Spring FileSystemResource NoSuchFileException

Question

I am using FileSystemResource and Spring Webflux to serve files from the hard drive.

@GetMapping("/news/file")
fun getImage(@RequestParam name: String): FileSystemResource {
    return FileSystemResource(propsStorage.path + "/" + name)
}

When the user requests an unknown file, it should be catched and an 404 error should be returned.

However I get this error:

java.nio.file.NoSuchFileException: C:\Users\SomeUser\Work\posts\32.jpg
    at java.base/sun.nio.fs.WindowsException.translateToIOException(WindowsException.java:85)
    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 

Unfortunately I don't know how to catch the error. You can answer in Java if you want, I can understand both languages.

Answer 1

Also you can make use of the spring FilesystemResource api exists method to avoid the FileNotFoundException

 fs =FileSystemResource(propsStorage.path + "/" + name)
if(fs.exists())
 return fs
else
return new ResponseEntity<>("File Not Found", HttpStatus.NOT_FOUND);

Also I saw that you used '/' as a separator, please note that on windows machines the file separator is ''. So for complying correctly use Paths.separator

Answer 2

You can have an @ExceptionHandler method for java.nio.file.NoSuchFileException and return 404 response.

Below is in Java you can translate in kotlin.

@ExceptionHandler(NoSuchFileException.class)
public ResponseEntity<String> handleUnexpectedRollbackException(NoSuchFileException exception) {
    LOGGER.error("File not found",exception);
    return new ResponseEntity<>("File Not Found", HttpStatus.NOT_FOUND);
}