalog.prefer`, and `javax.xml.catalog.resolve`.
- `CatalogManager` -- The `CatalogManager` class manages the creation of XML catalogs and catalog resolvers.
- `CatalogResolver` -- The `CatalogResolver` class is a `Catalog` resolver that implements `EntityResolver`, `XMLResolver`, `LSResourceResolver`, and `URIResolver`, and resolves external references using catalogs.

Unless otherwise noted, passing a null argument to a constructor or method in any class or interface in this package will cause a `NullPointerException` to be thrown.

Since:
  9

- Related Packages
  Package
  Description
  javax.xml
  Defines constants for XML processing.
- Class
  Description
  Catalog
  The Catalog class represents an entity Catalog as defined by XML Catalogs, OASIS Standard V1.1, 7 October 2005.
  CatalogException
  The exception class handles errors that may happen while processing or using a catalog.
  CatalogFeatures
  The CatalogFeatures holds a collection of features and properties.
  CatalogFeatures.Builder
  The Builder class for building the CatalogFeatures object.
  CatalogFeatures.Feature
  A Feature type as defined in the Catalog Features table.
  CatalogManager
  The Catalog Manager manages the creation of XML Catalogs and Catalog Resolvers.
  CatalogResolver
  A Catalog Resolver that implements SAX `EntityResolver`, StAX `XMLResolver`, DOM LS `LSResourceResolver` used by Schema Validation, and Transform `URIResolver`, and resolves external references using catalogs.
  CatalogResolver.NotFoundAction
  Defines the actions that a CatalogResolver may take when it is unable to resolve an external reference.