Retrofit下载文件

第一步，请求接口

//下载图片
@Streaming
@GET
Call<ResponseBody> downloadPicWithUrl(@Url String url);

第二步，请求网络

/**
 * 保存图片
 *
 * @param baseUrl
 * @param urlpic
 */
private void downFileWithPic(String baseUrl, final String urlpic, final int type) {

    OkHttpClient builder = new OkHttpClient.Builder().build();
    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(baseUrl)
            .client(builder)
            .build();

    final HttpPostService fileDownloadApi = retrofit.create(HttpPostService.class);
    Observable.create(new Observable.OnSubscribe<String>() {
        @Override
        public void call(Subscriber<? super String> subscriber) {

            try {
                Response<ResponseBody> response = fileDownloadApi.downloadPicWithUrl(urlpic).execute();
                if (response != null && response.isSuccessful()) {
                    //文件总长度
                    long fileSize = response.body().contentLength();
                    long fileSizeDownloaded = 0;
                    InputStream is = response.body().byteStream();

                    if (AppUtil.isExitsSdcard()) {
                        // 首先保存图片
                        File file = Environment.getExternalStorageDirectory().getAbsoluteFile();//注意小米手机必须这样获得public绝对路径
                        String fileName = "picture";
                        File appDir = new File(file, fileName);
                        if (!appDir.exists()) {
                            appDir.mkdirs();
                        }
                        String filePicName = null;
                        int indexOf = urlpic.lastIndexOf(".");
                        String picName = urlpic.substring(0, indexOf);
                       // LogUtil.e("picname"+picName);
                        if (type == 1) {
                            filePicName = picName + ".jpg";
                        } else {
                            filePicName = picName + ".gif";
                        }

                        File filePic = new File(appDir, filePicName);

                        FileOutputStream fos = null;
                        try {
                            fos = new FileOutputStream(filePic);
                            int count = 0;
                            byte[] buffer = new byte[1024];
                            while ((count = is.read(buffer)) != -1) {
                                fos.write(buffer, 0, count);
                                fileSizeDownloaded += count;
                                // subscriber.onNext("file download: " + fileSizeDownloaded + " of " + fileSize);
                            }

                            fos.flush();
                            fos.close();
                            subscriber.onCompleted();
                        } catch (Exception e) {
                            e.printStackTrace();
                        }

                        // 最后通知图库更新
                        context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(new File(filePic.getAbsolutePath()))));
                        ToastUtil.showSafeToast("保存成功");
                    }
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    })
            .subscribeOn(Schedulers.io())
            .subscribeOn(AndroidSchedulers.mainThread())
            .subscribe(new Subscriber<String>() {
                @Override
                public void onCompleted() {
                    Log.e("MainActivity", "文件下载完成");

                }

                @Override
                public void onError(Throwable e) {

                }

                @Override
                public void onNext(String s) {
                    //Log.e("onNext", s);
                }
            });

}