xmlparser.java

jetty SERVER連接資料庫用的軟體

// ========================================================================
// Copyright 2004-2005 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at 
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ========================================================================

package org.mortbay.xml;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.AbstractList;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Stack;
import java.util.StringTokenizer;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.mortbay.log.Log;
import org.mortbay.util.LazyList;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;

/*--------------------------------------------------------------*/
/**
 * XML Parser wrapper. This class wraps any standard JAXP1.1 parser with convieniant error and
 * entity handlers and a mini dom-like document tree.
 * <P>
 * By default, the parser is created as a validating parser only if xerces is present. This can be 
 * configured by setting the "org.mortbay.xml.XmlParser.Validating" system property.
 * 
 * @author Greg Wilkins (gregw)
 */
public class XmlParser
{
    private Map _redirectMap = new HashMap();
    private SAXParser _parser;
    private Map _observerMap;
    private Stack _observers = new Stack();
    private String _xpath;
    private Object _xpaths;
    private String _dtd;

    /* ------------------------------------------------------------ */
    /**
     * Construct
     */
    public XmlParser()
    {
        SAXParserFactory factory = SAXParserFactory.newInstance();
        boolean validating_dft = factory.getClass().toString().startsWith("org.apache.xerces.");
        String validating_prop = System.getProperty("org.mortbay.xml.XmlParser.Validating", validating_dft ? "true" : "false");
        boolean notValidating = Boolean.getBoolean("org.mortbay.xml.XmlParser.NotValidating"); // deprecated!
        boolean validating = !notValidating && Boolean.valueOf(validating_prop).booleanValue();
        setValidating(validating);
    }

    /* ------------------------------------------------------------ */
    /**
     * Constructor.
     */
    public XmlParser(boolean validating)
    {
        setValidating(validating);
    }
    
    /* ------------------------------------------------------------ */
    public void setValidating(boolean validating)
    {
        try
        {
            SAXParserFactory factory = SAXParserFactory.newInstance();
            factory.setValidating(validating);
            _parser = factory.newSAXParser();
            
            try
            {
                if (validating)
                    _parser.getXMLReader().setFeature("http://apache.org/xml/features/validation/schema", validating);
            }
            catch (Exception e)
            {
                if (validating)
                    Log.warn("Schema validation may not be supported: ", e);
                else
                    Log.ignore(e);
            }

            _parser.getXMLReader().setFeature("http://xml.org/sax/features/validation", validating);
            _parser.getXMLReader().setFeature("http://xml.org/sax/features/namespaces", true);
            _parser.getXMLReader().setFeature("http://xml.org/sax/features/namespace-prefixes", false);  
        }
        catch (Exception e)
        {
            Log.warn(Log.EXCEPTION, e);
            throw new Error(e.toString());
        }
    }
    
    /* ------------------------------------------------------------ */
    /**
     * @param name
     * @param entity
     */
    public synchronized void redirectEntity(String name, URL entity)
    {
        if (entity != null)
            _redirectMap.put(name, entity);
    }

    /* ------------------------------------------------------------ */
    /**
     * 
     * @return Returns the xpath.
     */
    public String getXpath()
    {
        return _xpath;
    }

    /* ------------------------------------------------------------ */
    /**
     * Set an XPath A very simple subset of xpath is supported to select a partial tree. Currently
     * only path like "/node1/nodeA | /node1/nodeB" are supported.
     * 
     * @param xpath The xpath to set.
     */
    public void setXpath(String xpath)
    {
        _xpath = xpath;
        StringTokenizer tok = new StringTokenizer(xpath, "| ");
        while (tok.hasMoreTokens())
            _xpaths = LazyList.add(_xpaths, tok.nextToken());
    }

    /* ------------------------------------------------------------ */
    public String getDTD()
    {
        return _dtd;
    }

    /* ------------------------------------------------------------ */
    /**
     * Add a ContentHandler. Add an additional _content handler that is triggered on a tag name. SAX
     * events are passed to the ContentHandler provided from a matching start element to the
     * corresponding end element. Only a single _content handler can be registered against each tag.
     * 
     * @param trigger Tag local or q name.
     * @param observer SAX ContentHandler
     */
    public synchronized void addContentHandler(String trigger, ContentHandler observer)
    {
        if (_observerMap == null)
            _observerMap = new HashMap();
        _observerMap.put(trigger, observer);
    }

    /* ------------------------------------------------------------ */
    public synchronized Node parse(InputSource source) throws IOException, SAXException
    {
        _dtd=null;
        Handler handler = new Handler();
        XMLReader reader = _parser.getXMLReader();
        reader.setContentHandler(handler);
        reader.setErrorHandler(handler);
        reader.setEntityResolver(handler);
        if (Log.isDebugEnabled())
            Log.debug("parsing: sid=" + source.getSystemId() + ",pid=" + source.getPublicId());
        _parser.parse(source, handler);
        if (handler._error != null)
            throw handler._error;
        Node doc = (Node) handler._top.get(0);
        handler.clear();
        return doc;
    }

    /* ------------------------------------------------------------ */
    /**
     * Parse String URL.
     */
    public synchronized Node parse(String url) throws IOException, SAXException
    {
        if (Log.isDebugEnabled())
            Log.debug("parse: " + url);
        return parse(new InputSource(url));
    }

    /* ------------------------------------------------------------ */
    /**
     * Parse File.
     */
    public synchronized Node parse(File file) throws IOException, SAXException
    {
        if (Log.isDebugEnabled())
            Log.debug("parse: " + file);
        return parse(new InputSource(file.toURL().toString()));
    }

    /* ------------------------------------------------------------ */
    /**
     * Parse InputStream.
     */
    public synchronized Node parse(InputStream in) throws IOException, SAXException
    {
        _dtd=null;
        Handler handler = new Handler();
        XMLReader reader = _parser.getXMLReader();
        reader.setContentHandler(handler);
        reader.setErrorHandler(handler);
        reader.setEntityResolver(handler);
        _parser.parse(new InputSource(in), handler);
        if (handler._error != null)
            throw handler._error;
        Node doc = (Node) handler._top.get(0);
        handler.clear();
        return doc;
    }

    /* ------------------------------------------------------------ */
    /* ------------------------------------------------------------ */
    private class NoopHandler extends DefaultHandler
    {
        Handler _next;
        int _depth;

        NoopHandler(Handler next)
        {
            this._next = next;
        }

        /* ------------------------------------------------------------ */
        public void startElement(String uri, String localName, String qName, Attributes attrs) throws SAXException
        {
            _depth++;
        }

        /* ------------------------------------------------------------ */
        public void endElement(String uri, String localName, String qName) throws SAXException
        {
            if (_depth == 0)
                _parser.getXMLReader().setContentHandler(_next);
            else
                _depth--;
        }
    }
    
    /* ------------------------------------------------------------ */
    /* ------------------------------------------------------------ */
    private class Handler extends DefaultHandler
    {
        Node _top = new Node(null, null, null);
        SAXParseException _error;
        private Node _context = _top;
        private NoopHandler _noop;

        Handler()
        {
            _noop = new NoopHandler(this);
        }

        /* ------------------------------------------------------------ */
        void clear()
        {
            _top = null;
            _error = null;
            _context = null;
        }

        /* ------------------------------------------------------------ */
        public void startElement(String uri, String localName, String qName, Attributes attrs) throws SAXException
        {
            String name = (uri == null || uri.equals("")) ? qName : localName;
            Node node = new Node(_context, name, attrs);
            

            // check if the node matches any xpaths set?
            if (_xpaths != null)
            {
                String path = node.getPath();
                boolean match = false;
                for (int i = LazyList.size(_xpaths); !match && i-- > 0;)
                {
                    String xpath = (String) LazyList.get(_xpaths, i);

                    match = path.equals(xpath) || xpath.startsWith(path) && xpath.length() > path.length() && xpath.charAt(path.length()) == '/';
                }

                if (match)
                {
                    _context.add(node);
                    _context = node;
                }
                else
                {
                    _parser.getXMLReader().setContentHandler(_noop);
                }
            }
            else
            {
                _context.add(node);
                _context = node;
            }

            ContentHandler observer = null;
            if (_observerMap != null)
                observer = (ContentHandler) _observerMap.get(name);
            _observers.push(observer);

            for (int i = 0; i < _observers.size(); i++)
                if (_observers.get(i) != null)
                    ((ContentHandler) _observers.get(i)).startElement(uri, localName, qName, attrs);
        }

        /* ------------------------------------------------------------ */
        public void endElement(String uri, String localName, String qName) throws SAXException
        {
            _context = _context._parent;
            for (int i = 0; i < _observers.size(); i++)
                if (_observers.get(i) != null)
                    ((ContentHandler) _observers.get(i)).endElement(uri, localName, qName);
            _observers.pop();
        }

        /* ------------------------------------------------------------ */
        public void ignorableWhitespace(char buf[], int offset, int len) throws SAXException
        {
            for (int i = 0; i < _observers.size(); i++)
                if (_observers.get(i) != null)
                    ((ContentHandler) _observers.get(i)).ignorableWhitespace(buf, offset, len);
        }

        /* ------------------------------------------------------------ */
        public void characters(char buf[], int offset, int len) throws SAXException
        {
            _context.add(new String(buf, offset, len));
            for (int i = 0; i < _observers.size(); i++)
                if (_observers.get(i) != null)
                    ((ContentHandler) _observers.get(i)).characters(buf, offset, len);
        }

        /* ------------------------------------------------------------ */
        public void warning(SAXParseException ex)
        {
            Log.debug(Log.EXCEPTION, ex);
            Log.warn("WARNING@" + getLocationString(ex) + " : " + ex.toString());
        }

        /* ------------------------------------------------------------ */
        public void error(SAXParseException ex) throws SAXException
        {
            // Save error and continue to report other errors
            if (_error == null)
                _error = ex;
            Log.debug(Log.EXCEPTION, ex);
            Log.warn("ERROR@" + getLocationString(ex) + " : " + ex.toString());
        }

        /* ------------------------------------------------------------ */
        public void fatalError(SAXParseException ex) throws SAXException
        {
            _error = ex;
            Log.debug(Log.EXCEPTION, ex);
            Log.warn("FATAL@" + getLocationString(ex) + " : " + ex.toString());
            throw ex;
        }

        /* ------------------------------------------------------------ */
        private String getLocationString(SAXParseException ex)
        {
            return ex.getSystemId() + " line:" + ex.getLineNumber() + " col:" + ex.getColumnNumber();
        }

        /* ------------------------------------------------------------ */
        public InputSource resolveEntity(String pid, String sid)
        {
            if (Log.isDebugEnabled())
                Log.debug("resolveEntity(" + pid + ", " + sid + ")");

            if (sid!=null && sid.endsWith(".dtd"))
                _dtd=sid;
            
            URL entity = null;