source: trunk/gli/src/org/greenstone/gatherer/util/XMLTools.java@ 14053

package org.greenstone.gatherer.util;


import java.io.*;
import java.net.*;
import java.util.*;
import org.apache.xerces.parsers.*;
import org.apache.xml.serialize.*;
import org.greenstone.gatherer.DebugStream;
import org.w3c.dom.*;
import org.xml.sax.*;

import java.io.FileReader;
import java.io.IOException;
import java.io.StringReader;

// SAX
import org.xml.sax.XMLReader;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.InputSource;

// JAXP
import javax.xml.parsers.FactoryConfigurationError;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

/** This class is a static class containing useful XML functions */
public class XMLTools {
    /** extracts the text out of a node */
    public static Node getNodeTextNode (Element param) {
        param.normalize ();
        Node n = param.getFirstChild ();
        while (n!=null && n.getNodeType () !=Node.TEXT_NODE) {
            n=n.getNextSibling ();
        }
        return n;
    }
    
    /** extracts the text out of a node */
    public static String getNodeText (Element param) {
        Node text_node = getNodeTextNode (param);
        if (text_node == null) {
            return "";
        }
        return text_node.getNodeValue ();
    }
    public static void setNodeText (Element elem, String text) {
        Node old_text_node = getNodeTextNode (elem);
        if (old_text_node != null) {
            elem.removeChild (old_text_node);
        }
        Text t = elem.getOwnerDocument ().createTextNode (text);
        elem.appendChild (t);
    }
    /** returns the (first) child element with the given name */
    public static Node getChildByTagName (Node n, String name) {
        
        Node child = n.getFirstChild ();
        while (child!=null) {
            if (child.getNodeName ().equals (name)) {
                return child;
            }
            child = child.getNextSibling ();
        }
        return null; //not found
    }
    
    /** returns the (nth) child element with the given name
     * index numbers start at 0 */
    public static Node getChildByTagNameIndexed (Node n, String name, int index) {
        if (index == -1) {
            return getChildByTagName (n, name);
        }
        int count = 0;
        Node child = n.getFirstChild ();
        while (child!=null) {
            if (child.getNodeName ().equals (name)) {
                if (count == index) {
                    return child;
                } else {
                    count++;
                }
            }
            child = child.getNextSibling ();
        }
        return null; //not found
    }
    
    /** returns the element parent/node_name[@attribute_name='attribute_value']
     */
    public static Element getNamedElement (Element parent, String node_name,
    String attribute_name,
    String attribute_value) {
        
        NodeList children = parent.getChildNodes ();
        for (int i=0; i<children.getLength (); i++) {
            Node child = children.item (i);
            //logger.debug("getnamed elem, node nmae="+child.getNodeName());
            if (child.getNodeName ().equals (node_name)) {
                if (((Element)child).getAttribute (attribute_name).equals (attribute_value))
                    return (Element)child;
            }
        }
        // not found
        return null;
    }
    /** returns a list of elements parent/node_name[@attribute_name='attribute_value']
     */
    public static ArrayList getNamedElementList (Element parent, String node_name,
    String attribute_name,
    String attribute_value) {
        ArrayList elements = new ArrayList ();
        NodeList children = parent.getChildNodes ();
        for (int i=0; i<children.getLength (); i++) {
            //System.out.println("getNamedElementList");
            Node child = children.item (i);
            //logger.debug("getnamed elem, node nmae="+child.getNodeName());
            if (child.getNodeName ().equals (node_name)) {
                if (((Element)child).getAttribute (attribute_name).equals (attribute_value))
                    elements.add ((Element)child);
            }
        }
        // not found
        if (elements.size () == 0) {
            elements = null;
        }
        return elements;
    }
    public static void copyAllChildren (Element to, Element from) {
        
        Document to_doc = to.getOwnerDocument ();
        Node child = from.getFirstChild ();
        while (child != null) {
            to.appendChild (to_doc.importNode (child, true));
            child = child.getNextSibling ();
        }
    }
    /** Duplicates an element */
    public static Element duplicateElement (Document owner, Element element, boolean with_attributes) {
        return duplicateElementNS (owner, element, null, with_attributes);
    }
    
    /** Duplicates an element */
    public static Element duplicateElementNS (Document owner,
    Element element,
    String namespace_uri,
    boolean with_attributes) {
        Element duplicate;
        if (namespace_uri == null) {
            duplicate = owner.createElement (element.getTagName ());
        } else {
            duplicate = owner.createElementNS (namespace_uri, element.getTagName ());
        }
        // Copy element attributes
        if (with_attributes) {
            NamedNodeMap attributes = element.getAttributes ();
            for (int i = 0; i < attributes.getLength (); i++) {
                Node attribute = attributes.item (i);
                duplicate.setAttribute (attribute.getNodeName (), attribute.getNodeValue ());
            }
        }
        
        // Copy element children
        NodeList children = element.getChildNodes ();
        for (int i = 0; i < children.getLength (); i++) {
            Node child = children.item (i);
            duplicate.appendChild (owner.importNode (child, true));
        }
        
        return duplicate;
    }
    
    
    /** Remove all of the child nodes from a certain node. */
    static final public void clear (Node node) {
        while (node.hasChildNodes ()) {
            node.removeChild (node.getFirstChild ());
        }
    }
    
    
    static public ArrayList getChildElementsByTagName (Element parent_element, String element_name) {
        ArrayList child_elements = new ArrayList ();
        
        NodeList children_nodelist = parent_element.getChildNodes ();
        for (int i = 0; i < children_nodelist.getLength (); i++) {
            Node child_node = children_nodelist.item (i);
            if (child_node.getNodeType () == Node.ELEMENT_NODE && child_node.getNodeName ().equals (element_name)) {
                child_elements.add (child_node);
            }
        }
        
        return child_elements;
    }
    
    
    static public String getElementTextValue (Element element) {
        // Find the first text node child
        NodeList children_nodelist = element.getChildNodes ();
        for (int i = 0; i < children_nodelist.getLength (); i++) {
            Node child_node = children_nodelist.item (i);
            if (child_node.getNodeType () == Node.TEXT_NODE) {
                return child_node.getNodeValue ();
            }
        }
        
        // None found
        return "";
    }
    
    
    /** Method to retrieve the value of a given node.
     * @param element The <strong>Element</strong> whose value we wish to find.
     * Soon to be deprecated!
     */
    static final public String getValue (Node element) {
        if (element == null) {
            return "";
        }
        // If we've been given a subject node first retrieve its value node.
        if(element.getNodeName ().equals ("Subject")) {
            element = getNodeFromNamed (element, "Value");
        }
        // If we've got a value node, then reconstruct the text. Remember that DOM will split text over 256 characters into several text nodes
        if(element != null && element.hasChildNodes ()) {
            StringBuffer text_buffer = new StringBuffer ();
            NodeList text_nodes = element.getChildNodes ();
            for(int i = 0; i < text_nodes.getLength (); i++) {
                Node possible_text = text_nodes.item (i);
                if(possible_text.getNodeName ().equals (StaticStrings.TEXT_NODE)) {
                    text_buffer.append (possible_text.getNodeValue ());
                }
            }
            return text_buffer.toString ();
        }
        return "";
    }
    
    
    /** Method to retrieve from the node given, a certain child node with the specified name.
     * @param parent The <strong>Node</strong> whose children should be searched.
     * @param name The required nodes name as a <strong>String</strong>.
     * @return The requested <strong>Node</strong> if it is found, <i>null</i> otherwise.
     * Soon to be deprecated!
     */
    static final public Node getNodeFromNamed (Node parent, String name) {
        Node child = null;
        for(Node i = parent.getFirstChild (); i != null && child == null;
        i = i.getNextSibling ()) {
            if(i.getNodeName ().equals (name)) {
                child = i;
            }
        }
        return child;
    }
    
    static final public String WELLFORMED= "well-formed !";
    static final public String NOTWELLFORMED= "not well-formed";
    static final private String HEADER = "<?xml version='1.0' encoding='UTF-8'?><collectionConfig xmlns:gsf='http://www.greenstone.org/greenstone3/schema/ConfigFormat' xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>";
    static final private String FOOTER = "</collectionConfig>";
       
public static String parse (String xml_str) {
        String validation_msg = WELLFORMED;
        xml_str = HEADER + xml_str + FOOTER;
        try {
            SAXParserFactory factory = SAXParserFactory.newInstance ();
            factory.setNamespaceAware (true);
            //factory.setValidating (true);
            SAXParser parser = factory.newSAXParser ();
            InputSource iSource = new InputSource ( new StringReader ( xml_str ) );
//              parser.parse (iSource, new DefaultHandler ());
            
            org.xml.sax.XMLReader reader = parser.getXMLReader ();
            reader.setContentHandler(new DefaultHandler());
            reader.setErrorHandler(new DefaultHandler());
            reader.parse(iSource);
        } catch (FactoryConfigurationError e) {
            validation_msg = "unable to get a document builder factory";
        } catch (ParserConfigurationException e) {
            validation_msg = "unable to configure parser";
        } catch (SAXParseException e) {
            validation_msg = NOTWELLFORMED + getLocationString(e) + e.getMessage ();
        } catch (SAXException e) {
            validation_msg += " Fatal error: " + e.toString ();
        } catch (IOException e) {
            validation_msg = "Unable to read the input, i/o error";
        }
        
        return validation_msg;
    }
//In this method, the parsed string xml_str is not wrapped by the header and footer strings.
public static String parseDOM (String xml_str) {
        String validation_msg = WELLFORMED;
        
        try {
            SAXParserFactory factory = SAXParserFactory.newInstance ();
            factory.setNamespaceAware (true);
            //factory.setValidating (true);
            SAXParser parser = factory.newSAXParser ();
            InputSource iSource = new InputSource ( new StringReader ( xml_str ) );
//              parser.parse (iSource, new DefaultHandler ());
            
            org.xml.sax.XMLReader reader = parser.getXMLReader ();
            reader.setContentHandler(new DefaultHandler());
            reader.setErrorHandler(new DefaultHandler());
            reader.parse(iSource);
        } catch (FactoryConfigurationError e) {
            validation_msg = "unable to get a document builder factory";
        } catch (ParserConfigurationException e) {
            validation_msg = "unable to configure parser";
        } catch (SAXParseException e) {
            validation_msg = NOTWELLFORMED + getLocationString(e) + e.getMessage ();
        } catch (SAXException e) {
            validation_msg += " " + e.toString ();
        } catch (IOException e) {
            validation_msg = "Unable to read the input, i/o error";
        }
        
        return validation_msg;
    }

public static String parse (File xml_file) {
        String validation_msg = WELLFORMED;

        try {
            SAXParserFactory factory = SAXParserFactory.newInstance ();
            factory.setNamespaceAware (true);
            //factory.setValidating (true);
            SAXParser parser = factory.newSAXParser ();
            FileReader r = new FileReader(xml_file);
            InputSource iSource = new InputSource(r);
            XMLReader reader = parser.getXMLReader ();
            reader.setContentHandler(new DefaultHandler());
            reader.setErrorHandler(new DefaultHandler());
            reader.parse(iSource);
        } catch (FactoryConfigurationError e) {
            validation_msg = "unable to get a document builder factory";
        } catch (ParserConfigurationException e) {
            validation_msg = "unable to configure parser";
        } catch (SAXParseException e) {
            validation_msg = NOTWELLFORMED + getLocationString(e) + e.getMessage ();
        } catch (SAXException e) {
            validation_msg += " Fatal error: " + e.toString ();
        } catch (IOException e) {
            validation_msg = "Unable to read the input, i/o error";
        }
        
        return validation_msg;
    }    
    /** Returns a string of the location. */
    private static String getLocationString(SAXParseException ex) {
        StringBuffer str = new StringBuffer();

        String systemId = ex.getSystemId();
        if (systemId != null) {
            int index = systemId.lastIndexOf('/');
            if (index != -1)
                systemId = systemId.substring(index + 1);
            str.append(systemId);
        }
        str.append("(line ");
        str.append(ex.getLineNumber()-1);
        str.append(", column ");
        str.append(ex.getColumnNumber());
        str.append("): ");

        return str.toString();

    } // getLocationString(SAXParseException):String

    /** Parse an XML document from a given file path */
    static public Document parseXMLFile (String xml_file_path, boolean use_class_loader) {
        if (use_class_loader == true) {
            InputStream is = JarTools.getResourceAsStream ("/" + xml_file_path);
            if (is != null) {
                return parseXML (is);
            }
        }
        
        // Try the file outside the classes directory
        return parseXMLFile (new File (xml_file_path));
    }
    
    
    /** Parse an XML document from a given file */
    static public Document parseXMLFile (File xml_file) {
        // No file? No point trying!
        if (xml_file.exists () == false) {
            return null;
        }
        
        try {
            return parseXML (new FileInputStream (xml_file));
        }
        catch (Exception exception) {
            DebugStream.printStackTrace (exception);
            return null;
        }
    }
    
    
    /** Parse an XML document from a given input stream */
    static public Document parseXML (InputStream xml_input_stream) {
        Document document = null;
        
        try {
            InputStreamReader isr = new InputStreamReader (xml_input_stream, "UTF-8");
            Reader xml_reader = new BufferedReader (isr);
            document = parseXML (xml_reader);
            isr.close ();
            xml_input_stream.close ();
        }
        catch (Exception exception) {
            DebugStream.printStackTrace (exception);
        }
        
        return document;
    }
    
    
    /** Parse an XML document from a given reader */
    static public Document parseXML (Reader xml_reader) {
        Document document = null;
        
        try {
            InputSource isc       = new InputSource (xml_reader);
            DOMParser parser      = new DOMParser ();
            parser.setFeature ("http://xml.org/sax/features/validation", false);
            parser.setFeature ("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
            // May or may not be ignored, the documentation for Xerces is contradictory. If it works then parsing -should- be faster.
            parser.setFeature ("http://apache.org/xml/features/dom/defer-node-expansion", true);
            parser.setFeature ("http://apache.org/xml/features/dom/include-ignorable-whitespace", false);
            parser.parse (isc);
            document = parser.getDocument ();
        }
        catch (SAXException exception) {
            System.err.println ("SAX exception: " + exception.getMessage ());
            DebugStream.printStackTrace (exception);
        }
        catch (Exception exception) {
            DebugStream.printStackTrace (exception);
        }
        
        return document;
    }
    
    
    static public StringBuffer readXMLStream (InputStream input_stream) {
        StringBuffer xml = new StringBuffer ("");
        
        try {
            InputStreamReader isr = new InputStreamReader (input_stream, "UTF-8");
            BufferedReader buffered_in = new BufferedReader (isr);
            
            String line = "";
            boolean xml_content = false;
            while((line = buffered_in.readLine ()) != null) {
                if(xml_content) {
                    xml.append (line);
                    xml.append ("\n");
                }
                else if(line.trim ().startsWith ("<?xml")) {
                    xml_content = true;
                    xml.append (line);
                    xml.append ("\n");
                }
            }
            buffered_in = null;
        }
        catch (Exception error) {
            System.err.println ("Failed when trying to parse XML stream");
            error.printStackTrace ();
        }
        
        return xml;
    }
    
    
    /** Removes characters that are invalid in XML (see http://www.w3.org/TR/2000/REC-xml-20001006#charsets) */
    static public String removeInvalidCharacters (String text) {
        char[] safe_characters = new char[text.length ()];
        int j = 0;
        
        char[] raw_characters = new char[text.length ()];
        text.getChars (0, text.length (), raw_characters, 0);
        for (int i = 0; i < raw_characters.length; i++) {
            char character = raw_characters[i];
            if ((character >= 0x20 && character <= 0xD7FF) || character == 0x09 || character == 0x0A || character == 0x0D || (character >= 0xE000 && character <= 0xFFFD) || (character >= 0x10000 && character <= 0x10FFFF)) {
                safe_characters[j] = character;
                j++;
            }
        }
        
        return new String (safe_characters, 0, j);
    }
    
    
    static public void setElementTextValue (Element element, String text) {
        // Remove all text node children
        NodeList children_nodelist = element.getChildNodes ();
        for (int i = children_nodelist.getLength () - 1; i >= 0; i--) {
            Node child_node = children_nodelist.item (i);
            if (child_node.getNodeType () == Node.TEXT_NODE) {
                element.removeChild (child_node);
            }
        }
        
        // Add a new text node
        if (text != null) {
            element.appendChild (element.getOwnerDocument ().createTextNode (text));
        }
    }
    
    
    /** Set the #text node value of some element.
     * @param element the Element whose value we wish to set
     * @param value the new value for the element as a String
     * Soon to be deprecated!
     */
    static final public void setValue (Element element, String value) {
        // Remove any existing child node(s)
        clear (element);
        // Add new text node.
        if (value != null) {
            element.appendChild (element.getOwnerDocument ().createTextNode (value));
        }
    }
    
    /** Write an XML document to a given file with the text node of the specified element unescaped*/
    static public void writeXMLFile (File xml_file, Document document, String[] nonEscapingTagNames) {
        try {
            OutputStream os = new FileOutputStream (xml_file);
            // Create an output format for our document.
            OutputFormat f = new OutputFormat (document);
            f.setEncoding ("UTF-8");
            f.setIndenting (true);
            f.setLineWidth (0); // Why isn't this working!
            f.setPreserveSpace (false);
            
            f.setNonEscapingElements (nonEscapingTagNames);
            // Create the necessary writer stream for serialization.
            OutputStreamWriter osw = new OutputStreamWriter (os, "UTF-8");
            Writer w               = new BufferedWriter (osw);
            // Generate a new serializer from the above.
            XMLSerializer s        = new XMLSerializer (w, f);
            s.asDOMSerializer ();
            // Finally serialize the document to file.
            s.serialize (document);
            // And close.
            os.close ();
        }
        catch (Exception exception) {
            DebugStream.printStackTrace (exception);
        }
    }
    
    /** Write an XML document to a given file */
    static public void writeXMLFile (File xml_file, Document document) {
        try {
            OutputStream os = new FileOutputStream (xml_file);
            // Create an output format for our document.
            OutputFormat f = new OutputFormat (document);
            f.setEncoding ("UTF-8");
            f.setIndenting (true);
            f.setLineWidth (0); // Why isn't this working!
            f.setPreserveSpace (false);
            // Create the necessary writer stream for serialization.
            OutputStreamWriter osw = new OutputStreamWriter (os, "UTF-8");
            Writer w               = new BufferedWriter (osw);
            // Generate a new serializer from the above.
            XMLSerializer s        = new XMLSerializer (w, f);
            s.asDOMSerializer ();
            // Finally serialize the document to file.
            s.serialize (document);
            // And close.
            os.close ();
        }
        catch (Exception exception) {
            DebugStream.printStackTrace (exception);
        }
    }
    
    public static void printXMLNode (Node e) {
        printXMLNode (e, 0) ;
    }
    
    public static void printXMLNode (Node e, int depth) { //recursive method call using DOM API...
        
        for (int i=0 ; i<depth ; i++)
            System.out.print (' ') ;
        
        if (e.getNodeType () == Node.TEXT_NODE){
            //System.out.println("text") ;
            if (e.getNodeValue () != "") {
                System.out.println (e.getNodeValue ()) ;
            }
            return ;
        }
        
        System.out.print ('<');
        System.out.print (e.getNodeName ());
        NamedNodeMap attrs = e.getAttributes ();
        if (attrs != null) {
            for (int i = 0; i < attrs.getLength (); i++) {
                Node attr = attrs.item (i);
                System.out.print (' ');
                System.out.print (attr.getNodeName ());
                System.out.print ("=\"");
                System.out.print (attr.getNodeValue ());
                System.out.print ('"');
            }
        }
        NodeList children = e.getChildNodes ();
        
        if (children == null || children.getLength () == 0)
            System.out.println ("/>") ;
        else {
            
            System.out.println ('>') ;
            
            int len = children.getLength ();
            for (int i = 0; i < len; i++) {
                printXMLNode (children.item (i), depth + 1);
            }
            
            for (int i=0 ; i<depth ; i++)
                System.out.print (' ') ;
            
            System.out.println ("</" + e.getNodeName () + ">");
        }
        
    }
    public static String xmlNodeToString (Node e){
        StringBuffer sb = new StringBuffer ("");
        xmlNodeToString (sb,e,0);
        return sb.toString ();
    }
    
    private static void xmlNodeToString (StringBuffer sb, Node e, int depth){
        
        for (int i=0 ; i<depth ; i++)
            sb.append (' ') ;
        
        if (e.getNodeType () == Node.TEXT_NODE){
            if (e.getNodeValue () != "") {
                sb.append (e.getNodeValue ()) ;
            }
            return ;
        }
        
        sb.append ('<');
        sb.append (e.getNodeName ());
        NamedNodeMap attrs = e.getAttributes ();
        if (attrs != null) {
            for (int i = 0; i < attrs.getLength (); i++) {
                Node attr = attrs.item (i);
                sb.append (' ');
                sb.append (attr.getNodeName ());
                sb.append ("=\"");
                sb.append (attr.getNodeValue ());
                sb.append ('"');
            }
        }
        NodeList children = e.getChildNodes ();
        
        if (children == null || children.getLength () == 0)
            sb.append ("/>\n") ;
        else {
            
            sb.append (">\n") ;
            
            int len = children.getLength ();
            for (int i = 0; i < len; i++) {
                xmlNodeToString (sb,children.item (i), depth + 1);
            }
            
            for (int i=0 ; i<depth ; i++)
                sb.append (' ') ;
            
            sb.append ("</" + e.getNodeName () + ">\n");
        }
        
        
    }
    public static String xmlNodeToStringWithoutNewline (Node e){
        StringBuffer sb = new StringBuffer ("");
        xmlNodeToStringWithoutNewline (sb,e,0);
        return sb.toString ();
    }
    
    private static void xmlNodeToStringWithoutNewline (StringBuffer sb, Node e, int depth){
        
        for (int i=0 ; i<depth ; i++)
            sb.append (' ') ;
        
        if (e.getNodeType () == Node.TEXT_NODE){
            if (e.getNodeValue () != "") {
                sb.append (e.getNodeValue ()) ;
            }
            return ;
        }
        
        sb.append ('<');
        sb.append (e.getNodeName ());
        NamedNodeMap attrs = e.getAttributes ();
        if (attrs != null) {
            for (int i = 0; i < attrs.getLength (); i++) {
                Node attr = attrs.item (i);
                sb.append (' ');
                sb.append (attr.getNodeName ());
                sb.append ("=\"");
                sb.append (attr.getNodeValue ());
                sb.append ('"');
            }
        }
        NodeList children = e.getChildNodes ();
        
        if (children == null || children.getLength () == 0)
            sb.append ("/>") ;
        else {
            
            sb.append (">") ;
            
            int len = children.getLength ();
            for (int i = 0; i < len; i++) {
                xmlNodeToStringWithoutNewline (sb,children.item (i), depth + 1);
            }
            
            for (int i=0 ; i<depth ; i++)
                sb.append (' ') ;
            
            sb.append ("</" + e.getNodeName () + ">");
        }
        
        
    }
    
}