EDItoXPATH.java

/*
 * Copyright 2005-2015 by BerryWorks Software, LLC. All rights reserved.
 *
 * This file is part of EDIReader. You may obtain a license for its use directly from
 * BerryWorks Software, and you may also choose to use this software under the terms of the
 * GPL version 3. Other products in the EDIReader software suite are available only by licensing
 * with BerryWorks. Only those files bearing the GPL statement below are available under the GPL.
 *
 * EDIReader is free software: you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * EDIReader is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with EDIReader.  If not,
 * see <http://www.gnu.org/licenses/>.
 */

package com.berryworks.edireader.demo;

import com.berryworks.edireader.EDIReaderFactory;
import org.w3c.dom.Node;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;

import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMResult;
import javax.xml.transform.sax.SAXSource;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import java.io.IOException;
import java.io.Reader;

import static com.berryworks.edireader.demo.EDItoXML.establishInput;

public class EDItoXPATH {
    private final InputSource inputSource;

    public EDItoXPATH(Reader inputReader) {
        inputSource = new InputSource(inputReader);
    }

    public void run() {

        try {
            // Establish the EDIReader, acting as an XMLReader
            XMLReader ediReader = EDIReaderFactory.createEDIReader(inputSource);

            // Establish the SAXSource
            SAXSource source = new SAXSource(ediReader, inputSource);

            // Establish a DOMResult to capture the generated XML
            DOMResult domResult = new DOMResult();

            // Call an XSL Transformer with no stylesheet to transform
            // the SAX output from EDIReader into a W3C DOM
            Transformer transformer = TransformerFactory.newInstance().newTransformer();
            transformer.transform(source, domResult);

            // Get the W3C DOM from the transformed domResult
            Node document = domResult.getNode();

            // Create a default XPath which is expecting a W3C DOM
            XPath xPath = XPathFactory.newInstance().newXPath();

            // Evaluate a particular XPath expression against the DOM
            String query = "/ediroot/interchange/group/transaction/@DocType";
            String xPathResult = xPath.evaluate(query, document);

            System.out.print("\nXPath query " + query + " produces result " + xPathResult + "\n");

        } catch (SAXException e) {
            System.err.println("\nUnable to create EDIReader: " + e);
        } catch (TransformerConfigurationException e) {
            System.err.println("\nUnable to create Transformer: " + e);
        } catch (TransformerException e) {
            System.err.println("\nUnable to transform EDI into DOM: " + e);
        } catch (IOException e) {
            System.err.println("\nUnable to read EDI input: " + e);
        } catch (XPathExpressionException e) {
            System.err.println("\nInvalid XPath expression: " + e);
        }
    }

    public static void main(String args[]) {
        String inputFileName = null;

        if (args.length == 1)
            inputFileName = args[0];
        else
            badArgs();

        Reader inputReader = establishInput(inputFileName);
        EDItoXPATH theObject = new EDItoXPATH(inputReader);
        theObject.run();
    }

    /**
     * Print summary of command line arguments expected.
     */
    private static void badArgs() {
        System.err.println("Usage: EDItoXPATH inputfile");
        throw new RuntimeException("Missing or invalid command line arguments");
    }

}