handle server errors more gracefully

Data.pde

@@ -134,6 +134,7 @@ class WebDataSource {
   {
     try {
       InputStream is = createInput(request);
+      if (is == null) return null;
       BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
       StringBuffer buf = new StringBuffer();
       String line = null;
@@ -165,6 +166,9 @@ class WebDataSource {
       catch (JSONException e) {
         println (e);
       }
+      catch (NullPointerException e) {
+
+      }
     }
     return countries;
   }

TopArtistView.pde

@@ -16,6 +16,7 @@ class CountryChooser extends Button implements ListDataSource {
   boolean showing = false;
   int chosen = 0;
   ListBox countryListbox;
+  List<Country> countries;
 
   CountryChooser(float x_, float y_, float w_, float h_)
   {
@@ -36,6 +37,7 @@ class CountryChooser extends Button implements ListDataSource {
   {
     showing = !showing;
     if (showing) {
+      countries = data.getCountries();  /* if it failed to load, we only want to retry when the menu is reopened */
       countryListbox.x = mouseX - lx;
       countryListbox.y = mouseY - ly + h;
       rootView.subviews.add(countryListbox);
@@ -45,15 +47,15 @@ class CountryChooser extends Button implements ListDataSource {
 
   String getText(int index) {
     if (index == 0) return "Any country";
-    else return data.countries.get(index - 1).name;
+    else return countries.get(index - 1).name;
   }
   Object get(int index) {
     if (index == 0) return null;
-    else return data.countries.get(index - 1);
+    else return countries.get(index - 1);
   }
   int count() {
     try {
-      return data.getCountries().size() + 1;
+      return countries.size() + 1;
     }
     catch (NullPointerException e) {
       return 1;

cs424p4.pde

@@ -24,7 +24,7 @@ void setup()
   smooth();
 
   /* load data */
-  if (true) data = new WebDataSource("http://localhost:3000/");
+  if (false) data = new WebDataSource("http://localhost:3000/");
   else data = new WebDataSource("http://radiogaga.heroku.com/");
 
   /* setup UI */

datasets/lastfm-dataset-360K/makeindices.sql

@@ -44,3 +44,15 @@ create index top_artists2_no_age_artist_id_idx on top_artists2_no_age(artist_id)
 cluster top_artists2_no_age_artist_id_idx on top_artists2_no_age;
 
 alter table countries2 rename to countries;
+
+
+create table top_artists2_no_age_no_country as
+select artist_id, gender, sum(plays) as plays from top_artists2_no_age
+group by artist_id, gender
+order by artist_id;
+
+create index top_artists2_no_age_no_country_artist_id_idx on top_artists2_no_age_no_country(artist_id);
+cluster top_artists2_no_age_no_country_artist_id_idx on top_artists2_no_age_no_country;
+
+
+create index top_artists2_age_country_id_idx on top_artists2(age,country_id);