Java用transferTo方式实现文件上传

import com.springbootemaildemo.entity.ResponseEntity;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import java.io.File;
import java.io.IOException;
import java.util.Date;
@RestController
@RequestMapping("/file")
@Api("文件操作")
public class FileController {
    private static final Logger logger = LoggerFactory.getLogger(FileController.class);
    @ApiOperation("文件上传")
    @PostMapping("/upload")
    public ResponseEntity uploadFile(@RequestParam("file") MultipartFile file) {
        long startTime = System.currentTimeMillis();
        String path = "";
        String originalFilename = file.getOriginalFilename();
        logger.info("fileName：" + originalFilename);
        int lastIndexOf = originalFilename.lastIndexOf(".");
        String fileType = originalFilename.substring(lastIndexOf + 1);
        //文件类型判断 doc,docx,jpg,png,xls
        logger.info("截取文件名类型:{}", fileType);
        if (fileType.equals("jpg") || fileType.equals("png") || fileType.equals("dox") || fileType.equals("docx") || fileType.equals("xls")) {
            path = "D:/filesss/" + new Date().getTime() + originalFilename;
            File newFile = new File(path);
            //通过CommonsMultipartFile的方法直接写文件(注意这个时候）
            try {
                file.transferTo(newFile);
                long endTime = System.currentTimeMillis();
                logger.info("采用file.Transto的运行时间：" + String.valueOf(endTime - startTime) + "ms");
            } catch (IOException e) {
                e.printStackTrace();
            }
        } else {
            return new ResponseEntity("500", "不允许该" + fileType + "文件类型上传", "fail");
        }
        return new ResponseEntity("200", path, "success");
    }
}