domrepresentation.java

BEA WebLogic Server 8.1大全 = BEA webLogic server 8.1 unleashed (美) Mark Artiges等著 袁毅 ... [等] 译 eng

/* 
 * WebLogic Server Unleashed
 *
 */
package com.wlsunleashed.xml.xpath;

import java.io.IOException;
import java.util.Iterator;
import java.util.Set;

import javax.swing.JFrame;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.xml.sax.SAXException;
import weblogic.apache.xerces.parsers.DOMParser;
import weblogic.xml.xpath.DOMXPath;
import weblogic.xml.xpath.XPathException;


/**
 * This class uses the WebLogic specific DOMXPath to search for items in an
 * XML DOM Document.
 *
 * @version 1.0
 */
public class DOMRepresentation extends JFrame {
    /** The Document that has to be searched */
    private Document document;

    /**
     * Creates a new DOMRepresentation object.
     *
     * @param filename The e-mail XML file.
     *
     * @throws SAXException Thrown when any SAX parsing goes wrong.
     * @throws IOException Thrown when the file is not found.
     */
    public DOMRepresentation(String filename)
                      throws SAXException, IOException {
         document = parseDocument(filename);
    }

    /**
     * The entry point into this application
     *
     * @param args All the command line parameters
     */
    public static void main(String[] args) {
        if (args.length != 1) {
            System.out.println("Usage DOMRepresentation <Any XML file>.xml");
            System.exit(1);	
        }

        try {
            DOMRepresentation anObj = new DOMRepresentation(args[0]);
            System.out.println(" Number of Recipients = "
                               + anObj.numRecipients());

            anObj.listRecipients();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    /**
     * Searches the XML document for all "to" and "cc" addresses and prints 
     * them out.
     *
     * @exception XPathException Thrown on any XPath search exception
     */
    private void listRecipients()
                         throws XPathException {
        DOMXPath recipientsXPath = new DOMXPath("email/to");
        Set recipients = recipientsXPath.evaluateAsNodeset(document);
        Iterator iter = recipients.iterator();
        System.out.println("This email is being addressed to");

        while (iter.hasNext()) {
            Node aNode = (Node) iter.next();
            System.out.println("* "
                               + aNode.getAttributes().getNamedItem("name")
                                      .getNodeValue());
        }

        recipientsXPath = new DOMXPath("email/cc");
        recipients = recipientsXPath.evaluateAsNodeset(document);
        iter = recipients.iterator();
        System.out.println("This email is being copied to");

        while (iter.hasNext()) {
            Node aNode = (Node) iter.next();
            System.out.println("* "
                               + aNode.getAttributes().getNamedItem("name")
                                      .getNodeValue());
        }
    }

    /**
     * Returns the number of recipients (to addresses) in the email
     *
     * @return double
     *
     * @exception XPathException Thrown on any XPath search exception
     */
    private double numRecipients()
                          throws XPathException {
        DOMXPath numRecipientsXPath = new DOMXPath("count(email/to)");

        return numRecipientsXPath.evaluateAsNumber(document);
    }

    /**
     * Method parseDocument. Parses the document and displays it on a tree
     *
     * @param xmlFile The file name
     *
     * @return Document
     *
     * @throws IOException When an IO exception occurs
     * @throws SAXException When an error occurs while parsing.
     */
    private Document parseDocument(String xmlFile)
                            throws IOException, SAXException {
        DOMParser aParser = new DOMParser();

        aParser.parse(xmlFile);

        return aParser.getDocument();
    }
}