| /* |
| * 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.drill.exec.store.pdf; |
| |
| import org.apache.drill.common.exceptions.UserException; |
| import org.apache.pdfbox.pdmodel.PDDocument; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import technology.tabula.ObjectExtractor; |
| import technology.tabula.Page; |
| import technology.tabula.PageIterator; |
| import technology.tabula.Rectangle; |
| import technology.tabula.RectangularTextContainer; |
| import technology.tabula.Table; |
| import technology.tabula.detectors.NurminenDetectionAlgorithm; |
| import technology.tabula.extractors.BasicExtractionAlgorithm; |
| import technology.tabula.extractors.ExtractionAlgorithm; |
| import technology.tabula.extractors.SpreadsheetExtractionAlgorithm; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| public class PdfUtils { |
| |
| public static final ExtractionAlgorithm DEFAULT_ALGORITHM = new BasicExtractionAlgorithm(); |
| private static final Logger logger = LoggerFactory.getLogger(PdfUtils.class); |
| |
| /** |
| * Returns a list of tables found in a given PDF document. There are several extraction algorithms |
| * available and this function uses the default Basic Extraction Algorithm. |
| * @param document The input PDF document to search for tables |
| * @return A list of tables found in the document. |
| */ |
| public static List<Table> extractTablesFromPDF(PDDocument document) { |
| return extractTablesFromPDF(document, DEFAULT_ALGORITHM); |
| } |
| |
| /** |
| * Returns a list of tables found in a given PDF document. There are several extraction algorithms |
| * available and this function allows the user to select which to use. |
| * @param document The input PDF document to search for tables |
| * @param algorithm The extraction algorithm |
| * @return A list of tables found in the document. |
| */ |
| public static List<Table> extractTablesFromPDF(PDDocument document, ExtractionAlgorithm algorithm) { |
| NurminenDetectionAlgorithm detectionAlgorithm = new NurminenDetectionAlgorithm(); |
| |
| ExtractionAlgorithm algExtractor; |
| |
| SpreadsheetExtractionAlgorithm extractor = new SpreadsheetExtractionAlgorithm(); |
| |
| ObjectExtractor objectExtractor = new ObjectExtractor(document); |
| PageIterator pages = objectExtractor.extract(); |
| List<Table> tables= new ArrayList<>(); |
| while (pages.hasNext()) { |
| Page page = pages.next(); |
| |
| algExtractor = algorithm; |
| List<Rectangle> tablesOnPage = detectionAlgorithm.detect(page); |
| |
| for (Rectangle guessRect : tablesOnPage) { |
| Page guess = page.getArea(guessRect); |
| tables.addAll(algExtractor.extract(guess)); |
| } |
| } |
| |
| try { |
| objectExtractor.close(); |
| } catch (Exception e) { |
| throw UserException.parseError(e) |
| .message("Error extracting table: " + e.getMessage()) |
| .build(logger); |
| } |
| |
| return tables; |
| } |
| |
| /** |
| * Returns a specific table from a PDF document. Returns null in the event that |
| * the user requests a table that does not exist. If there is an error with the document |
| * the function will throw a UserException. |
| * @param document The source PDF document |
| * @param tableIndex The index of the desired table |
| * @return The desired Table, null if the table is not valid, or if the document has no tables. |
| */ |
| public static Table getSpecificTable(PDDocument document, int tableIndex, ExtractionAlgorithm algorithm) { |
| NurminenDetectionAlgorithm detectionAlgorithm = new NurminenDetectionAlgorithm(); |
| ExtractionAlgorithm algExtractor; |
| |
| if (algorithm == null) { |
| algExtractor = DEFAULT_ALGORITHM; |
| } else { |
| algExtractor = algorithm; |
| } |
| |
| ObjectExtractor objectExtractor = new ObjectExtractor(document); |
| PageIterator pages = objectExtractor.extract(); |
| |
| Table specificTable; |
| int tableCounter = 0; |
| while (pages.hasNext()) { |
| Page page = pages.next(); |
| |
| List<Rectangle> rectanglesOnPage = detectionAlgorithm.detect(page); |
| List<Table> tablesOnPage = new ArrayList<>(); |
| |
| for (Rectangle guessRect : rectanglesOnPage) { |
| Page guess = page.getArea(guessRect); |
| tablesOnPage.addAll(algExtractor.extract(guess)); |
| if (tablesOnPage.size() == 0) { |
| return null; |
| } |
| |
| for (Table table : tablesOnPage) { |
| if (tableCounter == tableIndex) { |
| specificTable = table; |
| return specificTable; |
| } |
| tableCounter++; |
| } |
| } |
| } |
| try { |
| objectExtractor.close(); |
| } catch (Exception e) { |
| throw UserException.parseError(e) |
| .message("Error extracting table: " + e.getMessage()) |
| .build(logger); |
| } |
| |
| return null; |
| } |
| |
| /** |
| * Returns the values contained in a PDF Table row |
| * @param table The source table |
| * @return A list of the header rows |
| */ |
| public static List<String> extractFirstRowValues(Table table) { |
| List<String> values = new ArrayList<>(); |
| if (table == null) { |
| return values; |
| } |
| List<RectangularTextContainer> firstRow = table.getRows().get(0); |
| |
| if (firstRow != null) { |
| for (RectangularTextContainer rectangularTextContainer : firstRow) { |
| values.add(rectangularTextContainer.getText()); |
| } |
| } |
| return values; |
| } |
| |
| /** |
| * This function retuns the contents of a specific row in a PDF table as a list of Strings. |
| * @param table The table containing the data. |
| * @param rowIndex The desired row index |
| * @return A list of Strings with the data. |
| */ |
| public static List<String> getRowAsStringList(Table table, int rowIndex) { |
| List<String> values = new ArrayList<>(); |
| if (table == null) { |
| return values; |
| } |
| |
| List<RectangularTextContainer> row = table.getRows().get(rowIndex); |
| for (RectangularTextContainer rectangularTextContainer : row) { |
| values.add(rectangularTextContainer.getText()); |
| } |
| return values; |
| } |
| |
| public static List<String> convertRowToStringArray(List<RectangularTextContainer> input) { |
| List<String> values = new ArrayList<>(); |
| for (RectangularTextContainer rectangularTextContainer : input) { |
| values.add(rectangularTextContainer.getText()); |
| } |
| return values; |
| } |
| |
| |
| /** |
| * This function retuns the contents of a specific row in a PDF table as a list of Strings. |
| * @param table The table containing the data. |
| * @param rowIndex The desired row index |
| * @return A list of Strings with the data. |
| */ |
| public static List<RectangularTextContainer> getRow(Table table, int rowIndex) { |
| List<RectangularTextContainer> values = new ArrayList<>(); |
| if (table == null) { |
| return values; |
| } |
| return table.getRows().get(rowIndex); |
| } |
| } |