Spring boot 实现大文件分片，断点续传

   
        
            org.springframework.boot
            spring-boot-starter-thymeleaf
        
                
        
            cn.hutool
            hutool-all
            5.7.21
        

        
        
            com.alibaba
            fastjson
            1.2.80
        
        
        
            org.springframework.boot
            spring-boot-starter-web
        

	

	@PostMapping("/uploadBigFile")
	public ResponseData uploadBigFile(@RequestParam("file") MultipartFile file,@RequestParam("filename") String filename) {
		return fileService.uploadBigFile(file,filename);
	}


	

	@GetMapping("/mergeBigFile")
	public ResponseData mergeBigFile(@RequestParam("chunks")Integer chunks,String exname) {
		return fileService.mergeBigFile(chunks,exname);
	}

	@Override
	public ResponseData uploadBigFile(MultipartFile file, String filename) {

		try {
			String path = upload + "/" + filename;
			File fileUploadPath = new File(path);
			if (!fileUploadPath.exists()) {
				fileUploadPath.createNewFile();
				file.transferTo(fileUploadPath);
			}

			return ResponseData.success("上传成功", "");
		} catch (IOException e) {
			e.printStackTrace();
		}

		return ResponseData.failure("上传文件失败");
	}
	
	@Override
	public ResponseData mergeBigFile(Integer chunks,String exname) {

			RandomAccessFile raf = null;
			try {
				//申明随机读取文件RandomAccessFile
				File file = new File(upload+"/"+IdUtil.createId()+exname);
				if (!file.exists()) {
					file.createNewFile();
				}
				raf = new RandomAccessFile(file, "rw");
				//开始合并文件，对应切片的二进制文件
				for (int i = 0; i < chunks; i++) {
					File file1 = new File(upload + "/chunk_" + i + exname);
					//读取切片文件
					RandomAccessFile reader = new RandomAccessFile(file1, "r");
					byte[] b = new byte[1024];
					int n = 0;
					//先读后写
					while ((n = reader.read(b)) != -1) {
						raf.write(b, 0, n);
					}
					reader.close();
					if (file1.exists()) {
						file1.delete();
					}
				}

			} catch (Exception e) {
				e.printStackTrace();
			} finally {
				try {
					raf.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}

		return ResponseData.success("文件上传成功");
	}

@Component
public class IdUtil {
   private static Snowflake snowflake=null;
    public static String createId () {
        if(StrUtil.isBlankIfStr (snowflake)){
            snowflake = cn.hutool.core.util.IdUtil.getSnowflake (1, 1);
        }
        return snowflake.nextId ()+"";
    }



}