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org.apache.tika.parser.pdf.PDF2XHTML Maven / Gradle / Ivy
/*
* 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 org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.cos.COSStream;
import org.apache.pdfbox.filter.MissingImageReaderException;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.PDResources;
import org.apache.pdfbox.pdmodel.graphics.PDXObject;
import org.apache.pdfbox.pdmodel.graphics.color.PDDeviceGray;
import org.apache.pdfbox.pdmodel.graphics.color.PDDeviceRGB;
import org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject;
import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
import org.apache.pdfbox.text.PDFTextStripper;
import org.apache.pdfbox.text.TextPosition;
import org.apache.pdfbox.tools.imageio.ImageIOUtil;
import org.apache.pdfbox.util.Matrix;
import org.apache.tika.exception.TikaException;
import org.apache.tika.extractor.EmbeddedDocumentUtil;
import org.apache.tika.io.TikaInputStream;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.metadata.TikaCoreProperties;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.sax.EmbeddedContentHandler;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Writer;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Utility class that overrides the {@link PDFTextStripper} functionality
* to produce a semi-structured XHTML SAX events instead of a plain text
* stream.
*/
class PDF2XHTML extends AbstractPDF2XHTML {
private static final List JPEG = Arrays.asList(
COSName.DCT_DECODE.getName(),
COSName.DCT_DECODE_ABBREVIATION.getName());
private static final List JP2 =
Arrays.asList(COSName.JPX_DECODE.getName());
private static final List JB2 = Arrays.asList(
COSName.JBIG2_DECODE.getName());
/**
* This keeps track of the pdf object ids for inline
* images that have been processed.
* If {@link PDFParserConfig#getExtractUniqueInlineImagesOnly()
* is true, this will be checked before extracting an embedded image.
* The integer keeps track of the inlineImageCounter for that image.
* This integer is used to identify images in the markup.
*
* This is used across the document. To avoid infinite recursion
* TIKA-1742, we're limiting the export to one image per page.
*/
private Map processedInlineImages = new HashMap<>();
private int inlineImageCounter = 0;
private PDF2XHTML(PDDocument document, ContentHandler handler, ParseContext context, Metadata metadata,
PDFParserConfig config)
throws IOException {
super(document, handler, context, metadata, config);
}
/**
* Converts the given PDF document (and related metadata) to a stream
* of XHTML SAX events sent to the given content handler.
*
* @param document PDF document
* @param handler SAX content handler
* @param metadata PDF metadata
* @throws SAXException if the content handler fails to process SAX events
* @throws TikaException if there was an exception outside of per page processing
*/
public static void process(
PDDocument document, ContentHandler handler, ParseContext context, Metadata metadata,
PDFParserConfig config)
throws SAXException, TikaException {
PDF2XHTML pdf2XHTML = null;
try {
// Extract text using a dummy Writer as we override the
// key methods to output to the given content
// handler.
if (config.getDetectAngles()) {
pdf2XHTML = new AngleDetectingPDF2XHTML(document, handler, context, metadata, config);
} else {
pdf2XHTML = new PDF2XHTML(document, handler, context, metadata, config);
}
config.configure(pdf2XHTML);
pdf2XHTML.writeText(document, new Writer() {
@Override
public void write(char[] cbuf, int off, int len) {
}
@Override
public void flush() {
}
@Override
public void close() {
}
});
} catch (IOException e) {
if (e.getCause() instanceof SAXException) {
throw (SAXException) e.getCause();
} else {
throw new TikaException("Unable to extract PDF content", e);
}
}
if (pdf2XHTML.exceptions.size() > 0) {
//throw the first
throw new TikaException("Unable to extract PDF content", pdf2XHTML.exceptions.get(0));
}
}
@Override
public void processPage(PDPage page) throws IOException {
try {
super.processPage(page);
} catch (IOException e) {
handleCatchableIOE(e);
}
}
@Override
protected void endPage(PDPage page) throws IOException {
try {
writeParagraphEnd();
try {
extractImages(page.getResources(), new HashSet());
} catch (IOException e) {
handleCatchableIOE(e);
}
super.endPage(page);
} catch (SAXException e) {
throw new IOException("Unable to end a page", e);
} catch (IOException e) {
exceptions.add(e);
}
}
private void extractImages(PDResources resources, Set seenThisPage) throws SAXException, IOException {
if (resources == null || config.getExtractInlineImages() == false) {
return;
}
for (COSName name : resources.getXObjectNames()) {
PDXObject object = null;
try {
object = resources.getXObject(name);
} catch (MissingImageReaderException e) {
EmbeddedDocumentUtil.recordException(e, metadata);
continue;
} catch (IOException e) {
EmbeddedDocumentUtil.recordEmbeddedStreamException(e, metadata);
continue;
}
if (object == null) {
continue;
}
COSStream cosStream = object.getCOSObject();
if (seenThisPage.contains(cosStream)) {
//avoid infinite recursion TIKA-1742
continue;
}
seenThisPage.add(cosStream);
if (object instanceof PDFormXObject) {
extractImages(((PDFormXObject) object).getResources(), seenThisPage);
} else if (object instanceof PDImageXObject) {
PDImageXObject image = (PDImageXObject) object;
Metadata embeddedMetadata = new Metadata();
String extension = image.getSuffix();
if (extension == null || extension.equals("png")) {
embeddedMetadata.set(Metadata.CONTENT_TYPE, "image/png");
extension = "png";
} else if (extension.equals("jpg")) {
embeddedMetadata.set(Metadata.CONTENT_TYPE, "image/jpeg");
} else if (extension.equals("tiff")) {
embeddedMetadata.set(Metadata.CONTENT_TYPE, "image/tiff");
extension = "tif";
} else if (extension.equals("jpx")) {
embeddedMetadata.set(Metadata.CONTENT_TYPE, "image/jp2");
} else if (extension.equals("jb2")) {
embeddedMetadata.set(
Metadata.CONTENT_TYPE, "image/x-jbig2");
} else {
//TODO: determine if we need to add more image types
// throw new RuntimeException("EXTEN:" + extension);
}
Integer imageNumber = processedInlineImages.get(cosStream);
if (imageNumber == null) {
imageNumber = inlineImageCounter++;
}
String fileName = "image" + imageNumber + "."+extension;
embeddedMetadata.set(Metadata.RESOURCE_NAME_KEY, fileName);
// Output the img tag
AttributesImpl attr = new AttributesImpl();
attr.addAttribute("", "src", "src", "CDATA", "embedded:" + fileName);
attr.addAttribute("", "alt", "alt", "CDATA", fileName);
xhtml.startElement("img", attr);
xhtml.endElement("img");
//Do we only want to process unique COSObject ids?
//If so, have we already processed this one?
if (config.getExtractUniqueInlineImagesOnly() == true) {
if (processedInlineImages.containsKey(cosStream)) {
continue;
}
processedInlineImages.put(cosStream, imageNumber);
}
embeddedMetadata.set(TikaCoreProperties.EMBEDDED_RESOURCE_TYPE,
TikaCoreProperties.EmbeddedResourceType.INLINE.toString());
if (embeddedDocumentExtractor.shouldParseEmbedded(embeddedMetadata)) {
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
try {
//TODO: handle image.getMetadata()?
try {
writeToBuffer(image, extension, buffer);
} catch (IOException e) {
EmbeddedDocumentUtil.recordEmbeddedStreamException(e, metadata);
continue;
}
try (InputStream embeddedIs = TikaInputStream.get(buffer.toByteArray())) {
embeddedDocumentExtractor.parseEmbedded(
embeddedIs,
new EmbeddedContentHandler(xhtml),
embeddedMetadata, false);
}
} catch (IOException e) {
handleCatchableIOE(e);
}
}
}
}
}
//nearly directly copied from PDFBox ExtractImages
private void writeToBuffer(PDImageXObject pdImage, String suffix, OutputStream out)
throws IOException {
BufferedImage image = pdImage.getImage();
if (image != null) {
if ("jpg".equals(suffix)) {
String colorSpaceName = pdImage.getColorSpace().getName();
//TODO: figure out if we want directJPEG as a configuration
//previously: if (directJPeg || PDDeviceGray....
if (PDDeviceGray.INSTANCE.getName().equals(colorSpaceName) ||
PDDeviceRGB.INSTANCE.getName().equals(colorSpaceName)) {
// RGB or Gray colorspace: get and write the unmodifiedJPEG stream
InputStream data = pdImage.getStream().createInputStream(JPEG);
org.apache.pdfbox.io.IOUtils.copy(data, out);
org.apache.pdfbox.io.IOUtils.closeQuietly(data);
} else {
// for CMYK and other "unusual" colorspaces, the JPEG will be converted
ImageIOUtil.writeImage(image, suffix, out);
}
} else if ("jp2".equals(suffix) || "jpx".equals(suffix)) {
InputStream data = pdImage.createInputStream(JP2);
org.apache.pdfbox.io.IOUtils.copy(data, out);
org.apache.pdfbox.io.IOUtils.closeQuietly(data);
} else if ("jb2".equals(suffix)) {
InputStream data = pdImage.createInputStream(JB2);
org.apache.pdfbox.io.IOUtils.copy(data, out);
org.apache.pdfbox.io.IOUtils.closeQuietly(data);
} else{
ImageIOUtil.writeImage(image, suffix, out);
}
}
out.flush();
}
@Override
protected void writeParagraphStart() throws IOException {
super.writeParagraphStart();
try {
xhtml.startElement("p");
} catch (SAXException e) {
throw new IOException("Unable to start a paragraph", e);
}
}
@Override
protected void writeParagraphEnd() throws IOException {
super.writeParagraphEnd();
try {
xhtml.endElement("p");
} catch (SAXException e) {
throw new IOException("Unable to end a paragraph", e);
}
}
@Override
protected void writeString(String text) throws IOException {
try {
xhtml.characters(text);
} catch (SAXException e) {
throw new IOException(
"Unable to write a string: " + text, e);
}
}
@Override
protected void writeCharacters(TextPosition text) throws IOException {
try {
xhtml.characters(text.getUnicode());
} catch (SAXException e) {
throw new IOException(
"Unable to write a character: " + text.getUnicode(), e);
}
}
@Override
protected void writeWordSeparator() throws IOException {
try {
xhtml.characters(getWordSeparator());
} catch (SAXException e) {
throw new IOException(
"Unable to write a space character", e);
}
}
@Override
protected void writeLineSeparator() throws IOException {
try {
xhtml.newline();
} catch (SAXException e) {
throw new IOException(
"Unable to write a newline character", e);
}
}
class AngleCollector extends PDFTextStripper {
Set angles = new HashSet<>();
public Set getAngles() {
return angles;
}
/**
* Instantiate a new PDFTextStripper object.
*
* @throws IOException If there is an error loading the properties.
*/
AngleCollector() throws IOException {
}
@Override
protected void processTextPosition(TextPosition text) {
Matrix m = text.getTextMatrix();
m.concatenate(text.getFont().getFontMatrix());
int angle = (int) Math.round(Math.toDegrees(Math.atan2(m.getShearY(), m.getScaleY())));
angle = (angle + 360) % 360;
angles.add(angle);
}
}
private static class AngleDetectingPDF2XHTML extends PDF2XHTML {
private AngleDetectingPDF2XHTML(PDDocument document, ContentHandler handler, ParseContext context, Metadata metadata, PDFParserConfig config) throws IOException {
super(document, handler, context, metadata, config);
}
@Override
protected void startPage(PDPage page) throws IOException {
//no-op
}
@Override
protected void endPage(PDPage page) throws IOException {
//no-op
}
@Override
public void processPage(PDPage page) throws IOException {
try {
super.startPage(page);
detectAnglesAndProcessPage(page);
} catch (IOException e) {
handleCatchableIOE(e);
} finally {
super.endPage(page);
}
}
private void detectAnglesAndProcessPage(PDPage page) throws IOException {
//copied and pasted from https://issues.apache.org/jira/secure/attachment/12947452/ExtractAngledText.java
//PDFBOX-4371
AngleCollector angleCollector = new AngleCollector(); // alternatively, reset angles
angleCollector.setStartPage(getCurrentPageNo());
angleCollector.setEndPage(getCurrentPageNo());
angleCollector.getText(document);
int rotation = page.getRotation();
page.setRotation(0);
for (Integer angle : angleCollector.getAngles()) {
if (angle == 0) {
try {
super.processPage(page);
} catch (IOException e) {
handleCatchableIOE(e);
}
} else {
// prepend a transformation
try (PDPageContentStream cs = new PDPageContentStream(document, page, PDPageContentStream.AppendMode.PREPEND, false)) {
cs.transform(Matrix.getRotateInstance(-Math.toRadians(angle), 0, 0));
}
try {
super.processPage(page);
} catch (IOException e) {
handleCatchableIOE(e);
}
// remove transformation
COSArray contents = (COSArray) page.getCOSObject().getItem(COSName.CONTENTS);
contents.remove(0);
}
}
page.setRotation(rotation);
}
@Override
protected void processTextPosition(TextPosition text) {
Matrix m = text.getTextMatrix();
m.concatenate(text.getFont().getFontMatrix());
int angle = (int) Math.round(Math.toDegrees(Math.atan2(m.getShearY(), m.getScaleY())));
if (angle == 0) {
super.processTextPosition(text);
}
}
}
}
