apache poi Excel导入、导出单元格图片
本文将在导入Excel时获取其浮动在单元格内的图片（嵌入单元格获取不到），并下载到本地。导出也是浮动式图片。这里只提供导入图片部分的代码，仅供参考。与导入图片无关的代码部分已进行删除，如报错请忽略，关注导入图片业务即可。
业务层代码
/**
* 导出Excel XSSFWorkbook
*
* @param workbook 工作簿 XSSFWorkbook格式
* @param dataList 数据集合
* @param fieldList 字段集合
* @param sheetName 工作表名称
*/
public Result importExcel(HttpServletRequest request, HttpServletResponse response, String processDefinitionKey) {
long startTime = System.currentTimeMillis();
LoginUser user = (LoginUser) SecurityUtils.getSubject().getPrincipal();
try {
formFieldList = listFormFields(formType, processDefinition.getFormId(), null);
} catch (Exception e) {
log.error(e.getMessage(), e);
return Result.error("查询表单字段失败！");
}
// 文件处理
MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
List errorMessageList = new ArrayList<>();
Map fileMap = multipartRequest.getFileMap();
for (Map.Entry entity : fileMap.entrySet()) {
MultipartFile file = entity.getValue();
try {
// 读取excel
ExcelReader reader = ExcelUtil.getReader(file.getInputStream());
List> formList = reader.readAll();
// 获取所有的图画对象
Sheet sheet = reader.getSheet();
List>> pictureDataList = ExcelHutoolUtil.listSheetPicture(sheet);
int num = 1;
// 为了在子线程中获取token，使用InheritableThreadLocal存储token
InheritableThreadLocal tokenThreadLocal = new InheritableThreadLocal<>();
tokenThreadLocal.set(UserTokenContext.getToken());
// 创建线程池
ThreadPoolExecutor executor = new ThreadPoolExecutor(10, 10, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<>(), Executors.defaultThreadFactory(), new ThreadPoolExecutor.AbortPolicy());
CountDownLatch countDownLatch = new CountDownLatch(formList.size());
for (Map map : formList) {
int finalNum = num;
executor.submit(() -> {
TransactionStatus status = null;
try {
// 在子线程中获取token
UserTokenContext.setToken(tokenThreadLocal.get());
// 开始事务
DefaultTransactionDefinition def = new DefaultTransactionDefinition();
def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRES_NEW);
def.setIsolationLevel(TransactionDefinition.ISOLATION_READ_COMMITTED);
status = transactionManager.getTransaction(def);
boolean success = false;
// 设置重试次数，避免死锁
int retries = 3;
while (!success && retries > 0) {
try {
// 导入单个流程实例
importSingleProcessInstance(processDefinitionKey, user, processDefinition, formType, formId, formFieldList, pictureDataList, map, finalNum);
success = true;
} catch (Exception e) {
retries--;
if (retries == 0) {
errorMessageList.add("第" + finalNum + "行数据导入失败！" + e.getMessage());
throw e;
}
}
}
transactionManager.commit(status);
} catch (Exception e) {
if (status != null) {
transactionManager.rollback(status);
}
e.printStackTrace();
} finally {
countDownLatch.countDown();
UserTokenContext.remove();
}
});
num++;
}
executor.shutdown();
countDownLatch.await();
log.info("工作流导入成功！耗时：" + (System.currentTimeMillis() - startTime) + "ms");
return ImportExcelUtil.importReturnResTxt(errorMessageList.size(), formList.size() - errorMessageList.size(), errorMessageList);
} catch (Exception e) {
e.printStackTrace();
return Result.error("文件导入失败！" + e.getMessage());
} finally {
try {
file.getInputStream().close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
return Result.error("文件导入失败！");
}
/**
* 导出Excel HSSFWorkbook
*
* @param workbook 工作簿 HSSFWorkbook格式
* @param dataList 数据集合
* @param fieldList 字段集合
* @param sheetName 工作表名称
*/
public void exportExcel(HSSFWorkbook workbook, List> dataList, List> fieldList, String sheetName) {
// 开始时间
long startTime = System.currentTimeMillis();
Sheet sheet = workbook.createSheet(sheetName);
Row headerRow = sheet.createRow(0);
CellStyle headStyle = getHeadStyle(workbook);
CreationHelper creationHelper = workbook.getCreationHelper();
for (int i = 0; i < fieldList.size(); i++) {
Map map = fieldList.get(i);
String columnName = map.get("name");
// 必填项标识*，放在列名前面，例：*姓名
if (null != map.get("mustFlag") && "1".equals(map.get("mustFlag"))) {
String asterisk = "*";
columnName = asterisk + columnName;
}
Cell headerCell = headerRow.createCell(i);
headerCell.setCellValue(columnName);
headerCell.setCellStyle(headStyle);
// 判断当前列是否为importOrgType列，如果是则设置下拉框的数据验证
if (isImportOrgTypeColumn(map)) {
Sheet orgTypeSheet = getOrgTypeSheet(workbook, map);
setDropDownValidation(sheet, i, 1, 9999, orgTypeSheet);
}
sheet.setColumnWidth(i, 25 * 256);
}
// 输出内容
if (dataList != null && !dataList.isEmpty()) {
CellStyle bodyStyle = getBodyStyle(workbook);
for (int i = 0; i < dataList.size(); i++) {
Map map = dataList.get(i);
int rowIndex = i + 1;
Row row = sheet.createRow(rowIndex);
for (int j = 0; j < fieldList.size(); j++) {
Map fieldMap = fieldList.get(j);
String columnName = fieldMap.get("code");
Object value = map.get(columnName);
Cell cell = row.createCell(j);
if (value instanceof Date) {
cell.setCellValue((Date) value);
bodyStyle.setDataFormat(creationHelper.createDataFormat().getFormat("yyyy-MM-dd HH:mm:ss"));
cell.setCellStyle(bodyStyle);
} else {
cell.setCellValue(value != null ? value.toString() : "");
// 判断value中结尾是否为.jpeg/.jpg/.png，如果包含则为图片类型，设置单元格格式为图片
if (null != value && (String.valueOf(value).endsWith(".jpeg") || String.valueOf(value).endsWith(".jpg") || String.valueOf(value).endsWith(".png"))) {
try {
// 计算耗时
setPictures(sheet, value.toString(), rowIndex, j);
cell.setCellValue("");
} catch (Exception e) {
e.printStackTrace();
log.error("导出Excel设置图片失败：{}", e.getMessage());
}
}
cell.setCellStyle(bodyStyle);
}
}
}
}
log.info("导出Excel耗时：{}ms", System.currentTimeMillis() - startTime);
} importSingleProcessInstance
/**
* 导入单个流程实例
*
* @param processDefinitionKey 流程定义key
* @param user 登录用户
* @param processDefinition 流程定义
* @param formType 表单类型
* @param formId 表单id
* @param formFieldList 表单字段
* @param pictureDataList 图片数据
* @param map excel数据
* @param num 行数
*/
@Transactional(rollbackFor = Exception.class)
public void importSingleProcessInstance(String processDefinitionKey, LoginUser user, BpmProcessDefinitionExtDO processDefinition, Integer formType, String formId, List> formFieldList, List>> pictureDataList, Map map, int num) throws Exception {
Map form = new HashMap<>();
// 列索引
int columnNum = 0;
// 定义图片路径列表
List picPathList = new ArrayList<>();
try {
for (Map.Entry entry : map.entrySet()) {
String key = entry.getKey();
Object value = entry.getValue();
for (Map formField : formFieldList) {
// 如果是必填字段，去掉excel表头中的*号并判断数据是否为空，为空则抛出异常
if (null != formField.get("mustFlag") && formField.get("mustFlag").equals("1")) {
key = key.replace("*", "");
}
if (key.equals(formField.get("name"))) {
// mustFlag为1表示必填字段，如果为空则抛出异常
boolean isMustField = null != formField.get("mustFlag") && "1".equals(formField.get("mustFlag"));
boolean isValueEmpty = value == null || "".equals(value);
if (isMustField && isValueEmpty) {
throw new JeecgBootException(formField.get("name") + "不能为空");
}
String code = formField.get("code");
// 图片处理
if (CollUtil.isNotEmpty(pictureDataList) && pictureDataList.size() > 0) {
String picPath = ExcelHutoolUtil.readPic(pictureDataList, num, columnNum);
if (StrUtil.isNotEmpty(picPath)) {
value = picPath;
// 保存图片路径
String[] split = picPath.split(",");
for (String s : split) {
picPathList.add(s);
}
}
}
form.put(code, value);
break;
}
}
columnNum++;
}
if (form.size() == 0) {
throw new JeecgBootException("第" + num + "行数据不符合规范！");
}
} catch (Exception e) {
e.printStackTrace();
// 删除图片，判断picPathList是否为空，不为空则删除图片
if (CollUtil.isNotEmpty(picPathList)) {
picPathList.stream().map(picPath -> excelHutoolUtil.getPicObjectName(picPath)).forEach(picObjectName -> MinioUtil.removeObject(MinioUtil.getBucketName(), picObjectName));
}
throw new JeecgBootException(e.getMessage());
}
} ExcelUtil
/**
* 读取图片
*
* @param pictureDataList 图片集合
* @param rowIndex 图片所在单元格的行
* @param columnIndex 图片所在单元格的列
* @return String 图片路径
* @throws Exception
*/
public static String readPic(List>> pictureDataList, int rowIndex, int columnIndex) throws Exception {
if (pictureDataList == null || pictureDataList.isEmpty()) {
return null;
}
String key = rowIndex + "-" + columnIndex;
for (Map> map : pictureDataList) {
if (map.containsKey(key)) {
List pictureList = map.get(key);
String[] filePaths = new String[pictureList.size()];
for (int i = 0; i < pictureList.size(); i++) {
PictureData picture = pictureList.get(i);
byte[] imageData = picture.getData();
String fileExtension = picture.suggestFileExtension();
InputStream inputStream = new ByteArrayInputStream(imageData);
String fileName = UUID.randomUUID().toString().replaceAll("-", "");
fileName = fileName + "." + fileExtension;
MultipartFile multipartFile = new MockMultipartFile(fileName, fileName, ContentType.APPLICATION_OCTET_STREAM.toString(), inputStream);
String filePath = MinioUtil.upload(multipartFile, "temp");
filePaths[i] = filePath;
}
// 匹配成功，去掉图片数据
map.remove(key);
return String.join(",", filePaths);
}
}
return null;
}
/**
* 获取工作表Sheet的所有图片，并设置key为图片所在单元格的行索引+列索引，value为图数据
*
* @param sheet 工作表
* @return List 注意：导出图片时，只有将工作簿设置成HSSFWorkbook 才有效，具体原因未知。