Question

我正在回复一个网址。我想下载该URL的html，以便用户也可以离线查看。它是一个recyclerView，其中每个项目都包含一个URL。因此，当用户点击一个项目的URL时，它应该将其保存在外部磁盘中。

以下是代码：

NewsAdapter：

case R.id.save:
                        Gson gson = new GsonBuilder()
                                .setLenient()
                                .create();
                        Retrofit retrofit = new Retrofit.Builder()
                                .baseUrl("https://www.nytimes.com/")
                                .addConverterFactory(GsonConverterFactory.create(gson))
                                .build();
                        Log.i("Retrofit build", "initiated");
                        ApiInterface retrofitInterface = retrofit.create(ApiInterface.class);

                                final Call< ResponseBody > call = retrofitInterface.downloadFileWithDynamicUrlSync("2017/09/13/us/nursing-home-deaths-florida.html");

                        Log.i("Retrofit req execute", "initiated");

                            new AsyncTask<Void, Void, Void>() {
                                @Override
                                protected Void doInBackground(Void... voids) {
                                    boolean writtenToDisk = false;
                                    try {
                                        writtenToDisk = writeResponseBodyToDisk(call.execute().body());
                                    } catch (IOException e) {
                                        e.printStackTrace();
                                    }
                                    ;

                                    Log.d("success", "file download was a success? " + writtenToDisk);
                                    return null;
                                }
                            }.execute();


                        break;

 private boolean writeResponseBodyToDisk(ResponseBody body) {
        try {
            // todo change the file location/name according to your needs
            File futureStudioIconFile = new File(Environment.DIRECTORY_DOWNLOADS + File.separator + "Future Studio Icon.png");

            InputStream inputStream = null;
            OutputStream outputStream = null;

            try {
                byte[] fileReader = new byte[4096];

                long fileSize = body.contentLength();
                long fileSizeDownloaded = 0;

                inputStream = body.byteStream();
                outputStream = new FileOutputStream(futureStudioIconFile);

                while (true) {
                    int read = inputStream.read(fileReader);

                    if (read == -1) {
                        break;
                    }

                    outputStream.write(fileReader, 0, read);

                    fileSizeDownloaded += read;

                    Log.d("filedownload", "file download: " + fileSizeDownloaded + " of " + fileSize);
                }

                outputStream.flush();

                return true;
            } catch (IOException e) {
                return false;
            } finally {
                if (inputStream != null) {
                    inputStream.close();
                }

                if (outputStream != null) {
                    outputStream.close();
                }
            }
        } catch (IOException e) {
            return false;
        }
    }

ApiInterface：

// option 2: using a dynamic URL
@Streaming
    @GET
    Call<ResponseBody> downloadFileWithDynamicUrlSync(@Url String fileUrl);

我也收到错误：

Failed to invoke public com.squareup.okhttp.ResponseBody() with no args

有人能告诉我如何正确实施它。

Answer 1

使用带域名的URL下载文件。移动流注释不需要。

您没有收到文件正文，因为您没有使用完整的网址。

创建一个像这样的界面

@GET
Call<ResponseBody> downloadFile(@Url String url);

然后使用此代码：

public void onResponse(Call<ResponseBody> call, Response<ResponseBody> 
response) 
                        {
                            if (response.isSuccessful()) {
                                String filePath = Utils.downloadFile(response.body(),"filename");

                            }
                        }



public String downloadFile(ResponseBody body, String fileName) {
    String filePath = null;
    try {
        int count;
        byte data[] = new byte[1024 * 4];
        InputStream bis = new BufferedInputStream(body.byteStream(), 1024 * 8);
        File storageDir = new File(Environment.getExternalStorageDirectory(), "AppName");
        if (!storageDir.exists()) {
            storageDir.mkdirs();
        }
        File outputFile = new File(storageDir, fileName);
        OutputStream output = new FileOutputStream(outputFile);
        while ((count = bis.read(data)) != -1) {
            output.write(data, 0, count);
        }
        output.flush();
        output.close();
        bis.close();
        filePath = outputFile.getAbsolutePath();
    } catch (Exception e) {
        e.printStackTrace();
    }
    return filePath;
}

使用Retrofit从URL下载HTML文件

1 个答案: