digester.java

业界著名的tomcat服务器的最新6.0的源代码。

    /**
     * Set the XML Schema language used when parsing. By default, we use W3C.
     *
     * @param schemaLanguage a URI to the schema language.
     */
    public void setSchemaLanguage(String schemaLanguage){

        this.schemaLanguage = schemaLanguage;

    }   


    /**
     * Return the boolean as to whether the context classloader should be used.
     */
    public boolean getUseContextClassLoader() {

        return useContextClassLoader;

    }


    /**
     * Determine whether to use the Context ClassLoader (the one found by
     * calling <code>Thread.currentThread().getContextClassLoader()</code>)
     * to resolve/load classes that are defined in various rules.  If not
     * using Context ClassLoader, then the class-loading defaults to
     * using the calling-class' ClassLoader.
     *
     * @param use determines whether to use Context ClassLoader.
     */
    public void setUseContextClassLoader(boolean use) {

        useContextClassLoader = use;

    }


    /**
     * Return the validating parser flag.
     */
    public boolean getValidating() {

        return (this.validating);

    }


    /**
     * Set the validating parser flag.  This must be called before
     * <code>parse()</code> is called the first time.
     *
     * @param validating The new validating parser flag.
     */
    public void setValidating(boolean validating) {

        this.validating = validating;

    }


    /**
     * Return the XMLReader to be used for parsing the input document.
     *
     * FIX ME: there is a bug in JAXP/XERCES that prevent the use of a 
     * parser that contains a schema with a DTD.
     * @exception SAXException if no XMLReader can be instantiated
     */
    public XMLReader getXMLReader() throws SAXException {
        if (reader == null){
            reader = getParser().getXMLReader();
        }        
                               
        reader.setDTDHandler(this);           
        reader.setContentHandler(this);        
        
        if (entityResolver == null){
            reader.setEntityResolver(this);
        } else {
            reader.setEntityResolver(entityResolver);           
        }
        
        reader.setErrorHandler(this);
        return reader;
    }

    // ------------------------------------------------- ContentHandler Methods


    /**
     * Process notification of character data received from the body of
     * an XML element.
     *
     * @param buffer The characters from the XML document
     * @param start Starting offset into the buffer
     * @param length Number of characters from the buffer
     *
     * @exception SAXException if a parsing error is to be reported
     */
    public void characters(char buffer[], int start, int length)
            throws SAXException {

        if (saxLog.isDebugEnabled()) {
            saxLog.debug("characters(" + new String(buffer, start, length) + ")");
        }

        bodyText.append(buffer, start, length);

    }


    /**
     * Process notification of the end of the document being reached.
     *
     * @exception SAXException if a parsing error is to be reported
     */
    public void endDocument() throws SAXException {

        if (saxLog.isDebugEnabled()) {
            if (getCount() > 1) {
                saxLog.debug("endDocument():  " + getCount() +
                             " elements left");
            } else {
                saxLog.debug("endDocument()");
            }
        }

        while (getCount() > 1) {
            pop();
        }

        // Fire "finish" events for all defined rules
        Iterator rules = getRules().rules().iterator();
        while (rules.hasNext()) {
            Rule rule = (Rule) rules.next();
            try {
                rule.finish();
            } catch (Exception e) {
                log.error("Finish event threw exception", e);
                throw createSAXException(e);
            } catch (Error e) {
                log.error("Finish event threw error", e);
                throw e;
            }
        }

        // Perform final cleanup
        clear();

    }


    /**
     * Process notification of the end of an XML element being reached.
     *
     * @param namespaceURI - The Namespace URI, or the empty string if the
     *   element has no Namespace URI or if Namespace processing is not
     *   being performed.
     * @param localName - The local name (without prefix), or the empty
     *   string if Namespace processing is not being performed.
     * @param qName - The qualified XML 1.0 name (with prefix), or the
     *   empty string if qualified names are not available.
     * @exception SAXException if a parsing error is to be reported
     */
    public void endElement(String namespaceURI, String localName,
                           String qName) throws SAXException {

        boolean debug = log.isDebugEnabled();

        if (debug) {
            if (saxLog.isDebugEnabled()) {
                saxLog.debug("endElement(" + namespaceURI + "," + localName +
                        "," + qName + ")");
            }
            log.debug("  match='" + match + "'");
            log.debug("  bodyText='" + bodyText + "'");
        }

        // Parse system properties
        bodyText = updateBodyText(bodyText);

        // the actual element name is either in localName or qName, depending 
        // on whether the parser is namespace aware
        String name = localName;
        if ((name == null) || (name.length() < 1)) {
            name = qName;
        }

        // Fire "body" events for all relevant rules
        List rules = (List) matches.pop();
        if ((rules != null) && (rules.size() > 0)) {
            String bodyText = this.bodyText.toString();
            for (int i = 0; i < rules.size(); i++) {
                try {
                    Rule rule = (Rule) rules.get(i);
                    if (debug) {
                        log.debug("  Fire body() for " + rule);
                    }
                    rule.body(namespaceURI, name, bodyText);
                } catch (Exception e) {
                    log.error("Body event threw exception", e);
                    throw createSAXException(e);
                } catch (Error e) {
                    log.error("Body event threw error", e);
                    throw e;
                }
            }
        } else {
            if (debug) {
                log.debug("  No rules found matching '" + match + "'.");
            }
        }

        // Recover the body text from the surrounding element
        bodyText = (StringBuffer) bodyTexts.pop();
        if (debug) {
            log.debug("  Popping body text '" + bodyText.toString() + "'");
        }

        // Fire "end" events for all relevant rules in reverse order
        if (rules != null) {
            for (int i = 0; i < rules.size(); i++) {
                int j = (rules.size() - i) - 1;
                try {
                    Rule rule = (Rule) rules.get(j);
                    if (debug) {
                        log.debug("  Fire end() for " + rule);
                    }
                    rule.end(namespaceURI, name);
                } catch (Exception e) {
                    log.error("End event threw exception", e);
                    throw createSAXException(e);
                } catch (Error e) {
                    log.error("End event threw error", e);
                    throw e;
                }
            }
        }

        // Recover the previous match expression
        int slash = match.lastIndexOf('/');
        if (slash >= 0) {
            match = match.substring(0, slash);
        } else {
            match = "";
        }

    }


    /**
     * Process notification that a namespace prefix is going out of scope.
     *
     * @param prefix Prefix that is going out of scope
     *
     * @exception SAXException if a parsing error is to be reported
     */
    public void endPrefixMapping(String prefix) throws SAXException {

        if (saxLog.isDebugEnabled()) {
            saxLog.debug("endPrefixMapping(" + prefix + ")");
        }

        // Deregister this prefix mapping
        ArrayStack stack = (ArrayStack) namespaces.get(prefix);
        if (stack == null) {
            return;
        }
        try {
            stack.pop();
            if (stack.empty())
                namespaces.remove(prefix);
        } catch (EmptyStackException e) {
            throw createSAXException("endPrefixMapping popped too many times");
        }

    }


    /**
     * Process notification of ignorable whitespace received from the body of
     * an XML element.
     *
     * @param buffer The characters from the XML document
     * @param start Starting offset into the buffer
     * @param len Number of characters from the buffer
     *
     * @exception SAXException if a parsing error is to be reported
     */
    public void ignorableWhitespace(char buffer[], int start, int len)
            throws SAXException {

        if (saxLog.isDebugEnabled()) {
            saxLog.debug("ignorableWhitespace(" +
                    new String(buffer, start, len) + ")");
        }

        ;   // No processing required

    }


    /**
     * Process notification of a processing instruction that was encountered.
     *
     * @param target The processing instruction target
     * @param data The processing instruction data (if any)
     *
     * @exception SAXException if a parsing error is to be reported
     */
    public void processingInstruction(String target, String data)
            throws SAXException {

        if (saxLog.isDebugEnabled()) {
            saxLog.debug("processingInstruction('" + target + "','" + data + "')");
        }

        ;   // No processing is required

    }


    /**
     * Gets the document locator associated with our parser.
     *
     * @return the Locator supplied by the document parser
     */
    public Locator getDocumentLocator() {

        return locator;

    }

    /**
     * Sets the document locator associated with our parser.
     *
     * @param locator The new locator
     */
    public void setDocumentLocator(Locator locator) {

        if (saxLog.isDebugEnabled()) {
            saxLog.debug("setDocumentLocator(" + locator + ")");
        }

        this.locator = locator;

    }


    /**
     * Process notification of a skipped entity.
     *
     * @param name Name of the skipped entity
     *
     * @exception SAXException if a parsing error is to be reported
     */
    public void skippedEntity(String name) throws SAXException {

        if (saxLog.isDebugEnabled()) {
            saxLog.debug("skippedEntity(" + name + ")");
        }

        ; // No processing required

    }


    /**
     * Process notification of the beginning of the document being reached.
     *
     * @exception SAXException if a parsing error is to be reported
     */
    public void startDocument() throws SAXException {

        if (saxLog.isDebugEnabled()) {
            saxLog.debug("startDocument()");
        }

        // ensure that the digester is properly configured, as 
        // the digester could be used as a SAX ContentHandler
        // rather than via the parse() methods.
        configure();
    }


    /**
     * Process notification of the start of an XML element being reached.
     *
     * @param namespaceURI The Namespace URI, or the empty string if the element
     *   has no Namespace URI or if Namespace processing is not being performed.
     * @param localName The local name (without prefix), or the empty
     *   string if Namespace processing is not being performed.
     * @param qName The qualified name (with prefix), or the empty
     *   string if qualified names are not available.\
     * @param list The attributes attached to the element. If there are
     *   no attributes, it shall be an empty Attributes object. 
     * @exception SAXException if a parsing error is to be reported
     */
    public void startElement(String namespaceURI, String localName,
                             String qName, Attributes list)
            throws SAXException {
        boolean debug = log.isDebugEnabled();
        
        if (saxLog.isDebugEnabled()) {
            saxLog.debug("startElement(" + namespaceURI + "," + localName + "," +
                    qName + ")");
        }
        
        // Parse system properties
        list = updateAttributes(list);
        
        // Save the body text accumulated for our surrounding element
        bodyTexts.push(bodyText);