通过控制器调用静态方法时获得空指针异常，同时通过classname.method name

Question

公共静态无效createObject1（String bucketName，String file，String filePath）{_cosClient.putObject（bucketName，bucket文件，new File（filePath））; System.out.println（“文件为” + _cosClient.listObjects（“知识共享”）））;  }

@RequestMapping（值=“ / uploadFile”，方法= RequestMethod.POST）公共@ResponseBody字符串uploadFileHandler（@RequestParam（“ name”）字符串名称，@RequestParam（“ file”）MultipartFile文件）{

if (!file.isEmpty()) {
    try {
        byte[] bytes = file.getBytes();
        File convFile = new File( file.getOriginalFilename());
       String fileName=  file.transferTo(convFile);

                File filePath= convFile.getAbsoluteFile();
                System.out.println("file are-"+filePath);
                String bucketName = "knowledge-sharing";
                objectStorage.createObject1("bucketName", "file", "filePath");
                System.out.println(filePath);

        return "You successfully uploaded file=" + name;
    } catch (Exception e) {
        System.err.println(e.getMessage());
        return "You failed to upload " + name + " => " + e.getMessage();
    }
} else {
    return "You failed to upload " + name
            + " because the file was empty.";
}

}