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yacy_search_server/source/net/yacy/document/parser/pdfParser.java

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//pdfParser.java
//------------------------
//part of YaCy
//(C) by Michael Peter Christen; mc@yacy.net
//first published on http://www.anomic.de
//Frankfurt, Germany, 2005
//
//this file is contributed by Martin Thelian
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
//This program is free software; you can redistribute it and/or modify
//it under the terms of the GNU General Public License as published by
//the Free Software Foundation; either version 2 of the License, or
//(at your option) any later version.
//
//This program is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
//GNU General Public License for more details.
//
//You should have received a copy of the GNU General Public License
//along with this program; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package net.yacy.document.parser;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.HashSet;
import java.util.List;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.io.MemoryUsageSetting;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDDocumentInformation;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.encryption.AccessPermission;
import org.apache.pdfbox.pdmodel.interactive.action.PDAction;
import org.apache.pdfbox.pdmodel.interactive.action.PDActionURI;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotation;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationLink;
import org.apache.pdfbox.text.PDFTextStripper;
import net.yacy.cora.document.encoding.UTF8;
import net.yacy.cora.document.id.AnchorURL;
import net.yacy.cora.document.id.DigestURL;
import net.yacy.cora.document.id.MultiProtocolURL;
import net.yacy.cora.util.ConcurrentLog;
import net.yacy.document.AbstractParser;
import net.yacy.document.Document;
import net.yacy.document.Parser;
import net.yacy.document.VocabularyScraper;
import net.yacy.kelondro.io.CharBuffer;
import net.yacy.kelondro.util.FileUtils;
import net.yacy.kelondro.util.MemoryControl;
public class pdfParser extends AbstractParser implements Parser {
public static boolean individualPages = false;
public static String individualPagePropertyname = "page";
public pdfParser() {
super("Acrobat Portable Document Parser");
this.SUPPORTED_EXTENSIONS.add("pdf");
this.SUPPORTED_MIME_TYPES.add("application/pdf");
this.SUPPORTED_MIME_TYPES.add("application/x-pdf");
this.SUPPORTED_MIME_TYPES.add("application/acrobat");
this.SUPPORTED_MIME_TYPES.add("applications/vnd.pdf");
this.SUPPORTED_MIME_TYPES.add("text/pdf");
this.SUPPORTED_MIME_TYPES.add("text/x-pdf");
}
@Override
public Document[] parse(
final DigestURL location,
final String mimeType,
final String charset,
final VocabularyScraper scraper,
final int timezoneOffset,
final InputStream source) throws Parser.Failure, InterruptedException {
// check memory for parser
if (!MemoryControl.request(200 * 1024 * 1024, false))
throw new Parser.Failure("Not enough Memory available for pdf parser: " + MemoryControl.available(), location);
// create a pdf parser
PDDocument pdfDoc;
try {
Thread.currentThread().setPriority(Thread.MIN_PRIORITY); // the pdfparser is a big pain
MemoryUsageSetting mus = MemoryUsageSetting.setupMixed(200*1024*1024);
pdfDoc = PDDocument.load(source, mus);
} catch (final IOException e) {
throw new Parser.Failure(e.getMessage(), location);
} finally {
Thread.currentThread().setPriority(Thread.NORM_PRIORITY);
}
if (pdfDoc.isEncrypted()) {
final AccessPermission perm = pdfDoc.getCurrentAccessPermission();
if (perm == null || !perm.canExtractContent()) {
try {pdfDoc.close();} catch (final IOException ee) {}
throw new Parser.Failure("Document is encrypted and cannot be decrypted", location);
}
}
// extracting some metadata
PDDocumentInformation info = pdfDoc.getDocumentInformation();
String docTitle = null, docSubject = null, docAuthor = null, docPublisher = null, docKeywordStr = null;
Date docDate = new Date();
if (info != null) {
docTitle = info.getTitle();
docSubject = info.getSubject();
docAuthor = info.getAuthor();
docPublisher = info.getProducer();
if (docPublisher == null || docPublisher.isEmpty()) docPublisher = info.getCreator();
docKeywordStr = info.getKeywords();
if (info.getModificationDate() != null) docDate = info.getModificationDate().getTime();
// unused:
// info.getTrapped());
}
info = null;
if (docTitle == null || docTitle.isEmpty()) {
docTitle = MultiProtocolURL.unescape(location.getFileName());
}
if (docTitle == null) {
docTitle = docSubject;
}
String[] docKeywords = null;
if (docKeywordStr != null) {
docKeywords = docKeywordStr.split(" |,");
}
Document[] result = null;
try {
// get the links
final List<Collection<AnchorURL>> pdflinks = extractPdfLinks(pdfDoc);
// get the fulltext (either per document or for each page)
final PDFTextStripper stripper = new PDFTextStripper(/*StandardCharsets.UTF_8.name()*/);
if (individualPages) {
// this is a hack which stores individual pages of the source pdf into individual index documents
// the new documents will get a virtual link with a post argument page=X appended to the original url
// collect text
int pagecount = pdfDoc.getNumberOfPages();
String[] pages = new String[pagecount];
for (int page = 1; page <= pagecount; page++) {
stripper.setStartPage(page);
stripper.setEndPage(page);
pages[page - 1] = stripper.getText(pdfDoc);
//System.out.println("PAGE " + page + ": " + pages[page - 1]);
}
// create individual documents for each page
assert pages.length == pdflinks.size() : "pages.length = " + pages.length + ", pdflinks.length = " + pdflinks.size();
result = new Document[Math.min(pages.length, pdflinks.size())];
String loc = location.toNormalform(true);
for (int page = 0; page < result.length; page++) {
result[page] = new Document(
new AnchorURL(loc + (loc.indexOf('?') > 0 ? '&' : '?') + individualPagePropertyname + '=' + (page + 1)), // these are virtual new pages; we cannot combine them with '#' as that would be removed when computing the urlhash
mimeType,
StandardCharsets.UTF_8.name(),
this,
null,
docKeywords,
singleList(docTitle),
docAuthor,
docPublisher,
null,
null,
0.0d, 0.0d,
pages == null || page > pages.length ? new byte[0] : UTF8.getBytes(pages[page]),
pdflinks == null || page >= pdflinks.size() ? null : pdflinks.get(page),
null,
null,
false,
docDate);
}
} else {
// collect the whole text at once
final CharBuffer writer = new CharBuffer(odtParser.MAX_DOCSIZE);
byte[] contentBytes = new byte[0];
stripper.setEndPage(3); // get first 3 pages (always)
writer.append(stripper.getText(pdfDoc));
contentBytes = writer.getBytes(); // remember text in case of interrupting thread
if (pdfDoc.getNumberOfPages() > 3) { // spare creating/starting thread if all pages read
stripper.setStartPage(4); // continue with page 4 (terminated, resulting in no text)
stripper.setEndPage(Integer.MAX_VALUE); // set to default
// we start the pdf parsing in a separate thread to ensure that it can be terminated
final PDDocument pdfDocC = pdfDoc;
final Thread t = new Thread("pdfParser.getText:" + location) {
@Override
public void run() {
try {
writer.append(stripper.getText(pdfDocC));
} catch (final Throwable e) {}
}
};
t.start();
t.join(3000); // pdfbox likes to forget to terminate ... (quite often)
if (t.isAlive()) t.interrupt();
contentBytes = writer.getBytes(); // get final text before closing writer
writer.close(); // free writer resources
}
Collection<AnchorURL> pdflinksCombined = new HashSet<AnchorURL>();
for (Collection<AnchorURL> pdflinksx: pdflinks) if (pdflinksx != null) pdflinksCombined.addAll(pdflinksx);
result = new Document[]{new Document(
location,
mimeType,
StandardCharsets.UTF_8.name(),
this,
null,
docKeywords,
singleList(docTitle),
docAuthor,
docPublisher,
null,
null,
0.0d, 0.0d,
contentBytes,
pdflinksCombined,
null,
null,
false,
docDate)};
}
} catch (final Throwable e) {
//throw new Parser.Failure(e.getMessage(), location);
} finally {
try {pdfDoc.close();} catch (final Throwable e) {}
}
// clear cached resources in pdfbox.
pdfDoc = null;
clearPdfBoxCaches();
return result;
}
/**
* extract clickable links from pdf
* @param pdf the document to parse
* @return all detected links
*/
private List<Collection<AnchorURL>> extractPdfLinks(final PDDocument pdf) {
List<Collection<AnchorURL>> linkCollections = new ArrayList<>(pdf.getNumberOfPages());
for (PDPage page : pdf.getPages()) {
final Collection<AnchorURL> pdflinks = new ArrayList<AnchorURL>();
try {
List<PDAnnotation> annotations = page.getAnnotations();
if (annotations != null) {
for (PDAnnotation pdfannotation : annotations) {
if (pdfannotation instanceof PDAnnotationLink) {
PDAction link = ((PDAnnotationLink)pdfannotation).getAction();
if (link != null && link instanceof PDActionURI) {
PDActionURI pdflinkuri = (PDActionURI) link;
String uristr = pdflinkuri.getURI();
AnchorURL url = new AnchorURL(uristr);
pdflinks.add(url);
}
}
}
}
} catch (IOException ex) {}
linkCollections.add(pdflinks);
}
return linkCollections;
}
/**
* Clean up cache resources allocated by PDFBox that would otherwise not be released.
*/
public static void clearPdfBoxCaches() {
/*
* Prior to pdfbox 2.0.0 font cache occupied > 80MB RAM for a single pdf and
* then stayed forever (detected in YaCy with pdfbox version 1.2.1). The
* situation is now from far better, but one (unnecessary?) cache structure in
* the COSName class still needs to be explicitely cleared.
*/
// History of related issues :
// http://markmail.org/thread/quk5odee4hbsauhu
// https://issues.apache.org/jira/browse/PDFBOX-313
// https://issues.apache.org/jira/browse/PDFBOX-351
// https://issues.apache.org/jira/browse/PDFBOX-441
// https://issues.apache.org/jira/browse/PDFBOX-2200
// https://issues.apache.org/jira/browse/PDFBOX-2149
COSName.clearResources();
/*
* Prior to PDFBox 2.0.0, clearResources() function had to be called on the
* org.apache.pdfbox.pdmodel.font.PDFont class and its children. After version
* 2.0.0, there is no more such a function in PDFont class as font cache is
* handled differently and hopefully more properly.
*/
}
/**
* test
* @param args
*/
public static void main(final String[] args) {
if (args.length > 0 && args[0].length() > 0) {
// file
final File pdfFile = new File(args[0]);
if(pdfFile.canRead()) {
System.out.println(pdfFile.getAbsolutePath());
final long startTime = System.currentTimeMillis();
// parse
final AbstractParser parser = new pdfParser();
Document document = null;
FileInputStream inStream = null;
try {
inStream = new FileInputStream(pdfFile);
document = Document.mergeDocuments(null, "application/pdf", parser.parse(null, "application/pdf", null, new VocabularyScraper(), 0, inStream));
} catch (final Parser.Failure e) {
System.err.println("Cannot parse file " + pdfFile.getAbsolutePath());
ConcurrentLog.logException(e);
} catch (final InterruptedException e) {
System.err.println("Interrupted while parsing!");
ConcurrentLog.logException(e);
} catch (final NoClassDefFoundError e) {
System.err.println("class not found: " + e.getMessage());
} catch (final FileNotFoundException e) {
ConcurrentLog.logException(e);
} finally {
if(inStream != null) {
try {
inStream.close();
} catch(IOException e) {
System.err.println("Could not close input stream on file " + pdfFile);
}
}
}
// statistics
System.out.println("\ttime elapsed: " + (System.currentTimeMillis() - startTime) + " ms");
// output
if (document == null) {
System.out.println("\t!!!Parsing without result!!!");
} else {
System.out.println("\tParsed text with " + document.getTextLength() + " chars of text and " + document.getAnchors().size() + " anchors");
InputStream textStream = document.getTextStream();
try {
// write file
FileUtils.copy(textStream, new File("parsedPdf.txt"));
} catch (final IOException e) {
System.err.println("error saving parsed document");
ConcurrentLog.logException(e);
} finally {
try {
if(textStream != null) {
/* textStream can be a FileInputStream : we must close it to ensure releasing system resource */
textStream.close();
}
} catch (IOException e) {
ConcurrentLog.warn("PDFPARSER", "Could not close text input stream");
}
}
}
} else {
System.err.println("Cannot read file "+ pdfFile.getAbsolutePath());
}
} else {
System.out.println("Please give a filename as first argument.");
}
}
}