Question

In an application that uses Google Maps, what is the main usage of the class Geocoder?

What is the main benefit of using AsyncTask to execute IO operations?

The following piece of code is an excerpt from a class extends AsyncTask. When and on what thread does onPostExecute execute?

 private class GetExam extends AsyncTask<String, Integer, String> {
        @Override
        protected void onPostExecute(String value) {
        }

Briefly explain the role and data type of param.

  WebView myWebView =  findViewById(R.id.webview);
   myWebView.setWebViewClient(new WebViewClient());
   myWebView.loadUrl(param);

Answer 1

1. What is the main usage of the class Geocoder:

Allows for the conversion between an address and geographical coordinates.

2. What is the main benefit of using AsyncTask to execute IO operations:

Asynctask allows us to perform long lasting tasks/background operations on IO and show the result on the UI thread without affecting the main thread. Not blocking main UI thread is the main benefit

3. On what thread does onPostExecute execute

PostExecute executes on UI Thread

1. onPreExecute() : invoked on the UI thread before the task is executed.
2. doInBackground(Params...) : invoked on the background thread immediately after onPreExecute() finishes executing.
3. onProgressUpdate(Progress...): invoked on the UI thread after a call to publishProgress(Progress...).The timing of the execution is undefined.
4. onPostExecute(Result) : invoked on the UI thread after the background computation finishes. The result of the background computation is passed to this step as a parameter.

4. role and data type of param:

dataType: String

Role: It is path of url, relative path to the resource we would like to load in the WebView.

It can be either asset path as :

"file:///android_asset/index.html"

or url of remote site as - "https://www.google.com"