| /* ==================================================================== |
| 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.poi.examples.xssf.streaming; |
| |
| import java.io.FileInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| import org.apache.poi.xssf.eventusermodel.ReadOnlySharedStringsTable; |
| import org.apache.poi.xssf.eventusermodel.XSSFSheetXMLHandler; |
| import org.apache.poi.xssf.eventusermodel.XSSFSheetXMLHandler.SheetContentsHandler; |
| import org.apache.poi.xssf.usermodel.XSSFComment; |
| import org.apache.poi.xssf.usermodel.XSSFSheet; |
| import org.apache.poi.xssf.usermodel.XSSFWorkbook; |
| import org.openxmlformats.schemas.spreadsheetml.x2006.main.CTSheet; |
| import org.xml.sax.SAXException; |
| |
| /** |
| * This demonstrates how a hybrid approach to workbook read can be taken, using |
| * a mix of traditional XSSF and streaming one particular worksheet (perhaps one |
| * which is too big for the ordinary DOM parse). |
| */ |
| public class HybridStreaming { |
| |
| private static final String SHEET_TO_STREAM = "large sheet"; |
| |
| public static void main(String[] args) throws IOException, SAXException { |
| try (InputStream sourceBytes = new FileInputStream("workbook.xlsx")) { |
| XSSFWorkbook workbook = new XSSFWorkbook(sourceBytes) { |
| /** |
| * Avoid DOM parse of large sheet |
| */ |
| @Override |
| public void parseSheet(java.util.Map<String, XSSFSheet> shIdMap, CTSheet ctSheet) { |
| if (!SHEET_TO_STREAM.equals(ctSheet.getName())) { |
| super.parseSheet(shIdMap, ctSheet); |
| } |
| } |
| }; |
| |
| // Having avoided a DOM-based parse of the sheet, we can stream it instead. |
| ReadOnlySharedStringsTable strings = new ReadOnlySharedStringsTable(workbook.getPackage()); |
| new XSSFSheetXMLHandler(workbook.getStylesSource(), strings, createSheetContentsHandler(), false); |
| workbook.close(); |
| } |
| } |
| |
| private static SheetContentsHandler createSheetContentsHandler() { |
| return new SheetContentsHandler() { |
| |
| @Override |
| public void startRow(int rowNum) { |
| } |
| |
| @Override |
| public void endRow(int rowNum) { |
| } |
| |
| @Override |
| public void cell(String cellReference, String formattedValue, XSSFComment comment) { |
| } |
| }; |
| } |
| } |