Android 上传图片到服务器(多文件上传)

Android客户端的UI与《Android 上传图片到服务器(单文件上传)》唯一区别增加了多文件上传的功能。

1.Android客户端多文件上传核心代码：

     * 多文件上传
     * @param view
     */
    public void multiUpload(View view){

        List<File> fileList = new ArrayList<>();
        for (ItemBean itemBean : list) {
            if (itemBean.isButton()) continue;
            fileList.add(itemBean.getImageFileBean().getFile());
            itemBean.getImageFileBean().setStartUpload(true);
            adapter.notifyDataSetChanged();
        }
        // 用上传的文件生成RequestBody
        if(fileList == null || fileList.size() == 0)return;

        //创建MultipartBody.Builder，用于添加请求的数据
        MultipartBody.Builder builder = new MultipartBody.Builder();
        for (int i = 0; i < fileList.size(); i++) { //对文件进行遍历
            //根据文件的后缀名，获得文件类型
            builder.setType(MultipartBody.FORM)
                    .addFormDataPart("name",fileList.get(i).getName())// 其他信息
                    .addFormDataPart("id","12,13,14")// 其他信息
                    .addFormDataPart("type","2"+i)// 其他信
                    .addFormDataPart( //给Builder添加上传的文件
                            "images",  //请求的名字
                            fileList.get(i).getName(), //文件的文字，服务器端用来解析的
                            RequestBody.Companion.create(fileList.get(i),MediaType.parse("multipart/form-data"))//创建RequestBody，把上传的文件放入
                    );
        }
        RequestBody requestBody = builder.build();//根据Builder创建请求
        Request request = new Request.Builder()
                .url(Global.MULTI_FILE_UPLOAD_URL)
                .post(requestBody)
                .addHeader("user-agent", "PDA")
                .addHeader("x-userid", "752332")// 添加x-userid请求头
                .addHeader("x-sessionkey", "kjhsfjkaskfashfuiwf")// 添加x-sessionkey请求头
                .addHeader("x-tonce", Long.valueOf(System.currentTimeMillis()).toString())// 添加x-tonce请求头
                .addHeader("x-timestamp", Long.valueOf(System.currentTimeMillis()).toString())// 添加x-timestamp请求头
                .build();

        final Message msg = myHandler.obtainMessage();
        OkHttpClient okHttpClient = new OkHttpClient();
        okHttpClient.newCall(request)
                .enqueue(new Callback() {
            @Override
            public void onFailure(@NotNull Call call, @NotNull IOException e) {
                msg.obj = list;
                msg.what =0;
                myHandler.sendMessage(msg);
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                String result = response.body().string();
                Log.i("上传图片结果：", result);
                msg.obj = list;
                if (!response.isSuccessful()) {
                    Log.i("响应失败：", response.code() + "");
                    msg.what =1;
                    return;
                }
                msg.what = 3;
                myHandler.sendMessage(msg);

            }
        });
    }

2.服务器端接收多文件核心代码：

   /**
     * 多文件上传
     *
     * @param files
     * @param model
     * @param request
     * @return
     */
    @PostMapping("/api/multi_upload")
    public String multiFileUpload(@RequestParam(value = "images") MultipartFile[] files, Model model, HttpServletRequest request, @RequestParam(value = "type") int[] type, @RequestHeader(value = "user-agent") String userAgent) {
        if (files != null && files.length > 0) {
            System.out.println("文件为空空");
        }

        for (int i : type) {
            logger.info("获得的其他参数type=" + i);
        }

        logger.info("获得的Header user-agent=" + userAgent);


        // 如果参数比较少可以直接在方法上使用注解@RequestParam来映射到不同的名称上获得，当然如果不用此注解，也可以定义一个与传过来的参数名一样的形参来获得
        // 蒜从客户端传过来的其他参数
        Enumeration names = request.getParameterNames();
        while (names.hasMoreElements()) {
            String key = names.nextElement().toString();
            String[] values = request.getParameterValues(key);
            for(String str: values){
                String info = "客户端传过来的参数:key＝" + key + ",value=" + str;
                logger.info(info);
            }

        }

        Enumeration headers = request.getHeaderNames();
        while (headers.hasMoreElements()) {
            String key = headers.nextElement().toString();
            String info = "客户端传过来的Header参数:key＝" + key + ",value=" + request.getHeader(key);
            logger.info(info);
        }


        for (MultipartFile file : files) {
            saveFile(file);
        }
        return "上传成功";
    }

    private String saveFile(MultipartFile file) {
        // BMP、JPG、JPEG、PNG、GIF
        String fileName = file.getOriginalFilename();  // 文件名
        logger.info("上传文件名：" + fileName);
        String suffixName = fileName.substring(fileName.lastIndexOf("."));  // 后缀名
        // 验证上传的文件是否图片
        if (!".bmp".equalsIgnoreCase(suffixName) && !".jpg".equalsIgnoreCase(suffixName)
                && !".jpeg".equalsIgnoreCase(suffixName)
                && !".png".equalsIgnoreCase(suffixName)
                && !".gif".equalsIgnoreCase(suffixName)) {
            return "上传失败，请选择BMP、JPG、JPEG、PNG、GIF文件！";
        }

        fileName = UUID.randomUUID() + suffixName; // 新文件名
        File dest = new File(fileName);
        // 如果文件的父路径不存在，则创建
        if (fileName.startsWith("/") && !dest.getParentFile().exists()) {
            dest.getParentFile().mkdirs();
        }
        // 开始存放文件到指定目录去
        try {
            file.transferTo(dest);
            return "上传成功";
        } catch (IOException e) {
            e.printStackTrace();
            return "上传失败";

        }
    }

Demo如下：

Android客户端
文件上传服务器

Android客户端上传多文件时的HTTP报文如下：

Hypertext Transfer Protocol
    POST /api/multi_upload HTTP/1.1\r\n
        [Expert Info (Chat/Sequence): POST /api/multi_upload HTTP/1.1\r\n]
            [POST /api/multi_upload HTTP/1.1\r\n]
            [Severity level: Chat]
            [Group: Sequence]
        Request Method: POST
        Request URI: /api/multi_upload
        Request Version: HTTP/1.1
    user-agent: PDA\r\n
    x-userid: 752332\r\n
    x-sessionkey: kjhsfjkaskfashfuiwf\r\n
    x-tonce: 1592183885988\r\n
    x-timestamp: 1592183885988\r\n
    Content-Type: multipart/form-data; boundary=0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Content-Length: 59249\r\n
        [Content length: 59249]
    Host: 192.168.43.120:8080\r\n
    Connection: Keep-Alive\r\n
    Accept-Encoding: gzip\r\n
    \r\n
    [Full request URI: http://192.168.43.120:8080/api/multi_upload]
    [HTTP request 1/1]
    [Response in frame: 270]
    File Data: 59249 bytes
MIME Multipart Media Encapsulation, Type: multipart/form-data, Boundary: "0d03917a-192a-4b48-91b3-cae54dcbd929"
    [Type: multipart/form-data]
    First boundary: --0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part: 
        Content-Disposition: form-data; name="name"\r\n
        Content-Length: 36\r\n\r\n
        Data (36 bytes)
            Data: 313330633133303932316632343839663930663261656436…
            [Length: 36]
    Boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part: 
        Content-Disposition: form-data; name="id"\r\n
        Content-Length: 8\r\n\r\n
        Data (8 bytes)
            Data: 31322c31332c3134
            [Length: 8]
    Boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part: 
        Content-Disposition: form-data; name="type"\r\n
        Content-Length: 2\r\n\r\n
        Data (2 bytes)
            Data: 3230
            [Length: 2]
    Boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part:  (multipart/form-data)
        Content-Disposition: form-data; name="images"; filename="130c130921f2489f90f2aed6551f2c5f.jpg"\r\n
        Content-Type: multipart/form-data\r\n
        Content-Length: 47952\r\n\r\n
        The multipart dissector could not find a required parameter.
            [Expert Info (Error/Protocol): The multipart dissector could not find a required parameter.]
                [The multipart dissector could not find a required parameter.]
                [Severity level: Error]
                [Group: Protocol]
        Data (47952 bytes)
            Data: ffd8ffe12ee245786966000049492a00080000000b001001…
            [Length: 47952]
    Boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part: 
        Content-Disposition: form-data; name="name"\r\n
        Content-Length: 36\r\n\r\n
        Data (36 bytes)
            Data: 306432643236353564363332346234656238626235333763…
            [Length: 36]
    Boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part: 
        Content-Disposition: form-data; name="id"\r\n
        Content-Length: 8\r\n\r\n
        Data (8 bytes)
            Data: 31322c31332c3134
            [Length: 8]
    Boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part: 
        Content-Disposition: form-data; name="type"\r\n
        Content-Length: 2\r\n\r\n
        Data (2 bytes)
            Data: 3231
            [Length: 2]
    Boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part:  (multipart/form-data)
        Content-Disposition: form-data; name="images"; filename="0d2d2655d6324b4eb8bb537cac083cd0.jpg"\r\n
        Content-Type: multipart/form-data\r\n
        Content-Length: 6149\r\n\r\n
        The multipart dissector could not find a required parameter.
            [Expert Info (Error/Protocol): The multipart dissector could not find a required parameter.]
                [The multipart dissector could not find a required parameter.]
                [Severity level: Error]
                [Group: Protocol]
        Data (6149 bytes)
            Data: ffd8ffe10ad745786966000049492a00080000000b001001…
            [Length: 6149]
    Boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part: 
        Content-Disposition: form-data; name="name"\r\n
        Content-Length: 36\r\n\r\n
        Data (36 bytes)
            Data: 316431313536643461386238343033343839393963366464…
            [Length: 36]
    Boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part: 
        Content-Disposition: form-data; name="id"\r\n
        Content-Length: 8\r\n\r\n
        Data (8 bytes)
            Data: 31322c31332c3134
            [Length: 8]
    Boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part: 
        Content-Disposition: form-data; name="type"\r\n
        Content-Length: 2\r\n\r\n
        Data (2 bytes)
            Data: 3232
            [Length: 2]
    Boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929\r\n
    Encapsulated multipart part:  (multipart/form-data)
        Content-Disposition: form-data; name="images"; filename="1d1156d4a8b840348999c6ddd050df76.jpg"\r\n
        Content-Type: multipart/form-data\r\n
        Content-Length: 3407\r\n\r\n
        The multipart dissector could not find a required parameter.
            [Expert Info (Error/Protocol): The multipart dissector could not find a required parameter.]
                [The multipart dissector could not find a required parameter.]
                [Severity level: Error]
                [Group: Protocol]
        Data (3407 bytes)
            Data: ffd8ffe000104a46494600010100000100010000ffdb0043…
            [Length: 3407]
    Last boundary: \r\n--0d03917a-192a-4b48-91b3-cae54dcbd929--\r\n