<dependency>

      <groupId>org.apache.poi</groupId>

      <artifactId>poi</artifactId>

      <version>3.9</version>

    </dependency>

    <dependency>

      <groupId>org.apache.poi</groupId>

      <artifactId>poi-ooxml</artifactId>

      <version>3.9</version>

    </dependency>

 @Test

    public void test1() throws IOException {

        // 读取文件

        POIFSFileSystem fs = new POIFSFileSystem(Thread.currentThread().getContextClassLoader().getResourceAsStream("test.xls"));

        // 创建一个工作簿

        HSSFWorkbook workbook = new HSSFWorkbook(fs);

        // 获取第一个sheet

        HSSFSheet sheet = workbook.getSheetAt(0);

        System.out.println(sheet.getSheetName());

        // 获取第一行

        HSSFRow row = sheet.getRow(0);

        // 获取第一行第一列

        HSSFCell cell = row.getCell(0);

        System.out.println(cell.getStringCellValue());

        // 创建一行

        HSSFRow row1 = sheet.createRow(1);

        // 创建单元格

        HSSFCell cell1 = row1.createCell(0);

        // 单元格赋值

        cell1.setCellValue("我是程序创建的内容");

        System.out.println(cell1.getStringCellValue());

        // 创建输出流

        FileOutputStream os = new FileOutputStream(new File("D:\\8888.xls"));

        // 输出文件

        workbook.write(os);

    }

 @Test

    public void test2() {

        // 模拟导出数据

        Object[] obj = new Object[]{"哈哈", "呵呵", "哼哼"};

        List<Object[]> list = new ArrayList<Object[]>();

        // HSSFWorkbook 只支持2003版本及以下版本Excel 且容量最大为65536

        for (int i = 0; i < 65536; i++) {

            list.add(obj);

        }

        export("test.xls", list, 2);

    }

    /**

     * poi 导出

     * @param fileName

     * @param objs

     * @param rowIndex

     */

    private void export(String fileName, List<Object[]> objs, int rowIndex) {

        POIFSFileSystem fs = null;

        FileOutputStream os = null;

        try {

            fs = new POIFSFileSystem(Thread.currentThread().getContextClassLoader().getResourceAsStream(fileName));

        } catch (IOException e) {

            e.printStackTrace();

        }

        // 创建一个工作簿

        try {

            HSSFWorkbook workbook = new HSSFWorkbook(fs);

            HSSFCellStyle style = setCellStyle(workbook);

            // 获取一个sheet页

            HSSFSheet sheet = workbook.getSheetAt(0);

            for (int i = rowIndex - 1; i < objs.size(); i++) {

                // 创建行

                HSSFRow row = sheet.createRow(i);

                // 创建列

                for (int j = 0; j < objs.get(i).length; j++) {

                    HSSFCell cell = row.createCell(j);

                    // 设置单元格样式

                    cell.setCellStyle(style);

                    cell.setCellValue(objs.get(i)[j].toString());

                }

            }

            // 创建输出流

             os = new FileOutputStream(new File("D:\\8888.xls"));

            // 输出文件

            workbook.write(os);

        } catch (IOException e) {

            e.printStackTrace();

        }finally {

            if (os != null) {

                try {

                    os.close();

                } catch (IOException e) {

                    e.printStackTrace();

                }

            }

        }

    }

    /**

     * 设置样式

     * @param workbook

     */

    private HSSFCellStyle setCellStyle(HSSFWorkbook workbook) {

        HSSFCellStyle style = workbook.createCellStyle();

        HSSFFont font = workbook.createFont();

        // 字号

        font.setFontHeightInPoints((short) 12);

        style.setFont(font);

        // 左右居中 上下居中

        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);

        style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);

        return style;

    }

/**

     * 大数据量导出

     * @throws IOException

     */

    @Test

    public void text2() throws IOException {

        XSSFWorkbook xssfWorkbook = new   XSSFWorkbook(Thread.currentThread().getContextClassLoader().getResourceAsStream("bigdata.xlsx"));

        SXSSFWorkbook wb = new SXSSFWorkbook(xssfWorkbook, 100);

        Sheet sh = wb.getSheetAt(0);

        for(int rownum = 1; rownum < 75537; rownum++){

            Row row = sh.createRow(rownum);

            for(int cellnum = 0; cellnum < 10; cellnum++){

                Cell cell = row.createCell(cellnum);

                String address = new CellReference(cell).formatAsString();

                cell.setCellValue(address);

            }

        }

//        // Rows with rownum < 900 are flushed and not accessible

//        for(int rownum = 0; rownum < 900; rownum++){

//            Assert.assertNull(sh.getRow(rownum));

//        }

//

//        // ther last 100 rows are still in memory

//        for(int rownum = 900; rownum < 1000; rownum++){

//            Assert.assertNotNull(sh.getRow(rownum));

//        }

        FileOutputStream out = new FileOutputStream("D:\\sxssf.xlsx");

        wb.write(out);

        out.close();

        // dispose of temporary files backing this workbook on disk

        wb.dispose();

    }