如何使用 Java 從現實生活中的文件中讀取數據？

Question

我使用 MultipartFile 的原因是因為圖像中有一個 swagger 的按鈕圖像。 我成功地將收到的 excel 文件中的值添加到數據庫中，但同時我遇到了以下錯誤。

java.nio.file.NoSuchFileException: org.springframework.web.multipart.support.StandardMultipartHttpServletRequest$StandardMultipartFile@6417030b
    at sun.nio.fs.WindowsException.translateToIOException(WindowsException.java:79)
    at sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:97)
    at sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:102)
    at sun.nio.fs.WindowsFileCopy.move(WindowsFileCopy.java:318)
    at sun.nio.fs.WindowsFileSystemProvider.move(WindowsFileSystemProvider.java:287)
    at java.nio.file.Files.move(Files.java:1395)
    at az.expressbank.expressbankproject.service.impl.UserDetailServiceImpl.acceptExcellFileAndInsertToDatabase2(UserDetailServiceImpl.java:62)
    at az.expressbank.expressbankproject.controller.UserDetailController.writeExcelledRowColumnIntoDatabase(UserDetailController.java:24)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:681)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:764)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
    at org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:91)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1726)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
    at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)

但另一個問題，我無法將我的文件發送到我指定的文件夾。 我想我已經關閉了所有內容，但仍然無法將其發送到指定的文件夾，如果我發送並修復我上面解釋的錯誤，我的問題將不再存在。

 public Response acceptExcellFileAndInsertToDatabase2(MultipartFile file) throws IOException {
        String fileName = file.getOriginalFilename();
        if (fileName.substring(fileName.length() - 5, fileName.length()).equals(".xlsx")) {
            try (InputStream excelFile = file.getInputStream()) {
                String phoneNumber = "";
                String textMessage = "";
                Workbook workbook = WorkbookFactory.create(excelFile);
                Sheet sheet = workbook.getSheetAt(0);
                Iterator<Row> rowIt = sheet.rowIterator();
                while (rowIt.hasNext()) {
                    Row currentRow = rowIt.next();
                    Iterator<Cell> cellIterator = currentRow.iterator();
                    while (cellIterator.hasNext()) {
                        Cell currentCell = cellIterator.next();
                        if (currentCell.getCellTypeEnum() == CellType.NUMERIC) {
                            phoneNumber = NumberToTextConverter.toText(currentCell.getNumericCellValue());
                        } else if (currentCell.getCellTypeEnum() == CellType.STRING) {
                            textMessage = String.valueOf(currentCell.getStringCellValue());
                        }
                    }
                }
                UserDetail userDetail = new UserDetail();
                userDetail.setPhoneNumber(phoneNumber);
                userDetail.setTextMessage(textMessage);
                this.userDetailRepository.save(userDetail);
                excelFile.close();
                workbook.close();
                Path sourcePath = Paths.get(String.valueOf(file));
                Path targetPath = Paths.get("C:\\Users\\User\\Desktop\\ko\\" + sourcePath.getFileName());
                Files.move(sourcePath, targetPath);
                return new SuccessResponse(MessageCase.FILE_SUCCESSFULLY_WRITTEN_TO_DATABASE.getMessage(), 200);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return new ErrorResponse(MessageCase.FAILED_HAPPEND_WHEN_FILE_WRITTEN_TO_DATABASE, 404);
    }

Answer 1

您可以改為使用String path參數。 然后你可以做這樣的事情：

File file = new File(path);
FileInputStream excelFile = new FileInputStream(file);

Answer 2

問題可能是你在那里建立的這個無意義的targetPath ：

Path sourcePath = Paths.get(String.valueOf(file));
Path targetPath = Paths.get("C:\\Users\\User\\Desktop\\ko\\" + sourcePath.getFileName());

這可能已經失敗：

assertTrue(Files.exists(Paths.get("C:\\Users\\User\\Desktop\\ko\\")));

當不允許列出目錄時， Files.exists(Path)也會返回false 。

Answer 3

最后我成功解決了所有問題，一切正常。最困難的事情是將我從用戶那里得到的 excel 文件分配到我在計算機上指定的文件夾中。

 @Override
    public Response acceptExcellFileAndInsertToDatabase2(MultipartFile file) throws IOException {
        System.out.println(file.getContentType());
        String fileName = file.getOriginalFilename();
        if (fileName.substring(fileName.length() - 5).equals(".xlsx")) {
            try (InputStream excelFile = file.getInputStream()) {
                String phoneNumber = "";
                String textMessage = "";
                Workbook workbook = new XSSFWorkbook(excelFile);
                Sheet datatypeSheet = workbook.getSheetAt(0);
                for (Row currentRow : datatypeSheet) {
                    for (Cell currentCell : currentRow) {
                        if (currentCell.getCellTypeEnum() == CellType.NUMERIC) {
                            phoneNumber = NumberToTextConverter.toText(currentCell.getNumericCellValue());
                        } else if (currentCell.getCellTypeEnum() == CellType.STRING) {
                            textMessage = String.valueOf(currentCell.getStringCellValue());
                        }
                    }
                }
                UserDetail userDetail = new UserDetail();
                userDetail.setPhoneNumber(phoneNumber);
                userDetail.setTextMessage(textMessage);
                this.userDetailRepository.save(userDetail);
                excelFile.close();

                String destination = "C:\\Users\\User\\Desktop\\ko\\"  + file.getOriginalFilename();
                File file1 = new File(destination);
                file.transferTo(file1);

                return new SuccessResponse(MessageCase.FILE_SUCCESSFULLY_WRITTEN_TO_DATABASE.getMessage(), 200);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return new ErrorResponse(MessageCase.FAILED_HAPPEND_WHEN_FILE_WRITTEN_TO_DATABASE, 404);
    }