官方例子

package cn.com.ftms.utils;

import org.apache.poi.openxml4j.exceptions.OpenXML4JException;

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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

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See the License for the specific language governing permissions and

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import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.io.PrintStream;

import javax.xml.parsers.ParserConfigurationException;

import org.apache.poi.openxml4j.exceptions.OpenXML4JException;

import org.apache.poi.openxml4j.opc.OPCPackage;

import org.apache.poi.openxml4j.opc.PackageAccess;

import org.apache.poi.ss.usermodel.DataFormatter;

import org.apache.poi.ss.util.CellAddress;

import org.apache.poi.ss.util.CellReference;

import org.apache.poi.util.SAXHelper;

import org.apache.poi.xssf.eventusermodel.ReadOnlySharedStringsTable;

import org.apache.poi.xssf.eventusermodel.XSSFReader;

import org.apache.poi.xssf.eventusermodel.XSSFSheetXMLHandler;

import org.apache.poi.xssf.eventusermodel.XSSFSheetXMLHandler.SheetContentsHandler;

import org.apache.poi.xssf.extractor.XSSFEventBasedExcelExtractor;

import org.apache.poi.xssf.model.StylesTable;

import org.apache.poi.xssf.usermodel.XSSFComment;

import org.xml.sax.ContentHandler;

import org.xml.sax.InputSource;

import org.xml.sax.SAXException;

import org.xml.sax.XMLReader;

/**

* A rudimentary XLSX -> CSV processor modeled on the

* POI sample program XLS2CSVmra from the package

* org.apache.poi.hssf.eventusermodel.examples.

* As with the HSSF version, this tries to spot missing

* rows and cells, and output empty entries for them.

* <p/>

* Data sheets are read using a SAX parser to keep the

* memory footprint relatively small, so this should be

* able to read enormous workbooks. The styles table and

* the shared-string table must be kept in memory. The

* standard POI styles table class is used, but a custom

* (read-only) class is used for the shared string table

* because the standard POI SharedStringsTable grows very

* quickly with the number of unique strings.

* <p/>

* For a more advanced implementation of SAX event parsing

* of XLSX files, see {@link XSSFEventBasedExcelExtractor}

* and {@link XSSFSheetXMLHandler}. Note that for many cases,

* it may be possible to simply use those with a custom

* {@link SheetContentsHandler} and no SAX code needed of

* your own!

*/

public class XLSX2CSV {

/**

* Uses the XSSF Event SAX helpers to do most of the work

* of parsing the Sheet XML, and outputs the contents

* as a (basic) CSV.

*/

private class SheetToCSV implements SheetContentsHandler {

private boolean firstCellOfRow = false;

private int currentRow = -1;

private int currentCol = -1;

private void outputMissingRows(int number) {

for (int i = 0; i < number; i++) {

for (int j = 0; j < minColumns; j++) {

output.append(',');

}

output.append('\n');

}

}

@Override

public void startRow(int rowNum) {

// If there were gaps, output the missing rows

outputMissingRows(rowNum - currentRow - 1);

// Prepare for this row

firstCellOfRow = true;

currentRow = rowNum;

currentCol = -1;

}

@Override

public void endRow(int rowNum) {

// Ensure the minimum number of columns

for (int i = currentCol; i < minColumns; i++) {

output.append(',');

}

output.append('\n');

}

@Override

public void cell(String cellReference, String formattedValue,

XSSFComment comment) {

if (firstCellOfRow) {

firstCellOfRow = false;

} else {

output.append(',');

}

// gracefully handle missing CellRef here in a similar way as XSSFCell does

if (cellReference == null) {

cellReference = new CellAddress(currentRow, currentCol).formatAsString();

}

// Did we miss any cells?

int thisCol = (new CellReference(cellReference)).getCol();

int missedCols = thisCol - currentCol - 1;

for (int i = 0; i < missedCols; i++) {

output.append(',');

}

currentCol = thisCol;

// Number or string?

try {

Double.parseDouble(formattedValue);

output.append(formattedValue);

} catch (NumberFormatException e) {

output.append('"');

output.append(formattedValue);

output.append('"');

}

}

@Override

public void headerFooter(String text, boolean isHeader, String tagName) {

// Skip, no headers or footers in CSV

}

}

///

private final OPCPackage xlsxPackage;

/**

* Number of columns to read starting with leftmost

*/

private final int minColumns;

/**

* Destination for data

*/

private final PrintStream output;

/**

* Creates a new XLSX -> CSV converter

*

* @param pkg The XLSX package to process

* @param output The PrintStream to output the CSV to

* @param minColumns The minimum number of columns to output, or -1 for no minimum

*/

public XLSX2CSV(OPCPackage pkg, PrintStream output, int minColumns) {

this.xlsxPackage = pkg;

this.output = output;

this.minColumns = minColumns;

}

/**

* Parses and shows the content of one sheet

* using the specified styles and shared-strings tables.

*

* @param styles

* @param strings

* @param sheetInputStream

*/

public void processSheet(

StylesTable styles,

ReadOnlySharedStringsTable strings,

SheetContentsHandler sheetHandler,

InputStream sheetInputStream)

throws IOException, ParserConfigurationException, SAXException {

DataFormatter formatter = new DataFormatter();

InputSource sheetSource = new InputSource(sheetInputStream);

try {

XMLReader sheetParser = SAXHelper.newXMLReader();

ContentHandler handler = new XSSFSheetXMLHandler(

styles, null, strings, sheetHandler, formatter, false);

sheetParser.setContentHandler(handler);

sheetParser.parse(sheetSource);

} catch (ParserConfigurationException e) {

throw new RuntimeException("SAX parser appears to be broken - " + e.getMessage());

}

}

/**

* Initiates the processing of the XLS workbook file to CSV.

*

* @throws IOException

* @throws OpenXML4JException

* @throws ParserConfigurationException

* @throws SAXException

*/

public void process()

throws IOException, OpenXML4JException, ParserConfigurationException, SAXException {

ReadOnlySharedStringsTable strings = new ReadOnlySharedStringsTable(this.xlsxPackage);

XSSFReader xssfReader = new XSSFReader(this.xlsxPackage);

StylesTable styles = xssfReader.getStylesTable();

XSSFReader.SheetIterator iter = (XSSFReader.SheetIterator) xssfReader.getSheetsData();

int index = 0;

while (iter.hasNext()) {

InputStream stream = iter.next();

String sheetName = iter.getSheetName();

this.output.println();

this.output.println(sheetName + " [index=" + index + "]:");

processSheet(styles, strings, new SheetToCSV(), stream);

stream.close();

++index;

}

}

public static void main(String[] args) throws Exception {

/* if (args.length < 1) {

System.err.println("Use:");

System.err.println(" XLSX2CSV <xlsx file> [min columns]");

return;

}*/

File xlsxFile = new File("F:\\8月数据.xlsx");

if (!xlsxFile.exists()) {

System.err.println("Not found or not a file: " + xlsxFile.getPath());

return;

}

int minColumns = -1;

if (args.length >= 2)

minColumns = Integer.parseInt(args[1]);

// The package open is instantaneous, as it should be.

OPCPackage p = OPCPackage.open(xlsxFile.getPath(), PackageAccess.READ);

XLSX2CSV xlsx2csv = new XLSX2CSV(p, System.out, minColumns);

xlsx2csv.process();

p.close();

}

}