Java tutorial
package org.apache.tika.parser.pdf18; /* * 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 javax.xml.stream.XMLStreamException; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.util.Arrays; import java.util.Calendar; import java.util.Collections; import java.util.List; import java.util.Locale; import java.util.Set; import org.apache.commons.io.input.CloseShieldInputStream; import org.apache.jempbox.xmp.XMPSchema; import org.apache.jempbox.xmp.XMPSchemaDublinCore; import org.apache.jempbox.xmp.XMPSchemaMediaManagement; import org.apache.jempbox.xmp.pdfa.XMPSchemaPDFAId; import org.apache.pdfbox.cos.COSArray; import org.apache.pdfbox.cos.COSBase; import org.apache.pdfbox.cos.COSDictionary; import org.apache.pdfbox.cos.COSName; import org.apache.pdfbox.cos.COSString; import org.apache.pdfbox.exceptions.CryptographyException; import org.apache.pdfbox.io.RandomAccess; import org.apache.pdfbox.io.RandomAccessBuffer; import org.apache.pdfbox.io.RandomAccessFile; import org.apache.pdfbox.pdmodel.PDDocument; import org.apache.pdfbox.pdmodel.PDDocumentInformation; import org.apache.pdfbox.pdmodel.encryption.AccessPermission; import org.apache.pdfbox.pdmodel.font.PDFont; import org.apache.tika.exception.EncryptedDocumentException; import org.apache.tika.exception.TikaException; import org.apache.tika.extractor.EmbeddedDocumentExtractor; import org.apache.tika.io.TemporaryResources; import org.apache.tika.io.TikaInputStream; import org.apache.tika.metadata.AccessPermissions; import org.apache.tika.metadata.Metadata; import org.apache.tika.metadata.PagedText; import org.apache.tika.metadata.Property; import org.apache.tika.metadata.TikaCoreProperties; import org.apache.tika.mime.MediaType; import org.apache.tika.parser.AbstractParser; import org.apache.tika.parser.ParseContext; import org.apache.tika.parser.PasswordProvider; import org.apache.tika.sax.XHTMLContentHandler; import org.xml.sax.ContentHandler; import org.xml.sax.SAXException; /** * PDF parser. * <p/> * This parser can process also encrypted PDF documents if the required * password is given as a part of the input metadata associated with a * document. If no password is given, then this parser will try decrypting * the document using the empty password that's often used with PDFs. If * the PDF contains any embedded documents (for example as part of a PDF * package) then this parser will use the {@link EmbeddedDocumentExtractor} * to handle them. * <p/> * As of Tika 1.6, it is possible to extract inline images with * the {@link EmbeddedDocumentExtractor} as if they were regular * attachments. By default, this feature is turned off because of * the potentially enormous number and size of inline images. To * turn this feature on, see * {@link PDFParserConfig#setExtractInlineImages(boolean)}. */ public class PDFParser extends AbstractParser { /** * Metadata key for giving the document password to the parser. * * @since Apache Tika 0.5 * @deprecated Supply a {@link PasswordProvider} on the {@link ParseContext} instead */ public static final String PASSWORD = "org.apache.tika.parser.pdf.password"; private static final MediaType MEDIA_TYPE = MediaType.application("pdf"); /** * Serial version UID */ private static final long serialVersionUID = -752276948656079347L; private static final Set<MediaType> SUPPORTED_TYPES = Collections.singleton(MEDIA_TYPE); private PDFParserConfig defaultConfig = new PDFParserConfig(); public Set<MediaType> getSupportedTypes(ParseContext context) { return SUPPORTED_TYPES; } public void parse(InputStream stream, ContentHandler handler, Metadata metadata, ParseContext context) throws IOException, SAXException, TikaException { PDDocument pdfDocument = null; TemporaryResources tmp = new TemporaryResources(); //config from context, or default if not set via context PDFParserConfig localConfig = context.get(PDFParserConfig.class, defaultConfig); String password = ""; try { // PDFBox can process entirely in memory, or can use a temp file // for unpacked / processed resources // Decide which to do based on if we're reading from a file or not already TikaInputStream tstream = TikaInputStream.cast(stream); password = getPassword(metadata, context); if (tstream != null && tstream.hasFile()) { // File based, take that as a cue to use a temporary file RandomAccess scratchFile = new RandomAccessFile(tmp.createTemporaryFile(), "rw"); if (localConfig.getUseNonSequentialParser() == true) { pdfDocument = PDDocument.loadNonSeq(new CloseShieldInputStream(stream), scratchFile, password); } else { pdfDocument = PDDocument.load(new CloseShieldInputStream(stream), scratchFile, true); } } else { // Go for the normal, stream based in-memory parsing if (localConfig.getUseNonSequentialParser() == true) { pdfDocument = PDDocument.loadNonSeq(new CloseShieldInputStream(stream), new RandomAccessBuffer(), password); } else { pdfDocument = PDDocument.load(new CloseShieldInputStream(stream), true); } } metadata.set("pdf:encrypted", Boolean.toString(pdfDocument.isEncrypted())); //if using the classic parser and the doc is encrypted, we must manually decrypt if (!localConfig.getUseNonSequentialParser() && pdfDocument.isEncrypted()) { pdfDocument.decrypt(password); } metadata.set(Metadata.CONTENT_TYPE, "application/pdf"); extractMetadata(pdfDocument, metadata); AccessChecker checker = localConfig.getAccessChecker(); checker.check(metadata); if (handler != null) { if (shouldHandleXFAOnly(pdfDocument, localConfig)) { handleXFAOnly(pdfDocument, handler, metadata); } else { PDF2XHTML.process(pdfDocument, handler, context, metadata, localConfig); } } } catch (CryptographyException e) { //seq parser throws CryptographyException for bad password throw new EncryptedDocumentException(e); } catch (IOException e) { //nonseq parser throws IOException for bad password //At the Tika level, we want the same exception to be thrown if (e.getMessage() != null && e.getMessage().contains("Error (CryptographyException)")) { metadata.set("pdf:encrypted", Boolean.toString(true)); throw new EncryptedDocumentException(e); } //rethrow any other IOExceptions throw e; } finally { if (pdfDocument != null) { pdfDocument.close(); } tmp.dispose(); //TODO: once we migrate to PDFBox 2.0, remove this (PDFBOX-2200) PDFont.clearResources(); } } private String getPassword(Metadata metadata, ParseContext context) { String password = null; // Did they supply a new style Password Provider? PasswordProvider passwordProvider = context.get(PasswordProvider.class); if (passwordProvider != null) { password = passwordProvider.getPassword(metadata); } // Fall back on the old style metadata if set if (password == null && metadata.get(PASSWORD) != null) { password = metadata.get(PASSWORD); } // If no password is given, use an empty string as the default if (password == null) { password = ""; } return password; } private void extractMetadata(PDDocument document, Metadata metadata) throws TikaException { //first extract AccessPermissions AccessPermission ap = document.getCurrentAccessPermission(); metadata.set(AccessPermissions.EXTRACT_FOR_ACCESSIBILITY, Boolean.toString(ap.canExtractForAccessibility())); metadata.set(AccessPermissions.EXTRACT_CONTENT, Boolean.toString(ap.canExtractContent())); metadata.set(AccessPermissions.ASSEMBLE_DOCUMENT, Boolean.toString(ap.canAssembleDocument())); metadata.set(AccessPermissions.FILL_IN_FORM, Boolean.toString(ap.canFillInForm())); metadata.set(AccessPermissions.CAN_MODIFY, Boolean.toString(ap.canModify())); metadata.set(AccessPermissions.CAN_MODIFY_ANNOTATIONS, Boolean.toString(ap.canModifyAnnotations())); metadata.set(AccessPermissions.CAN_PRINT, Boolean.toString(ap.canPrint())); metadata.set(AccessPermissions.CAN_PRINT_DEGRADED, Boolean.toString(ap.canPrintDegraded())); //now go for the XMP org.apache.jempbox.xmp.XMPMetadata xmp = null; XMPSchemaDublinCore dcSchema = null; XMPSchemaMediaManagement mmSchema = null; try { if (document.getDocumentCatalog().getMetadata() != null) { xmp = document.getDocumentCatalog().getMetadata().exportXMPMetadata(); } } catch (IOException e) { } if (xmp != null) { try { dcSchema = xmp.getDublinCoreSchema(); } catch (IOException e) { } JempboxExtractor.extractXMPMM(xmp, metadata); } PDDocumentInformation info = document.getDocumentInformation(); metadata.set(PagedText.N_PAGES, document.getNumberOfPages()); extractMultilingualItems(metadata, TikaCoreProperties.TITLE, info.getTitle(), dcSchema); extractDublinCoreListItems(metadata, TikaCoreProperties.CREATOR, info.getAuthor(), dcSchema); extractDublinCoreListItems(metadata, TikaCoreProperties.CONTRIBUTOR, null, dcSchema); addMetadata(metadata, TikaCoreProperties.CREATOR_TOOL, info.getCreator()); addMetadata(metadata, TikaCoreProperties.KEYWORDS, info.getKeywords()); addMetadata(metadata, "producer", info.getProducer()); extractMultilingualItems(metadata, TikaCoreProperties.DESCRIPTION, null, dcSchema); // TODO: Move to description in Tika 2.0 addMetadata(metadata, TikaCoreProperties.TRANSITION_SUBJECT_TO_OO_SUBJECT, info.getSubject()); addMetadata(metadata, "trapped", info.getTrapped()); try { // TODO Remove these in Tika 2.0 addMetadata(metadata, "created", info.getCreationDate()); addMetadata(metadata, TikaCoreProperties.CREATED, info.getCreationDate()); } catch (IOException e) { // Invalid date format, just ignore } try { Calendar modified = info.getModificationDate(); addMetadata(metadata, Metadata.LAST_MODIFIED, modified); addMetadata(metadata, TikaCoreProperties.MODIFIED, modified); } catch (IOException e) { // Invalid date format, just ignore } // All remaining metadata is custom // Copy this over as-is List<String> handledMetadata = Arrays.asList("Author", "Creator", "CreationDate", "ModDate", "Keywords", "Producer", "Subject", "Title", "Trapped"); for (COSName key : info.getDictionary().keySet()) { String name = key.getName(); if (!handledMetadata.contains(name)) { addMetadata(metadata, name, info.getDictionary().getDictionaryObject(key)); } } //try to get the various versions //Caveats: // there is currently a fair amount of redundancy // TikaCoreProperties.FORMAT can be multivalued // There are also three potential pdf specific version keys: pdf:PDFVersion, pdfa:PDFVersion, pdf:PDFExtensionVersion metadata.set("pdf:PDFVersion", Float.toString(document.getDocument().getVersion())); metadata.add(TikaCoreProperties.FORMAT.getName(), MEDIA_TYPE.toString() + "; version=" + Float.toString(document.getDocument().getVersion())); try { if (xmp != null) { xmp.addXMLNSMapping(XMPSchemaPDFAId.NAMESPACE, XMPSchemaPDFAId.class); XMPSchemaPDFAId pdfaxmp = (XMPSchemaPDFAId) xmp.getSchemaByClass(XMPSchemaPDFAId.class); if (pdfaxmp != null) { if (pdfaxmp.getPart() != null) { metadata.set("pdfaid:part", Integer.toString(pdfaxmp.getPart())); } if (pdfaxmp.getConformance() != null) { metadata.set("pdfaid:conformance", pdfaxmp.getConformance()); String version = "A-" + pdfaxmp.getPart() + pdfaxmp.getConformance().toLowerCase(Locale.ROOT); metadata.set("pdfa:PDFVersion", version); metadata.add(TikaCoreProperties.FORMAT.getName(), MEDIA_TYPE.toString() + "; version=\"" + version + "\""); } } // TODO WARN if this XMP version is inconsistent with document header version? } } catch (IOException e) { metadata.set(TikaCoreProperties.TIKA_META_PREFIX + "pdf:metadata-xmp-parse-failed", "" + e); } //TODO: Let's try to move this into PDFBox. //Attempt to determine Adobe extension level, if present: COSDictionary root = document.getDocumentCatalog().getCOSDictionary(); COSDictionary extensions = (COSDictionary) root.getDictionaryObject(COSName.getPDFName("Extensions")); if (extensions != null) { for (COSName extName : extensions.keySet()) { // If it's an Adobe one, interpret it to determine the extension level: if (extName.equals(COSName.getPDFName("ADBE"))) { COSDictionary adobeExt = (COSDictionary) extensions.getDictionaryObject(extName); if (adobeExt != null) { String baseVersion = adobeExt.getNameAsString(COSName.getPDFName("BaseVersion")); int el = adobeExt.getInt(COSName.getPDFName("ExtensionLevel")); //-1 is sentinel value that something went wrong in getInt if (el != -1) { metadata.set("pdf:PDFExtensionVersion", baseVersion + " Adobe Extension Level " + el); metadata.add(TikaCoreProperties.FORMAT.getName(), MEDIA_TYPE.toString() + "; version=\"" + baseVersion + " Adobe Extension Level " + el + "\""); } } } else { // WARN that there is an Extension, but it's not Adobe's, and so is a 'new' format'. metadata.set("pdf:foundNonAdobeExtensionName", extName.getName()); } } } } /** * Try to extract all multilingual items from the XMPSchema * <p/> * This relies on the property having a valid xmp getName() * <p/> * For now, this only extracts the first language if the property does not allow multiple values (see TIKA-1295) * * @param metadata * @param property * @param pdfBoxBaseline * @param schema */ private void extractMultilingualItems(Metadata metadata, Property property, String pdfBoxBaseline, XMPSchema schema) { //if schema is null, just go with pdfBoxBaseline if (schema == null) { if (pdfBoxBaseline != null && pdfBoxBaseline.length() > 0) { addMetadata(metadata, property, pdfBoxBaseline); } return; } for (String lang : schema.getLanguagePropertyLanguages(property.getName())) { String value = schema.getLanguageProperty(property.getName(), lang); if (value != null && value.length() > 0) { //if you're going to add it below in the baseline addition, don't add it now if (pdfBoxBaseline != null && value.equals(pdfBoxBaseline)) { continue; } addMetadata(metadata, property, value); if (!property.isMultiValuePermitted()) { return; } } } if (pdfBoxBaseline != null && pdfBoxBaseline.length() > 0) { //if we've already added something above and multivalue is not permitted //return. if (!property.isMultiValuePermitted()) { if (metadata.get(property) != null) { return; } } addMetadata(metadata, property, pdfBoxBaseline); } } /** * This tries to read a list from a particular property in * XMPSchemaDublinCore. * If it can't find the information, it falls back to the * pdfboxBaseline. The pdfboxBaseline should be the value * that pdfbox returns from its PDDocumentInformation object * (e.g. getAuthor()) This method is designed include the pdfboxBaseline, * and it should not duplicate the pdfboxBaseline. * <p/> * Until PDFBOX-1803/TIKA-1233 are fixed, do not call this * on dates! * <p/> * This relies on the property having a DublinCore compliant getName() * * @param property * @param pdfBoxBaseline * @param dc * @param metadata */ private void extractDublinCoreListItems(Metadata metadata, Property property, String pdfBoxBaseline, XMPSchemaDublinCore dc) { //if no dc, add baseline and return if (dc == null) { if (pdfBoxBaseline != null && pdfBoxBaseline.length() > 0) { addMetadata(metadata, property, pdfBoxBaseline); } return; } List<String> items = getXMPBagOrSeqList(dc, property.getName()); if (items == null) { if (pdfBoxBaseline != null && pdfBoxBaseline.length() > 0) { addMetadata(metadata, property, pdfBoxBaseline); } return; } for (String item : items) { if (pdfBoxBaseline != null && !item.equals(pdfBoxBaseline)) { addMetadata(metadata, property, item); } } //finally, add the baseline if (pdfBoxBaseline != null && pdfBoxBaseline.length() > 0) { addMetadata(metadata, property, pdfBoxBaseline); } } /** * As of this writing, XMPSchema can contain bags or sequence lists * for some attributes...despite standards documentation. * JempBox expects one or the other for specific attributes. * Until more flexibility is added to JempBox, Tika will have to handle both. * * @param schema * @param name * @return list of values or null */ private List<String> getXMPBagOrSeqList(XMPSchema schema, String name) { List<String> ret = schema.getBagList(name); if (ret == null) { ret = schema.getSequenceList(name); } return ret; } private void addMetadata(Metadata metadata, Property property, String value) { if (value != null) { String decoded = decode(value); if (property.isMultiValuePermitted() || metadata.get(property) == null) { metadata.add(property, decoded); } //silently skip adding property that already exists if multiple values are not permitted } } private void addMetadata(Metadata metadata, String name, String value) { if (value != null) { metadata.add(name, decode(value)); } } private String decode(String value) { if (PDFEncodedStringDecoder.shouldDecode(value)) { PDFEncodedStringDecoder d = new PDFEncodedStringDecoder(); return d.decode(value); } return value; } private void addMetadata(Metadata metadata, String name, Calendar value) { if (value != null) { metadata.set(name, value.getTime().toString()); } } private void addMetadata(Metadata metadata, Property property, Calendar value) { if (value != null) { metadata.set(property, value.getTime()); } } /** * Used when processing custom metadata entries, as PDFBox won't do * the conversion for us in the way it does for the standard ones */ private void addMetadata(Metadata metadata, String name, COSBase value) { if (value instanceof COSArray) { for (Object v : ((COSArray) value).toList()) { addMetadata(metadata, name, ((COSBase) v)); } } else if (value instanceof COSString) { addMetadata(metadata, name, ((COSString) value).getString()); } // Avoid calling COSDictionary#toString, since it can lead to infinite // recursion. See TIKA-1038 and PDFBOX-1835. else if (value != null && !(value instanceof COSDictionary)) { addMetadata(metadata, name, value.toString()); } } private boolean shouldHandleXFAOnly(PDDocument pdDocument, PDFParserConfig config) { if (config.getIfXFAExtractOnlyXFA() && pdDocument.getDocumentCatalog() != null && pdDocument.getDocumentCatalog().getAcroForm() != null && pdDocument.getDocumentCatalog().getAcroForm().getXFA() != null) { return true; } return false; } private void handleXFAOnly(PDDocument pdDocument, ContentHandler handler, Metadata metadata) throws SAXException, IOException, TikaException { XFAExtractor ex = new XFAExtractor(); XHTMLContentHandler xhtml = new XHTMLContentHandler(handler, metadata); xhtml.startDocument(); try { ex.extract(new ByteArrayInputStream(pdDocument.getDocumentCatalog().getAcroForm().getXFA().getBytes()), xhtml, metadata); } catch (XMLStreamException e) { throw new TikaException("XML error in XFA", e); } xhtml.endDocument(); } public PDFParserConfig getPDFParserConfig() { return defaultConfig; } public void setPDFParserConfig(PDFParserConfig config) { this.defaultConfig = config; } /** * @see #setUseNonSequentialParser(boolean) * @deprecated use {@link #getPDFParserConfig()} */ public boolean getUseNonSequentialParser() { return defaultConfig.getUseNonSequentialParser(); } /** * If true, the parser will use the NonSequentialParser. This may * be faster than the full doc parser. * If false (default), this will use the full doc parser. * * @deprecated use {@link #setPDFParserConfig(PDFParserConfig)} */ public void setUseNonSequentialParser(boolean v) { defaultConfig.setUseNonSequentialParser(v); } /** * @see #setEnableAutoSpace(boolean) * @deprecated use {@link #getPDFParserConfig()} */ public boolean getEnableAutoSpace() { return defaultConfig.getEnableAutoSpace(); } /** * If true (the default), the parser should estimate * where spaces should be inserted between words. For * many PDFs this is necessary as they do not include * explicit whitespace characters. * * @deprecated use {@link #setPDFParserConfig(PDFParserConfig)} */ public void setEnableAutoSpace(boolean v) { defaultConfig.setEnableAutoSpace(v); } /** * If true, text in annotations will be extracted. * * @deprecated use {@link #getPDFParserConfig()} */ public boolean getExtractAnnotationText() { return defaultConfig.getExtractAnnotationText(); } /** * If true (the default), text in annotations will be * extracted. * * @deprecated use {@link #setPDFParserConfig(PDFParserConfig)} */ public void setExtractAnnotationText(boolean v) { defaultConfig.setExtractAnnotationText(v); } /** * @see #setSuppressDuplicateOverlappingText(boolean) * @deprecated use {@link #getPDFParserConfig()} */ public boolean getSuppressDuplicateOverlappingText() { return defaultConfig.getSuppressDuplicateOverlappingText(); } /** * If true, the parser should try to remove duplicated * text over the same region. This is needed for some * PDFs that achieve bolding by re-writing the same * text in the same area. Note that this can * slow down extraction substantially (PDFBOX-956) and * sometimes remove characters that were not in fact * duplicated (PDFBOX-1155). By default this is disabled. * * @deprecated use {@link #setPDFParserConfig(PDFParserConfig)} */ public void setSuppressDuplicateOverlappingText(boolean v) { defaultConfig.setSuppressDuplicateOverlappingText(v); } /** * @see #setSortByPosition(boolean) * @deprecated use {@link #getPDFParserConfig()} */ public boolean getSortByPosition() { return defaultConfig.getSortByPosition(); } /** * If true, sort text tokens by their x/y position * before extracting text. This may be necessary for * some PDFs (if the text tokens are not rendered "in * order"), while for other PDFs it can produce the * wrong result (for example if there are 2 columns, * the text will be interleaved). Default is false. * * @deprecated use {@link #setPDFParserConfig(PDFParserConfig)} */ public void setSortByPosition(boolean v) { defaultConfig.setSortByPosition(v); } }