saxoutputter.java

JAVA的Jdom包

    /**
     * <p>
     * This will invoke the callbacks for the content of an element.
     * </p>
     *
     * @param node a <code>Content</code> node.
     * @param namespaces <code>List</code> stack of Namespaces in scope.
     */
    private void elementContent(Content node, NamespaceStack namespaces)
                      throws JDOMException {
        // update locator
        if (locator != null) {
          locator.setNode(node);
        }

        if (node instanceof Element) {
            element((Element) node, namespaces);
        }
        else if (node instanceof CDATA) {
            cdata(((CDATA) node).getText());
        }
        else if (node instanceof Text) {
            // contentHandler.characters()
            characters(((Text) node).getText());
        }
        else if (node instanceof ProcessingInstruction) {
            // contentHandler.processingInstruction()
            processingInstruction((ProcessingInstruction) node);
        }
        else if (node instanceof Comment) {
            // lexicalHandler.comment()
            comment(((Comment) node).getText());
        }
        else if (node instanceof EntityRef) {
            // contentHandler.skippedEntity()
            entityRef((EntityRef) node);
        }
        else {
            // Not a valid element child. This could happen with
            // application-provided lists which may contain non
            // JDOM objects.
            handleError(new JDOMException("Invalid element content: " + node));
        }
    }

    /**
     * <p>
     * This will be called for each chunk of CDATA section encountered.
     * </p>
     *
     * @param cdataText all text in the CDATA section, including whitespace.
     */
    private void cdata(String cdataText) throws JDOMException {
        try {
            if (lexicalHandler != null) {
                lexicalHandler.startCDATA();
                characters(cdataText);
                lexicalHandler.endCDATA();
            }
            else {
                characters(cdataText);
            }
        }
        catch (SAXException se) {
            throw new JDOMException("Exception in CDATA", se);
        }
    }

    /**
     * <p>
     * This will be called for each chunk of character data encountered.
     * </p>
     *
     * @param elementText all text in an element, including whitespace.
     */
    private void characters(String elementText) throws JDOMException {
        char[] c = elementText.toCharArray();
        try {
            contentHandler.characters(c, 0, c.length);
        }
        catch (SAXException se) {
            throw new JDOMException("Exception in characters", se);
        }
    }

    /**
     * <p>
     *  This will be called for each chunk of comment data encontered.
     * </p>
     *
     * @param commentText all text in a comment, including whitespace.
     */
    private void comment(String commentText) throws JDOMException {
        if (lexicalHandler != null) {
            char[] c = commentText.toCharArray();
            try {
                lexicalHandler.comment(c, 0, c.length);
            } catch (SAXException se) {
                throw new JDOMException("Exception in comment", se);
            }
        }
    }

    /**
     * <p>
     * This will invoke the <code>ContentHandler.skippedEntity</code>
     * callback when an entity reference is encountered.
     * </p>
     *
     * @param entity <code>EntityRef</code>.
     */
    private void entityRef(EntityRef entity) throws JDOMException {
        if (entity != null) {
            try {
                // No need to worry about appending a '%' character as
                // we do not support parameter entities
                contentHandler.skippedEntity(entity.getName());
            }
            catch (SAXException se) {
                throw new JDOMException("Exception in entityRef", se);
            }
        }
    }


    /**
     * <p>
     * Appends a namespace declaration in the form of a xmlns attribute to
     * an attribute list, crerating this latter if needed.
     * </p>
     *
     * @param atts <code>AttributeImpl</code> where to add the attribute.
     * @param ns <code>Namespace</code> the namespace to declare.
     *
     * @return <code>AttributeImpl</code> the updated attribute list.
     */
    private AttributesImpl addNsAttribute(AttributesImpl atts, Namespace ns) {
        if (this.declareNamespaces) {
            if (atts == null) {
                atts = new AttributesImpl();
            }

            String prefix = ns.getPrefix();
            if (prefix.equals("")) {
                atts.addAttribute("",                        // namespace
                                  "",                        // local name
                                  "xmlns",                   // qualified name
                                  "CDATA",                   // type
                                  ns.getURI());              // value
            }
            else {
                atts.addAttribute("",                        // namespace
                                  "",                        // local name
                                  "xmlns:" + ns.getPrefix(), // qualified name
                                  "CDATA",                   // type
                                  ns.getURI());              // value
            }
        }
        return atts;
    }

    /**
     * <p>
     * Returns the SAX 2.0 attribute type string from the type of
     * a JDOM Attribute.
     * </p>
     *
     * @param type <code>int</code> the type of the JDOM attribute.
     *
     * @return <code>String</code> the SAX 2.0 attribute type string.
     *
     * @see org.jdom.Attribute#getAttributeType
     * @see org.xml.sax.Attributes#getType
     */
    private static String getAttributeTypeName(int type) {
        if ((type < 0) || (type >= attrTypeToNameMap.length)) {
            type = Attribute.UNDECLARED_TYPE;
        }
        return attrTypeToNameMap[type];
    }

    /**
     * <p>
     * Notifies the registered {@link ErrorHandler SAX error handler}
     * (if any) of an input processing error. The error handler can
     * choose to absorb the error and let the processing continue.
     * </p>
     *
     * @param exception <code>JDOMException</code> containing the
     *                  error information; will be wrapped in a
     *                  {@link SAXParseException} when reported to
     *                  the SAX error handler.
     *
     * @throws JDOMException if no error handler has been registered
     *                       or if the error handler fired a
     *                       {@link SAXException}.
     */
    private void handleError(JDOMException exception) throws JDOMException {
        if (errorHandler != null) {
            try {
                errorHandler.error(new SAXParseException(
                                exception.getMessage(), null, exception));
            }
            catch (SAXException se) {
               if (se.getException() instanceof JDOMException) {
                   throw (JDOMException)(se.getException());
               }
               else {
                   throw new JDOMException(se.getMessage(), se);
               }
            }
        }
        else {
            throw exception;
        }
    }

    /**
     * <p>
     * Creates a SAX XMLReader.
     * </p>
     *
     * @return <code>XMLReader</code> a SAX2 parser.
     *
     * @throws Exception if no parser can be created.
     */
    protected XMLReader createParser() throws Exception {
        XMLReader parser = null;

        // Try using JAXP...
        // Note we need JAXP 1.1, and if JAXP 1.0 is all that's
        // available then the getXMLReader call fails and we skip
        // to the hard coded default parser
        try {
            Class factoryClass =
                    Class.forName("javax.xml.parsers.SAXParserFactory");

            // factory = SAXParserFactory.newInstance();
            Method newParserInstance =
                    factoryClass.getMethod("newInstance", null);
            Object factory = newParserInstance.invoke(null, null);

            // jaxpParser = factory.newSAXParser();
            Method newSAXParser = factoryClass.getMethod("newSAXParser", null);
            Object jaxpParser   = newSAXParser.invoke(factory, null);

            // parser = jaxpParser.getXMLReader();
            Class parserClass = jaxpParser.getClass();
            Method getXMLReader =
                    parserClass.getMethod("getXMLReader", null);
            parser = (XMLReader)getXMLReader.invoke(jaxpParser, null);
        } catch (ClassNotFoundException e) {
            //e.printStackTrace();
        } catch (InvocationTargetException e) {
            //e.printStackTrace();
        } catch (NoSuchMethodException e) {
            //e.printStackTrace();
        } catch (IllegalAccessException e) {
            //e.printStackTrace();
        }

        // Check to see if we got a parser yet, if not, try to use a
        // hard coded default
        if (parser == null) {
            parser = XMLReaderFactory.createXMLReader(
                                "org.apache.xerces.parsers.SAXParser");
        }
        return parser;
    }

    /**
     * <p>
     * This will create a SAX XMLReader capable of parsing a DTD and
     * configure it so that the DTD parsing events are routed to the
     * handlers registered onto this SAXOutputter.
     * </p>
     *
     * @return <code>XMLReader</code> a SAX2 parser.
     *
     * @throws JDOMException if no parser can be created.
     */
    private XMLReader createDTDParser() throws JDOMException {
        XMLReader parser = null;

        // Get a parser instance
        try
        {
            parser = createParser();
        }
        catch (Exception ex1) {
           throw new JDOMException("Error in SAX parser allocation", ex1);
        }

        // Register handlers
        if (this.getDTDHandler() != null) {
            parser.setDTDHandler(this.getDTDHandler());
        }
        if (this.getEntityResolver() != null) {
            parser.setEntityResolver(this.getEntityResolver());
        }
        if (this.getLexicalHandler() != null) {
            try {
                parser.setProperty(LEXICAL_HANDLER_SAX_PROPERTY,
                                   this.getLexicalHandler());
            }
            catch (SAXException ex1) {
                try {
                    parser.setProperty(LEXICAL_HANDLER_ALT_PROPERTY,
                                       this.getLexicalHandler());
                } catch (SAXException ex2) {
                    // Forget it!
                }
            }
        }
        if (this.getDeclHandler() != null) {
            try {
                parser.setProperty(DECL_HANDLER_SAX_PROPERTY,
                                   this.getDeclHandler());
            }
            catch (SAXException ex1) {
                try {
                    parser.setProperty(DECL_HANDLER_ALT_PROPERTY,
                                       this.getDeclHandler());
                } catch (SAXException ex2) {
                    // Forget it!
                }
            }
        }

        // Absorb errors as much as possible, per Laurent
        parser.setErrorHandler(new DefaultHandler());

        return parser;
    }

    /**
     * Returns a JDOMLocator object referencing the node currently
     * being processed by this outputter.  The returned object is a
     * snapshot of the  location information and can thus safely be
     * memorized for later use.
     * <p>
     * This method allows direct access to the location information
     * maintained by SAXOutputter without requiring to implement
     * <code>XMLFilter</code>. (In SAX, locators are only available
     * though the <code>ContentHandler</code> interface).</p>
     * <p>
     * Note that location information is only available while
     * SAXOutputter is outputting nodes. Hence this method should
     * only be used by objects taking part in the output processing
     * such as <code>ErrorHandler</code>s.
     *
     * @return a JDOMLocator object referencing the node currently
     *         being processed or <code>null</code> if no output
     *         operation is being performed.
     */
    public JDOMLocator getLocator() {
        return (locator != null)? new JDOMLocator(locator): null;
    }
}