XML

XML 处理实践

一：　DOM解析
1. 把XML文挡以String读出
File docFile = new File( fileName);
//FileUtils. commons-io-1.4.jar
String result = FileUtils.readFileToString(new File(fileName), UTF_8);

2.　把String写出到XML文挡
File dest = new File (fileName);
String contens = contents;
FileUtils.writeStringToFile(dest, contents, UTF_8);

3. String to org.w3c.dom.Document
//DocumentBuilderFactory. xml-apis.jar
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
String nodeData = xml content;
Document result = builder.parse(new InputSource(new StringReader(nodeData)));

4. String to org.apache.xerces.dom.DocumentImpl
     //DocumentImpl.  xercesImpl.jar
     DocumentImpl result = null;
     //DOMParser.  xercesImpl.jar
     DOMParser parser = new DOMParser();
     //xml-apis.jar
     DefaultHandler defaultHandler = new DefaultHandler();
     parser.setErrorHandler(defaultHandler);
     InputSource is = new InputSource(new StringReader(nodeData));
     parser.parse(is);
     result = (DocumentImpl) parser.getDocument();

5.  通过父节点，　返回一个　（所有）的子节点
    /**Given any parent element and the tag name of a child element, this returns
    the first child element. If there is multiple child elements, this method
    only retrieves the first. It will also create a child element if it does
    not exist and add it to the parent element if the <code>addChildIfNotPresent</code>
    flag is set to true.
    */

    public static Element findChildForParent(Element parentElement, String childTagName, boolean addChildIfNotPresent) {
        Element childElement = null;
        if (parentElement != null) {
            NodeList list = parentElement.getElementsByTagName(childTagName);
            if (list != null && list.getLength() > 0) {
                childElement = (Element)list.item(0);
            } else {
                if (addChildIfNotPresent) {
                    childElement = addElement(parentElement, childTagName);
                }
            }
        }
        return childElement;
    }

     public static Element addElement(Element parentElement, String childTagName, String value) {
        Element childElement = null;
        if (parentElement != null) {
            childElement = parentElement.getOwnerDocument().createElement(childTagName);
            parentElement.appendChild(childElement);
            if (value != null) {
                Node text = parentElement.getOwnerDocument().createTextNode(value);
                childElement.appendChild(text);
            }
        }
        return childElement;
    }

６。　取得text文本的一些方法

   a. //xmi-apis.jar
　　/**
     *  Get the text of an Element
     *
     *@param  textElement  the Element to retrieve the text from
     *@return              the text of the Element
     */
    public static String textForElement(Element textElement) {
        String value = null;

        if (textElement != null) {
            Node child = textElement.getFirstChild();
            while (child != null) {
                if ((child.getNodeType() == Node.TEXT_NODE) || (child.getNodeType() == Node.CDATA_SECTION_NODE)) {
                    value = child.getNodeValue();
                    child = null;
                } else {
                    child = child.getNextSibling();
                }
            }
        }

        return value;
    }

    b. // CachedXPathAPI come from  xalan.jar
       //org.w3c.dom.Node implement in xml-apis.jar
      /**
     *  Description of the Method
     *
     *@param  xpathToElement      Description of the Parameter
     *@param  cachedXpath         Description of the Parameter
     *@param  node                Description of the Parameter
     *@return                     Description of the Return Value
     *@exception  CVXMLException  Description of the Exception
     */
    public static String textForElement(String xpathToElement, Node node, org.apache.xpath.CachedXPathAPI cachedXpath) throws CVXMLException {
        String results = null;
        if (cachedXpath != null) {
            try {
                if (logger.isDebugEnabled()) logger.debug("getting textForElement using cachedxpath and xpath : " + cachedXpath + " -- " + xpathToElement);
                Node n = cachedXpath.selectSingleNode(node, xpathToElement);
                if (n != null) {
                    results = textForElement((Element)n);
                }
            } catch (Throwable t) {
                if (logger.isDebugEnabled()) logger.debug("Error getting textForElement", t);
                //throw new CVXMLException(t);
            }
        } else {
            results = textForElement(xpathToElement, node);
        }

        return results;
    }
   
    c. Using xpath get the text from Document.
    //XPathAPI. xalan.jar
    /**
     *  Description of the Method
     *
     *@param  xpathToElement      Description of the Parameter
     *@param  doc                 Description of the Parameter
     *@return                     Description of the Return Value
     *@exception  CVXMLException  Description of the Exception
     */
    public static String textForElement(String xpathToElement, Document doc) throws CVXMLException {
        String results = null;
        try {
            if (logger.isDebugEnabled()) logger.debug("getting textForElement using old way -- no cachedxpathapi");
            Node n = XPathAPI.selectSingleNode(doc.getDocumentElement(), xpathExpression);
            if (n != null) {
                results = textForElement((Element)n);
            }
        } catch (CVXMLException e) {
            e.appendLogInfo("Unable to find a node using the xpath : " + xpathToElement);
            throw e;
        } catch (Throwable t) {
            if (logger.isDebugEnabled()) logger.debug("Error getting textForElement", t);
        }

        return results;
    }

7. 取得Attibute的方法
　//xml-apis.jar
  public static String textForAttribute(Element parentElement, String attributeName) {
        String attributeText = null;
        Attr classAttribute = parentElement.getAttributeNode(attributeName);
        if (classAttribute != null) {
            attributeText = classAttribute.getValue();
        }

        return attributeText;
    }

  8. 设置text和attribute的方法
     //xml-apis.jar
   public static void setTextForElement(Element textElement, String textToBeUsed) {
        if (textToBeUsed != null) {
            if (textToBeUsed.length() > 0){
                textToBeUsed = StringUtils.removeIncompatibilityCharacters(textToBeUsed);
            }
            if (textElement.hasChildNodes()) {
                // search for a text or cdata node to set the value of
                boolean found = false;
                boolean done = false;
                Node child = textElement.getFirstChild();
                while (!found && !done) {
                    if (child.getNodeType() == Node.TEXT_NODE || child.getNodeType() == Node.CDATA_SECTION_NODE) {
                        done = true;
                        found = true;
                    } else {
                        child = child.getNextSibling();
                        if (child == null) {
                            done = true;
                        }
                    }
                }

                if (found) {
                    child.setNodeValue(textToBeUsed);
                } else {

                    //Node text = textElement.getOwnerDocument().createTextNode(textToBeUsed);//GR 04/01/2004 -- Changed to create CData Section instead
                    Node text = textElement.getOwnerDocument().createCDATASection(textToBeUsed);
                    textElement.appendChild(text);
                }
            }

            else {
                // no text nodes found to set a value for, so must create one
                //textElement.appendChild(textElement.getOwnerDocument().createTextNode(textToBeUsed));//GR 04/01/2004 -- Changed to create CData Section instead
                textElement.appendChild(textElement.getOwnerDocument().createCDATASection(textToBeUsed));
            }
        }
    }

　　 public static String removeIncompatibilityCharacters(String textStr) {

        CharArrayWriter charArrayWriter = new CharArrayWriter();

        for (int i = 0; i < textStr.length(); i++) {
            if (Character.isDefined(textStr.charAt(i))) {

                int charVal = (int) textStr.charAt(i);
                // Control Characters --> NUL, SOH, STX, ETX, EOT, ENQ, ACK, BEL, BS
                if (charVal >= 0x00 && charVal <= 0x08) {
                    continue;
                }
                // Control Characters --> CR, SO, SI, DLE, DC1, DC2, DC3, DC4, NAK, SYN, ETB, CAN, EM, SUB, ESC, FS, GS, RS, US
                if (charVal >= 0x0B && charVal <= 0x1F) {
                    continue;
                }
                // The remaining characters are defined at http://www.w3.org/TR/2006/REC-xml-20060816/#charsets
                if (charVal >= 0x7F && charVal <= 0x84) {
                    continue;
                }
                if (charVal >= 0x86 && charVal <= 0x9F) {
                    continue;
                }
                if (charVal >= 0xFDD0 && charVal <= 0xFDDF) {
                    continue;
                }
                if (charVal >= 0x1FFFE && charVal <= 0x1FFFF) {
                    continue;
                }
                if (charVal >= 0x2FFFE && charVal <= 0x2FFFF) {
                    continue;
                }
                if (charVal >= 0x3FFFE && charVal <= 0x3FFFF) {
                    continue;
                }
                if (charVal >= 0x4FFFE && charVal <= 0x4FFFF) {
                    continue;
                }
                if (charVal >= 0x5FFFE && charVal <= 0x5FFFF) {
                    continue;
                }
                if (charVal >= 0x6FFFE && charVal <= 0x6FFFF) {
                    continue;
                }
                if (charVal >= 0x7FFFE && charVal <= 0x7FFFF) {
                    continue;
                }
                if (charVal >= 0x8FFFE && charVal <= 0x8FFFF) {
                    continue;
                }
                if (charVal >= 0x9FFFE && charVal <= 0x9FFFF) {
                    continue;
                }
                if (charVal >= 0xAFFFE && charVal <= 0xAFFFF) {
                    continue;
                }
                if (charVal >= 0xBFFFE && charVal <= 0xBFFFF) {
                    continue;
                }
                if (charVal >= 0xCFFFE && charVal <= 0xCFFFF) {
                    continue;
                }
                if (charVal >= 0xDFFFE && charVal <= 0xDFFFF) {
                    continue;
                }
                if (charVal >= 0xEFFFE && charVal <= 0xEFFFF) {
                    continue;
                }
                if (charVal >= 0xFFFFE && charVal <= 0xFFFFF) {
                    continue;
                }
                if (charVal >= 0x10FFFE && charVal <= 0x10FFFF) {
                    continue;
                }

                charArrayWriter.write(charVal);
            }
        }

        return new String(charArrayWriter.toCharArray());
    }

     public static void setTextForAttribute(Element parentElement, String attributeName, String attributeValue) {
        parentElement.setAttribute(attributeName, attributeValue);
    }


９. 创建Document
   a. //xml-apis.jar
   //Creates a new document object with the root node having the name: <code>rootElementName</code>\
    public static Document createDocumentWithRoot(String rootElementName, boolean x) {
        Document newRecordDoc = null;
        if (rootElementName != null && !rootElementName.trim().equals("")) {
            newRecordDoc = createDocument(true);
            // Once the new document has been created, add the necessary root element
            newRecordDoc.appendChild(newRecordDoc.createElement(rootElementName));
        }
        return newRecordDoc;
    }


    b. //Creates a new document object without the root node being set on the
   public static Document createDocument(boolean x) {
        Document newRecordDoc = null;
        try {
            DocumentBuilder docBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
            newRecordDoc = docBuilder.newDocument();
        } catch (Exception e) {
            ExceptionLogWriter.logException(e, "DOMHelper.createDocument(). Problem instantiating a new DocumentBuilder");
        }
        return newRecordDoc;
    }
   
10. 替换节点
　　a. //xml-apis.jar
     public static Document replaceRootNodeName(String xml, String newValue) throws CVXMLException {
        Document doc = stringToDocument(xml, true);
        replaceRootNodeName(doc, newValue);
        return doc;
    }
   
    b.
     public static void replaceRootNodeName(Document doc, String newValue) {
        replaceNodeName(doc, doc.getDocumentElement(), newValue);
    }
   
    c.
     public static void replaceNodeName(Document doc, Element element, String newValue) {
       //Create an element with the new name
        Element element = doc.createElement(newValue);
       
       // Copy the attributes to the new element
        NamedNodeMap attrs = element.getAttributes();
        for (int i = 0; i < attrs.getLength(); i++) {
            Attr attr2 = (Attr)doc.importNode(attrs.item(i), true);
            element2.getAttributes().setNamedItem(attr2);
        }
       
        // Move all the children
        while (element.hasChildNodes()) {
            element2.appendChild(element.getFirstChild());
        }
       
         // Replace the old node with the new node
        element.getParentNode().replaceChild(element2, element);

     }
    
    
二. SAX　解析
   class XMLDocument extends DefaultHandler {
        Document doc;
        String elementName = "";
        String attribName = "";
        String attribVal = "";
        boolean addAttr = false;
        Element currElement;
        Element root;
        String rootName;
        boolean hasDocument = false;
        boolean hasRoot = false;
        int count = 0;

        /**  Constructor for the XMLDocument object */
        XMLDocument() {
            super();
            hasDocument = false;
        }

        /**
         *@param  val  Document
         */
        XMLDocument(Document val) {
            super();
            doc = val;
            hasDocument = true;
        }

        /**
         *  Method to set the Root
         *
         *@param  val  The new root value
         */
        public void setRoot(String val) {
            rootName = val;
            hasRoot = true;
        }

        /**
         *  Method to add an attribute.
         *
         *@param  element    String containing the elementName
         *@param  attribute  String containing the attribute name
         *@param  value      String containing the attribute value
         */
        public void addAttribute(String element, String attribute, String value) {
            elementName = element;
            attribName = attribute;
            attribVal = value;
            addAttr = true;
        }

        /**
         *@exception  SAXException  If the root element name is missing
         */
        public void startDocument() throws SAXException {
            if (!hasDocument) {
                try {
                    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                    DocumentBuilder parser = factory.newDocumentBuilder();
                    doc = parser.newDocument();
                } catch (Exception e) {
                    throw new SAXException(e);
                }

                if (rootName == null || rootName.equals("")) {
                    throw new SAXException("Missing root element name, call setRoot() first");
                }
            }
            if (hasRoot) {
                root = (Element)doc.createElement(rootName);
                doc.appendChild(root);
            }

        }

        /**
         *@param  uri               String containing the uri
         *@param  localName         String containing the localName
         *@param  rawName           String containing the rawName
         *@param  atts              Attributes
         *@exception  SAXException  Description of the Exception
         */
        public void startElement(String uri, String localName, String rawName, Attributes atts) throws SAXException {
            // Assume the first element encountered is the root element

            // Check the element to see if it is one we are interested in processing
            if (hasRoot) {
                if (!rawName.equalsIgnoreCase(rootName)) {
                    currElement = (Element)doc.createElement(rawName);
                    for (int i = 0; i < atts.getLength(); i++) {
                        currElement.setAttribute(atts.getQName(i), atts.getValue(i));
                    }
                    if (rawName.equals(elementName) && addAttr) {
                        // Add the new attribute if specified
                        currElement.setAttribute(attribName, attribVal);
                    }
                    root.appendChild(currElement);
                } else {
                    currElement = (Element)doc.createElement(rawName);
                    for (int i = 0; i < atts.getLength(); i++) {
                        currElement.setAttribute(atts.getQName(i), atts.getValue(i));
                    }

                }
            } else {
                // Create a new element - used for stringToDoc(String) method
                if (count == 0) {
                    root = (Element)doc.createElement(rawName);
                    doc.appendChild(root);
                }
                currElement = (Element)doc.createElement(rawName);
                for (int i = 0; i < atts.getLength(); i++) {
                    currElement.setAttribute(atts.getQName(i), atts.getValue(i));
                }
                root.appendChild(currElement);
                count++;
            }
        }

        /**
         *@param  ch                Description of the Parameter
         *@param  start             Description of the Parameter
         *@param  length            Description of the Parameter
         *@exception  SAXException  Description of the Exception
         */
        public void characters(char[] ch, int start, int length) throws SAXException {
            Text text = doc.createTextNode(new String(ch, start, length));
            if (currElement != null) {
                currElement.appendChild(text);
            }
        }

        /**
         *  Description of the Method
         *
         *@return    Description of the Return Value
         */
        public Document document() {
            return doc;
        }

    }
   
    //xml-apis.jar
    public Object process( InputSource is ) {
           protected List tags = new ArrayList(0);
           SAXParserFactory spf = SAXParserFactory.newInstance();
           spf.setValidating( strict );
           SAXParser sp = spf.newSAXParser();
           XMLReader xmlReader = sp.getXMLReader();
           xmlReader.setContentHandler( this );
           xmlReader.setErrorHandler( this );
           if( entityResolver != null ) {
               xmlReader.setEntityResolver( entityResolver );
           }
           xmlReader.parse( is );
           if( tags.size() == 0 ) return finish( null );
           return finish( tags.remove(0) );

    }
   
    MyProcess processor = new ProcessImpl(conf, rc);
    //XMLBuilder extends XMLDocument 策略模式
    XMLBuilder xb = new XMLBuilder(processor);
    xb.process(new StringReader( ""));
   
    三. xsl parse xml
    //xml-apis.jar
    protected void transformXml(String path, String documentXml) {
StreamSource xsl = new StreamSource(new File(xslFileName));
StringReader reader = new StringReader(documentXml);
StreamSource xml = new StreamSource(reader);
StringWriter writer = new StringWriter();
StreamResult result = new StreamResult(writer);

Transformer transformer = null;
try {
transformer = TransformerFactory.newInstance().newTransformer(xsl);
}

try {
if(null != transformer) {
transformer.transform(xml, result);
}
}


      xsl:
        <root>
        <xsl:template match="/book">
        <xsl:if test="date/text()" >
          <newnode><xsl:value-of select="date"/></facet>
        </xsl:if>
        <xsl:apply-templates select="Auther/lan"/>
        </root>


    <xsl:template match="Auther/lan">
     <xsl:if test="position()=1">
        <p><xsl:value-of select="key"/></p>
    </xsl:if>
   </xsl:template>