java - 当返回 ResponseEntity 的方法抛出错误时如何返回 ModelandView？

Question

我有以下方法

@GetMapping("/{fileName}")
public Object downloadFile(@PathVariable String fileName) {
    // Load file from database
    errors.clear();

    DBFile dbFile;

    try {
        dbFile = dBFileStorageService.getFileByName(fileName);

    } catch (MyFileNotFoundException ex) {
        logger.info("File has not been found.");
        errors.add(ex.getMessage());

        return new ModelAndView("redirect:/");
    }
    logger.info("Delivering file");
    return ResponseEntity.ok()
            .contentType(MediaType.parseMediaType(dbFile.getFileType()))
            .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + dbFile.getFileName() + "\"")
            .body(new ByteArrayResource(dbFile.getData()));

}

我不想返回 Object，而是想返回 ResponseEntity<Resource>是否可以返回文件或 ModelAndView("redirect:/")否则。

我尝试过:

HttpHeaders headers = new HttpHeaders();
headers.add("Location", "/member/uploadImage");    
return new ResponseEntity<>(headers,HttpStatus.FOUND);

但是我没有得到重定向，而是收到消息，表明我尝试下载的文件已损坏。总结一下，我想将方法​​签名更改为:

public ResponseEntiry<Resource> downloadFile(@PathVariable String fileName)  

Answer 1

关于通过 ResponseEntity 返回文件的第一个问题已在此处得到解答: Return file from Spring @Controller having OutputStream

同意 @chrylis，因为他建议您在发生异常时采取的最佳方法是抛出异常并使用 @ExceptionHandler< 在 sprint @ControllerAdvice 类中处理它 方法注释。

@ControllerAdvice
class GlobalControllerExceptionHandler {
    @ResponseStatus(HttpStatus.CONFLICT)  // 409 or according to your need any code
    @ExceptionHandler(Exception.class)
    protected ModelAndView unhandledExceptionHandler(Exception ex){
        System.out.println("handling exception here!!!");
        ModelAndView mv = new ModelAndView();
        mv.setViewName("errorView");
        mv.addObject("ERROR", "ERROR OCCURRED REDIRECTED "+ex.getMessage());
        return mv;
    }
}

官方Doc .