Java tutorial
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package FeatureExtraction; import IO.Console; import java.io.File; import java.io.IOException; import java.util.HashMap; import java.util.HashSet; import java.util.Map; import org.apache.pdfbox.cos.COSArray; import org.apache.pdfbox.cos.COSBase; import org.apache.pdfbox.cos.COSDictionary; import org.apache.pdfbox.cos.COSDocument; import org.apache.pdfbox.cos.COSName; import org.apache.pdfbox.cos.COSObject; import org.apache.pdfbox.io.RandomAccess; import org.apache.pdfbox.io.RandomAccessFile; import org.apache.pdfbox.pdmodel.PDDocument; /** * * @author Aviad * @param <T> An element used by this feature extractor */ public class FeatureExtractorPDFStructuralPathsNew<T> extends AFeatureExtractor<T> { private final long serialVersionUID = 1L; public ParserType m_parserType; public FeatureExtractorPDFStructuralPathsNew(ParserType parserType) { m_parserType = parserType; } public enum ParserType { Sequential, NonSequential } /** * * @return the features extractor name */ @Override public String GetName() { return "PDF Structural Paths"; } @Override public Map ExtractFeaturesFrequencyFromSingleElement(T element) { Map<String, Integer> structuralPaths = new HashMap<>(); HashSet<COSBase> visitedObjects = new HashSet<>(); String filePath = (String) element; String parentPath = ""; String pdfObjectName = "Trailer"; File pdfFile = new File(filePath); try { switch (m_parserType) { case Sequential: try (PDDocument pdf = PDDocument.load(pdfFile); COSDocument pdfDocument = pdf.getDocument()) { ExtractPDFStructuralPathsRecursively(pdfDocument.getTrailer().getCOSObject(), pdfObjectName, parentPath, structuralPaths, visitedObjects, 1); } catch (Exception e) { throw e; } break; case NonSequential: File randomAccessFile = new File(filePath + ".ra"); RandomAccess randomAccess = new RandomAccessFile(randomAccessFile, "rwd"); try (PDDocument pdf = PDDocument.loadNonSeq(pdfFile, randomAccess); COSDocument pdfDocument = pdf.getDocument()) { ExtractPDFStructuralPathsRecursively(pdfDocument.getTrailer().getCOSObject(), pdfObjectName, parentPath, structuralPaths, visitedObjects, 1); } catch (Exception e) { throw e; } finally { randomAccessFile.delete(); } break; } } catch (IOException e) { //AddPDFStructuralPath("General Parsing Error", structuralPaths); //Canceled Console.PrintException(String.format("Error parsing PDF file: '%s'", filePath), e); } return structuralPaths; } /** * Extract the PDF structural paths recursively * * @param pdfObject the object * @param pdfObjectName the name of the current object * @param parentPath the path of the parent node * @param structuralPaths the Map to add the feature to * @param visitedObjects HashSet of visited objects * @param recursionIteration recursion iteration */ private void ExtractPDFStructuralPathsRecursively(COSBase pdfObject, String pdfObjectName, String parentPath, Map<String, Integer> structuralPaths, HashSet<COSBase> visitedObjects, int recursionIteration) { //To avoid infinite loop if (recursionIteration > 100) { AddPDFStructuralPath("Recursion Iteration > 100", structuralPaths); return; } if (pdfObject != null) { try { String objectPath = String.format("%s\\%s", parentPath, pdfObjectName); visitedObjects.add(pdfObject); switch (pdfObject.getClass().getName().replace("org.apache.pdfbox.cos.", "")) { //An Embedded PDF document case "COSDocument": ExtractPDFStructuralPathsRecursively(((COSDocument) pdfObject).getTrailer().getCOSObject(), "Trailer", "", new HashMap<>(), new HashSet<>(), 1); break; //Data Structure - Array case "COSArray": AddPDFStructuralPath(objectPath, structuralPaths); for (int i = 0; i < ((COSArray) pdfObject).size(); i++) { if (!visitedObjects.contains(((COSArray) pdfObject).get(i))) { ExtractPDFStructuralPathsRecursively(((COSArray) pdfObject).get(i), ".", objectPath, structuralPaths, visitedObjects, recursionIteration + 1); } } break; //Data Structure - Stream & Dictionary case "COSStreamArray": case "COSStream": case "COSDictionaryLateBinding": case "COSDictionary": AddPDFStructuralPath(objectPath, structuralPaths); for (Map.Entry<COSName, COSBase> objectEntry : ((COSDictionary) pdfObject).entrySet()) { if (!visitedObjects.contains(objectEntry.getValue())) { ExtractPDFStructuralPathsRecursively(objectEntry.getValue(), objectEntry.getKey().getName(), objectPath, structuralPaths, visitedObjects, recursionIteration + 1); } /*if (!Arrays.asList("Parent", "P", "ParentTree", "StructTreeRoot").contains(objectEntry.getKey().getName())) {}*/ } break; case "COSObject": if (!visitedObjects.contains(((COSObject) pdfObject).getObject())) { ExtractPDFStructuralPathsRecursively(((COSObject) pdfObject).getObject(), pdfObjectName, parentPath, structuralPaths, visitedObjects, recursionIteration + 1); } break; //Primitive Objects case "COSNull": case "COSUnread": case "COSBoolean": case "COSInteger": case "COSFloat": case "COSNumber": case "COSString": case "COSName": AddPDFStructuralPath(objectPath, structuralPaths); break; } } catch (Exception e) { AddPDFStructuralPath("Recursion Parsing Failure", structuralPaths); } } } /** * Add structural path to the given Map * * @param structuralPath the key to add to the map * @param structuralPath (structural path) to add to the Map */ private void AddPDFStructuralPath(String structuralPath, Map<String, Integer> structuralPaths) { if (!structuralPaths.containsKey(structuralPath)) { structuralPaths.put(structuralPath, 1); } else { structuralPaths.put(structuralPath, structuralPaths.get(structuralPath) + 1); } } /** * Return true if the PDF is compatible * * @param filePath pdf file path * @return true if the PDF is compatible */ public boolean IsCompatiblePDF(String filePath) { File pdfFile = new File(filePath); try (PDDocument pdf = PDDocument.load(pdfFile)) { return true; } catch (Exception e) { return false; } } /** * Return true if the PDF is compatible * * @param filePath pdf file path * @return true if the PDF is compatible */ public boolean IsCompatiblePDF2(String filePath) { File pdfFile = new File(filePath); Map<String, Integer> structuralPaths = new HashMap<>(); HashSet<COSBase> visitedObjects = new HashSet<>(); boolean compatible = true; PDDocument pdf = new PDDocument(); COSDocument pdfDocument = new COSDocument(); String parentPath = ""; String pdfObjectName = "Trailer"; try { pdf = PDDocument.load(pdfFile); pdfDocument = pdf.getDocument(); ExtractPDFStructuralPathsRecursively(pdfDocument.getTrailer().getCOSObject(), pdfObjectName, parentPath, structuralPaths, visitedObjects, 1); } catch (IOException e) { compatible = false; } finally { try { pdf.close(); pdfDocument.close(); } catch (IOException e) { Console.PrintException(String.format("Error closing PDF file: '%s'", filePath), e); } } return compatible; } /*private class PDFObject { private final COSBase m_pdfObject; private final String m_objectName; private final String m_path; public COSBase getObject() { return m_pdfObject; } public String getName() { return m_objectName; } public String getPath() { return m_path; } public PDFObject(COSBase pdfObject, String objectName, String parentPath) { m_pdfObject = pdfObject; m_objectName = objectName; m_path = String.format("%s\\%s", parentPath, objectName); } }*/ /** * Extract the PDF structural paths * * @param pdfRootObject the root of the PDF tree * @param structuralPaths the Map to add the feature to */ /*public void ExtractPDFStructuralPathsQUEUE(COSBase pdfRootObject, Map<String, Integer> structuralFeatures) { Queue<PDFObject> queue = new LinkedList<>(); PDFObject pdfObjectRoot = new PDFObject(pdfRootObject, "Trailer", ""); queue.add(pdfObjectRoot); PDFObject pdfObject; while (!queue.isEmpty()) { pdfObject = queue.remove(); switch (pdfObject.getObject().getClass().getName().replace("org.apache.pdfbox.cos.", "")) { case "COSNull": case "COSUnread": case "COSBoolean": case "COSInteger": case "COSFloat": case "COSNumber": case "COSString": case "COSName": AddPDFStructuralPath(pdfObject.getPath(), structuralFeatures); break; case "COSDocument": break; case "COSArray": AddPDFStructuralPath(pdfObject.getPath(), structuralFeatures); for (int i = 0; i < ((COSArray) pdfObject.getObject()).size(); i++) { queue.add(new PDFObject(((COSArray) pdfObject.getObject()).get(i), ".", pdfObject.getPath())); } break; case "COSStreamArray": case "COSStream": case "COSDictionaryLateBinding": case "COSDictionary": AddPDFStructuralPath(pdfObject.getPath(), structuralFeatures); for (Map.Entry<COSName, COSBase> objectEntry : ((COSDictionary) pdfObject.getObject()).entrySet()) { if (!Arrays.asList("Parent", "P", "ParentTree", "StructTreeRoot", "Reference").contains(objectEntry.getKey().getName())) { queue.add(new PDFObject(objectEntry.getValue(), objectEntry.getKey().getName(), pdfObject.getPath())); } } break; case "COSObject": queue.add(new PDFObject(((COSObject) pdfObject.getObject()).getObject(), pdfObject.getName(), pdfObject.getPath())); break; default: break; } } }*/ }