nrssdataextractor.java

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/*
*  Copyright (c) 2001 Sun Microsystems, Inc.  All rights
*  reserved.
*
*  Redistribution and use in source and binary forms, with or without
*  modification, are permitted provided that the following conditions
*  are met:
*
*  1. Redistributions of source code must retain the above copyright
*  notice, this list of conditions and the following disclaimer.
*
*  2. Redistributions in binary form must reproduce the above copyright
*  notice, this list of conditions and the following disclaimer in
*  the documentation and/or other materials provided with the
*  distribution.
*
*  3. The end-user documentation included with the redistribution,
*  if any, must include the following acknowledgment:
*  "This product includes software developed by the
*  Sun Microsystems, Inc. for Project JXTA."
*  Alternately, this acknowledgment may appear in the software itself,
*  if and wherever such third-party acknowledgments normally appear.
*
*  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
*  must not be used to endorse or promote products derived from this
*  software without prior written permission. For written
*  permission, please contact Project JXTA at http://www.jxta.org.
*
*  5. Products derived from this software may not be called "JXTA",
*  nor may "JXTA" appear in their name, without prior written
*  permission of Sun.
*
*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
*  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
*  DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
*  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
*  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
*  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
*  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
*  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
*  SUCH DAMAGE.
*  ====================================================================
*
*  This software consists of voluntary contributions made by many
*  individuals on behalf of Project JXTA.  For more
*  information on Project JXTA, please see
*  <http://www.jxta.org/>.
*
*  This license is based on the BSD license adopted by the Apache Foundation.
*
*  $Id: NRSSDataExtractor.java,v 1.2 2006/07/13 05:26:36 nano Exp $
*/
//package net.java.netbeams.protocol;
package net.jxta.myjxta.misc.beam;

import org.xml.sax.InputSource;

import javax.xml.parsers.DocumentBuilderFactory;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;


/**
 * @author dave
 */
public class NRSSDataExtractor {

    /**
     * Creates a new instance of NRSSDataExtractor
     */
    public NRSSDataExtractor() {
    }

    public static String getValueFromString(String input, String expression) {
        String returnValue = new String();
        //see http://www.docjar.com/html/api/java/io/Reader.java.html
        java.io.StringReader sr = new java.io.StringReader(input);
        //see http://www.docjar.com/html/api/org/xml/sax/InputSource.java.html
        org.xml.sax.InputSource inputSource = new org.xml.sax.InputSource(sr);

        try {
            // Example used
            // http://www.onjava.com/pub/a/onjava/2005/01/12/xpath.html
// xxx: gonzo, 1.5 goodness
/*
            XPathFactory factory2=XPathFactory.newInstance();
            XPath xPath = factory2.newXPath();
            NamespaceContext namespaceContext=new NamespaceContextImpl(NameSpaceName, NameSpaceURL);
            xPath.setNamespaceContext(namespaceContext);
*/

            // passed
            //XPathExpression xPathExpression = xPath.compile("/rss/channel/item/description/nrss:metadata/nrss:arg[@n='size']");

            // passed
            //XPathExpression xPathExpression = xPath.compile("/rss/channel/item/description/nrss:data/nrss:content/nrss:argArray[@n='current']");
            // passed
            //XPathExpression xPathExpression = xPath.compile("/rss/channel/title");

            //String expression = "/rss/channel/item/description/nrss:data/nrss:content/nrss:argArray[@n='current']";
            //xPathExpression.evaluate(inputSource, returnType)

            // See http://java.sun.com/j2se/1.5.0/docs/api/javax/xml/xpath/package-summary.html
// xxx: gonzo, 1.5 goodness
/*
            XPathExpression xPathExpression = xPath.compile(expression);
            returnValue = xPathExpression.evaluate(inputSource);
*/
            returnValue = null;
            // String returnValue = xPath.evaluate(expression, inputSource);
            //is.close();
            //System.out.println("value = "+value.toString());

        } catch (Exception e) {
            e.printStackTrace();
        }
        return returnValue;
    }

    // Example Used: http://www.idevelopment.info/data/Programming/java/xml/DOMExample.java
    public static String getValueFromInputStream(InputStream is, String expression) {
        String returnValue = new String();
        try {
            // Example used
            // http://www.onjava.com/pub/a/onjava/2005/01/12/xpath.html
// xxx: gonzo, 1.5 goodness
/*
            XPathFactory factory2=XPathFactory.newInstance();
            XPath xPath = factory2.newXPath();
            NamespaceContext namespaceContext=new NamespaceContextImpl(NameSpaceName, NameSpaceURL);
            xPath.setNamespaceContext(namespaceContext);
*/

            // passed
            //XPathExpression xPathExpression = xPath.compile("/rss/channel/item/description/nrss:metadata/nrss:arg[@n='size']");

            // passed
            //XPathExpression xPathExpression = xPath.compile("/rss/channel/item/description/nrss:data/nrss:content/nrss:argArray[@n='current']");
            // passed
            //XPathExpression xPathExpression = xPath.compile("/rss/channel/title");
            InputSource inputSource = new InputSource(is);
            //String expression = "/rss/channel/item/description/nrss:data/nrss:content/nrss:argArray[@n='current']";
            //xPathExpression.evaluate(inputSource, returnType)

            // See http://java.sun.com/j2se/1.5.0/docs/api/javax/xml/xpath/package-summary.html
// xxx: gonzo, 1.5 goodness
/*
            XPathExpression xPathExpression = xPath.compile(expression);
            returnValue = xPathExpression.evaluate(inputSource);
*/
            returnValue = null;
            // String returnValue = xPath.evaluate(expression, inputSource);
            is.close();
            //System.out.println("value = "+value.toString());

        } catch (Exception e) {
            e.printStackTrace();
        }
        return returnValue;
    }

    public static String getValueFromURL(String nrssURL, String expression) {

        // get the NRSS
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        try {
            // Example used
            // http://java.sun.com/docs/books/tutorial/networking/urls/readingWriting.html
            URL u = new URL(nrssURL);
            URLConnection c = u.openConnection();
            InputStream is = c.getInputStream();
            return getValueFromInputStream(is, expression);
        } catch (IOException e) {
            e.printStackTrace();
            // log.severe(e.toString());
        } catch (Exception ea) {
            // log.severe(ea.toString());
            ea.printStackTrace();
        }
        return null;
    }

    public static void main(String[] args) {
        String url = "http://fuzzy.sfbay.sun.com/~tl109030/samplenrss02.xml";
        String expression = "/rss/channel/item/description/nrss:data/nrss:content/nrss:argArray[@n='current']/nrss:arg[@n='value']";
        //String expression = "/rss/channel/title";
        try {
            String result = getValueFromURL(url, expression);
            System.out.println("Result: " + result);
        } catch (Exception e) {
            e.printStackTrace();
        }
        try {
            // Example used
            // http://java.sun.com/docs/books/tutorial/networking/urls/readingWriting.html
            URL u = new URL(url);
            URLConnection c = u.openConnection();
            InputStream is = c.getInputStream();
            System.out.println("getVAlueFromInputStream: " + getValueFromInputStream(is, expression));
        } catch (IOException e) {
            e.printStackTrace();
            // log.severe(e.toString());
        } catch (Exception ea) {
            // log.severe(ea.toString());
            ea.printStackTrace();
        }

//        System.err.println("Usage: java NRSS2Array <url> <expression>");
        // add interface that handles InputStream
    }
}