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读取大xls和xlsx文件

apache-poi excel java

abr · 技术社区 · 6 年前

我知道周围的帖子,我已经尝试了几次来达到我的目标,我将在下面详细说明:

我有一个 .zip / .rar ,包含多个 xls &安培 xlsx 文件夹。

每个excel文件包含多达数千行的duzen,大约有90列左右(每个excel文件可以有更多或更少的列)。

我已经创建了一个Java WindowBuilder应用程序,在其中我选择了 邮编 / .rar公司 文件并选择将这些文件解压缩到的位置,并使用 FileOutputStream . 保存每个文件后,我将读取文件的内容。

到现在为止,一直都还不错。在几次尝试避免OOM(OutofMemory)并加快速度之后,我已经达到了“最终版本”(非常糟糕,但直到我找到正确的阅读方法),我将解释:

File file = new File('certainFile.xlsx'); //or xls, For example purposes
Workbook wb;
Sheet sheet;
/*
There is a ton of other things up to this point that I don't consider relevant, as it's related to unzipping and renaming, etc. 
This is within a cycle

/
In every zip file, there is at least 1 or 2 files that somehow, when it goes to
WorkbookFactory.create(), it still gives an OOM because it recognizes is has 
a bit over a million rows, meaning it's an 2007 format file (according to our friend Google.com), or so I believe so.
When I open the xlsx file, it indeed has like 10-20mb size and thousands of empty rows. When I save it again
it has 1mb and a couple thousand. After many attempts to read as InputStream, File or trying to save it in 
an automatic way, I've worked with converting it to a CSV and read it differently, 
ence, this 'solution'. if parseAsXLS is true, it applies my regular logic 
per row per cell, otherwise I parse the CSV.
*/
if (file.getName().contains("xlsx")) {
    this.parseAsXLS = false;
    OPCPackage pkg = OPCPackage.open(file);
    //This is just to output the content into a csv file, that I will read later on and it gets overwritten everytime it comes by
    FileOutputStream fo = new FileOutputStream(this.filePath + File.separator + "excel.csv");
    PrintStream ps = new PrintStream(fo);
    XLSX2CSV xlsxCsvConverter = new XLSX2CSV(pkg, ps, 90);
    try {
        xlsxCsvConverter.process();
    } catch (Exception e) {
        //I've added a count at the XLSX2CSV class in order to limit the ammount of rows I want to fetch and throw an Exception on purpose
        System.out.println("Limited the file at 60k rows");
    }
} else {
    this.parseAsXLS = true;
    this.wb = WorkbookFactory.create(file);
    this.sheet = wb.getSheetAt(0);
}

现在发生的是 .xlsx (来自 .zip文件 与其他几个文件一起归档 .xls 和 .xlsx文件 )在一行中有一个特定的字符,xlsx2csv将其视为endrow,这将导致不正确的输出。

这是一个例子: imagelink

注意:目标是只从每个excel文件中获取它们在commum中的特定列集(或者可能有,但不是强制的),并将它们放在一个新的excel中。email列(包含多封用逗号分隔的电子邮件)在电子邮件之前有一个我认为是“enter”的内容,因为如果我手动删除它,它会解决问题。但是,目标不是手动打开每个excel并修复它,否则我只打开每个excel并复制粘贴所需的列。在这个例子中,我需要列: 菲尔达 我是说, 菲尔达格 我是说, 菲尔达尔 和 菲尔丹 .

xlsx2csv.java语言 (我不是这个文件的创建者,我只是应用了我的需要)

import java.awt.List;
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;
        private int currentRow = -1;
        private int currentCol = -1;
        private int maxrows = 60000;



        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;

            if (rowNum == maxrows) {
                    throw new RuntimeException("Force stop at maxrows");
            }
        }

        @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 {
                //noinspection ResultOfMethodCallIgnored
                Double.parseDouble(formattedValue);
                output.append(formattedValue);
            } catch (NumberFormatException e) {
                output.append('"');
                output.append(formattedValue);
                output.append('"');
            }
        }

        @Override
        public void headerFooter(String arg0, boolean arg1, String arg2) {
            // TODO Auto-generated method stub

        }
    }


    ///////////////////////////////////////

    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 The table of styles that may be referenced by cells in the sheet
     * @param strings The table of strings that may be referenced by cells in the sheet
     * @param sheetInputStream The stream to read the sheet-data from.

     * @exception java.io.IOException An IO exception from the parser,
     *            possibly from a byte stream or character stream
     *            supplied by the application.
     * @throws SAXException if parsing the XML data fails.
     */
    public void processSheet(
            StylesTable styles,
            ReadOnlySharedStringsTable strings,
            SheetContentsHandler sheetHandler, 
            InputStream sheetInputStream) throws IOException, 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 If reading the data from the package fails.
     * @throws SAXException if parsing the XML data fails.
     */
    public void process() throws IOException, OpenXML4JException, 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()) {
            try (InputStream stream = iter.next()) {
                processSheet(styles, strings, new SheetToCSV(), stream);
            }
            ++index;
        }
    }
}

我在寻找实现我目标的不同方法。

谢谢你抽出时间

3 回复 | 直到 6 年前

micael cunha 6 年前

好吧,我已经试过复制你的excel文件,我完全把xlsx2csv扔出了窗口。我不认为将xlsx转换为csv的方法是正确的,因为根据xlsx的格式,它可以读取所有空行(您可能知道这一点,因为您将行计数器设置为60k)。不仅如此,如果我们考虑字段,它可能会导致或可能不会导致特殊字符的不正确输出,比如您的问题。

我所做的是我用过这个图书馆 https://github.com/davidpelfree/sjxlsx 读取和重新写入文件。这是非常直接的,新的xlsx生成的文件已经纠正了字段。

我建议您尝试这种方法(可能不使用这个lib),尝试重新编写文件以更正它。

Yy-- 6 年前

这个怎么样:

//获取zip流

ZipFile zipFile = new ZipFile(billWater, Charset.forName("gbk"));


ZipInputStream zipInputStream = new ZipInputStream(new FileInputStream(billWater),  Charset.forName("gbk"));
//ZipEntry zipEntry;
//use openCsv 
 public static <T> List<T> processCSVFileByZip(ZipFile zipFile, ZipEntry zipEntry, Class<? extends T> clazz, Charset charset) throws IOException {
    Reader in = new InputStreamReader(zipFile.getInputStream(zipEntry), charset);
    return processCSVFile(in, clazz, charset, ',');
}

public static <T> List<T> processCSVFile(Reader in, Class<? extends T> clazz, Charset charset, char sep) {
    CsvToBean<T> csvToBean = new CsvToBeanBuilder(in)
            .withType(clazz).withSkipLines(1)
            .withIgnoreLeadingWhiteSpace(true).withSeparator(sep)
            .build();
    return csvToBean.parse();
}

//似乎依赖于xlsx文件格式

Rich 6 年前

我认为这里至少有两个开放性问题:

内存不足 WorkbookFactory.create() 打开旧样式的xls文件时 sparse
XLSX2CSV正在损坏新样式的XLSX文件,可能是由于“某个字符[错误地视为]endRow”

对于(1),我认为您需要找到一个java xls库,它可以在不分配空格的情况下处理稀疏文件,也可以找到一个javaxls库,它可以在 streaming 方法而不是工作簿工厂采取的批处理方法

对于(2),需要找到一个不会损坏数据的Java XLSX库。

我不知道(1)或(2)有什么好的Java库,对不起。

但是,我建议您用excel而不是java编写这个脚本。excel内置了一种优秀的脚本语言excel vba,它可以处理打开多个文件、从中提取数据等。此外,您可以确信,在excel vba中运行的脚本不会对您在java中遇到的诸如稀疏表或xlsx解析之类的excel功能产生任何问题。

(如果是一次性工作,您可能还想退后一步,评估手动完成此任务所需的时间,与编写此任务所需的时间相比。)

祝你好运!