cl.vmetrix.operation.persistence.XmlValidator.java Source code

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Here is the source code for cl.vmetrix.operation.persistence.XmlValidator.java

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/*******************************************************************************
 * Copyright (c) 2016 VMetrix SPA.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 *******************************************************************************/
package cl.vmetrix.operation.persistence;

import javax.xml.XMLConstants;
import javax.xml.transform.Source;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.*;

import org.apache.commons.io.IOUtils;
import org.apache.log4j.Logger;
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

import java.util.List;
import java.io.*;
import java.util.LinkedList;

/**
 * This class validates a string XML against XSD schema.
 * 
 * @author REcheverri
 * @version 1.0 30/08/2016
 *
 */
public class XmlValidator {
    final static Logger logger = Logger.getLogger(XmlValidator.class);

    //   public static void main(String[] args) throws Exception {

    /**
     * The method validatorXMLstg determinate if the String XML is correct. 
     * @return a boolean (true or false) to indicate if the XML is correct.
     * @param xml is the String XML to validate against XSD Schema
     * @throws SAXException
     * @throws IOException
     */

    public boolean validateXMLstg(String xml) throws SAXException, IOException {
        String rpta = "";

        boolean validation = true;
        try {

            xml = new String(xml.getBytes("UTF-8"));

            //         System.out.println("---> XML in UTF-8: "+ xml);
            // convert String into InputStream
            InputStream is = new ByteArrayInputStream(xml.getBytes());

            Source xmlFile = new StreamSource(is);//new File("C:/XML/424437.xml"));

            // XSD schema
            String schemea = getFileSchema("operationSchema.xsd");

            InputStream sch = new ByteArrayInputStream(schemea.getBytes());

            Source schemaFile = new StreamSource(sch);//new File("main/resources/Operation.xsd"));

            // Preparing the schema
            SchemaFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
            Schema schema = schemaFactory.newSchema(schemaFile);

            // Validator creation
            Validator validator = schema.newValidator();

            // DException handle of validator
            final List<SAXParseException> exceptions = new LinkedList<SAXParseException>();
            validator.setErrorHandler(new ErrorHandler() {
                @Override
                public void warning(SAXParseException exception) throws SAXException {
                    exceptions.add(exception);
                }

                @Override
                public void fatalError(SAXParseException exception) throws SAXException {
                    exceptions.add(exception);
                }

                @Override
                public void error(SAXParseException exception) throws SAXException {
                    exceptions.add(exception);
                }
            });

            // XML validation
            validator.validate(xmlFile);

            // Validation result. If there are errors, detailed the exact position in the XML  and the error
            if (exceptions.size() == 0) {
                rpta = "XML IS VALID";
            } else {
                validation = false;
                StringBuffer sb = new StringBuffer();
                sb.append("XML IS INVALID");
                sb.append("\n");
                sb.append("NUMBER OF ERRORS: " + exceptions.size());
                sb.append("\n");
                for (int i = 0; i < exceptions.size(); i++) {
                    i = i + 1;
                    sb.append("Error # " + i + ":");
                    sb.append("\n");
                    i = i - 1;
                    sb.append("    - Line: " + ((SAXParseException) exceptions.get(i)).getLineNumber());
                    sb.append("\n");
                    sb.append("    - Column: " + ((SAXParseException) exceptions.get(i)).getColumnNumber());
                    sb.append("\n");
                    sb.append("    - Error message: " + ((Throwable) exceptions.get(i)).getLocalizedMessage());
                    sb.append("\n");
                    sb.append("------------------------------");
                }
                rpta = sb.toString();
                logger.debug(rpta);

            }
        } catch (SAXException e) {
            logger.error("SAXException in XML validator: ", e);
            logger.debug(rpta);
            throw new SAXException(e);
        } catch (IOException e) {
            logger.error("IOException in XML validator: ", e);
            logger.debug(rpta);
            throw new IOException(e);
        }

        return validation;
    }

    /*
     * The method getFileSchema look for the xsd file in the 
     * resources carpet of the project.
     * 
     * @parameter fileName is the name of the .xsd file.
     * @return the content of the .xsd file in String format.
     * @throws IOException
     */
    private String getFileSchema(String fileName) throws IOException {

        String result = "";

        ClassLoader classLoader = getClass().getClassLoader();
        try {
            result = IOUtils.toString(classLoader.getResourceAsStream(fileName));
        } catch (IOException e) {
            throw new IOException(e);
        }

        return result;

    }
}