Java tutorial
/* * 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. */ package org.apache.tika.gui; import javax.swing.Box; import javax.swing.JDialog; import javax.swing.JEditorPane; import javax.swing.JFileChooser; import javax.swing.JFrame; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTextPane; import javax.swing.ProgressMonitorInputStream; import javax.swing.SwingUtilities; import javax.swing.UIManager; import javax.swing.event.HyperlinkEvent; import javax.swing.event.HyperlinkEvent.EventType; import javax.swing.event.HyperlinkListener; import javax.xml.transform.OutputKeys; import javax.xml.transform.TransformerConfigurationException; import javax.xml.transform.sax.SAXTransformerFactory; import javax.xml.transform.sax.TransformerHandler; import javax.xml.transform.stream.StreamResult; import java.awt.CardLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.Toolkit; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import java.awt.event.WindowEvent; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.io.StringWriter; import java.io.Writer; import java.net.MalformedURLException; import java.net.URL; import java.util.Arrays; import java.util.HashMap; import java.util.Map; import java.util.Set; import org.apache.commons.io.IOUtils; import org.apache.tika.config.TikaConfig; import org.apache.tika.exception.TikaException; import org.apache.tika.extractor.DocumentSelector; import org.apache.tika.io.TikaInputStream; import org.apache.tika.metadata.Metadata; import org.apache.tika.metadata.serialization.JsonMetadataList; import org.apache.tika.mime.MediaType; import org.apache.tika.parser.AbstractParser; import org.apache.tika.parser.AutoDetectParser; import org.apache.tika.parser.DigestingParser; import org.apache.tika.parser.ParseContext; import org.apache.tika.parser.Parser; import org.apache.tika.parser.RecursiveParserWrapper; import org.apache.tika.parser.html.BoilerpipeContentHandler; import org.apache.tika.parser.utils.CommonsDigester; import org.apache.tika.sax.BasicContentHandlerFactory; import org.apache.tika.sax.BodyContentHandler; import org.apache.tika.sax.ContentHandlerDecorator; import org.apache.tika.sax.TeeContentHandler; import org.apache.tika.sax.XHTMLContentHandler; import org.xml.sax.Attributes; import org.xml.sax.ContentHandler; import org.xml.sax.SAXException; import org.xml.sax.helpers.AttributesImpl; import static java.nio.charset.StandardCharsets.UTF_8; /** * Simple Swing GUI for Apache Tika. You can drag and drop files on top * of the window to have them parsed. */ public class TikaGUI extends JFrame implements ActionListener, HyperlinkListener { //maximum length to allow for mark for reparse to get JSON private static final int MAX_MARK = 20 * 1024 * 1024;//20MB /** * Serial version UID. */ private static final long serialVersionUID = 5883906936187059495L; /** * Main method. Sets the Swing look and feel to the operating system * settings, and starts the Tika GUI with an {@link AutoDetectParser} * instance as the default parser. * * @param args ignored * @throws Exception if an error occurs */ public static void main(String[] args) throws Exception { TikaConfig config = TikaConfig.getDefaultConfig(); if (args.length > 0) { File configFile = new File(args[0]); config = new TikaConfig(configFile); } UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); final TikaConfig finalConfig = config; SwingUtilities.invokeLater(new Runnable() { public void run() { new TikaGUI(new DigestingParser(new AutoDetectParser(finalConfig), new CommonsDigester(MAX_MARK, CommonsDigester.DigestAlgorithm.MD5, CommonsDigester.DigestAlgorithm.SHA256))) .setVisible(true); } }); } /** * Parsing context. */ private final ParseContext context; /** * Configured parser instance. */ private final Parser parser; /** * Captures requested embedded images */ private final ImageSavingParser imageParser; /** * The card layout for switching between different views. */ private final CardLayout layout = new CardLayout(); /** * Container for the editor cards. */ private final JPanel cards; /** * Formatted XHTML output. */ private final JEditorPane html; /** * Plain text output. */ private final JEditorPane text; /** * Main content output. */ private final JEditorPane textMain; /** * Raw XHTML source. */ private final JEditorPane xml; /** * Raw JSON source. */ private final JEditorPane json; /** * Document metadata. */ private final JEditorPane metadata; /** * File chooser. */ private final JFileChooser chooser = new JFileChooser(); public TikaGUI(Parser parser) { super("Apache Tika"); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); addMenuBar(); cards = new JPanel(layout); addWelcomeCard(cards, "welcome"); metadata = addCard(cards, "text/plain", "metadata"); html = addCard(cards, "text/html", "html"); text = addCard(cards, "text/plain", "text"); textMain = addCard(cards, "text/plain", "main"); xml = addCard(cards, "text/plain", "xhtml"); json = addCard(cards, "text/plain", "json"); add(cards); layout.show(cards, "welcome"); setPreferredSize(new Dimension(640, 480)); pack(); this.context = new ParseContext(); this.parser = parser; this.imageParser = new ImageSavingParser(parser); this.context.set(DocumentSelector.class, new ImageDocumentSelector()); this.context.set(Parser.class, imageParser); } private void addMenuBar() { JMenuBar bar = new JMenuBar(); JMenu file = new JMenu("File"); file.setMnemonic(KeyEvent.VK_F); addMenuItem(file, "Open...", "openfile", KeyEvent.VK_O); addMenuItem(file, "Open URL...", "openurl", KeyEvent.VK_U); file.addSeparator(); addMenuItem(file, "Exit", "exit", KeyEvent.VK_X); bar.add(file); JMenu view = new JMenu("View"); view.setMnemonic(KeyEvent.VK_V); addMenuItem(view, "Metadata", "metadata", KeyEvent.VK_M); addMenuItem(view, "Formatted text", "html", KeyEvent.VK_F); addMenuItem(view, "Plain text", "text", KeyEvent.VK_P); addMenuItem(view, "Main content", "main", KeyEvent.VK_C); addMenuItem(view, "Structured text", "xhtml", KeyEvent.VK_S); addMenuItem(view, "Recursive JSON", "json", KeyEvent.VK_J); bar.add(view); bar.add(Box.createHorizontalGlue()); JMenu help = new JMenu("Help"); help.setMnemonic(KeyEvent.VK_H); addMenuItem(help, "About Tika", "about", KeyEvent.VK_A); bar.add(help); setJMenuBar(bar); } private void addMenuItem(JMenu menu, String title, String command, int key) { JMenuItem item = new JMenuItem(title, key); item.setActionCommand(command); item.addActionListener(this); menu.add(item); } public void actionPerformed(ActionEvent e) { String command = e.getActionCommand(); if ("openfile".equals(command)) { int rv = chooser.showOpenDialog(this); if (rv == JFileChooser.APPROVE_OPTION) { openFile(chooser.getSelectedFile()); } } else if ("openurl".equals(command)) { Object rv = JOptionPane.showInputDialog(this, "Enter the URL of the resource to be parsed:", "Open URL", JOptionPane.PLAIN_MESSAGE, null, null, ""); if (rv != null && rv.toString().length() > 0) { try { openURL(new URL(rv.toString().trim())); } catch (MalformedURLException exception) { JOptionPane.showMessageDialog(this, "The given string is not a valid URL", "Invalid URL", JOptionPane.ERROR_MESSAGE); } } } else if ("html".equals(command)) { layout.show(cards, command); } else if ("text".equals(command)) { layout.show(cards, command); } else if ("main".equals(command)) { layout.show(cards, command); } else if ("xhtml".equals(command)) { layout.show(cards, command); } else if ("metadata".equals(command)) { layout.show(cards, command); } else if ("json".equals(command)) { layout.show(cards, command); } else if ("about".equals(command)) { textDialog("About Apache Tika", TikaGUI.class.getResource("about.html")); } else if ("exit".equals(command)) { Toolkit.getDefaultToolkit().getSystemEventQueue() .postEvent(new WindowEvent(this, WindowEvent.WINDOW_CLOSING)); } } public void openFile(File file) { try { Metadata metadata = new Metadata(); try (TikaInputStream stream = TikaInputStream.get(file, metadata)) { handleStream(stream, metadata); } } catch (Throwable t) { handleError(file.getPath(), t); } } public void openURL(URL url) { try { Metadata metadata = new Metadata(); try (TikaInputStream stream = TikaInputStream.get(url, metadata)) { handleStream(stream, metadata); } } catch (Throwable t) { handleError(url.toString(), t); } } private void handleStream(InputStream input, Metadata md) throws Exception { StringWriter htmlBuffer = new StringWriter(); StringWriter textBuffer = new StringWriter(); StringWriter textMainBuffer = new StringWriter(); StringWriter xmlBuffer = new StringWriter(); StringBuilder metadataBuffer = new StringBuilder(); ContentHandler handler = new TeeContentHandler(getHtmlHandler(htmlBuffer), getTextContentHandler(textBuffer), getTextMainContentHandler(textMainBuffer), getXmlContentHandler(xmlBuffer)); context.set(DocumentSelector.class, new ImageDocumentSelector()); input = TikaInputStream.get(new ProgressMonitorInputStream(this, "Parsing stream", input)); if (input.markSupported()) { int mark = -1; if (input instanceof TikaInputStream) { if (((TikaInputStream) input).hasFile()) { mark = (int) ((TikaInputStream) input).getLength(); } } if (mark == -1) { mark = MAX_MARK; } input.mark(mark); } parser.parse(input, handler, md, context); String[] names = md.names(); Arrays.sort(names); for (String name : names) { for (String val : md.getValues(name)) { metadataBuffer.append(name); metadataBuffer.append(": "); metadataBuffer.append(val); metadataBuffer.append("\n"); } } String name = md.get(Metadata.RESOURCE_NAME_KEY); if (name != null && name.length() > 0) { setTitle("Apache Tika: " + name); } else { setTitle("Apache Tika: unnamed document"); } setText(metadata, metadataBuffer.toString()); setText(xml, xmlBuffer.toString()); setText(text, textBuffer.toString()); setText(textMain, textMainBuffer.toString()); setText(html, htmlBuffer.toString()); if (!input.markSupported()) { setText(json, "InputStream does not support mark/reset for Recursive Parsing"); layout.show(cards, "metadata"); return; } boolean isReset = false; try { input.reset(); isReset = true; } catch (IOException e) { setText(json, "Error during stream reset.\n" + "There's a limit of " + MAX_MARK + " bytes for this type of processing in the GUI.\n" + "Try the app with command line argument of -J."); } if (isReset) { RecursiveParserWrapper wrapper = new RecursiveParserWrapper(parser, new BasicContentHandlerFactory(BasicContentHandlerFactory.HANDLER_TYPE.BODY, -1)); wrapper.parse(input, null, new Metadata(), new ParseContext()); StringWriter jsonBuffer = new StringWriter(); JsonMetadataList.setPrettyPrinting(true); JsonMetadataList.toJson(wrapper.getMetadata(), jsonBuffer); setText(json, jsonBuffer.toString()); } layout.show(cards, "metadata"); } private void handleError(String name, Throwable t) { StringWriter writer = new StringWriter(); writer.append("Apache Tika was unable to parse the document\n"); writer.append("at " + name + ".\n\n"); writer.append("The full exception stack trace is included below:\n\n"); t.printStackTrace(new PrintWriter(writer)); JEditorPane editor = new JEditorPane("text/plain", writer.toString()); editor.setEditable(false); editor.setBackground(Color.WHITE); editor.setCaretPosition(0); editor.setPreferredSize(new Dimension(600, 400)); JDialog dialog = new JDialog(this, "Apache Tika error"); dialog.add(new JScrollPane(editor)); dialog.pack(); dialog.setVisible(true); } private void addWelcomeCard(JPanel panel, String name) { try { JEditorPane editor = new JEditorPane(TikaGUI.class.getResource("welcome.html")); editor.setContentType("text/html"); editor.setEditable(false); editor.setBackground(Color.WHITE); editor.setTransferHandler(new ParsingTransferHandler(editor.getTransferHandler(), this)); panel.add(new JScrollPane(editor), name); } catch (IOException e) { e.printStackTrace(); } } private JEditorPane addCard(JPanel panel, String type, String name) { JEditorPane editor = new JTextPane(); editor.setBackground(Color.WHITE); editor.setContentType(type); editor.setTransferHandler(new ParsingTransferHandler(editor.getTransferHandler(), this)); panel.add(new JScrollPane(editor), name); return editor; } private void textDialog(String title, URL resource) { try { JDialog dialog = new JDialog(this, title); JEditorPane editor = new JEditorPane(resource); editor.setContentType("text/html"); editor.setEditable(false); editor.setBackground(Color.WHITE); editor.setPreferredSize(new Dimension(400, 250)); editor.addHyperlinkListener(this); dialog.add(editor); dialog.pack(); dialog.setVisible(true); } catch (IOException e) { e.printStackTrace(); } } public void hyperlinkUpdate(HyperlinkEvent e) { if (e.getEventType() == EventType.ACTIVATED) { try { URL url = e.getURL(); try (InputStream stream = url.openStream()) { JEditorPane editor = new JEditorPane("text/plain", IOUtils.toString(stream, UTF_8)); editor.setEditable(false); editor.setBackground(Color.WHITE); editor.setCaretPosition(0); editor.setPreferredSize(new Dimension(600, 400)); String name = url.toString(); name = name.substring(name.lastIndexOf('/') + 1); JDialog dialog = new JDialog(this, "Apache Tika: " + name); dialog.add(new JScrollPane(editor)); dialog.pack(); dialog.setVisible(true); } } catch (IOException exception) { exception.printStackTrace(); } } } private void setText(JEditorPane editor, String text) { editor.setText(text); editor.setCaretPosition(0); } /** * Creates and returns a content handler that turns XHTML input to * simplified HTML output that can be correctly parsed and displayed * by {@link JEditorPane}. * <p> * The returned content handler is set to output <code>html</code> * to the given writer. The XHTML namespace is removed from the output * to prevent the serializer from using the <tag/> empty element * syntax that causes extra ">" characters to be displayed. * The <head> tags are dropped to prevent the serializer from * generating a <META> content type tag that makes * {@link JEditorPane} fail thinking that the document character set * is inconsistent. * <p> * Additionally, it will use ImageSavingParser to re-write embedded:(image) * image links to be file:///(temporary file) so that they can be loaded. * * @param writer output writer * @return HTML content handler * @throws TransformerConfigurationException if an error occurs */ private ContentHandler getHtmlHandler(Writer writer) throws TransformerConfigurationException { SAXTransformerFactory factory = (SAXTransformerFactory) SAXTransformerFactory.newInstance(); TransformerHandler handler = factory.newTransformerHandler(); handler.getTransformer().setOutputProperty(OutputKeys.METHOD, "html"); handler.setResult(new StreamResult(writer)); return new ContentHandlerDecorator(handler) { @Override public void startElement(String uri, String localName, String name, Attributes atts) throws SAXException { if (XHTMLContentHandler.XHTML.equals(uri)) { uri = null; } if (!"head".equals(localName)) { if ("img".equals(localName)) { AttributesImpl newAttrs; if (atts instanceof AttributesImpl) { newAttrs = (AttributesImpl) atts; } else { newAttrs = new AttributesImpl(atts); } for (int i = 0; i < newAttrs.getLength(); i++) { if ("src".equals(newAttrs.getLocalName(i))) { String src = newAttrs.getValue(i); if (src.startsWith("embedded:")) { String filename = src.substring(src.indexOf(':') + 1); try { File img = imageParser.requestSave(filename); String newSrc = img.toURI().toString(); newAttrs.setValue(i, newSrc); } catch (IOException e) { System.err.println("Error creating temp image file " + filename); // The html viewer will show a broken image too to alert them } } } } super.startElement(uri, localName, name, newAttrs); } else { super.startElement(uri, localName, name, atts); } } } @Override public void endElement(String uri, String localName, String name) throws SAXException { if (XHTMLContentHandler.XHTML.equals(uri)) { uri = null; } if (!"head".equals(localName)) { super.endElement(uri, localName, name); } } @Override public void startPrefixMapping(String prefix, String uri) { } @Override public void endPrefixMapping(String prefix) { } }; } private ContentHandler getTextContentHandler(Writer writer) { return new BodyContentHandler(writer); } private ContentHandler getTextMainContentHandler(Writer writer) { return new BoilerpipeContentHandler(writer); } private ContentHandler getXmlContentHandler(Writer writer) throws TransformerConfigurationException { SAXTransformerFactory factory = (SAXTransformerFactory) SAXTransformerFactory.newInstance(); TransformerHandler handler = factory.newTransformerHandler(); handler.getTransformer().setOutputProperty(OutputKeys.METHOD, "xml"); handler.setResult(new StreamResult(writer)); return handler; } /** * A {@link DocumentSelector} that accepts only images. */ private static class ImageDocumentSelector implements DocumentSelector { public boolean select(Metadata metadata) { String type = metadata.get(Metadata.CONTENT_TYPE); return type != null && type.startsWith("image/"); } } /** * A recursive parser that saves certain images into the temporary * directory, and delegates everything else to another downstream * parser. */ private static class ImageSavingParser extends AbstractParser { private Map<String, File> wanted = new HashMap<String, File>(); private Parser downstreamParser; private File tmpDir; private ImageSavingParser(Parser downstreamParser) { this.downstreamParser = downstreamParser; try { File t = File.createTempFile("tika", ".test"); tmpDir = t.getParentFile(); } catch (IOException e) { } } public File requestSave(String embeddedName) throws IOException { String suffix = ".tika"; int splitAt = embeddedName.lastIndexOf('.'); if (splitAt > 0) { embeddedName.substring(splitAt); } File tmp = File.createTempFile("tika-embedded-", suffix); wanted.put(embeddedName, tmp); return tmp; } public Set<MediaType> getSupportedTypes(ParseContext context) { // Never used in an auto setup return null; } public void parse(InputStream stream, ContentHandler handler, Metadata metadata, ParseContext context) throws IOException, SAXException, TikaException { String name = metadata.get(Metadata.RESOURCE_NAME_KEY); if (name != null && wanted.containsKey(name)) { FileOutputStream out = new FileOutputStream(wanted.get(name)); IOUtils.copy(stream, out); out.close(); } else { if (downstreamParser != null) { downstreamParser.parse(stream, handler, metadata, context); } } } } }