How to clear android cache onCreate

Question

I'm new to Android development and I've started creating this app where I read an XML feed and list the contents. But even though the feed changes I still get the same data displayed. Although over night the cache seemed to clear itself. I would like to force reading of the feed each time I start my app. I tried the methods described here How to clear cache Android but it didn't help.

My guess is that I would have to do it onCreate in my main activity (at least that's what I have tried so far).

Can anyone point me in the right direction?

Thanks in advance :-)

Here are some code snippets.

From my activity:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_list_game);
    deleteCache(this);
    new ReadLeagueXml().execute();
}

deleteCache is the method from the other thread I linked to.

Then in my doInBackground I have

InputStream inputStream = new URL(xmlURL).openStream();

if (inputStream != null) {
    list = parse(inputStream);
}

And finally in my onPostExecute:

ListView matchListView = (ListView)findViewById(R.id.match_list);
List<String> matchArray = new ArrayList<String>();
for (int i = 0; i < matches.size(); i++) {
    matchArray.add(matches.get(i).HomeTeam + " - " + matches.get(i).AwayTeam);
}
matchArray.toArray();
matchesArrayAdapter = new MatchListAdapter(ListGameActivity.this, matches);
matchListView.setAdapter(matchesArrayAdapter);

Could you post more data? Maybe some of the code and more details about what your app exactly does, like where the data is assigned to the ListView? — Ahmed Aeon Axan, Feb 17 '13 at 10:16

score 2 · Accepted Answer · answered Feb 17 '13 at 10:49

Your code seems perfectly Fine. Also you do not need to "clear cache".

Now back to the question, If i understand your question correctly, The feed is not getting refreshed. This is because you download the new data on onCreate(). So when you launch the app for the first time the data is downloaded. Then the user goes to another application (remember Android will not close your activity, it will simply pause it). So when the user comes back, If the application is not closed Android will resume it! So your onCreate() will not be called again.

In short, Update the data in onResume() which is called everytime your activity is shown to the user. Move the new ReadLeagueXml().execute(); to onResume() and new data will be downloaded every time the user opens the app.

You might want to look at the Android Activity Life Cycle here

That makes perfect sense! One thing though: Is onResume executed at the same time as OnCreate? In other words do I have to call ReadLeagueXml().execute(); in both onCreate AND onResume or is it enough with onResume? — CJe, Feb 17 '13 at 11:03
No. If you see the Android life cycle, the first time your app is run `onCreate()` is called first and then `onResume()` is called. So you need to do it only in `onResume()` — Ahmed Aeon Axan, Feb 17 '13 at 11:05

How to clear android cache onCreate

1 Answers1