001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert and Contributors.
006 *
007 * Project Info:  http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022 * USA.
023 *
024 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * ------------------
028 * DatasetReader.java
029 * ------------------
030 * (C) Copyright 2002-present, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.data.xml;
038
039import java.io.File;
040import java.io.FileInputStream;
041import java.io.IOException;
042import java.io.InputStream;
043
044import javax.xml.XMLConstants;
045import javax.xml.parsers.ParserConfigurationException;
046import javax.xml.parsers.SAXParser;
047import javax.xml.parsers.SAXParserFactory;
048
049import org.jfree.chart.util.Args;
050import org.jfree.data.category.CategoryDataset;
051import org.jfree.data.general.PieDataset;
052import org.xml.sax.SAXException;
053import org.xml.sax.SAXNotRecognizedException;
054import org.xml.sax.SAXNotSupportedException;
055
056/**
057 * A utility class for reading datasets from XML.
058 */
059public class DatasetReader {
060
061    /** A factory for creating new parser instances. */
062    static SAXParserFactory factory;
063
064    /**
065     * Returns the {@link SAXParserFactory} used to create {@link SAXParser} instances.
066     * 
067     * @return The {@link SAXParserFactory} (never {@code null}).
068     */
069    public static SAXParserFactory getSAXParserFactory() {
070        if (factory == null) {
071            SAXParserFactory f = SAXParserFactory.newInstance();
072            try {
073                f.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
074                f.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
075                f.setFeature("http://xml.org/sax/features/external-general-entities", false);
076                factory = f;
077            } catch (SAXNotRecognizedException | SAXNotSupportedException | ParserConfigurationException e) {
078                throw new RuntimeException(e);
079            }
080        }
081        return factory;
082    }
083    
084    /**
085     * Sets the SAXParserFactory that will be used to create SAXParser instances.  
086     * You would only call this method if you wish to configure a new factory because
087     * the default does not meet requirements.
088     * 
089     * @param f  the new factory ({@code null} not permitted).
090     */
091    public static void setSAXParserFactory(SAXParserFactory f) {
092        Args.nullNotPermitted(f, "f");
093        factory = f;
094    }
095
096    /**
097     * Reads a {@link PieDataset} from an XML file.
098     *
099     * @param file  the file ({@code null} not permitted).
100     *
101     * @return A dataset.
102     *
103     * @throws IOException if there is a problem reading the file.
104     */
105    public static PieDataset readPieDatasetFromXML(File file)
106        throws IOException {
107        InputStream in = new FileInputStream(file);
108        return readPieDatasetFromXML(in);
109    }
110
111    /**
112     * Reads a {@link PieDataset} from a stream.
113     *
114     * @param in  the input stream.
115     *
116     * @return A dataset.
117     *
118     * @throws IOException if there is an I/O error.
119     */
120    public static PieDataset readPieDatasetFromXML(InputStream in)
121            throws IOException {
122        PieDataset result = null;
123        try {
124            SAXParser parser = getSAXParserFactory().newSAXParser();
125            PieDatasetHandler handler = new PieDatasetHandler();
126            parser.parse(in, handler);
127            result = handler.getDataset();
128        }
129        catch (SAXException | ParserConfigurationException e) {
130            throw new RuntimeException(e);
131        }
132        return result;
133    }
134
135    /**
136     * Reads a {@link CategoryDataset} from a file.
137     *
138     * @param file  the file.
139     *
140     * @return A dataset.
141     *
142     * @throws IOException if there is a problem reading the file.
143     */
144    public static CategoryDataset readCategoryDatasetFromXML(File file)
145            throws IOException {
146        InputStream in = new FileInputStream(file);
147        return readCategoryDatasetFromXML(in);
148    }
149
150    /**
151     * Reads a {@link CategoryDataset} from a stream.
152     *
153     * @param in  the stream.
154     *
155     * @return A dataset.
156     *
157     * @throws IOException if there is a problem reading the file.
158     */
159    public static CategoryDataset readCategoryDatasetFromXML(InputStream in)
160            throws IOException {
161        CategoryDataset result = null;
162        try {
163            SAXParser parser = getSAXParserFactory().newSAXParser();
164            CategoryDatasetHandler handler = new CategoryDatasetHandler();
165            parser.parse(in, handler);
166            result = handler.getDataset();
167        }
168        catch (SAXException | ParserConfigurationException e) {
169            throw new RuntimeException(e);
170        }
171        return result;
172    }
173
174}