Java tutorial
package com.sustainalytics.crawlerfilter; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.util.logging.FileHandler; import java.util.logging.Logger; import java.util.logging.SimpleFormatter; import org.apache.commons.io.FileUtils; import org.apache.commons.io.FilenameUtils; import org.apache.tika.metadata.Metadata; import org.apache.tika.parser.ParseContext; import org.apache.tika.parser.pdf.PDFParser; import org.apache.tika.sax.BodyContentHandler; import org.xml.sax.ContentHandler; import com.foxit.gsdk.PDFException; import com.itextpdf.text.pdf.PdfReader; import com.itextpdf.text.pdf.parser.PdfReaderContentParser; import com.itextpdf.text.pdf.parser.SimpleTextExtractionStrategy; import com.itextpdf.text.pdf.parser.TextExtractionStrategy; import com.snowtide.PDF; import com.snowtide.pdf.Document; import com.snowtide.pdf.OutputTarget; /** * 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. */ /** * This program takes a PDF file name as input and uses DocEar API to generate its title. * The title is then added with the creation date or custom date of the PDF. The contents * of the PDF are then extracted using Apache PDFBox and their digest is created using * Apache Codec. Finally these three information are combined to generate the title. The PDF * file is renamed only if no other PDF with the same name exists. The .txt file is saved * only if the PDF file is renamed and no other .txt file with the same name exists. * * * @author rushdi.shams, 08/09/2015 * @version 2.0.0 * * CHANGE: * - PDF data extraction using 5 different parser options. This functionality previously was * part of one filter, now separated. * */ public class PDFtoText { /*logger variable*/ private static Logger logger = Logger.getLogger("MyLog"); /** * Method to initiate logger * @param file is a File object. The log file will be placed in this file's folder */ public static void initiateLogger(File file) { FileHandler fileHandler; try { // This block configure the logger with handler and formatter fileHandler = new FileHandler(file.getParentFile().getAbsolutePath() + "/" + "log.txt", true); logger.addHandler(fileHandler); SimpleFormatter formatter = new SimpleFormatter(); fileHandler.setFormatter(formatter); } catch (SecurityException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } /** * Method to extract text from PDF using Apache PDFBox * @param file is a File object that indicates the PDF file * @return the extracted content of the PDF file as String */ public static String extractPDFText(File file) { PdfDataExtractor extractor = new PdfDataExtractor(file); String content = ""; try { content = extractor.extractPlainText(); logger.info("PDF text extracted from " + file.getName() + "\n"); } catch (IOException e) { logger.info("Error in parsing with Apache PDFBox parser\n"); } return content; }// Method to extract and return PDF content has ended. /** * Method to extract text from PDF using Apache PDFBox * @param file is a File object that indicates the PDF file * @return the extracted content of the PDF file as String */ public static String extractFoxitText(String file) { Parse test = new Parse(); test.initLib(); String PDFContent = ""; try { PDFContent = test.pdfOperation(file); logger.info("PDF text extracted from " + file + "\n"); } catch (PDFException e) { logger.info("Error in parsing with Foxit parser\n"); } test.release(); return PDFContent; }// Method to extract and return PDF content has ended. public static String extractPDFExtremeText(String file) { Document pdf = PDF.open(file); StringBuilder text = new StringBuilder(); pdf.pipe(new OutputTarget(text)); logger.info("PDF text extracted from " + file + "\n"); try { pdf.close(); } catch (IOException e) { logger.info("Error in closing with PDFExtreme parser\n"); } return text.toString(); } public static String extractTikaText(String file) { InputStream is = null; ContentHandler contenthandler = null; try { is = new FileInputStream(file); contenthandler = new BodyContentHandler(-1); Metadata metadata = new Metadata(); PDFParser pdfparser = new PDFParser(); pdfparser.parse(is, contenthandler, metadata, new ParseContext()); logger.info("PDF text extracted from " + file + "\n"); } catch (Exception e) { logger.info("Error in parsing with Apache Tika parser\n"); } finally { if (is != null) try { is.close(); } catch (IOException e) { logger.info("Error in closing file with Apache Tika\n"); } } return contenthandler.toString(); } public static String extractITextText(String pdf) { PdfReader reader = null; try { reader = new PdfReader(pdf); } catch (IOException e) { logger.info("Error in reading file with iText parser\n"); } PdfReaderContentParser parser = new PdfReaderContentParser(reader); TextExtractionStrategy strategy; String text = ""; for (int i = 1; i <= reader.getNumberOfPages(); i++) { try { strategy = parser.processContent(i, new SimpleTextExtractionStrategy()); text += strategy.getResultantText(); } catch (IOException e) { logger.info("Error in parsing with iText parser\n"); } logger.info("PDF text extracted from " + pdf + "\n"); } reader.close(); return text; } /** * Method to display banner on cmd line */ public static void showBanner() { System.out.println("//----------------------------------------------------------------------------//"); System.out.println("\tPDF Converter Filter v-2.0.0, 08/09/2015"); System.out.println("\t\t\tAuthor: Rushdi Shams"); System.out.println("\tUSAGE: java -jar pdftotext-2.0.0.jar directorypath/filename.pdf [digit]"); System.out.println("\tUSAGE: [digit]: 1-Apache PDFBox, 2-Foxit, 3-PDFXtreme, 4-iText, 5-Apache Tika"); System.out.println("//----------------------------------------------------------------------------//"); } /** * Method to write the parsed content * @param filePath is the PDF file path, String * @param content is the parsed content, String */ public static void writeParsedFile(String filePath, String content) { String fileWithoutExtension = FilenameUtils.removeExtension(filePath); if (content != null) { try { FileUtils.write(new File(fileWithoutExtension + ".txt"), content); } catch (IOException e) { logger.info("Error writing parsed content\n"); } } else { logger.info("Nothing to write as parsed content\n"); } } /** * Driver method for the class * @param args contains the file path and name */ public static void main(String[] args) { showBanner(); File file = new File(args[0]); initiateLogger(file); int parserChoice = Integer.parseInt(args[1]); String content = null; if (parserChoice == 1) { content = extractPDFText(file); } else if (parserChoice == 2) { content = extractFoxitText(args[0]); } else if (parserChoice == 3) { content = extractPDFExtremeText(args[0]); } else if (parserChoice == 4) { content = extractITextText(args[0]); } else if (parserChoice == 5) { content = extractTikaText(args[0]); } writeParsedFile(args[0], content); }/*End of driver method*/ }/*End of class*/