JAVA操作excel（写XSSFWorkbook）

1：实体对象

@Data
@Accessors(chain = true)
public class UserExcelVO {
    @Label("用户号")
    private String userNo;

    @Label("期数")
    private Integer suserNum;

    @Label("金额")
    private String amt;
}

@Target({ METHOD, FIELD })
@Retention(RUNTIME)
@Documented
public @interface Label {
    String value() default "";
}

2：工具类

public class ExcelUtils {
    public static <T> XSSFWorkbook createExcel(List<T> list, Class<T> clazz, String sheetName)
            throws IllegalArgumentException, IllegalAccessException {
        XSSFWorkbook workbook = new XSSFWorkbook();
        addExcelSheet(list, clazz, workbook, sheetName);
        return workbook;
    }

    public static <T> XSSFSheet addExcelSheet(List<T> list, Class<T> clazz, XSSFWorkbook workbook, String sheetName)
            throws IllegalArgumentException, IllegalAccessException {
        XSSFSheet sheet = workbook.createSheet(sheetName);
        int sheetIndex = 0;
        int sheetColumn = 0;

        Field[] fields = clazz.getDeclaredFields();
        int num = fields.length;
        List<Field> usedFields = Lists.newArrayList();
        // title
        List<String> titles = Lists.newArrayList();
        for (int i = 0; i < num; ++i) {
            Field field = fields[i];
            Annotation[] ans = field.getDeclaredAnnotations();
            for (Annotation an : ans) {
                if (an instanceof Label) {
                    Label label = (Label) an;
                    String value = label.value();
                    titles.add(value);
                    field.setAccessible(true);
                    usedFields.add(field);
                }
            }
        }
        Row row = sheet.createRow(sheetIndex++);
        for (; sheetColumn < titles.size(); ++sheetColumn) {
            row.createCell(sheetColumn).setCellValue(titles.get(sheetColumn));
        }

        // lines
        for (T item : list) {
            sheetColumn = 0;
            row = sheet.createRow(sheetIndex++);
            for (Field field : usedFields) {
                Object fieldValue = field.get(item);
                String value = fieldValue == null ? "" : fieldValue.toString();
                row.createCell(sheetColumn++).setCellValue(value);
            }
        }

        return sheet;
    }
}

3：下载excel

@Override
@RequestMapping(value = "/download", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
public void download(HttpServletResponse response) {
        FileOutputStream fos = null;
        try {
        List<UserExcelVO> list = userService.finaAll();
        XSSFWorkbook book = ExcelUtils.createExcel(
                    list, UserExcelVO.class,
                    "用户交费成功表");
            response.setContentType("application/vnd.ms-excel");
            response.setHeader("Content-Disposition",
                    "attachment; filename=" +  "userList_" + cmd.getCompareBatchNo() + "_compareDetails.xlsx");
            book.write(response.getOutputStream());
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (fos != null) {
                IOUtils.closeQuietly(fos);
            }
        }
    }