org.roda.core.common.XMLUtility.java Source code

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Here is the source code for org.roda.core.common.XMLUtility.java

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/**
 * The contents of this file are subject to the license and copyright
 * detailed in the LICENSE file at the root of the source
 * tree and available online at
 *
 * https://github.com/keeps/roda
 */
package org.roda.core.common;

import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.apache.commons.io.IOUtils;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;

public final class XMLUtility {

    /** Private empty constructor */
    private XMLUtility() {
        // do nothing
    }

    public static String getStringFromFile(Path file, String xpath) {
        String ret = "";
        try {
            InputStream inputStream = Files.newInputStream(file);
            return getString(inputStream, xpath);
        } catch (IOException e) {
            // do nothing
        }
        return ret;
    }

    /**
     * 20160518 hsilva: the inputStream gets closed in the end
     */
    public static String getString(InputStream inputStream, String xpath) {
        String ret = "";
        try {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            builder.setEntityResolver(new RodaEntityResolver());
            Document doc;
            doc = builder.parse(inputStream);
            XPathFactory xPathfactory = XPathFactory.newInstance();
            XPath xPath = xPathfactory.newXPath();
            XPathExpression expr = xPath.compile(xpath);
            ret = (String) expr.evaluate(doc, XPathConstants.STRING);
        } catch (SAXException | ParserConfigurationException | XPathExpressionException | IOException e) {
            // do nothing and return already defined OTHER
        } finally {
            IOUtils.closeQuietly(inputStream);
        }
        return ret;
    }
}