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/*
 * The MIT License
 *
 *  Copyright (c) 2016, Mahmoud Ben Hassine ([email protected])
 *
 *  Permission is hereby granted, free of charge, to any person obtaining a copy
 *  of this software and associated documentation files (the "Software"), to deal
 *  in the Software without restriction, including without limitation the rights
 *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *  copies of the Software, and to permit persons to whom the Software is
 *  furnished to do so, subject to the following conditions:
 *
 *  The above copyright notice and this permission notice shall be included in
 *  all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *  THE SOFTWARE.
 */

package org.easybatch.xml;

import org.easybatch.core.reader.RecordReader;
import org.easybatch.core.record.Header;

import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.*;
import java.io.InputStream;
import java.util.Date;
import java.util.Iterator;

/**
 * A record reader that reads xml records from an xml stream.
 * 

* This reader produces {@link XmlRecord} instances. * * @author Mahmoud Ben Hassine ([email protected]) */ public class XmlRecordReader implements RecordReader { /** * The root element name. */ private String rootElementName; /** * The xml input stream. */ private InputStream xmlInputStream; /** * The xml reader. */ private XMLEventReader xmlEventReader; /** * The current record number. */ private long currentRecordNumber; public XmlRecordReader(final String rootElementName, final InputStream xmlInputStream) { this.rootElementName = rootElementName; this.xmlInputStream = xmlInputStream; } @Override public void open() throws Exception { currentRecordNumber = 0; xmlEventReader = XMLInputFactory.newInstance().createXMLEventReader(xmlInputStream); } @Override public XmlRecord readRecord() throws Exception { if (hasNextRecord()) { StringBuilder stringBuilder = new StringBuilder(""); while (!nextTagIsRootElementEnd()) { XMLEvent xmlEvent = xmlEventReader.nextEvent(); if (xmlEvent.isStartElement()) { escapeStartElementAttributes(stringBuilder, xmlEvent); } else if (xmlEvent.isEndElement()) { writeEndElement(stringBuilder, xmlEvent); } else { stringBuilder.append(xmlEvent.asCharacters().getData()); } } writeEndElement(stringBuilder, xmlEventReader.nextEvent()); Header header = new Header(++currentRecordNumber, getDataSourceName(), new Date()); return new XmlRecord(header, stringBuilder.toString()); } else { return null; } } private String getDataSourceName() { return "XML stream"; } @Override public void close() throws Exception { if (xmlEventReader != null) { xmlEventReader.close(); } } private boolean hasNextRecord() { try { while (!nextTagIsRootElementStart()) { XMLEvent xmlEvent = xmlEventReader.nextEvent(); if (xmlEvent instanceof EndDocument) { return false; } } return true; } catch (Exception e) { return false; } } /** * Utility method to check if the next tag matches a start tag of the root element. * * @return true if the next tag matches a start element of the root element, false else * @throws XMLStreamException thrown if no able to peek the next xml element */ private boolean nextTagIsRootElementStart() throws XMLStreamException { return xmlEventReader.peek().isStartElement() && xmlEventReader.peek().asStartElement().getName().getLocalPart().equalsIgnoreCase(rootElementName); } /** * Utility method to check if the next tag matches an end tag of the root element. * * @return true if the next tag matches an end tag of the root element, false else * @throws XMLStreamException thrown if no able to peek the next xml element */ private boolean nextTagIsRootElementEnd() throws XMLStreamException { return xmlEventReader.peek().isEndElement() && xmlEventReader.peek().asEndElement().getName().getLocalPart().equalsIgnoreCase(rootElementName); } /** * Write end element. * * @param stringBuilder the string builder to write element into. * @throws XMLStreamException thrown when an exception occurs during xml streaming */ private void writeEndElement(StringBuilder stringBuilder, XMLEvent xmlEvent) throws XMLStreamException { if (xmlEvent.isEndElement()) { EndElement endElement = xmlEvent.asEndElement(); stringBuilder.append(""); } } /** * Escape values of start element attributes. * * @param stringBuilder the builder in which writes escaped attributes. * @param xmlEvent the start element to escape */ private void escapeStartElementAttributes(StringBuilder stringBuilder, XMLEvent xmlEvent) { StartElement startElement = xmlEvent.asStartElement(); stringBuilder.append("<").append(startElement.getName().getLocalPart()); Iterator iterator = startElement.getAttributes(); while (iterator.hasNext()) { Attribute attribute = (Attribute) iterator.next(); stringBuilder.append(" ") .append(attribute.getName()) .append("='") .append(escape(attribute.getValue())) .append("'"); } stringBuilder.append(">"); } /** * Escape the xml content. Only &, " and ' need to be escaped. * * @param xmlToEscape the xml content to escape * @return the escaped xml */ private String escape(String xmlToEscape) { return xmlToEscape.replaceAll("&", "&") .replaceAll("'", "'") .replaceAll("\"", """); } }





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