org.hibernate.internal.util.xml.XMLHelper.java Source code

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Here is the source code for org.hibernate.internal.util.xml.XMLHelper.java

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/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.internal.util.xml;

import org.hibernate.internal.util.ClassLoaderHelper;

import org.dom4j.DocumentFactory;
import org.dom4j.Element;
import org.dom4j.io.DOMReader;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
import org.xml.sax.EntityResolver;
import org.xml.sax.ErrorHandler;

/**
 * Small helper class that lazy loads DOM and SAX reader and keep them for fast use afterwards.
 */
public final class XMLHelper {

    public static final EntityResolver DEFAULT_DTD_RESOLVER = new DTDEntityResolver();

    private DOMReader domReader;
    private SAXReader saxReader;

    /**
     * @param errorHandler the sax error handler
     * @param entityResolver an xml entity resolver
     *
     * @return Create and return a dom4j {@code SAXReader} which will append all validation errors
     *         to the passed error list
     */
    public SAXReader createSAXReader(ErrorHandler errorHandler, EntityResolver entityResolver) {
        SAXReader saxReader = resolveSAXReader();
        saxReader.setEntityResolver(entityResolver);
        saxReader.setErrorHandler(errorHandler);
        return saxReader;
    }

    private SAXReader resolveSAXReader() {
        if (saxReader == null) {
            saxReader = new SAXReader();
            saxReader.setMergeAdjacentText(true);
            saxReader.setValidation(true);
        }
        return saxReader;
    }

    /**
     * @return create and return a dom4j DOMReader
     */
    public DOMReader createDOMReader() {
        if (domReader == null) {
            domReader = new DOMReader();
        }
        return domReader;
    }

    public static Element generateDom4jElement(String elementName) {
        return getDocumentFactory().createElement(elementName);
    }

    public static DocumentFactory getDocumentFactory() {

        ClassLoader cl = ClassLoaderHelper.getContextClassLoader();
        DocumentFactory factory;
        try {
            Thread.currentThread().setContextClassLoader(XMLHelper.class.getClassLoader());
            factory = DocumentFactory.getInstance();
        } finally {
            Thread.currentThread().setContextClassLoader(cl);
        }
        return factory;
    }

    public static void dump(Element element) {
        try {
            // try to "pretty print" it
            OutputFormat outFormat = OutputFormat.createPrettyPrint();
            XMLWriter writer = new XMLWriter(System.out, outFormat);
            writer.write(element);
            writer.flush();
            System.out.println("");
        } catch (Throwable t) {
            // otherwise, just dump it
            System.out.println(element.asXML());
        }

    }
}