Download and Install App programmatically

Science Fantasy

You can download an apk file of any application and install it thru your app and all this you can do programmatically. Let's see how to do it:

1. First download the apk file programmatically and store it in external storage.

private void download(){
try {
    URL url = new URL("url from apk file is to be downloaded");
    HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
    urlConnection.setRequestMethod("GET");
    urlConnection.setDoOutput(true);
    urlConnection.connect();

    File sdcard = Environment.getExternalStorageDirectory();
    File file = new File(sdcard, "filename.ext");

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

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

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

} catch (MalformedURLException e) {
        e.printStackTrace();
} catch (IOException e) {
        e.printStackTrace();
}
}

Permission: To write to external storage, you need to add this permission:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Note: The above download method can be used to download any file and store the file to external storage.

2. Now initiate installing process.

private void initiateInstallation(){
    Intent intent = new Intent(Intent.ACTION_VIEW);
    Uri uri = Uri.fromFile(new File("/sdcard/filename.apk"));
    intent.setDataAndType(uri, "application/vnd.android.package-archive");
    startActivity(intent);
}