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package javax.xml.catalog;

import java.io.InputStream;

import javax.xml.stream.XMLResolver;

import javax.xml.transform.Source;

import javax.xml.transform.URIResolver;

import org.w3c.dom.ls.LSInput;

import org.w3c.dom.ls.LSResourceResolver;

import org.xml.sax.EntityResolver;

import org.xml.sax.InputSource;

/**

 * A Catalog Resolver that implements SAX {@link org.xml.sax.EntityResolver},

 * StAX {@link javax.xml.stream.XMLResolver},

 * DOM LS {@link org.w3c.dom.ls.LSResourceResolver} used by Schema Validation, and

 * Transform {@link javax.xml.transform.URIResolver}, and resolves

 * external references using catalogs.

 * <p>

 * The <a href="https://www.oasis-open.org/committees/download.php/14809/xml-catalogs.html">

 * Catalog Standard</a> distinguished {@code external identifiers} from {@code uri entries}

 * as being used to solely identify DTDs, while {@code uri entries} for

 * other resources such as stylesheets and schema. The Java APIs, such as

 * {@link javax.xml.stream.XMLResolver} and {@link org.w3c.dom.ls.LSResourceResolver}

 * however, make no such distinction.

 * In consistent with the existing Java API, this CatalogResolver recognizes a

 * entries in a catalog in order to find a matching entry.

 * <p>

 * The search is started in the current catalog. If a match is found,

 * no further attempt will be made. Only if there is no match in the current

 * catalog, will alternate catalogs including delegate and next catalogs be considered.

 * <p>

 * <h3>Search Order</h3>

 * The resolver will first search the system-type of entries with the specified

 * {@code systemId}. The system entries include {@code system},

 * {@code rewriteSystem} and {@code systemSuffix} entries.

 * <p>

 * If no match is found, {@code public} entries may be searched in accordance with

 * the {@code prefer} attribute.

 * <p>

 * <b>The {@code prefer} attribute</b>: if the {@code prefer} is public,

 * and there is no match found through the system entries, {@code public} entries

 * will be considered. If it is not specified, the {@code prefer} is public

 * by default (Note that by the OASIS standard, system entries will always

 * be considered before public entries. Prefer public means that public entries

 * will be matched when both system and public identifiers are specified.

 * In general therefore, prefer public is recommended.)

 * <p>

 * If no match is found with the {@code systemId} and {@code public} identifier,

 * the resolver will continue searching {@code uri} entries

 * with the specified {@code systemId} or {@code href}. The {@code uri} entries

 * include {@code uri}, {@code rewriteURI}, and {@code uriSuffix} entries.

 *

 * <p>

 * <h3>Error Handling</h3>

 * The interfaces that the CatalogResolver extend specified checked exceptions, including:

 * <ul>

 * <li>

 * {@link org.xml.sax.SAXException} and {@link java.io.IOException} by

 * {@link org.xml.sax.EntityResolver#resolveEntity(java.lang.String, java.lang.String)}

 * </li>

 * <li>

 * {@link javax.xml.stream.XMLStreamException} by

 * {@link javax.xml.stream.XMLResolver#resolveEntity(java.lang.String, java.lang.String, java.lang.String, java.lang.String)}

 * </li>

 * <li>

 * {@link javax.xml.transform.TransformerException} by

 * {@link javax.xml.transform.URIResolver#resolve(java.lang.String, java.lang.String)}

 * </li>

 * </ul>

 * <p>

 * The CatalogResolver however, will throw {@link javax.xml.catalog.CatalogException}

 * only when {@code javax.xml.catalog.resolve} is specified as {@code strict}.

 * For applications that expect to handle the checked Exceptions, it may be

 * necessary to use a custom resolver to wrap the CatalogResolver or implement it

 * with a {@link javax.xml.catalog.Catalog} object.

 *

 * @since 9

 */

public interface CatalogResolver extends EntityResolver, XMLResolver,

        URIResolver, LSResourceResolver {

    /**

     * Implements {@link org.xml.sax.EntityResolver}. The method searches through

     * the catalog entries in the main and alternative catalogs to attempt to find

     * a match with the specified {@code publicId} or systemId.

     *

     * @param publicId the public identifier of the external entity being

     * referenced, or null if none was supplied

     *

     * @param systemId the system identifier of the external entity being

     * referenced. A system identifier is required on all external entities. XML

     * requires a system identifier on all external entities, so this value is

     * always specified.

     *

     * @return a {@link org.xml.sax.InputSource} object if a mapping is found.

     * If no mapping is found, returns a {@link org.xml.sax.InputSource} object

     * containing an empty {@link java.io.Reader} if the

     * {@code javax.xml.catalog.resolve} property is set to {@code ignore};

     * returns null if the

     * {@code javax.xml.catalog.resolve} property is set to {@code continue}.

     *

     * @throws CatalogException if no mapping is found and

     * {@code javax.xml.catalog.resolve} is specified as {@code strict}

     */

    @Override

    public InputSource resolveEntity(String publicId, String systemId);

    /**

     * Implements URIResolver. The method searches through the catalog entries

     * in the main and alternative catalogs to attempt to find a match

     * with the specified {@code href} attribute. The {@code href} attribute will

     * be used literally, with no attempt to be made absolute to the {@code base}.

     * <p>

     * {@code publicId}, and used to search {@code public} entries.

     * search both {@code system} and {@code uri} entries.

     *

     *

     * @param href the href attribute that specifies the URI of a style sheet,

     * which may be relative or absolute

     * @param base The base URI against which the href attribute will be made

     * absolute if the absolute URI is required

     *

     * @return a {@link javax.xml.transform.Source} object if a mapping is found.

     * If no mapping is found, returns an empty {@link javax.xml.transform.Source}

     * object if the {@code javax.xml.catalog.resolve} property is set to

     * {@code ignore};

     * returns a {@link javax.xml.transform.Source} object with the original URI

     * (href, or href resolved with base if base is not null) if the

     * {@code javax.xml.catalog.resolve} property is set to {@code continue}.

     *

     * @throws CatalogException if no mapping is found and

     * {@code javax.xml.catalog.resolve} is specified as {@code strict}

     */

    @Override

    public Source resolve(String href, String base);

    /**

     * Implements {@link javax.xml.stream.XMLResolver}. For the purpose of resolving

     * {@code publicId} and {@code systemId}, this method is equivalent to

     * {@link #resolveEntity(java.lang.String, java.lang.String) }.

     * <p>

     * The {@code systemId} will be used literally, with no attempt to be made

     * absolute to the {@code baseUri}. The {@code baseUri} and {@code namespace}

     * are not used in the search for a match in a catalog. However, a relative

     * {@code systemId} in an xml source may have been made absolute by the parser

     * with the {@code baseURI}, thus making it unable to find a {@code system} entry.

     * In such a case, a {@code systemSuffix} entry is recommended over a

     * {@code system} entry.

     *

     * @param publicId the public identifier of the external entity being

     * referenced, or null if none was supplied

     *

     * @param systemId the system identifier of the external entity being

     * referenced. A system identifier is required on all external entities. XML

     * requires a system identifier on all external entities, so this value is

     * always specified.

     * @param baseUri  the absolute base URI, not used by the CatalogResolver

     * @param namespace the namespace of the entity to resolve, not used by the

     * CatalogResolver.

     *

     * @return an {@link java.io.InputStream} object if a mapping is found; null

     * if no mapping is found and the {@code javax.xml.catalog.resolve} property

     * is set to {@code continue} or {@code ignore}. Note that for XMLResolver,

     * it is not possible to ignore a reference, {@code ignore} is therefore

     * treated the same as {@code continue}.

     *

     * @throws CatalogException if no mapping is found and

     * {@code javax.xml.catalog.resolve} is specified as {@code strict}

     */

    @Override

    public InputStream resolveEntity(String publicId, String systemId,

            String baseUri, String namespace);

    /**

     * Implements {@link org.w3c.dom.ls.LSResourceResolver}. For the purpose of

     * resolving {@code publicId} and {@code systemId}, this method is equivalent

     * to {@link #resolveEntity(java.lang.String, java.lang.String) }.

     * <p>

     * The {@code systemId} will be used literally, with no attempt to be made

     * absolute to the {@code baseUri}. The {@code baseUri}, {@code namespaceUri}

     * and {@code type} are not used in the search for a match in a catalog.

     * However, a relative {@code systemId} in a source may have been made absolute

     * by the parser with the {@code baseURI}, thus making it unable to find a

     * {@code system} entry. In such a case, a {@code systemSuffix} entry is

     * recommended over a {@code system} entry.

     *

     * @param type  the type of the resource being resolved,

     * not used by the CatalogResolver

     * @param namespaceUri  the namespace of the resource being resolved,

     * not used by the CatalogResolver

     * @param publicId  the public identifier of the external entity being

     *   referenced, or {@code null} if no public identifier was

     *   supplied or if the resource is not an entity.

     *   external resource being referenced

     * @param baseUri  the absolute base URI, not used by the CatalogResolver

     *

     * @return a {@link org.w3c.dom.ls.LSInput} object if a mapping is found; null

     * if no mapping is found and the {@code javax.xml.catalog.resolve} property

     * is set to {@code continue} or {@code ignore}. Note that for

     * {@link org.w3c.dom.ls.LSResourceResolver}, it is not possible to ignore a

     * reference, {@code ignore} is therefore treated the same as {@code continue}.

     *

     * @throws CatalogException if no mapping is found and

     * {@code javax.xml.catalog.resolve} is specified as {@code strict}

     */

    @Override

    public LSInput resolveResource(String type, String namespaceUri,

            String publicId, String systemId, String baseUri);

}