- // XMLReader.java - read an XML document.
- // Written by David Megginson, sax@megginson.com
- // NO WARRANTY! This class is in the Public Domain.
-
- // $Id: XMLReader.java,v 1.1 2001/05/20 03:12:56 curcuru Exp $
-
- package org.xml.sax;
-
- import java.io.IOException;
-
-
- /**
- * Interface for reading an XML document using callbacks.
- *
- * <blockquote>
- * <em>This module, both source code and documentation, is in the
- * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
- * </blockquote>
- *
- * <p><strong>Note:</strong> despite its name, this interface does
- * <em>not</em> extend the standard Java {@link java.io.Reader Reader}
- * interface, because reading XML is a fundamentally different activity
- * than reading character data.</p>
- *
- * <p>XMLReader is the interface that an XML parser's SAX2 driver must
- * implement. This interface allows an application to set and
- * query features and properties in the parser, to register
- * event handlers for document processing, and to initiate
- * a document parse.</p>
- *
- * <p>All SAX interfaces are assumed to be synchronous: the
- * {@link #parse parse} methods must not return until parsing
- * is complete, and readers must wait for an event-handler callback
- * to return before reporting the next event.</p>
- *
- * <p>This interface replaces the (now deprecated) SAX 1.0 {@link
- * org.xml.sax.Parser Parser} interface. The XMLReader interface
- * contains two important enhancements over the old Parser
- * interface:</p>
- *
- * <ol>
- * <li>it adds a standard way to query and set features and
- * properties; and</li>
- * <li>it adds Namespace support, which is required for many
- * higher-level XML standards.</li>
- * </ol>
- *
- * <p>There are adapters available to convert a SAX1 Parser to
- * a SAX2 XMLReader and vice-versa.</p>
- *
- * @since SAX 2.0
- * @author David Megginson,
- * <a href="mailto:sax@megginson.com">sax@megginson.com</a>
- * @version 2.0r2pre
- * @see org.xml.sax.XMLFilter
- * @see org.xml.sax.helpers.ParserAdapter
- * @see org.xml.sax.helpers.XMLReaderAdapter
- */
- public interface XMLReader
- {
-
-
- ////////////////////////////////////////////////////////////////////
- // Configuration.
- ////////////////////////////////////////////////////////////////////
-
-
- /**
- * Look up the value of a feature.
- *
- * <p>The feature name is any fully-qualified URI. It is
- * possible for an XMLReader to recognize a feature name but
- * to be unable to return its value; this is especially true
- * in the case of an adapter for a SAX1 Parser, which has
- * no way of knowing whether the underlying parser is
- * performing validation or expanding external entities.</p>
- *
- * <p>All XMLReaders are required to recognize the
- * http://xml.org/sax/features/namespaces and the
- * http://xml.org/sax/features/namespace-prefixes feature names.</p>
- *
- * <p>Some feature values may be available only in specific
- * contexts, such as before, during, or after a parse.</p>
- *
- * <p>Typical usage is something like this:</p>
- *
- * <pre>
- * XMLReader r = new MySAXDriver();
- *
- * // try to activate validation
- * try {
- * r.setFeature("http://xml.org/sax/features/validation", true);
- * } catch (SAXException e) {
- * System.err.println("Cannot activate validation.");
- * }
- *
- * // register event handlers
- * r.setContentHandler(new MyContentHandler());
- * r.setErrorHandler(new MyErrorHandler());
- *
- * // parse the first document
- * try {
- * r.parse("http://www.foo.com/mydoc.xml");
- * } catch (IOException e) {
- * System.err.println("I/O exception reading XML document");
- * } catch (SAXException e) {
- * System.err.println("XML exception reading document.");
- * }
- * </pre>
- *
- * <p>Implementors are free (and encouraged) to invent their own features,
- * using names built on their own URIs.</p>
- *
- * @param name The feature name, which is a fully-qualified URI.
- * @return The current state of the feature (true or false).
- * @exception org.xml.sax.SAXNotRecognizedException When the
- * XMLReader does not recognize the feature name.
- * @exception org.xml.sax.SAXNotSupportedException When the
- * XMLReader recognizes the feature name but
- * cannot determine its value at this time.
- * @see #setFeature
- */
- public boolean getFeature (String name)
- throws SAXNotRecognizedException, SAXNotSupportedException;
-
-
- /**
- * Set the state of a feature.
- *
- * <p>The feature name is any fully-qualified URI. It is
- * possible for an XMLReader to recognize a feature name but
- * to be unable to set its value; this is especially true
- * in the case of an adapter for a SAX1 {@link org.xml.sax.Parser Parser},
- * which has no way of affecting whether the underlying parser is
- * validating, for example.</p>
- *
- * <p>All XMLReaders are required to support setting
- * http://xml.org/sax/features/namespaces to true and
- * http://xml.org/sax/features/namespace-prefixes to false.</p>
- *
- * <p>Some feature values may be immutable or mutable only
- * in specific contexts, such as before, during, or after
- * a parse.</p>
- *
- * @param name The feature name, which is a fully-qualified URI.
- * @param state The requested state of the feature (true or false).
- * @exception org.xml.sax.SAXNotRecognizedException When the
- * XMLReader does not recognize the feature name.
- * @exception org.xml.sax.SAXNotSupportedException When the
- * XMLReader recognizes the feature name but
- * cannot set the requested value.
- * @see #getFeature
- */
- public void setFeature (String name, boolean value)
- throws SAXNotRecognizedException, SAXNotSupportedException;
-
-
- /**
- * Look up the value of a property.
- *
- * <p>The property name is any fully-qualified URI. It is
- * possible for an XMLReader to recognize a property name but
- * to be unable to return its state; this is especially true
- * in the case of an adapter for a SAX1 {@link org.xml.sax.Parser
- * Parser}.</p>
- *
- * <p>XMLReaders are not required to recognize any specific
- * property names, though an initial core set is documented for
- * SAX2.</p>
- *
- * <p>Some property values may be available only in specific
- * contexts, such as before, during, or after a parse.</p>
- *
- * <p>Implementors are free (and encouraged) to invent their own properties,
- * using names built on their own URIs.</p>
- *
- * @param name The property name, which is a fully-qualified URI.
- * @return The current value of the property.
- * @exception org.xml.sax.SAXNotRecognizedException When the
- * XMLReader does not recognize the property name.
- * @exception org.xml.sax.SAXNotSupportedException When the
- * XMLReader recognizes the property name but
- * cannot determine its value at this time.
- * @see #setProperty
- */
- public Object getProperty (String name)
- throws SAXNotRecognizedException, SAXNotSupportedException;
-
-
- /**
- * Set the value of a property.
- *
- * <p>The property name is any fully-qualified URI. It is
- * possible for an XMLReader to recognize a property name but
- * to be unable to set its value; this is especially true
- * in the case of an adapter for a SAX1 {@link org.xml.sax.Parser
- * Parser}.</p>
- *
- * <p>XMLReaders are not required to recognize setting
- * any specific property names, though a core set is provided with
- * SAX2.</p>
- *
- * <p>Some property values may be immutable or mutable only
- * in specific contexts, such as before, during, or after
- * a parse.</p>
- *
- * <p>This method is also the standard mechanism for setting
- * extended handlers.</p>
- *
- * @param name The property name, which is a fully-qualified URI.
- * @param state The requested value for the property.
- * @exception org.xml.sax.SAXNotRecognizedException When the
- * XMLReader does not recognize the property name.
- * @exception org.xml.sax.SAXNotSupportedException When the
- * XMLReader recognizes the property name but
- * cannot set the requested value.
- */
- public void setProperty (String name, Object value)
- throws SAXNotRecognizedException, SAXNotSupportedException;
-
-
-
- ////////////////////////////////////////////////////////////////////
- // Event handlers.
- ////////////////////////////////////////////////////////////////////
-
-
- /**
- * Allow an application to register an entity resolver.
- *
- * <p>If the application does not register an entity resolver,
- * the XMLReader will perform its own default resolution.</p>
- *
- * <p>Applications may register a new or different resolver in the
- * middle of a parse, and the SAX parser must begin using the new
- * resolver immediately.</p>
- *
- * @param resolver The entity resolver.
- * @exception java.lang.NullPointerException If the resolver
- * argument is null.
- * @see #getEntityResolver
- */
- public void setEntityResolver (EntityResolver resolver);
-
-
- /**
- * Return the current entity resolver.
- *
- * @return The current entity resolver, or null if none
- * has been registered.
- * @see #setEntityResolver
- */
- public EntityResolver getEntityResolver ();
-
-
- /**
- * Allow an application to register a DTD event handler.
- *
- * <p>If the application does not register a DTD handler, all DTD
- * events reported by the SAX parser will be silently ignored.</p>
- *
- * <p>Applications may register a new or different handler in the
- * middle of a parse, and the SAX parser must begin using the new
- * handler immediately.</p>
- *
- * @param handler The DTD handler.
- * @exception java.lang.NullPointerException If the handler
- * argument is null.
- * @see #getDTDHandler
- */
- public void setDTDHandler (DTDHandler handler);
-
-
- /**
- * Return the current DTD handler.
- *
- * @return The current DTD handler, or null if none
- * has been registered.
- * @see #setDTDHandler
- */
- public DTDHandler getDTDHandler ();
-
-
- /**
- * Allow an application to register a content event handler.
- *
- * <p>If the application does not register a content handler, all
- * content events reported by the SAX parser will be silently
- * ignored.</p>
- *
- * <p>Applications may register a new or different handler in the
- * middle of a parse, and the SAX parser must begin using the new
- * handler immediately.</p>
- *
- * @param handler The content handler.
- * @exception java.lang.NullPointerException If the handler
- * argument is null.
- * @see #getContentHandler
- */
- public void setContentHandler (ContentHandler handler);
-
-
- /**
- * Return the current content handler.
- *
- * @return The current content handler, or null if none
- * has been registered.
- * @see #setContentHandler
- */
- public ContentHandler getContentHandler ();
-
-
- /**
- * Allow an application to register an error event handler.
- *
- * <p>If the application does not register an error handler, all
- * error events reported by the SAX parser will be silently
- * ignored; however, normal processing may not continue. It is
- * highly recommended that all SAX applications implement an
- * error handler to avoid unexpected bugs.</p>
- *
- * <p>Applications may register a new or different handler in the
- * middle of a parse, and the SAX parser must begin using the new
- * handler immediately.</p>
- *
- * @param handler The error handler.
- * @exception java.lang.NullPointerException If the handler
- * argument is null.
- * @see #getErrorHandler
- */
- public void setErrorHandler (ErrorHandler handler);
-
-
- /**
- * Return the current error handler.
- *
- * @return The current error handler, or null if none
- * has been registered.
- * @see #setErrorHandler
- */
- public ErrorHandler getErrorHandler ();
-
-
-
- ////////////////////////////////////////////////////////////////////
- // Parsing.
- ////////////////////////////////////////////////////////////////////
-
- /**
- * Parse an XML document.
- *
- * <p>The application can use this method to instruct the XML
- * reader to begin parsing an XML document from any valid input
- * source (a character stream, a byte stream, or a URI).</p>
- *
- * <p>Applications may not invoke this method while a parse is in
- * progress (they should create a new XMLReader instead for each
- * nested XML document). Once a parse is complete, an
- * application may reuse the same XMLReader object, possibly with a
- * different input source.</p>
- *
- * <p>During the parse, the XMLReader will provide information
- * about the XML document through the registered event
- * handlers.</p>
- *
- * <p>This method is synchronous: it will not return until parsing
- * has ended. If a client application wants to terminate
- * parsing early, it should throw an exception.</p>
- *
- * @param source The input source for the top-level of the
- * XML document.
- * @exception org.xml.sax.SAXException Any SAX exception, possibly
- * wrapping another exception.
- * @exception java.io.IOException An IO exception from the parser,
- * possibly from a byte stream or character stream
- * supplied by the application.
- * @see org.xml.sax.InputSource
- * @see #parse(java.lang.String)
- * @see #setEntityResolver
- * @see #setDTDHandler
- * @see #setContentHandler
- * @see #setErrorHandler
- */
- public void parse (InputSource input)
- throws IOException, SAXException;
-
-
- /**
- * Parse an XML document from a system identifier (URI).
- *
- * <p>This method is a shortcut for the common case of reading a
- * document from a system identifier. It is the exact
- * equivalent of the following:</p>
- *
- * <pre>
- * parse(new InputSource(systemId));
- * </pre>
- *
- * <p>If the system identifier is a URL, it must be fully resolved
- * by the application before it is passed to the parser.</p>
- *
- * @param systemId The system identifier (URI).
- * @exception org.xml.sax.SAXException Any SAX exception, possibly
- * wrapping another exception.
- * @exception java.io.IOException An IO exception from the parser,
- * possibly from a byte stream or character stream
- * supplied by the application.
- * @see #parse(org.xml.sax.InputSource)
- */
- public void parse (String systemId)
- throws IOException, SAXException;
-
- }
-
- // end of XMLReader.java