Shared data between Activities and threading

Question

I have an application called ListApp like this

public class ListApp extends Application {

public static RSmovies[] appRsMovie=new RSmovies[1];
public static ImageDownloader id =new ImageDownloader();
public static String cur=null;
public static String movieGetInfo="http://hive.tn/TMDb/test11.php?param=";

}

In my first activity i tried to make modification to the appRsMovie in a new thread, like this

new Thread(new Runnable() {
        @Override
        public void run() {

            try {
                InputStream source = retrieveStream("http://hive.tn/TMDb/test6.php");
                Gson gson = new Gson();

                Reader reader = new InputStreamReader(source);
                    ListApp.appRsMovie = gson.fromJson(reader, RSmovies[].class);

                lv
                        .setAdapter(new LazyAdapter1(
                                ListControlActivity.this, z));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }).start();

Application crash and this is the exception that i got

12-26 17:21:55.643: W/dalvikvm(958): Exception Ljava/lang/RuntimeException; thrown during Lcom/test/list/ListApp;.<clinit>

Answer 1

Try this:

try moving the statement

lv.setAdapter(new LazyAdapter1(ListControlActivity.this, z));

from thread to Handler

create a Handler:

    Handler handler = new Handler() {

    public void handleMessage(android.os.Message msg) {
        lv.setAdapter(new LazyAdapter1(ListControlActivity.this, z));
    }
};

and replace the lv.setAdapter statement with handler's sendMessage

new Thread(new Runnable() {
    @Override
    public void run() {

        try {
            InputStream source = retrieveStream("http://hive.tn/TMDb/test6.php");
            Gson gson = new Gson();

            Reader reader = new InputStreamReader(source);
                ListApp.appRsMovie = gson.fromJson(reader, RSmovies[].class);

            handler.sendEmptyMessage(0);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}).start();

Answer 2

You can't update a listview (or any other view) from any Thread other than the UI thread. Use an AsyncTask instead of a plain thread, and make sure you update the listview in onPostExecute().