Spring项目MultipartFile转File调用transferTo抛IOException问题求助

我正在尝试将MultipartFile转换为File，但执行multipartFile.transferTo(uploadedFile);时抛出了IOException。

我观察到应用是在'/tmp/tomcat.8080.434182389216770471/work/Tomcat/localhost/ROOT/upload_43f33560_23be_4189_843c_d9062cb44ec2_00000000.tmp'路径下查找uploadedFile，而非我指定的src/main/resources/targetFile.tmp路径。

@GetMapping("/reportError")
public String error(Model model) throws MessagingException, IOException {
    EmailService emailService = new EmailService();
    File uploadedFile = new File("src/main/resources/targetFile.tmp");
    multipartFile.transferTo(uploadedFile);
    emailService.sendmail(Arrays.asList(uploadedFile, dailyReportFile, shiftReportFile));
    model.addAttribute("msg", "Thanks for reporting.\nIt helps us improve the app.");
    return "messageView";
}

java.io.IOException: java.io.FileNotFoundException:
/tmp/tomcat.8080.434182389216770471/work/Tomcat/localhost/ROOT/upload_43f33560_23be_4189_843c_d9062cb44ec2_00000000.tmp
(No such file or directory) at
org.apache.catalina.core.ApplicationPart.write(ApplicationPart.java:122)
~[tomcat-embed-core-9.0.45.jar:9.0.45] at
org.springframework.web.multipart.support.StandardMultipartHttpServletRequest$StandardMultipartFile.transferTo(StandardMultipartHttpServletRequest.java:256)
~[spring-web-5.3.6.jar:5.3.6] at
gmailgdogra.controller.AppController.error(AppController.java:202)
~[classes/:na] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native
Method) ~[na:1.8.0_292] at
java.lang.Thread.run(Thread.java:748) [na:1.8.0_292] Caused by:
java.io.FileNotFoundException:
/tmp/tomcat.8080.434182389216770471/work/Tomcat/localhost/ROOT/upload_43f33560_23be_4189_843c_d9062cb44ec2_00000000.tmp
(No such file or directory) at java.io.FileInputStream.open0(Native
Method) ~[na:1.8.0_292] at
java.io.FileInputStream.open(FileInputStream.java:195) ~[na:1.8.0_292]
at java.io.FileInputStream.(FileInputStream.java:138)
~[na:1.8.0_292] at
org.apache.tomcat.util.http.fileupload.disk.DiskFileItem.write(DiskFileItem.java:404)
~[tomcat-embed-core-9.0.45.jar:9.0.45] at
org.apache.catalina.core.ApplicationPart.write(ApplicationPart.java:120)
~[tomcat-embed-core-9.0.45.jar:9.0.45] ... 52 common frames omitted

同类代码在测试环境中可正常运行

@Test
void convert() throws IOException {
    MultipartFile multipartFile = new MockMultipartFile("sourceFile.tmp", "Hello World".getBytes());
    File file = new File("src/main/resources/targetFile.tmp");
    multipartFile.transferTo(file);
    assertThat(FileUtils.readFileToString(new File("src/main/resources/targetFile.tmp"), "UTF-8"))
            .isEqualTo("Hello World");
}

如果我不发送转换后的Multipart文件，以下代码可以正常运行

@GetMapping("/reportError")
public String error(Model model) throws MessagingException, IOException {
    EmailService emailService = new EmailService();
    emailService.sendmail(Arrays.asList(dailyReportFile, shiftReportFile));
    model.addAttribute("msg", "Thanks for reporting.\nIt helps us improve the app.");
    return "messageView";
}

@GetMapping("/reportError")
public String error(Model model) throws MessagingException, IOException {
    InputStream initialStream = multipartFile.getInputStream();
    byte[] buffer = new byte[initialStream.available()];
    initialStream.read(buffer);

    File targetFile = new File("src/main/resources/targetFile.tmp");

    try (OutputStream outStream = new FileOutputStream(targetFile)) {
        outStream.write(buffer);
    }

    EmailService emailService = new EmailService();
    emailService.sendmail(Arrays.asList(targetFile, dailyReportFile, shiftReportFile));
    model.addAttribute("msg", "Thanks for reporting.\nIt helps us improve the app.");
    return "messageView";
}

我尝试过上述代码，但依旧抛出以下报错信息：

java.io.FileNotFoundException:
/tmp/tomcat.8080.486619881437185002/work/Tomcat/localhost/ROOT/upload_43ba6a8d_27c9_49de_a73e_4f9026fc852e_00000000.tmp
(No such file or directory) at java.io.FileInputStream.open0(Native
Method) ~[na:1.8.0_292] at
java.io.FileInputStream.open(FileInputStream.java:195) ~[na:1.8.0_292]
at java.io.FileInputStream.(FileInputStream.java:138)
~[na:1.8.0_292] at
org.apache.tomcat.util.http.fileupload.disk.DiskFileItem.getInputStream(DiskFileItem.java:194)
~[tomcat-embed-core-9.0.45.jar:9.0.45] at
org.apache.catalina.core.ApplicationPart.getInputStream(ApplicationPart.java:100)
~[tomcat-embed-core-9.0.45.jar:9.0.45] at

编辑
存在同类问题，但其中提供的所有解决方案均无效。

我还尝试了以下代码，依旧运行失败

@GetMapping("/reportError")
public String error(Model model) throws MessagingException, IOException {
    EmailService emailService = new EmailService();
    File uploadedFile = convert(multipartFile);
    System.out.println("transferTo completed");
    emailService.sendmail(Arrays.asList(uploadedFile, dailyReportFile, shiftReportFile));
    model.addAttribute("msg", "Thanks for reporting.\nIt helps us improve the app.");
    return "messageView";
}

public File convert(MultipartFile file) throws IOException {
    File convFile = new File(file.getOriginalFilename());
    convFile.createNewFile();
    FileOutputStream fos = new FileOutputStream(convFile);
    fos.write(file.getBytes());
    fos.close();
    return convFile;
}

内容的提问来源于stack exchange，提问作者gdogra