使用 OkHttp 版本如下：

compile 'com.squareup.okhttp3:okhttp:3.4.1'

public void upLoadFile(final String url, final Map<String, Object> map, File file) {
        OkHttpClient client = new OkHttpClient();
        // form 表單形式上傳
        MultipartBody.Builder requestBody = new MultipartBody.Builder
 
().setType(MultipartBody.FORM);
        if (file != null) {
            // MediaType.parse() 裡面是上傳的檔案型別。
            RequestBody body = RequestBody.create(MediaType.parse("image/*"), file);
            String filename = file.getName();
            // 引數分別為， 請求key ，檔名稱 ， RequestBody
            requestBody.addFormDataPart
 
("file", file.getName(), body);
        }
        if (map != null) {
            // map 裡面是請求中所需要的 key 和 value
            for (Map.Entry entry : map.entrySet()) {
                requestBody.addFormDataPart(valueOf(entry.getKey()), valueOf(entry.getValue()));
            }
        }
        Request request = new Request.Builder
 
().url(url).post(requestBody.build()).build();
        // readTimeout("請求超時時間" , 時間單位);
        client.newBuilder().readTimeout(5000, TimeUnit.MILLISECONDS).build().newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                Log.i("lfq", "onFailure");
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                if (response.isSuccessful()) {
                    String str = response.body().string();
                    Log.e(TAG, str);

                } else {
                    Log.i("lfq", response.message() + " error : body " + response.body().string());
                }
            }
        });

    }

MultipartBody.Builder 的 addFormDataPart 方法，是對於之前的 addPart 方法做了一個封裝，所以，不需要再去配置 Header 之類的。

或者,多檔案上傳

/**
     * post方式二：stirng型別引數和上傳檔案引數
     */
    public static Call uploadMoreFile(Map<String, Object> params) {
        //post請求方式二：multipart/form-data(不僅能夠上傳string型別的引數，還可以上傳檔案（流的形式，file）)
        OkHttpClient okHttpClient1 = new OkHttpClient();
        MultipartBody.Builder builder1 = new MultipartBody.Builder();
        builder1.setType(MultipartBody.FORM);
        for (Map.Entry<String, Object> stringObjectEntry : params.entrySet()) {
            String key = stringObjectEntry.getKey();
            Object value = stringObjectEntry.getValue();
            if (value instanceof File) {//如果請求的值是檔案
                File file = (File) value;
                //MediaType.parse("application/octet-stream")以二進位制的形式上傳檔案
                builder1.addFormDataPart("引數名(檔案引數)", ((File) value).getName(), RequestBody.create(MediaType.parse("multipart/form-data"), file));
            } else {//如果請求的值是string型別
                builder1.addFormDataPart(key, value.toString());
            }
        }
        Request request1 = new Request.Builder().post(builder1.build()).url(Constant.UPLOAD).build();
        Call call = okHttpClient1.newCall(request1);
        return call;
    }

使用方法

   //TODO 上傳
                new Thread() {
                    @Override
                    public void run() {
                        super.run();

                        Map<String, Object> map = new HashMap<>();
                        map.put("params", "value");

                        File[] files = new File[images.size()];
                        for (int i = 0; i < images.size(); i++) {
                            files[i] = new File(images.get(i));
                            map.put("file" + i, files[i]);
                        }
                        Util.upload(map).enqueue(new Callback() {
                            @Override
                            public void onFailure(Call call, IOException e) {
                            }

                            @Override
                            public void onResponse(Call call, Response response) throws IOException {
                                Gson gson = new Gson();
                                CrosseTalk duanzi = gson.fromJson(response.body().string(), CrosseTalk.class);
                                if (duanzi.getCode().equals("0")) {
                                    Log.d("TAG", "onResponse: " + "成功");
                                } else {
                                    Log.d("TAG", "onResponse: " + duanzi.getMsg());
                                }

                            }
                        });
                    }
                }.start();

單純的 Post 攜帶引數，那麼直接使用 FormBody

FormBody.Builder formBody = new FormBody.Builder();
if (map != null) {
    for (Map.Entry entry : map.entrySet()) {
        formBody.add(String.valueOf(entry.getKey()),String.valueOf(entry.getValue()));
    }
}