- * This module, both source code and documentation, is in the - * Public Domain, and comes with NO WARRANTY. - * See http://www.saxproject.org - * for further information. - *- * - *
If a SAX application needs to implement customized handling - * for external entities, it must implement this interface and - * register an instance with the SAX driver using the - * {@link org.xml.sax.XMLReader#setEntityResolver setEntityResolver} - * method.
- * - *The XML reader will then allow the application to intercept any - * external entities (including the external DTD subset and external - * parameter entities, if any) before including them.
- * - *Many SAX applications will not need to implement this interface, - * but it will be especially useful for applications that build - * XML documents from databases or other specialised input sources, - * or for applications that use URI types other than URLs.
- * - *The following resolver would provide the application - * with a special character stream for the entity with the system - * identifier "http://www.myhost.com/today":
- * - *
- * import org.xml.sax.EntityResolver;
- * import org.xml.sax.InputSource;
- *
- * public class MyResolver implements EntityResolver {
- * public InputSource resolveEntity (String publicId, String systemId)
- * {
- * if (systemId.equals("http://www.myhost.com/today")) {
- * // return a special input source
- * MyReader reader = new MyReader();
- * return new InputSource(reader);
- * } else {
- * // use the default behaviour
- * return null;
- * }
- * }
- * }
- *
- *
- * The application can also use this interface to redirect system - * identifiers to local URIs or to look up replacements in a catalog - * (possibly by using the public identifier).
- * - * @since SAX 1.0 - * @author David Megginson - * @version 2.0.1 (sax2r2) - * @see org.xml.sax.XMLReader#setEntityResolver - * @see org.xml.sax.InputSource - */ -public interface EntityResolver { - - - /** - * Allow the application to resolve external entities. - * - *The parser will call this method before opening any external - * entity except the top-level document entity. Such entities include - * the external DTD subset and external parameter entities referenced - * within the DTD (in either case, only if the parser reads external - * parameter entities), and external general entities referenced - * within the document element (if the parser reads external general - * entities). The application may request that the parser locate - * the entity itself, that it use an alternative URI, or that it - * use data provided by the application (as a character or byte - * input stream).
- * - *Application writers can use this method to redirect external - * system identifiers to secure and/or local URIs, to look up - * public identifiers in a catalogue, or to read an entity from a - * database or other input source (including, for example, a dialog - * box). Neither XML nor SAX specifies a preferred policy for using - * public or system IDs to resolve resources. However, SAX specifies - * how to interpret any InputSource returned by this method, and that - * if none is returned, then the system ID will be dereferenced as - * a URL.
- * - *If the system identifier is a URL, the SAX parser must - * resolve it fully before reporting it to the application.
- * - * @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. - * @return An InputSource object describing the new input source, - * or null to request that the parser open a regular - * URI connection to the system identifier. - * @exception org.xml.sax.SAXException Any SAX exception, possibly - * wrapping another exception. - * @exception java.io.IOException A Java-specific IO exception, - * possibly the result of creating a new InputStream - * or Reader for the InputSource. - * @see org.xml.sax.InputSource - */ - public abstract InputSource resolveEntity (String publicId, - String systemId) - throws SAXException, IOException; - -} - -// end of EntityResolver.java