Java XML Document Create createDocument(final File file)

Description

create Document

License

Apache License

Parameter

Parameter	Description
file	The XML file to parse.

Exception

Parameter	Description
IOException	<ul><li>If there is an error finding or reading from the file.</li></ul>
SAXException	<ul><li>If the file does not contain valid a XML document.</li></ul>

Return

A new DOM Document with the contents of the given XML file.

Declaration

public static Document createDocument(final File file) throws IOException, SAXException

Method Source Code


//package com.java2s;
/* //from   w ww  . j  a  va  2 s  .  c o  m
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 */

import java.io.File;

import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;

import java.net.URI;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;

import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

public class Main {
    private static final ThreadLocal<?> tls = new ThreadLocal<Object>() {
        // CTw for handling code that sets the context classloader when the TLS is used from a different thread context classloader.
        // "this" is used as the initialization occurs on the correct classloader. The current context classloader also can't be garaunteed.
        ClassLoader cl = Thread.currentThread().getContextClassLoader();

        @Override
        protected Object initialValue() {

            // CTw fix for classloaders
            final ClassLoader ct = Thread.currentThread().getContextClassLoader();
            Thread.currentThread().setContextClassLoader(cl);
            try {

                //1
                // create the builder that will be shared throughout the process
                //
                final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

                //
                // don't forget - turn on namespaces!!!
                //
                factory.setNamespaceAware(true);

                //
                // we don't need comment nodes - they'll only slow us down
                //
                factory.setIgnoringComments(true);

                try {
                    return factory.newDocumentBuilder();
                }

                //
                // this exception would be thrown if you have the DOM interfaces 
                // but not the implementation
                //
                catch (final ParserConfigurationException error) {
                    throw new RuntimeException(error.getMessage(), error);
                }
            } finally {
                // reset it
                Thread.currentThread().setContextClassLoader(ct);
            }
        }
    };

    /**
     * @return A new DOM Document.
     */
    public static Document createDocument() {
        return createBuilder().newDocument();
    }

    /**
     * @param file
     *            The XML file to parse.
     * @return A new DOM Document with the contents of the given XML file.
     * @throws IOException
     *             <ul>
     *             <li>If there is an error finding or reading from the file.</li>
     *             </ul>
     * @throws SAXException
     *             <ul>
     *             <li>If the file does not contain valid a XML document.</li>
     *             </ul>
     */
    public static Document createDocument(final File file) throws IOException, SAXException {
        return createBuilder().parse(file);
    }

    /**
     * @param source
     *            A SAX InputSource that points to a valid XML document.
     * @return A new DOM Document with the contents of the given XML data.
     * @throws IOException
     *             <ul>
     *             <li>If there is an error reading the data from the source;
     *             this exception is usually generated when the input source is
     *             file or network-based.</li>
     *             </ul>
     * @throws SAXException
     *             <ul>
     *             <li>If the stream does not contain a valid XML document.</li>
     *             </ul>
     */
    public static Document createDocument(final InputSource source) throws IOException, SAXException {
        return createBuilder().parse(source);
    }

    /**
     * @param stream
     *            A stream containing a valid XML document.
     * @return A new DOM Document with the contents of the given XML data.
     * @throws IOException
     *             <ul>
     *             <li>If there is an error reading the bytes in the stream;
     *             this exception is usually generated when the input source is
     *             file or network-based.</li>
     *             </ul>
     * @throws SAXException
     *             <ul>
     *             <li>If the stream does not contain a valid XML document.</li>
     *             </ul>
     */
    public static Document createDocument(final InputStream stream) throws IOException, SAXException {
        return createBuilder().parse(stream);
    }

    /**
     * @param xml
     *            A string containing a valid XML document.
     * @return A new DOM Document with the contents of the given XML string.
     * @throws IOException
     *             <ul>
     *             <li>If there is an error reading the bytes in the string,
     *             which is highly unlikely; this exception is usually generated
     *             when the input source is file or network-based.</li>
     *             </ul>
     * @throws SAXException
     *             <ul>
     *             <li>If the string does not contain a valid XML document.</li>
     *             </ul>
     */
    public static Document createDocument(final String xml) throws IOException, SAXException {
        //
        // have to convert the string to bytes in order to parse it
        //
        final InputSource source = new InputSource(new StringReader(xml));
        return createDocument(source);
    }

    /**
     * This is a convenience method that converts the given URI to a File
     * and invokes createDocument(File).
     * 
     * @param uri
     *            The URI of the XML file to parse.
     * @see #createDocument(File)
     */
    public static Document createDocument(final URI uri) throws IOException, SAXException {
        return createDocument(new File(uri));
    }

    /**
     * @return A new DocumentBuilder, which can be used to parse XML
     *         by <b>a single thread.</b> Because DocumentBuilder.parse() is
     *         <b>not</b> thread-safe
     *         the calling code should not share the document builder (or its
     *         Documents) across threads.
     *         The backing ThreadLocal ensures quick re-use, as such this
     *         function should be called for each
     *         operation on a DocumentBuilder.
     */
    private static DocumentBuilder createBuilder() {
        return (DocumentBuilder) tls.get();
    }
}

Java XML Document Create createDocument(final File file)

Description

License

Parameter

Exception

Return

Declaration

Method Source Code

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