1.pdf转换base64

    public static String encodeBase64File(String path) {
        File file = new File(path);
        byte[] buffer = new byte[(int) file.length()];
        try {
            FileInputStream inputFile = new FileInputStream(file);
            inputFile.read(buffer);
            inputFile.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return Base64.encodeToString(buffer, Base64.DEFAULT);
    }

2.上传

    public void fileupload(Callback callback,String path,String serverUrl,String pdfPath) {
       // File file = new File(path);
        //String pdfbase64=NewBase64(file);


            String pdfbase64=encodeBase64File(path);

        OkHttpClient client = new OkHttpClient();
        // 上传文件使用MultipartBody.Builder
        RequestBody requestBody = new MultipartBody.Builder()
                .setType(MultipartBody.FORM)
                .addFormDataPart("pdfpath", pdfPath) // 提交普通字段
                .addFormDataPart("filebase64", pdfbase64) // 提交图片，第一个参数是键（name="第一个参数"），第二个参数是文件名，第三个是一个RequestBody
                .build();
        // POST请求
        Request request = new Request.Builder()
                .url(serverUrl)
                .post(requestBody)
                .build();
        client.newCall(request).enqueue(callback);
    }

3.服务端接收转换

    @RequestMapping("/save_pdf")
    public void saveAztFile(HttpServletRequest request, ModelMap model, HttpServletResponse response, String filebase64,
                            String pdfpath) throws Exception {
        SaveMsgEntity entity = new SaveMsgEntity();
        entity.setCode("0");// 0失败 1成功
        if (filebase64 != null && pdfpath != null && !filebase64.equals("") && !pdfpath.equals("")) {
            try {
                String localPath = "";
                String filePath = "";
                String basePath = Constants.UPLOAD_PATH + Constants.SOUND_PATH;
                filePath = pdfpath.split("//")[2];
                if (!filePath.equals("")) {
                    filePath = filePath.replace("/", "\\");
                    localPath = basePath + filePath;
                }
                /**
                 * 解码
                 */
                byte[] pdfbyte= new BASE64Decoder().decodeBuffer(filebase64);
                /**
                 * 保存到pdf
                 */
                File file = new File(localPath);
                FileUtils.writeByteArrayToFile(file, pdfbyte);
                entity.setCode("1");// 0失败 1成功
                entity.setMsg("保存成功！");
            } catch (Exception e) {
                entity.setMsg("保存pdf失败，请稍后重试！");
            }
        } else {
            entity.setMsg("数据流和路径不能为空，请稍后重试！");
        }
        ResponseUtil.responseText(response, JSON.toJSONString(entity));
    }