Spring MVC's MultipartFile to File read

The first method:

　　   MultipartFile file = xxx;
        CommonsMultipartFile cf= (CommonsMultipartFile)file;
        DiskFileItem fi = (DiskFileItem)cf.getFileItem();

        File f = fi.getStoreLocation();

　　will be in the temporary folder of the project's root directory Generate a file; the

second method:

　　  transferTo(File dest);

　　a new file will be generated in the project; the

third method:　 

　　File f = (File) xxx Just force the transfer. The premise is to configure multipartResolver, otherwise an exception of type conversion failure will be reported.

　　　　<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="maxUploadSize" value="104857600"/>
        <property name="maxInMemorySize" value="4096"/ >
    </bean>


　　Workbook wb = Workbook.getWorkbook(xxx .getInputStream());
　　Convert to input stream and read directly;
The fifth method:
　　byte[] buffer = myfile.getBytes();
　　Convert to byte array first, haven't tried it;