Question

我创建了一个应用程序，该应用程序从url下载文件并打开它，但是当我尝试从驱动器中下载文件时，它下载了，但是格式不同，为什么该文件无法打开，我想在其中下载驱动器文件我也尝试过PDF格式 http://docs.google.com/uc?export=download&id=FILE_ID ，但我该怎么做呢？

驱动器链接： https://drive.google.com/file/d/1cBkp1kNVnsUp13_qIuX0G-IcCVHPEqj-/view?usp=sharing

Answer 1

为下载文件创建异步任务，然后单击按钮

执行

BtnClick事件：

url="https://drive.google.com/file/d/1cBkp1kNVnsUp13_qIuX0G-IcCVHPEqj-/view?usp=sharing";
extension="pdf";
download.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new DownloadFile(){
                    @Override
                    protected void onPostExecute(Long aLong) {
                        System.out.println("--------------Success : " + aLong);
                    }
                }.execute(url,extension);
                //file.execute(url,extension);
            }
        });

Asyn类：

class DownloadFile extends AsyncTask<String,Integer,Long> {
    ProgressDialog mProgressDialog = new ProgressDialog(DisplayFullScreenImage.this);// Change Mainactivity.this with your activity name.

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        mProgressDialog.setMessage("Downloading");
        mProgressDialog.setIndeterminate(false);
        mProgressDialog.setMax(100);
        mProgressDialog.setCancelable(true);
        mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        mProgressDialog.show();
    }
    @Override
    protected Long doInBackground(String... aurl) {
        int count;
        try {
            URL url = new URL((String) aurl[0]);
            URLConnection conexion = url.openConnection();
            conexion.connect();
            String targetFileName=filename+"."+aurl[1];//Change name and subname
            int lenghtOfFile = conexion.getContentLength();
            String PATH = Environment.getExternalStorageDirectory()+ "/"+"TalentsList"+"/";
            File folder = new File(PATH);
            if(!folder.exists()){
                folder.mkdir();//If there is no folder it will be created.
            }
            InputStream input = new BufferedInputStream(url.openStream());
            OutputStream output = new FileOutputStream(PATH+targetFileName);
            byte data[] = new byte[1024];
            long total = 0;
            while ((count = input.read(data)) != -1) {
                total += count;
                publishProgress ((int)(total*100/lenghtOfFile));
                output.write(data, 0, count);
            }
            output.flush();
            output.close();
            input.close();
        } catch (Exception e) {}
        return Long.valueOf(123155);
    }
    protected void onProgressUpdate(Integer... progress) {
        mProgressDialog.setProgress(progress[0]);
        if(mProgressDialog.getProgress()==mProgressDialog.getMax()){
            mProgressDialog.dismiss();
            Toast.makeText(DisplayFullScreenImage.this, "File Downloaded", Toast.LENGTH_SHORT).show();
        }
    }
    protected void onPostExecute(Long result) {
        super.onPostExecute(result);
    }
}

Answer 2

您将无法直接使用Google api进行操作，下面是代码。

**Dependencies:** 
compile 'com.google.android.gms:play-services-identity:8.3.0'
    compile('com.google.api-client:google-api-client-android:1.20.0') {
        exclude group: 'org.apache.httpcomponents'
    }

在异步任务中执行以下操作

   try{
           URL url = new URL(URL);
           HttpURLConnection conn = (HttpURLConnection) url.openConnection();
           conn.setRequestMethod("GET");
           conn.setRequestProperty("Authorization", "OAuth " + GoogleAuthUtil.getToken(mContext, mCredential.getSelectedAccountName(), Constants.SCOPE));
           conn.setDoInput(true);
           // Starts the query
           conn.connect();
           int responseCode = conn.getResponseCode();
            //you will recive the file in input stream
            File sdcard = Environment.getExternalStorageDirectory();
                File file = new File(sdcard, "filename.pdf");

                FileOutputStream fileOutput = new FileOutputStream(file);
                InputStream inputStream = conn.getInputStream();

                byte[] buffer = new byte[1024];
                int bufferLength = 0;

                while ( (bufferLength = inputStream.read(buffer)) > 0 ) {
                    fileOutput.write(buffer, 0, bufferLength);
                }
                fileOutput.close();
          }

我如何从Android驱动器中下载pdf文件

2 个答案: