利用SXSSFWorkbook导出excel

项目需要一次性导出几十万数据，于是乎就SXSSFWorkbook导出excel了，写了个导出的工具类，还能要完善它，这个只是1.0版本，但是基本需求能够满足了

package com.fnst.frame.core.common.excel;import org.apache.poi.ss.usermodel.Cell;import org.apache.poi.ss.usermodel.RichTextString;import org.apache.poi.ss.usermodel.Row;import org.apache.poi.ss.usermodel.Sheet;import org.apache.poi.xssf.streaming.SXSSFWorkbook;import org.apache.poi.xssf.usermodel.XSSFWorkbook;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.util.Calendar;import java.util.Date;import java.util.HashMap;import java.util.Map;/** * SXSSFWorkbook 导出 excel工具类 * Created by loup on 2017/12/4. */public abstract class ExcelSXSSFWriter {    /**     * 写入标题     *     * @param sheet     * @param rowNum 第几行的行号     * @param values key:第几列的列号  value:值     */    public static void genSheetHead(Sheet sheet, int rowNum, Map<Integer, Object> values) {        Row row = sheet.createRow(rowNum);        for (Integer cellNum : values.keySet()) {            Cell cell = row.createCell(cellNum);            Object value = values.get(cellNum);            generateValue(value, cell);        }    }    /**     * @param row     * @param cellNum 第几列的列号     * @param value   值     */    public static void createCell(Row row, int cellNum, Object value) {        Cell cell = row.createCell(cellNum);        generateValue(value, cell);    }    private static void generateValue(Object value, Cell cell) {        if (value instanceof String) {            cell.setCellValue((String) value);        } else if (value instanceof Boolean) {            cell.setCellValue((Boolean) value);        } else if (value instanceof Double) {            cell.setCellValue((Double) value);        } else if (value instanceof Date) {            cell.setCellValue((Date) value);        } else if (value instanceof Calendar) {            cell.setCellValue((Calendar) value);        } else if (value instanceof RichTextString) {            cell.setCellValue((RichTextString) value);        }    }    public static void main(String[] args) throws Exception {        //输入模板文件        XSSFWorkbook xssfWorkbook = new XSSFWorkbook(new FileInputStream("F:\\test\\ceshi.xlsx"));        SXSSFWorkbook workbook = new SXSSFWorkbook(xssfWorkbook, 1000);        //导出文件        File file = new File("F:\\test\\test2.xlsx");        long start = System.currentTimeMillis();        for (int i = 0; i < 2; i++) {            Sheet sheet = workbook.getSheet("sheet" + (i + 1));            if (sheet == null) {                sheet = workbook.createSheet("sheet" + (i + 1));            }//            生成标题            Map<Integer, Object> firstTitles = new HashMap<>();            firstTitles.put(0, "部门:");            firstTitles.put(1, "test12221");            firstTitles.put(7, "时间:");            firstTitles.put(8, "2017-09-11");            genSheetHead(sheet, 0, firstTitles);            Map<Integer, Object> twoTitles = new HashMap<>();            twoTitles.put(0, "工号：");            twoTitles.put(1, "test12221");            twoTitles.put(2, "姓名:");            twoTitles.put(3, "aaaa");            genSheetHead(sheet, 1, twoTitles);            for (int rownum = 2; rownum < 100000; rownum++) {                Row row = sheet.createRow(rownum);                int k = -1;                createCell(row, ++k, "第 " + rownum + " 行");                createCell(row, ++k, 34343.123456789);                createCell(row, ++k, "23.67%");                createCell(row, ++k, "12:12:23");                createCell(row, ++k, "2014-10-<11 12:12:23");                createCell(row, ++k, "true");                createCell(row, ++k, "false");                createCell(row, ++k, "fdsa");                createCell(row, ++k, "123");                createCell(row, ++k, "321");                createCell(row, ++k, "3213");                createCell(row, ++k, "321");                createCell(row, ++k, "321");                createCell(row, ++k, "43432");                createCell(row, ++k, "54");                createCell(row, ++k, "fal45se");                createCell(row, ++k, "fal6se");                createCell(row, ++k, "fal64321se");                createCell(row, ++k, "fal43126se");                createCell(row, ++k, "432432");                createCell(row, ++k, "432432");                createCell(row, ++k, "r54");                createCell(row, ++k, "543");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1a");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");                createCell(row, ++k, "few1");            }        }        FileOutputStream out = new FileOutputStream(file);        workbook.write(out);        System.out.println((System.currentTimeMillis()-start));        out.close();    }}