I'm super new to Android development and Java in general. Here's the basic setup: I have a splash screen with an AsyncTask
to check server availability. Following this thread I made a callback in my activity. This makes more sense than doing the work in OnPostExecute()
as I want to reuse this task in different activities.
However, in my callback I do a check if the status is okay. If it is, it should launch the next activity. But from the context of my callback, I don't get how I can get my Activity
reference, which I need as a parameter for the Intent.
This is the code in my Activity under OnCreate:
//Check server status
CheckServiceTask t = new CheckServiceTask(new OnTaskCompleted<ShaggyServiceStatus>() {
@Override
public void onTaskCompleted(ShaggyServiceStatus result) {
Log.i(TAG, "Callback. Result: " + result.getStatus());
ProgressBar pb = (ProgressBar) findViewById(R.id.splash_progress);
pb.setVisibility(View.INVISIBLE);
if (result.getStatusCode() == 999){
TextView t = (TextView) findViewById(R.id.splash_status_text);
t.setText(result.getStatus());
return;
}
Intent i = new Intent(getActivity(), LoginActivity.class);
startActivity(i);
finish();
}
});
t.execute();
The part where this fails is at getActivity()
. That call is not available. Using this
throws an error (which I understand, as I'm in the context of OnTaskCompleted
).
For completeness, this is the interface for OnTaskCompleted:
public interface OnTaskCompleted<T> {
public void onTaskCompleted(T result);
}
And this is the CheckServiceTask class:
public class CheckServiceTask extends AsyncTask<Void, Void, ShaggyServiceStatus>{
private static final String TAG = "coo";
public OnTaskCompleted<ShaggyServiceStatus> listener;
public CheckServiceTask (OnTaskCompleted<ShaggyServiceStatus> l){
this.listener = l;
}
@Override
protected ShaggyServiceStatus doInBackground(Void... params) {
try {
Log.i(TAG, "Connecting to server...");
//TODO: Make this a setting
final String url = "https://someplace.com/status";
RestTemplate restTemplate = new RestTemplate();
restTemplate.getMessageConverters().add(new MappingJackson2HttpMessageConverter());
//restTemplate.postForObject("url", bodyObject, ShaggySer.class);
ShaggyServiceStatus sss = restTemplate.getForObject(url, ShaggyServiceStatus.class);
Log.d(TAG, "Got the status.");
return sss;
} catch (Exception e) {
//TODO: Exception handling
Log.e(TAG, e.getMessage(), e);
}
//If we're here, it's not okay.
ShaggyServiceStatus r = new ShaggyServiceStatus("Cannot connect to server", 999, "none");
return r;
}
@Override
protected void onPostExecute(ShaggyServiceStatus result) {
super.onPostExecute(result);
listener.onTaskCompleted(result);
}
}
Use
CurrentClassName.this
getActivity()
: used with Fragmentsclass.this
isn't the same asthis
when you have nested class.If The activity that you use Called "
MyActivity
" then you can do the following:This chunk of code will return the this "current" object of outer class