Content validation is added to get rid of Retry errors.

Author: tasomaniac

app/src/main/java/com/tasomaniac/muzei/comiccovers/ComicVineArtSource.java

@@ -8,19 +8,22 @@
 import com.google.android.apps.muzei.api.Artwork;
 import com.google.android.apps.muzei.api.RemoteMuzeiArtSource;
 import com.tasomaniac.muzei.comiccovers.model.Comic;
+import com.tasomaniac.muzei.comiccovers.util.IOUtil;
 
 import java.util.Random;
 
 import retrofit.ErrorHandler;
 import retrofit.RequestInterceptor;
 import retrofit.RestAdapter;
 import retrofit.RetrofitError;
+import timber.log.Timber;
 
 public class ComicVineArtSource extends RemoteMuzeiArtSource {
     private static final String SOURCE_NAME = "ComicVineArtSource";
     public static final String NUM_OF_TOTAL_RESULTS = "number_of_total_results";
 
-    private static final int ROTATE_TIME_MILLIS = 24 * 60 * 60 * 1000; // rotate every 3 hours
+    private static final int ROTATE_TIME_MILLIS = 24 * 60 * 60 * 1000; // rotate every 24 hours
+    private static final int NEXT_ON_ERROR_TIME_MILLIS = 60 * 60 * 1000; // rotate every 24 hours
 
     Random random;
 
@@ -60,14 +63,15 @@ public Throwable handleError(RetrofitError retrofitError) {
                                 || (500 <= statusCode && statusCode < 600)) {
                             return new RetryException();
                         }
-                        scheduleUpdate(System.currentTimeMillis() + ROTATE_TIME_MILLIS);
+                        scheduleUpdate(System.currentTimeMillis() + NEXT_ON_ERROR_TIME_MILLIS);
+
+                        Timber.d(retrofitError, "Error getting the image %s", retrofitError.getUrl());
+
                         return retrofitError;
                     }
                 })
                 .build();
 
-
-
         final ComicVineService service = restAdapter.create(ComicVineService.class);
         Comic comic = getNextComic(service);
         if (comic != null) {
@@ -76,8 +80,10 @@ public Throwable handleError(RetrofitError retrofitError) {
                 name.append(comic.getVolume().getName());
             }
             if (comic.getName() != null) {
-                name.append(" | ")
-                        .append(comic.getName());
+                if (name.length() > 0) {
+                    name.append(" | ");
+                }
+                name.append(comic.getName());
             }
 
             publishArtwork(new Artwork.Builder()
@@ -96,26 +102,36 @@ public Throwable handleError(RetrofitError retrofitError) {
     private Comic getNextComic(final ComicVineService service) throws RetryException {
         String currentToken = (getCurrentArtwork() != null) ? getCurrentArtwork().getToken() : null;
 
+        String offset = String.valueOf(random.nextInt(max_size));
         ComicVineService.ComicVineResponse response =
-                service.getIssues(String.valueOf(random.nextInt(max_size)));
+                service.getIssues(offset);
 
         if (response == null || response.getResults() == null) {
+            Timber.d("Error getting the image %s", offset);
             throw new RetryException();
         }
 
         max_size = response.getNumberOfTotalResult();
         prefs.edit().putInt(NUM_OF_TOTAL_RESULTS, max_size).apply();
 
         if (response.getResults().size() < 1) {
-            scheduleUpdate(System.currentTimeMillis() + ROTATE_TIME_MILLIS);
+            scheduleUpdate(System.currentTimeMillis() + NEXT_ON_ERROR_TIME_MILLIS);
             return null;
         }
         Comic comic = response.getResults().get(0);
         String newToken = String.valueOf(comic.getId());
-        if (currentToken == null || !currentToken.equals(newToken)) {
-            return comic;
-        } else {
-            return getNextComic(service);
+        try {
+            boolean isContentValid = IOUtil.checkContentType(getApplicationContext(),
+                    Uri.parse(comic.getImage().getSuperUrl()), "image/");
+            if ((currentToken == null || !currentToken.equals(newToken)) && isContentValid) {
+                return comic;
+            } else {
+                return getNextComic(service);
+            }
+        } catch (IOUtil.OpenUriException e) {
+            Timber.e(e, "Error on the image. Will try in an hour.");
+            scheduleUpdate(System.currentTimeMillis() + NEXT_ON_ERROR_TIME_MILLIS);
+            return null;
         }
     }
 }

app/src/main/java/com/tasomaniac/muzei/comiccovers/util/IOUtil.java

@@ -0,0 +1,88 @@
+package com.tasomaniac.muzei.comiccovers.util;
+
+import android.net.Uri;
+
+import com.squareup.okhttp.OkHttpClient;
+import com.squareup.okhttp.OkUrlFactory;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+
+import timber.log.Timber;
+
+public class IOUtil {
+    private static final int DEFAULT_READ_TIMEOUT = 30 * 1000; // 30s
+    private static final int DEFAULT_CONNECT_TIMEOUT = 15 * 1000; // 15s
+
+    public static boolean checkContentType(Uri uri, String reqContentTypeSubstring)
+            throws OpenUriException {
+
+        if (uri == null) {
+            throw new IllegalArgumentException("Uri cannot be empty");
+        }
+
+        String scheme = uri.getScheme();
+        if (scheme == null) {
+            throw new OpenUriException(false, new IOException("Uri had no scheme"));
+        }
+
+        OkHttpClient client = new OkHttpClient();
+        HttpURLConnection conn;
+        int responseCode = 0;
+        String responseMessage = null;
+        try {
+            conn = new OkUrlFactory(client).open(new URL(uri.toString()));
+        } catch (MalformedURLException e) {
+            throw new OpenUriException(false, e);
+        }
+
+        try {
+            conn.setConnectTimeout(DEFAULT_CONNECT_TIMEOUT);
+            conn.setReadTimeout(DEFAULT_READ_TIMEOUT);
+            responseCode = conn.getResponseCode();
+            responseMessage = conn.getResponseMessage();
+            if (!(responseCode >= 200 && responseCode < 300)) {
+                throw new IOException("HTTP error response.");
+            }
+            if (reqContentTypeSubstring != null) {
+                String contentType = conn.getContentType();
+                if (contentType == null || !contentType.contains(reqContentTypeSubstring)) {
+
+                    Timber.e("Wrong content type. Will retry in an hour. ");
+                    return false;
+                }
+            }
+
+        } catch (IOException e) {
+            if (responseCode > 0) {
+                throw new OpenUriException(
+                        500 <= responseCode && responseCode < 600,
+                        responseMessage, e);
+            } else {
+                throw new OpenUriException(false, e);
+            }
+        }
+
+        return true;
+    }
+
+    public static class OpenUriException extends Exception {
+        private boolean mRetryable;
+
+        public OpenUriException(boolean retryable, String message, Throwable cause) {
+            super(message, cause);
+            mRetryable = retryable;
+        }
+
+        public OpenUriException(boolean retryable, Throwable cause) {
+            super(cause);
+            mRetryable = retryable;
+        }
+
+        public boolean isRetryable() {
+            return mRetryable;
+        }
+    }
+}