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The Adobe Experience Manager SDK
/*
* 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.parser.pdf;
import java.io.IOException;
import java.io.InputStream;
import java.util.Calendar;
import java.util.List;
import java.util.Locale;
import org.apache.jempbox.xmp.XMPMetadata;
import org.apache.jempbox.xmp.XMPSchema;
import org.apache.jempbox.xmp.XMPSchemaBasic;
import org.apache.jempbox.xmp.XMPSchemaDublinCore;
import org.apache.jempbox.xmp.XMPSchemaPDF;
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.COSString;
import org.apache.pdfbox.pdmodel.common.PDMetadata;
import org.apache.tika.exception.TikaException;
import org.apache.tika.extractor.EmbeddedDocumentUtil;
import org.apache.tika.io.IOUtils;
import org.apache.tika.metadata.DublinCore;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.metadata.PDF;
import org.apache.tika.metadata.Property;
import org.apache.tika.metadata.TikaCoreProperties;
import org.apache.tika.metadata.XMP;
import org.apache.tika.mime.MediaType;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.parser.image.xmp.JempboxExtractor;
import org.apache.tika.utils.XMLReaderUtils;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;
class PDMetadataExtractor {
private static final MediaType MEDIA_TYPE = MediaType.application("pdf");
static void extract(PDMetadata pdMetadata, Metadata metadata, ParseContext context) {
if (pdMetadata == null) {
metadata.set(PDF.HAS_XMP, "false");
return;
}
//this file has XMP...
//whether or not it is readable or throws an exception is another story...
metadata.set(PDF.HAS_XMP, "true");
//now go for the XMP
Document dom = loadDOM(pdMetadata, metadata, context);
if (dom == null) {
return;
}
XMPMetadata xmp = new XMPMetadata(dom);
XMPSchemaDublinCore dcSchema = null;
try {
dcSchema = xmp.getDublinCoreSchema();
} catch (IOException e) {
}
if (dcSchema != null) {
extractMultilingualItems(metadata, TikaCoreProperties.DESCRIPTION, null, dcSchema);
extractDublinCoreListItems(metadata, TikaCoreProperties.CONTRIBUTOR, dcSchema);
extractDublinCoreListItems(metadata, TikaCoreProperties.CREATOR, dcSchema);
extractMultilingualItems(metadata, TikaCoreProperties.TITLE, null, dcSchema);
}
extractBasic(xmp, metadata);
extractPDF(xmp, metadata);
JempboxExtractor.extractXMPMM(xmp, metadata);
try {
xmp.addXMLNSMapping(XMPSchemaPDFAId.NAMESPACE, XMPSchemaPDFAId.class);
XMPSchemaPDFAId pdfaxmp = (XMPSchemaPDFAId) xmp.getSchemaByClass(XMPSchemaPDFAId.class);
if (pdfaxmp != null) {
if (pdfaxmp.getPart() != null) {
metadata.set(PDF.PDFAID_PART, Integer.toString(pdfaxmp.getPart()));
}
if (pdfaxmp.getConformance() != null) {
metadata.set(PDF.PDFAID_CONFORMANCE, pdfaxmp.getConformance());
String version = "A-" + pdfaxmp.getPart() + pdfaxmp.getConformance().toLowerCase(Locale.ROOT);
metadata.set(PDF.PDFA_VERSION, 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);
}
}
private static void extractPDF(XMPMetadata xmp, Metadata metadata) {
if (xmp == null) {
return;
}
XMPSchemaPDF pdf = null;
try {
pdf = xmp.getPDFSchema();
} catch (IOException e) {
return;
}
if (pdf == null) {
return;
}
setNotNull(PDF.PRODUCER, pdf.getProducer(), metadata);
setNotNull(TikaCoreProperties.KEYWORDS, pdf.getKeywords(), metadata);
setNotNull(PDF.PDF_VERSION, pdf.getPDFVersion(), metadata);
}
private static void extractBasic(XMPMetadata xmp, Metadata metadata) {
if (xmp == null) {
return;
}
XMPSchemaBasic basic = null;
try {
basic = xmp.getBasicSchema();
} catch (IOException e) {
return;
}
if (basic == null) {
return;
}
//add the elements from the basic schema if they haven't already
//been extracted from dublin core
setNotNull(XMP.CREATOR_TOOL, basic.getCreatorTool(), metadata);
setNotNull(DublinCore.TITLE, basic.getTitle(), metadata);
setNotNull(XMP.ABOUT, basic.getAbout(), metadata);
setNotNull(XMP.LABEL, basic.getLabel(), metadata);
try {
setNotNull(XMP.CREATE_DATE, basic.getCreateDate(), metadata);
} catch (IOException e) {
}
try {
setNotNull(XMP.MODIFY_DATE, basic.getModifyDate(), metadata);
} catch (IOException e) {
}
try {
setNotNull(XMP.METADATA_DATE, basic.getMetadataDate(), metadata);
} catch (IOException e) {
}
List identifiers = basic.getIdentifiers();
if (identifiers != null) {
for (String identifier : identifiers) {
metadata.add(XMP.IDENTIFIER, identifier);
}
}
List advisories = basic.getAdvisories();
if (advisories != null) {
for (String advisory : advisories) {
metadata.add(XMP.ADVISORY, advisory);
}
}
setNotNull(XMP.NICKNAME, basic.getNickname(), metadata);
setNotNull(XMP.RATING, basic.getRating(), metadata);
//TODO: find an example where basic.getThumbNail is not null
//and figure out how to add that info
}
private static void setNotNull(Property property, String value, Metadata metadata) {
if (metadata.get(property) == null && value != null && value.trim().length() > 0) {
metadata.set(property, decode(value));
}
}
private static void setNotNull(Property property, Calendar value, Metadata metadata) {
if (metadata.get(property) == null && value != null) {
metadata.set(property, value);
}
}
private static void setNotNull(Property property, Integer value, Metadata metadata) {
if (metadata.get(property) == null && value != null) {
metadata.set(property, value);
}
}
/**
* 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
*/
static List getXMPBagOrSeqList(XMPSchema schema, String name) {
List ret = schema.getBagList(name);
if (ret == null) {
ret = schema.getSequenceList(name);
}
return ret;
}
/**
* Try to extract all multilingual items from the XMPSchema
*
* This relies on the property having a valid xmp getName()
*
* 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 static 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.
*
* Until PDFBOX-1803/TIKA-1233 are fixed, do not call this
* on dates!
*
* This relies on the property having a DublinCore compliant getName()
*
* @param property
* @param dc
* @param metadata
*/
private static void extractDublinCoreListItems(Metadata metadata, Property property, XMPSchemaDublinCore dc) {
//if no dc, add baseline and return
if (dc == null) {
return;
}
List items = getXMPBagOrSeqList(dc, property.getName());
if (items == null) {
return;
}
for (String item : items) {
addMetadata(metadata, property, item);
}
}
static 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
}
}
static void addMetadata(Metadata metadata, String name, String value) {
if (value != null) {
metadata.add(name, decode(value));
}
}
static String decode(String value) {
if (PDFEncodedStringDecoder.shouldDecode(value)) {
PDFEncodedStringDecoder d = new PDFEncodedStringDecoder();
return d.decode(value);
}
return value;
}
//can return null!
private static Document loadDOM(PDMetadata pdMetadata, Metadata metadata, ParseContext context) {
if (pdMetadata == null) {
return null;
}
InputStream is = null;
try {
try {
is = pdMetadata.exportXMPMetadata();
} catch (IOException e) {
EmbeddedDocumentUtil.recordEmbeddedStreamException(e, metadata);
return null;
}
return XMLReaderUtils.buildDOM(is, context);
} catch (IOException| SAXException | TikaException e) {
EmbeddedDocumentUtil.recordException(e, metadata);
} finally {
IOUtils.closeQuietly(is);
}
return null;
}
static void addMetadata(Metadata metadata, Property property, Calendar value) {
if (value != null) {
metadata.set(property, value);
}
}
/**
* Used when processing custom metadata entries, as PDFBox won't do
* the conversion for us in the way it does for the standard ones
*/
static 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());
}
}
}
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