org.openxdata.designer.server.util.XmlUtil.java Source code

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Here is the source code for org.openxdata.designer.server.util.XmlUtil.java

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package org.openxdata.designer.server.util;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.StringWriter;
import java.util.Enumeration;
import java.util.Vector;

import javax.servlet.http.HttpServletRequest;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.apache.commons.io.IOUtils;
import org.openxdata.designer.server.xpath.XPathExpression;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

/**
 * This class contains utilities used to manipulate xml documents.
 * 
 *  www.openxdata.org - Licensed as written in license.txt and original sources of this file and its authors are found in sources.txt.
 *
 */
public class XmlUtil {

    /**
     * Reads text data from an http request stream.
     * 
     * @param request the http request stream.
     * @return the text data.
     * @throws java.io.IOException
     */
    public static String getRequestAsString(HttpServletRequest request) throws java.io.IOException {
        BufferedReader requestData = new BufferedReader(new InputStreamReader(request.getInputStream()));
        StringBuffer stringBuffer = new StringBuffer();
        String line;
        try {
            while ((line = requestData.readLine()) != null)
                stringBuffer.append(line);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return stringBuffer.toString();
        //return IOUtils.toString(request.getInputStream());
    }

    /**
     * Converts a document to its text representation.
     * 
     * @param doc - the document.
     * @return - the text representation of the document.
     */
    public static String doc2String(Document doc) {
        try {
            TransformerFactory tFactory = TransformerFactory.newInstance();
            Transformer transformer = tFactory.newTransformer();
            //transformer.setOutputProperty(OutputKeys.INDENT, "yes");

            StringWriter outStream = new StringWriter();
            DOMSource source = new DOMSource(doc);
            StreamResult result = new StreamResult(outStream);
            transformer.transform(source, result);
            return outStream.getBuffer().toString();
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * Creates an xml document from its xml text.
     * 
     * @param xml the xml text.
     * @return the xml document.
     */
    public static Document fromString2Doc(String xml) {
        try {
            return DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(IOUtils.toInputStream(xml));
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }

    /**
     * Gets the text or attribute value of an xpath expression from an xforms instance data document.
     * 
     * @param doc the instance data document.
     * @param xpath the xpath expression.
     * @return the text or attribute value.
     */
    /*public static String getNodeValue(Document doc, String xpath){
       //xpath = new String(xpath.toCharArray(), 1, xpath.length()-1);
       int pos = xpath.lastIndexOf('@'); String attributeName = null;
       if(pos > 0){
     attributeName = xpath.substring(pos+1,xpath.length());
     xpath = xpath.substring(0,pos-1);
       }
           
       XPathExpression xpls = new XPathExpression(doc.getDocumentElement(), xpath);
       Vector result = xpls.getResult();
       for (Enumeration e = result.elements(); e.hasMoreElements();) {
     Object obj = e.nextElement();
     if (obj instanceof Element){
        if(pos > 0) //Check if we are to set attribute value.
           return ((Element) obj).getAttribute(attributeName);
        else
           return ((Element) obj).getTextContent();
     }
       }
       return null;
    }*/

    /**
     * Gets the value of the description template for an xforms xml model.
     * 
     * @param node the child of the xforms model node.
     * @param template the description template.
     * @return the description template value.
     */
    public static String getDescriptionTemplateValue(Element node, String template) {
        if (template == null || template.trim().length() == 0)
            return null;

        //      String s = "Where does ${name}$ come from?";
        String f, v, text = template;

        int startIndex, j, i = 0;
        do {
            startIndex = i; //mark the point where we found the first $ character.

            i = text.indexOf("${", startIndex); //check the opening $ character
            if (i == -1)
                break; //token not found.

            j = text.indexOf("}$", i + 1); //check the closing $ character
            if (j == -1)
                break; //closing token not found. possibly wrong syntax.

            f = text.substring(0, i); //get the text before token
            v = getValue(node, text.substring(i + 2, j)); //append value of token.

            f += (v == null) ? "" : v;
            f += text.substring(j + 2, text.length()); //append value after token.

            text = f;

        } while (true); //will break out when dollar symbols are out.

        return text;
    }

    /**
     * Gets the text or attribute value of an xpath expression from an xforms instance data node.
     * 
     * @param dataNode the instance data node.
     * @param xpath the xpath expression.
     * @return the text or attribute value.
     */
    private static String getValue(Element dataNode, String xpath) {
        int pos = xpath.lastIndexOf('@');
        String attributeName = null;
        if (pos > 0) {
            attributeName = xpath.substring(pos + 1, xpath.length());
            xpath = xpath.substring(0, pos - 1);
        }

        XPathExpression xpls = new XPathExpression(dataNode, xpath);
        Vector<?> result = xpls.getResult();

        for (Enumeration<?> e = result.elements(); e.hasMoreElements();) {
            Object obj = e.nextElement();
            if (obj instanceof Element) {
                if (pos > 0) //Check if we are to set attribute value.
                    return ((Element) obj).getAttribute(attributeName);
                else
                    return ((Element) obj).getTextContent();
            }
        }

        return null;
    }

    /**
     * Gets the value of the description template value in an xml xform model document.
     * 
     * @param xml the xml for the xforms model.
     */
    public static String getDescriptionTemplateValue(String xml) throws Exception {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = dbf.newDocumentBuilder();
        Document doc = db.parse(IOUtils.toInputStream(xml));

        String descTemplate = doc.getDocumentElement().getAttribute("description-template");
        return getDescriptionTemplateValue(doc.getDocumentElement(), descTemplate);
    }

    /**
     * Creates a new xml document.
     * 
     * @return the new xml document.
     * @throws Exception
     */
    public static Document getNewDocument() throws Exception {
        return DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
    }
}