快速入门，使用EasyExcel导入导出文件
maven依赖包
com.alibaba
easyexcel
1.1.2-beta5
org.projectlombok
lombok
一：集成Util
一般而言，除去业务逻辑操作之外，文件的导入导出操作应该是通用的，使用easyexcel进行导入导出操作，需要实体类继承BaseRowModel,因此我们可以基于easyexcel集成一个工具类：ExcelUtils
二：将前端上传的文件转换成对象列表
public static List convertFile2ImportList(MultipartFile file, Class clazz) {
if (null == file) {
throw new IllegalArgumentException("文件不能为空");
}
if (StringUtils.isBlank(file.getOriginalFilename())) {
throw new IllegalArgumentException("文件名不能为空");
}
String fileName = file.getOriginalFilename();
String suffix = fileName.substring(fileName.lastIndexOf("."));
if (!(Constants.EXCEL_03_SUFFIX.equals(suffix) || Constants.EXCEL_07_SUFFIX.equals(suffix))) {
throw new IllegalArgumentException("文件格式不正确");
}
List **关于EasyExcelFactory.read()这个方法，对于读取内容的大小有限制，一般不宜超过1000行，有时间再写关于导出的内容，本次就只写个能快速使用的实例。
三：导出数据
public static void exportExcel(Class clazz, String fileName, String sheetName, HttpServletResponse response, List data) {
try {
ExcelWriter writer = EasyExcelFactory.getWriter(response.getOutputStream());
List> head = new ArrayList<>();
ExcelHeadProperty excelHeadProperty = new ExcelHeadProperty(clazz, head);
Sheet sheet = new Sheet(1, 1);
sheet.setHead(excelHeadProperty.getHead());
sheet.setSheetName(sheetName);
setSheetStyle(sheet);
downloadExcel(writer, fileName, sheet, response, data);
} catch (IOException e) {
log.error("下载" + fileName + "失败: " + e);
throw new RuntimeException(ErrCodeEnum.FILE_DOWNLOAD_FAIL);
}
}
DownlodaExcel:
private static void downloadExcel(ExcelWriter writer, String fileName, Sheet sheet, HttpServletResponse response, List data) throws IOException {
response.setCharacterEncoding("UTF-8");
response.setHeader("content-Type", "application/vnd.ms-excel");
response.setHeader("Content-Disposition",
"attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
writer.write(data, sheet);
writer.finish();
response.getOutputStream().flush();
}
SheetStyle:
private static void setSheetStyle(Sheet sheet) {
sheet.setTableStyle(ExcelUtils.createTableStyle());
sheet.setAutoWidth(true);
}
private static TableStyle createTableStyle() {
TableStyle tableStyle = new TableStyle();
Font headFont = new Font();
headFont.setBold(true);
headFont.setFontHeightInPoints((short) 13);
headFont.setFontName("楷体");
tableStyle.setTableHeadFont(headFont);
tableStyle.setTableHeadBackGroundColor(IndexedColors.LIGHT_GREEN);
Font contentFont = new Font();
contentFont.setFontHeightInPoints((short) 12);
contentFont.setFontName("楷体");
tableStyle.setTableContentFont(contentFont);
tableStyle.setTableContentBackGroundColor(IndexedColors.WHITE);
return tableStyle;
}
四：导出文件到本地
public static void exportExcel2Local(List data, Class clazz, String fileName) {
//去掉后缀
String suffix = fileName.substring(fileName.lastIndexOf("."));
fileName = fileName.replace(suffix, "");
String current = DateUtils.format(new Date(), DateUtils.DATETIME_PATTERN);
File dir = new File("D:\\uploadResult");
if (!dir.exists()) {
dir.mkdir();
}
File file = new File(fileName + "结果" + current + suffix);
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
log.error("创建文件失败");
return;
}
}
String path = dir.getPath() + "\\" + file.getPath();
try (OutputStream os = new FileOutputStream(path)) {
ExcelWriter writer = EasyExcelFactory.getWriter(os);
Sheet sheet = new Sheet(1, 0, clazz);
writer.write(data, sheet);
writer.finish();
} catch (IOException e) {
log.error("批量导入失败: " + e);
}
}