Excel大批量数据导出

package com.tebon.ams.util;

import lombok.extern.slf4j.Slf4j;
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.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.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;

import javax.xml.parsers.ParserConfigurationException;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @description: ${description}
 * @author: dfz
 * @create: 2018-12-14
 **/
@Slf4j
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 List<String[]> rows = new ArrayList<String[]>();

private final OPCPackage xlsxPackage;

/**
     * Number of columns to read starting with leftmost
     */
    private int[] minColumns;

/**
     * Destination for data
     */
    private class SheetToCSV implements SheetContentsHandler {
        private String[] record;
        private int minColumns;
        private int thisColumn = 0;

public SheetToCSV(int minColumns) {
            super();
            this.minColumns = minColumns;
        }

@Override
        public void startRow(int rowNum) {
            record = new String[this.minColumns];
            // System.out.println("################################:"+rowNum);
        }

@Override
        public void endRow(int rowNum) {
            thisColumn = 0;
            if (!ObjectUtil.isEmpty(this.record) && !ObjectUtil.isEmpty(this.record[0])) {
                rows.add(this.record);
            }
            //一行结束要把此属性置""
            preXy = "";
            //System.out.println("**********************************");

}

//前一个单元格的xy
        private String preXy = "";
        //当前单元格的xy
        private String currXy = "";
        //前一个单元格的x
        private String preX = "";
        //当前单元格的x
        private String currX = "";
        //两个不为空的单元格之间隔了多少个空的单元格
        private int flag = 0;

@Override
        public void cell(String cellReference, String formattedValue, XSSFComment comment) {

//与判断空单元格有关
            if ("".equals(preXy)) {
                preXy = cellReference;
            }
            currXy = cellReference;
            preX = preXy.replaceAll("\\d", "").trim();
            currX = currXy.replaceAll("\\d", "").trim();
            int preAscii = 0;
            int curAscii = 0;
            preAscii = excelColStrToNum(preX, preX.length());
            curAscii = excelColStrToNum(currX, currX.length());
            flag = curAscii - preAscii;
            if (flag != 0 && flag != 1 && flag > 0) {
                //isSkipCeil = true;
                for (int i = 0; i < (flag - 1); i++) {
                    //appStr = appStr + ",";
                    record[thisColumn] = null;
                    thisColumn++;
                }
            }
            preXy = cellReference;
            if (thisColumn < this.minColumns)
                record[thisColumn] = formattedValue.trim();
            thisColumn++;

}

@Override
        public void headerFooter(String text, boolean isHeader, String tagName) {
            // Skip, no headers or footers in CSV
        }

}

/**
     * Creates a new XLSX -> CSV converter
     *
     * @param pkg        The XLSX package to process
     * @param minColumns The minimum number of columns to output, or -1 for no minimum
     */
    public XLSX2CSV(OPCPackage pkg, int... minColumns) {
        this.xlsxPackage = pkg;
        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 Map<Integer, List<String[]>> process() throws IOException, OpenXML4JException, ParserConfigurationException, SAXException {
        Map<Integer, List<String[]>> map = new HashMap<>();
        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;
        int length = 0;
        while (iter.hasNext()) {
            InputStream stream = iter.next();
            String sheetName = iter.getSheetName();
            //this.output.println();
            //this.output.println(sheetName + " [index=" + index + "]:");
            if (this.minColumns.length < index + 1) {
                log.info("请求参数不符合sheet页数...直接退出");
                return map;
            }
            processSheet(styles, strings, new SheetToCSV(this.minColumns[index]), stream);
            stream.close();
            //map.put(index, this.rows.subList(length, this.rows.size()));
            length = length + this.rows.size();
            map.put(index, this.rows);
            this.rows = new ArrayList<String[]>();
            ++index;
        }
        return map;
    }

/**
     * 得到excel的记录
     *
     * @param excelPath
     * @param minColumns 输出多少列
     * @return
     * @throws Exception
     */
    public static Map<Integer, List<String[]>> getRecords(String excelPath, int... minColumns) throws Exception {
        File xlsxFile = new File(excelPath);
        if (!xlsxFile.exists()) {
            System.err.println("Not found or not a file: " + xlsxFile.getPath());
            return null;
        }
        // The package open is instantaneous, as it should be.
        OPCPackage p = OPCPackage.open(xlsxFile.getPath(), PackageAccess.READ);
        XLSX2CSV xlsx2csv = new XLSX2CSV(p, minColumns);
        Map<Integer, List<String[]>> map = xlsx2csv.process();
        p.close();
        return map;
    }

/**
     * 得到excel的记录
     *
     * @param minColumns 输出多少列
     * @return
     * @throws Exception
     */
    public static Map<Integer, List<String[]>> getRecords(File file, int... minColumns) throws Exception {
        OPCPackage p = OPCPackage.open(file);
        XLSX2CSV xlsx2csv = new XLSX2CSV(p, minColumns);
        Map<Integer, List<String[]>> map = xlsx2csv.process();
        p.close();
        return map;
    }

/**
     * Excel列号数字与字母互换
     * Excel column index begin 1
     *
     * @param colStr
     * @param length
     * @return
     */
    public static int excelColStrToNum(String colStr, int length) {
        int num = 0;
        int result = 0;
        for (int i = 0; i < length; i++) {
            char ch = colStr.charAt(length - i - 1);
            num = (int) (ch - 'A' + 1);
            num *= Math.pow(26, i);
            result += num;
        }
        return result;
    }

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

Map<Integer, List<String[]>> map = getRecords("C:\\Users\\lenovo\\Desktop\\333.xlsx", 63, 4, 4);
        int preAscii = excelColStrToNum("AC", 2);
        int curAscii = excelColStrToNum("Z", 1);
        System.out.println(preAscii);
        System.out.println(curAscii);
    }

}

参考文档：https://blog.csdn.net/daiyutage/article/details/53023020