Springboot提供檔案的上傳、下載下傳、預覽接口

檔案上傳

@PostMapping("/upload/tocheckfile")
public JSONObject upload(@RequestPart("uploadFile") MultipartFile file){

    JSONObject response = new JSONObject();
    try {
        FilesUtils.uploadFile(file, toCheckFileDir);
        response.put("code", 2000);
    } catch (Exception e) {
        e.printStackTrace();
        log.error("上傳檔案出現異常！");
        response.put("code", 5000);
        response.put("error", "上傳檔案失敗, e"+e.toString());
    }
    return response;
}

public static void uploadFile(MultipartFile file, String filePath) {

    File toFile = new File(filePath + file.getOriginalFilename());

    FileOutputStream fileOutputStream = null;
    try {
        fileOutputStream = new FileOutputStream(toFile);
        IOUtils.copy(file.getInputStream(), fileOutputStream);
        log.info("file:{} upload succ !", file.getOriginalFilename());
    }catch (Exception e){
        e.printStackTrace();
        log.error("file:{} upload failed!", file.getOriginalFilename());
    }finally {
        try {
            fileOutputStream.close();
        }catch (Exception e){
            log.error("關閉fileOutputStream 發生異常，\n e:{}", e);
        }
    }
}
           

檔案下載下傳或者預覽

檔案下載下傳和預覽可以使用相同接口，前端代碼做調整即可

@PostMapping("/download")
public ResponseEntity<byte[]> download(@RequestBody JSONObject params){
    try{
        
        String filePath = params.getString("filePath");
        return FilesUtils.download(filePath);
    }catch (Exception e){
        e.printStackTrace();
    }
    return null;
}
public static ResponseEntity<byte[]> download(String filepath) throws Exception{
    File file = new File(filepath);
    HttpHeaders httpHeaders = new HttpHeaders();
    httpHeaders.setContentDispositionFormData("attachment",
            new String(file.getName().getBytes(StandardCharsets.UTF_8), "utf-8"));// 部分浏覽器需要将"utf-8"改"為ISO8859-1"，否則會出現檔案名中文亂碼
    httpHeaders.add("Access-Control-Expose-Headers", "Content-Disposition");
    httpHeaders.setContentType(MediaType.APPLICATION_OCTET_STREAM);

    // 擷取檔案的字元數組
    byte[] content = FileUtils.readFileToByteArray(file);
    return new ResponseEntity<>(content, httpHeaders, HttpStatus.OK);
}