Increased use of library methods

src/de/danoeh/antennapod/activity/AudioplayerActivity.java

@@ -16,16 +16,27 @@ import android.view.MenuItem;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.View.OnLongClickListener;
-import android.view.Window;
+import android.widget.AdapterView;
-import android.widget.*;
+import android.widget.ArrayAdapter;
+import android.widget.Button;
+import android.widget.ImageButton;
 import android.widget.ImageView.ScaleType;
+import android.widget.ListView;
+import android.widget.TextView;
+
+import org.apache.commons.lang3.StringUtils;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.adapter.ChapterListAdapter;
 import de.danoeh.antennapod.adapter.NavListAdapter;
 import de.danoeh.antennapod.asynctask.ImageLoader;
 import de.danoeh.antennapod.dialog.VariableSpeedDialog;
-import de.danoeh.antennapod.feed.*;
+import de.danoeh.antennapod.feed.Chapter;
+import de.danoeh.antennapod.feed.EventDistributor;
+import de.danoeh.antennapod.feed.Feed;
+import de.danoeh.antennapod.feed.MediaType;
+import de.danoeh.antennapod.feed.SimpleChapter;
 import de.danoeh.antennapod.fragment.CoverFragment;
 import de.danoeh.antennapod.fragment.ItemDescriptionFragment;
 import de.danoeh.antennapod.preferences.UserPreferences;
@@ -215,8 +226,7 @@ public class AudioplayerActivity extends MediaplayerActivity implements ItemDesc
     @Override
     protected void onResume() {
         super.onResume();
-        if (getIntent().getAction() != null
+        if (StringUtils.equals(getIntent().getAction(), Intent.ACTION_VIEW)) {
-                && getIntent().getAction().equals(Intent.ACTION_VIEW)) {
             Intent intent = getIntent();
             if (BuildConfig.DEBUG)
                 Log.d(TAG, "Received VIEW intent: "

src/de/danoeh/antennapod/activity/DownloadAuthenticationActivity.java

@@ -9,6 +9,9 @@ import android.view.View;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.TextView;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.preferences.UserPreferences;
@@ -58,7 +61,8 @@ public class DownloadAuthenticationActivity extends ActionBarActivity {
         butCancel = (Button) findViewById(R.id.butCancel);
         txtvDescription = (TextView) findViewById(R.id.txtvDescription);
 
-        if (!getIntent().hasExtra(ARG_DOWNLOAD_REQUEST)) throw new IllegalArgumentException("Download request missing");
+        Validate.isTrue(getIntent().hasExtra(ARG_DOWNLOAD_REQUEST), "Download request missing");
+
         request = getIntent().getParcelableExtra(ARG_DOWNLOAD_REQUEST);
         sendToDownloadRequester = getIntent().getBooleanExtra(ARG_SEND_TO_DOWNLOAD_REQUESTER_BOOL, false);
 

src/de/danoeh/antennapod/activity/MainActivity.java

@@ -19,6 +19,9 @@ import android.util.Log;
 import android.view.*;
 import android.widget.AdapterView;
 import android.widget.ListView;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.adapter.NavListAdapter;
@@ -219,7 +222,7 @@ public class MainActivity extends ActionBarActivity {
     }
 
     public void loadChildFragment(Fragment fragment) {
-        if (fragment == null) throw new IllegalArgumentException("fragment = null");
+        Validate.notNull(fragment);
         FragmentManager fm = getSupportFragmentManager();
         fm.beginTransaction()
                 .replace(R.id.main_view, fragment, "main")

src/de/danoeh/antennapod/activity/StorageErrorActivity.java

@@ -7,6 +7,9 @@ import android.content.IntentFilter;
 import android.os.Bundle;
 import android.support.v7.app.ActionBarActivity;
 import android.util.Log;
+
+import org.apache.commons.lang3.StringUtils;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.preferences.UserPreferences;
@@ -54,7 +57,7 @@ public class StorageErrorActivity extends ActionBarActivity {
 
 		@Override
 		public void onReceive(Context context, Intent intent) {
-			if (intent.getAction().equals(Intent.ACTION_MEDIA_MOUNTED)) {
+			if (StringUtils.equals(intent.getAction(), Intent.ACTION_MEDIA_MOUNTED)) {
 				if (intent.getBooleanExtra("read-only", true)) {
 					if (BuildConfig.DEBUG)
 						Log.d(TAG, "Media was mounted; Finishing activity");

src/de/danoeh/antennapod/adapter/ActionButtonUtils.java

@@ -4,6 +4,9 @@ import android.content.Context;
 import android.content.res.TypedArray;
 import android.view.View;
 import android.widget.ImageButton;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.feed.FeedItem;
 import de.danoeh.antennapod.feed.FeedMedia;
@@ -20,7 +23,8 @@ public class ActionButtonUtils {
     private final Context context;
 
     public ActionButtonUtils(Context context) {
-        if (context == null) throw new IllegalArgumentException("context = null");
+        Validate.notNull(context);
+
         this.context = context;
         drawables = context.obtainStyledAttributes(new int[]{
                 R.attr.av_play, R.attr.navigation_cancel, R.attr.av_download, R.attr.navigation_chapters});
@@ -32,7 +36,8 @@ public class ActionButtonUtils {
      * action button so that it matches the state of the FeedItem.
      */
     public void configureActionButton(ImageButton butSecondary, FeedItem item) {
-        if (butSecondary == null || item == null) throw new IllegalArgumentException("butSecondary or item was null");
+        Validate.isTrue(butSecondary != null && item != null, "butSecondary or item was null");
+
         final FeedMedia media = item.getMedia();
         if (media != null) {
             final boolean isDownloadingMedia = DownloadRequester.getInstance().isDownloadingFile(media);

src/de/danoeh/antennapod/adapter/DefaultActionButtonCallback.java

@@ -2,6 +2,9 @@ package de.danoeh.antennapod.adapter;
 
 import android.content.Context;
 import android.widget.Toast;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.dialog.DownloadRequestErrorDialogCreator;
 import de.danoeh.antennapod.feed.FeedItem;
@@ -19,7 +22,7 @@ public class DefaultActionButtonCallback implements ActionButtonCallback {
     private final Context context;
 
     public DefaultActionButtonCallback(Context context) {
-        if (context == null) throw new IllegalArgumentException("context = null");
+        Validate.notNull(context);
         this.context = context;
     }
 

src/de/danoeh/antennapod/asynctask/DownloadObserver.java

@@ -5,6 +5,9 @@ import android.content.*;
 import android.os.Handler;
 import android.os.IBinder;
 import android.util.Log;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.service.download.DownloadService;
 import de.danoeh.antennapod.service.download.Downloader;
@@ -45,9 +48,9 @@ public class DownloadObserver {
      * @throws java.lang.IllegalArgumentException if one of the arguments is null.
      */
     public DownloadObserver(Activity activity, Handler handler, Callback callback) {
-        if (activity == null) throw new IllegalArgumentException("activity = null");
+        Validate.notNull(activity);
-        if (handler == null) throw new IllegalArgumentException("handler = null");
+        Validate.notNull(handler);
-        if (callback == null) throw new IllegalArgumentException("callback = null");
+        Validate.notNull(callback);
 
         this.activity = activity;
         this.handler = handler;
@@ -166,7 +169,7 @@ public class DownloadObserver {
     }
 
     public void setActivity(Activity activity) {
-        if (activity == null) throw new IllegalArgumentException("activity = null");
+        Validate.notNull(activity);
         this.activity = activity;
     }
 

src/de/danoeh/antennapod/asynctask/FlattrClickWorker.java

@@ -11,6 +11,7 @@ import android.support.v4.app.NotificationCompat;
 import android.util.Log;
 import android.widget.Toast;
 
+import org.apache.commons.lang3.Validate;
 import org.shredzone.flattr4j.exception.FlattrException;
 
 import java.util.LinkedList;
@@ -65,7 +66,7 @@ public class FlattrClickWorker extends AsyncTask<Void, Integer, FlattrClickWorke
      * @param context A context for accessing the database and posting notifications. Must not be null.
      */
     public FlattrClickWorker(Context context) {
-        if (context == null) throw new IllegalArgumentException("context = null");
+        Validate.notNull(context);
         this.context = context.getApplicationContext();
     }
 

src/de/danoeh/antennapod/asynctask/ImageDiskCache.java

@@ -11,6 +11,7 @@ import de.danoeh.antennapod.service.download.DownloadRequest;
 import de.danoeh.antennapod.service.download.HttpDownloader;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.Validate;
 
 import java.io.*;
 import java.util.ArrayList;
@@ -48,9 +49,8 @@ public class ImageDiskCache {
      * Return an instance of an ImageDiskCache that stores images in the specified folder.
      */
     public static synchronized ImageDiskCache getInstance(String path, long maxCacheSize) {
-        if (path == null) {
+        Validate.notNull(path);
-            throw new NullPointerException();
+
-        }
         if (cacheSingletons.containsKey(path)) {
             return cacheSingletons.get(path);
         }
@@ -358,9 +358,7 @@ public class ImageDiskCache {
         private final long size;
 
         public DiskCacheObject(String fileUrl, long size) {
-            if (fileUrl == null) {
+            Validate.notNull(fileUrl);
-                throw new NullPointerException();
-            }
             this.fileUrl = fileUrl;
             this.timestamp = System.currentTimeMillis();
             this.size = size;

src/de/danoeh/antennapod/dialog/FeedItemDialog.java

@@ -36,6 +36,7 @@ import de.danoeh.antennapod.util.QueueAccess;
 import de.danoeh.antennapod.util.ShownotesProvider;
 import de.danoeh.antennapod.util.menuhandler.FeedItemMenuHandler;
 import org.apache.commons.lang3.StringEscapeUtils;
+import org.apache.commons.lang3.Validate;
 
 import java.util.Collection;
 import java.util.List;
@@ -59,7 +60,7 @@ public class FeedItemDialog extends Dialog {
     private PopupMenu popupMenu;
 
     public static FeedItemDialog newInstance(Context context, FeedItemDialogSavedInstance savedInstance) {
-        if (savedInstance == null) throw new IllegalArgumentException("savedInstance = null");
+        Validate.notNull(savedInstance);
         FeedItemDialog dialog = newInstance(context, savedInstance.item, savedInstance.queueAccess);
         if (savedInstance.isShowing) {
             dialog.show();
@@ -77,8 +78,8 @@ public class FeedItemDialog extends Dialog {
 
     public FeedItemDialog(Context context, int theme, FeedItem item, QueueAccess queue) {
         super(context, theme);
-        if (item == null) throw new IllegalArgumentException("item = null");
+        Validate.notNull(item);
-        if (queue == null) throw new IllegalArgumentException("queue = null");
+        Validate.notNull(queue);
         this.item = item;
         this.queue = queue;
     }
@@ -350,7 +351,7 @@ public class FeedItemDialog extends Dialog {
 
 
     public void setItem(FeedItem item) {
-        if (item == null) throw new IllegalArgumentException("item = null");
+        Validate.notNull(item);
         this.item = item;
     }
 
@@ -371,7 +372,7 @@ public class FeedItemDialog extends Dialog {
     }
 
     public void setQueue(QueueAccess queue) {
-        if (queue == null) throw new IllegalArgumentException("queue = null");
+        Validate.notNull(queue);
         this.queue = queue;
     }
 

src/de/danoeh/antennapod/feed/EventDistributor.java

@@ -2,6 +2,9 @@ package de.danoeh.antennapod.feed;
 
 import android.os.Handler;
 import android.util.Log;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.BuildConfig;
 
 import java.util.AbstractQueue;
@@ -90,10 +93,7 @@ public class EventDistributor extends Observable {
 	@Override
 	public void addObserver(Observer observer) {
 		super.addObserver(observer);
-		if (!(observer instanceof EventListener)) {
+        Validate.isInstanceOf(EventListener.class, observer);
-			throw new IllegalArgumentException(
-					"Observer must be instance of EventListener");
-		}
 	}
 
 	public void sendDownloadQueuedBroadcast() {

src/de/danoeh/antennapod/fragment/ItemlistFragment.java

@@ -17,6 +17,9 @@ import android.widget.ImageButton;
 import android.widget.ImageView;
 import android.widget.ListView;
 import android.widget.TextView;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.activity.FeedInfoActivity;
@@ -97,7 +100,7 @@ public class ItemlistFragment extends ListFragment {
         setHasOptionsMenu(true);
 
         Bundle args = getArguments();
-        if (args == null) throw new IllegalArgumentException("args invalid");
+        Validate.notNull(args);
         feedID = args.getLong(ARGUMENT_FEED_ID);
     }
 

src/de/danoeh/antennapod/fragment/gpodnet/SearchListFragment.java

@@ -4,6 +4,9 @@ import android.os.Bundle;
 import android.support.v7.widget.SearchView;
 import android.view.Menu;
 import android.view.MenuInflater;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.activity.MainActivity;
 import de.danoeh.antennapod.fragment.SearchFragment;
@@ -68,9 +71,8 @@ public class SearchListFragment extends PodcastListFragment {
     }
 
     public void changeQuery(String query) {
-        if (query == null) {
+        Validate.notNull(query);
-            throw new NullPointerException();
+
-        }
         this.query = query;
         loadData();
     }

src/de/danoeh/antennapod/fragment/gpodnet/TagFragment.java

@@ -1,6 +1,9 @@
 package de.danoeh.antennapod.fragment.gpodnet;
 
 import android.os.Bundle;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.activity.MainActivity;
 import de.danoeh.antennapod.gpoddernet.GpodnetService;
 import de.danoeh.antennapod.gpoddernet.GpodnetServiceException;
@@ -21,7 +24,7 @@ public class TagFragment extends PodcastListFragment {
     private GpodnetTag tag;
 
     public static TagFragment newInstance(String tagName) {
-        if (tagName == null) throw new IllegalArgumentException("tagName = null");
+        Validate.notNull(tagName);
         TagFragment fragment = new TagFragment();
         Bundle args = new Bundle();
         args.putString("tag", tagName);
@@ -34,7 +37,7 @@ public class TagFragment extends PodcastListFragment {
         super.onCreate(savedInstanceState);
 
         Bundle args = getArguments();
-        if (args == null || args.getString("tag") == null) throw new IllegalArgumentException("args invalid");
+        Validate.isTrue(args != null && args.getString("tag") != null, "args invalid");
 
         tag = new GpodnetTag(args.getString("tag"));
         ((MainActivity) getActivity()).getMainActivtyActionBar().setTitle(tag.getName());

src/de/danoeh/antennapod/gpoddernet/GpodnetService.java

@@ -1,8 +1,6 @@
 package de.danoeh.antennapod.gpoddernet;
 
-import de.danoeh.antennapod.gpoddernet.model.*;
+import org.apache.commons.lang3.Validate;
-import de.danoeh.antennapod.preferences.GpodnetPreferences;
-import de.danoeh.antennapod.service.download.AntennapodHttpClient;
 import org.apache.http.Header;
 import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
@@ -32,6 +30,14 @@ import java.util.Collection;
 import java.util.LinkedList;
 import java.util.List;
 
+import de.danoeh.antennapod.gpoddernet.model.GpodnetDevice;
+import de.danoeh.antennapod.gpoddernet.model.GpodnetPodcast;
+import de.danoeh.antennapod.gpoddernet.model.GpodnetSubscriptionChange;
+import de.danoeh.antennapod.gpoddernet.model.GpodnetTag;
+import de.danoeh.antennapod.gpoddernet.model.GpodnetUploadChangesResponse;
+import de.danoeh.antennapod.preferences.GpodnetPreferences;
+import de.danoeh.antennapod.service.download.AntennapodHttpClient;
+
 /**
  * Communicates with the gpodder.net service.
  */
@@ -89,10 +95,8 @@ public class GpodnetService {
      */
     public List<GpodnetPodcast> getPodcastsForTag(GpodnetTag tag, int count)
             throws GpodnetServiceException {
-        if (tag == null) {
+        Validate.notNull(tag);
-            throw new IllegalArgumentException(
+
-                    "Tag and title of tag must not be null");
-        }
         try {
             URI uri = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/api/2/tag/%s/%d.json", tag.getName(), count), null);
@@ -120,9 +124,8 @@ public class GpodnetService {
      */
     public List<GpodnetPodcast> getPodcastToplist(int count)
             throws GpodnetServiceException {
-        if (count < 1 || count > 100) {
+        Validate.isTrue(count >= 1 && count <= 100, "Count must be in range 1..100");
-            throw new IllegalArgumentException("Count must be in range 1..100");
+
-        }
         try {
             URI uri = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/toplist/%d.json", count), null);
@@ -155,9 +158,8 @@ public class GpodnetService {
      * @throws GpodnetServiceAuthenticationException If there is an authentication error.
      */
     public List<GpodnetPodcast> getSuggestions(int count) throws GpodnetServiceException {
-        if (count < 1 || count > 100) {
+        Validate.isTrue(count >= 1 && count <= 100, "Count must be in range 1..100");
-            throw new IllegalArgumentException("Count must be in range 1..100");
+
-        }
         try {
             URI uri = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/suggestions/%d.json", count), null);
@@ -220,9 +222,8 @@ public class GpodnetService {
      */
     public List<GpodnetDevice> getDevices(String username)
             throws GpodnetServiceException {
-        if (username == null) {
+        Validate.notNull(username);
-            throw new IllegalArgumentException("Username must not be null");
+
-        }
         try {
             URI uri = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/api/2/devices/%s.json", username), null);
@@ -255,10 +256,9 @@ public class GpodnetService {
     public void configureDevice(String username, String deviceId,
                                 String caption, GpodnetDevice.DeviceType type)
             throws GpodnetServiceException {
-        if (username == null || deviceId == null) {
+        Validate.notNull(username);
-            throw new IllegalArgumentException(
+        Validate.notNull(deviceId);
-                    "Username and device ID must not be null");
+
-        }
         try {
             URI uri = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/api/2/devices/%s/%s.json", username, deviceId), null);
@@ -303,10 +303,9 @@ public class GpodnetService {
      */
     public String getSubscriptionsOfDevice(String username, String deviceId)
             throws GpodnetServiceException {
-        if (username == null || deviceId == null) {
+        Validate.notNull(username);
-            throw new IllegalArgumentException(
+        Validate.notNull(deviceId);
-                    "Username and device ID must not be null");
+
-        }
         try {
             URI uri = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/subscriptions/%s/%s.opml", username, deviceId), null);
@@ -332,9 +331,8 @@ public class GpodnetService {
      */
     public String getSubscriptionsOfUser(String username)
             throws GpodnetServiceException {
-        if (username == null) {
+        Validate.notNull(username);
-            throw new IllegalArgumentException("Username must not be null");
+
-        }
         try {
             URI uri = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/subscriptions/%s.opml", username), null);
@@ -406,10 +404,11 @@ public class GpodnetService {
      */
     public GpodnetUploadChangesResponse uploadChanges(String username, String deviceId, Collection<String> added,
                                                       Collection<String> removed) throws GpodnetServiceException {
-        if (username == null || deviceId == null || added == null || removed == null) {
+        Validate.notNull(username);
-            throw new IllegalArgumentException(
+        Validate.notNull(deviceId);
-                    "Username, device ID, added and removed must not be null");
+        Validate.notNull(added);
-        }
+        Validate.notNull(removed);
+
         try {
             URI uri = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/api/2/subscriptions/%s/%s.json", username, deviceId), null);
@@ -453,10 +452,9 @@ public class GpodnetService {
      */
     public GpodnetSubscriptionChange getSubscriptionChanges(String username,
                                                             String deviceId, long timestamp) throws GpodnetServiceException {
-        if (username == null || deviceId == null) {
+        Validate.notNull(username);
-            throw new IllegalArgumentException(
+        Validate.notNull(deviceId);
-                    "Username and device ID must not be null");
+
-        }
         String params = String.format("since=%d", timestamp);
         String path = String.format("/api/2/subscriptions/%s/%s.json",
                 username, deviceId);
@@ -486,10 +484,9 @@ public class GpodnetService {
      */
     public void authenticate(String username, String password)
             throws GpodnetServiceException {
-        if (username == null || password == null) {
+        Validate.notNull(username);
-            throw new IllegalArgumentException(
+        Validate.notNull(password);
-                    "Username and password must not be null");
+
-        }
         URI uri;
         try {
             uri = new URI(BASE_SCHEME, BASE_HOST, String.format(
@@ -517,9 +514,8 @@ public class GpodnetService {
 
     private String executeRequest(HttpRequestBase request)
             throws GpodnetServiceException {
-        if (request == null) {
+        Validate.notNull(request);
-            throw new IllegalArgumentException("request must not be null");
+
-        }
         String responseString = null;
         HttpResponse response = null;
         try {
@@ -586,9 +582,8 @@ public class GpodnetService {
 
     private String getStringFromEntity(HttpEntity entity)
             throws GpodnetServiceException {
-        if (entity == null) {
+        Validate.notNull(entity);
-            throw new IllegalArgumentException("entity must not be null");
+
-        }
         ByteArrayOutputStream outputStream;
         int contentLength = (int) entity.getContentLength();
         if (contentLength > 0) {
@@ -613,9 +608,7 @@ public class GpodnetService {
 
     private void checkStatusCode(HttpResponse response)
             throws GpodnetServiceException {
-        if (response == null) {
+        Validate.notNull(response);
-            throw new IllegalArgumentException("response must not be null");
-        }
         int responseCode = response.getStatusLine().getStatusCode();
         if (responseCode != HttpStatus.SC_OK) {
             if (responseCode == HttpStatus.SC_UNAUTHORIZED) {
@@ -629,9 +622,8 @@ public class GpodnetService {
 
     private List<GpodnetPodcast> readPodcastListFromJSONArray(JSONArray array)
             throws JSONException {
-        if (array == null) {
+        Validate.notNull(array);
-            throw new IllegalArgumentException("array must not be null");
+
-        }
         List<GpodnetPodcast> result = new ArrayList<GpodnetPodcast>(
                 array.length());
         for (int i = 0; i < array.length(); i++) {
@@ -685,9 +677,8 @@ public class GpodnetService {
 
     private List<GpodnetDevice> readDeviceListFromJSONArray(JSONArray array)
             throws JSONException {
-        if (array == null) {
+        Validate.notNull(array);
-            throw new IllegalArgumentException("array must not be null");
+
-        }
         List<GpodnetDevice> result = new ArrayList<GpodnetDevice>(
                 array.length());
         for (int i = 0; i < array.length(); i++) {
@@ -707,9 +698,8 @@ public class GpodnetService {
 
     private GpodnetSubscriptionChange readSubscriptionChangesFromJSONObject(
             JSONObject object) throws JSONException {
-        if (object == null) {
+        Validate.notNull(object);
-            throw new IllegalArgumentException("object must not be null");
+
-        }
         List<String> added = new LinkedList<String>();
         JSONArray jsonAdded = object.getJSONArray("add");
         for (int i = 0; i < jsonAdded.length(); i++) {

src/de/danoeh/antennapod/gpoddernet/model/GpodnetDevice.java

@@ -1,5 +1,7 @@
 package de.danoeh.antennapod.gpoddernet.model;
 
+import org.apache.commons.lang3.Validate;
+
 public class GpodnetDevice {
 
     private String id;
@@ -9,9 +11,7 @@ public class GpodnetDevice {
 
     public GpodnetDevice(String id, String caption, String type,
                          int subscriptions) {
-        if (id == null) {
+        Validate.notNull(id);
-            throw new IllegalArgumentException("ID must not be null");
-        }
 
         this.id = id;
         this.caption = caption;

src/de/danoeh/antennapod/gpoddernet/model/GpodnetPodcast.java

@@ -1,5 +1,7 @@
 package de.danoeh.antennapod.gpoddernet.model;
 
+import org.apache.commons.lang3.Validate;
+
 public class GpodnetPodcast {
     private String url;
     private String title;
@@ -11,10 +13,9 @@ public class GpodnetPodcast {
 
     public GpodnetPodcast(String url, String title, String description,
                           int subscribers, String logoUrl, String website, String mygpoLink) {
-        if (url == null || title == null || description == null) {
+        Validate.notNull(url);
-            throw new IllegalArgumentException(
+        Validate.notNull(title);
-                    "URL, title and description must not be null");
+        Validate.notNull(description);
-        }
 
         this.url = url;
         this.title = title;

src/de/danoeh/antennapod/gpoddernet/model/GpodnetSubscriptionChange.java

@@ -1,5 +1,7 @@
 package de.danoeh.antennapod.gpoddernet.model;
 
+import org.apache.commons.lang3.Validate;
+
 import java.util.List;
 
 public class GpodnetSubscriptionChange {
@@ -9,10 +11,9 @@ public class GpodnetSubscriptionChange {
 
     public GpodnetSubscriptionChange(List<String> added, List<String> removed,
                                      long timestamp) {
-        if (added == null || removed == null) {
+        Validate.notNull(added);
-            throw new IllegalArgumentException(
+        Validate.notNull(removed);
-                    "added and remove must not be null");
+
-        }
         this.added = added;
         this.removed = removed;
         this.timestamp = timestamp;

src/de/danoeh/antennapod/gpoddernet/model/GpodnetTag.java

@@ -1,5 +1,7 @@
 package de.danoeh.antennapod.gpoddernet.model;
 
+import org.apache.commons.lang3.Validate;
+
 import java.util.Comparator;
 
 public class GpodnetTag {
@@ -8,9 +10,7 @@ public class GpodnetTag {
     private int usage;
 
     public GpodnetTag(String name, int usage) {
-        if (name == null) {
+        Validate.notNull(name);
-            throw new IllegalArgumentException("Name must not be null");
-        }
 
         this.name = name;
         this.usage = usage;

src/de/danoeh/antennapod/preferences/PlaybackPreferences.java

@@ -4,6 +4,9 @@ import android.content.Context;
 import android.content.SharedPreferences;
 import android.preference.PreferenceManager;
 import android.util.Log;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.BuildConfig;
 
 /**
@@ -66,8 +69,8 @@ public class PlaybackPreferences implements
 	public static void createInstance(Context context) {
 		if (BuildConfig.DEBUG)
 			Log.d(TAG, "Creating new instance of UserPreferences");
-		if (context == null)
+		Validate.notNull(context);
-			throw new IllegalArgumentException("Context must not be null");
+
 		instance = new PlaybackPreferences(context);
 
 		PreferenceManager.getDefaultSharedPreferences(context)

src/de/danoeh/antennapod/preferences/UserPreferences.java

@@ -12,6 +12,7 @@ import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.activity.OpmlImportFromPathActivity;
 import de.danoeh.antennapod.receiver.FeedUpdateReceiver;
 import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.Validate;
 import org.json.JSONArray;
 import org.json.JSONException;
 
@@ -92,8 +93,8 @@ public class UserPreferences implements
 	public static void createInstance(Context context) {
 		if (BuildConfig.DEBUG)
 			Log.d(TAG, "Creating new instance of UserPreferences");
-		if (context == null)
+		Validate.notNull(context);
-			throw new IllegalArgumentException("Context must not be null");
+
 		instance = new UserPreferences(context);
 
 		createImportDirectory();

src/de/danoeh/antennapod/receiver/AlarmUpdateReceiver.java

@@ -4,6 +4,9 @@ import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.util.Log;
+
+import org.apache.commons.lang3.StringUtils;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.preferences.UserPreferences;
 
@@ -15,10 +18,10 @@ public class AlarmUpdateReceiver extends BroadcastReceiver {
 	public void onReceive(Context context, Intent intent) {
 		if (BuildConfig.DEBUG)
 			Log.d(TAG, "Received intent");
-		if (intent.getAction().equals(Intent.ACTION_BOOT_COMPLETED)) {
+		if (StringUtils.equals(intent.getAction(), Intent.ACTION_BOOT_COMPLETED)) {
 			if (BuildConfig.DEBUG)
 				Log.d(TAG, "Resetting update alarm after reboot");
-		} else if (intent.getAction().equals(Intent.ACTION_PACKAGE_REPLACED)) {
+		} else if (StringUtils.equals(intent.getAction(), Intent.ACTION_PACKAGE_REPLACED)) {
 			if (BuildConfig.DEBUG)
 				Log.d(TAG, "Resetting update alarm after app upgrade");
 		}

src/de/danoeh/antennapod/receiver/ConnectivityActionReceiver.java

@@ -6,6 +6,9 @@ import android.content.Intent;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.util.Log;
+
+import org.apache.commons.lang3.StringUtils;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.storage.DBTasks;
 import de.danoeh.antennapod.storage.DownloadRequester;
@@ -16,7 +19,7 @@ public class ConnectivityActionReceiver extends BroadcastReceiver {
 
 	@Override
 	public void onReceive(final Context context, Intent intent) {
-		if (intent.getAction().equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
+		if (StringUtils.equals(intent.getAction(), ConnectivityManager.CONNECTIVITY_ACTION)) {
 			if (BuildConfig.DEBUG)
 				Log.d(TAG, "Received intent");
 

src/de/danoeh/antennapod/receiver/FeedUpdateReceiver.java

@@ -6,6 +6,9 @@ import android.content.Intent;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.util.Log;
+
+import org.apache.commons.lang3.StringUtils;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.preferences.UserPreferences;
 import de.danoeh.antennapod.storage.DBTasks;
@@ -17,7 +20,7 @@ public class FeedUpdateReceiver extends BroadcastReceiver {
 
 	@Override
 	public void onReceive(Context context, Intent intent) {
-		if (intent.getAction().equals(ACTION_REFRESH_FEEDS)) {
+		if (StringUtils.equals(intent.getAction(), ACTION_REFRESH_FEEDS)) {
 			if (BuildConfig.DEBUG)
 				Log.d(TAG, "Received intent");
 			boolean mobileUpdate = UserPreferences.isAllowMobileUpdate();

src/de/danoeh/antennapod/receiver/PlayerWidget.java

@@ -5,6 +5,9 @@ import android.appwidget.AppWidgetProvider;
 import android.content.Context;
 import android.content.Intent;
 import android.util.Log;
+
+import org.apache.commons.lang3.StringUtils;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.service.playback.PlayerWidgetService;
 
@@ -15,9 +18,9 @@ public class PlayerWidget extends AppWidgetProvider {
 
 	@Override
 	public void onReceive(Context context, Intent intent) {
-		if (intent.getAction().equals(FORCE_WIDGET_UPDATE)) {
+		if (StringUtils.equals(intent.getAction(), FORCE_WIDGET_UPDATE)) {
 			startUpdate(context);
-		} else if (intent.getAction().equals(STOP_WIDGET_UPDATE)) {
+		} else if (StringUtils.equals(intent.getAction(), STOP_WIDGET_UPDATE)) {
 			stopUpdate(context);
 		}
 

src/de/danoeh/antennapod/service/download/DownloadRequest.java

@@ -3,6 +3,8 @@ package de.danoeh.antennapod.service.download;
 import android.os.Parcel;
 import android.os.Parcelable;
 
+import org.apache.commons.lang3.Validate;
+
 public class DownloadRequest implements Parcelable {
 
     private final String destination;
@@ -21,15 +23,9 @@ public class DownloadRequest implements Parcelable {
 
     public DownloadRequest(String destination, String source, String title,
                            long feedfileId, int feedfileType, String username, String password, boolean deleteOnFailure) {
-        if (destination == null) {
+        Validate.notNull(destination);
-            throw new IllegalArgumentException("Destination must not be null");
+        Validate.notNull(source);
-        }
+        Validate.notNull(title);
-        if (source == null) {
-            throw new IllegalArgumentException("Source must not be null");
-        }
-        if (title == null) {
-            throw new IllegalArgumentException("Title must not be null");
-        }
 
         this.destination = destination;
         this.source = source;
@@ -110,11 +106,14 @@ public class DownloadRequest implements Parcelable {
         if (size != that.size) return false;
         if (soFar != that.soFar) return false;
         if (statusMsg != that.statusMsg) return false;
-        if (destination != null ? !destination.equals(that.destination) : that.destination != null) return false;
+        if (destination != null ? !destination.equals(that.destination) : that.destination != null)
-        if (password != null ? !password.equals(that.password) : that.password != null) return false;
+            return false;
+        if (password != null ? !password.equals(that.password) : that.password != null)
+            return false;
         if (source != null ? !source.equals(that.source) : that.source != null) return false;
         if (title != null ? !title.equals(that.title) : that.title != null) return false;
-        if (username != null ? !username.equals(that.username) : that.username != null) return false;
+        if (username != null ? !username.equals(that.username) : that.username != null)
+            return false;
 
         return true;
     }

src/de/danoeh/antennapod/service/download/DownloadService.java

@@ -34,6 +34,7 @@ import de.danoeh.antennapod.util.DownloadError;
 import de.danoeh.antennapod.util.InvalidFeedException;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.Validate;
 import org.apache.http.HttpStatus;
 import org.xml.sax.SAXException;
 
@@ -394,12 +395,10 @@ public class DownloadService extends Service {
 
         @Override
         public void onReceive(Context context, Intent intent) {
-            if (intent.getAction().equals(ACTION_CANCEL_DOWNLOAD)) {
+            if (StringUtils.equals(intent.getAction(), ACTION_CANCEL_DOWNLOAD)) {
                 String url = intent.getStringExtra(EXTRA_DOWNLOAD_URL);
-                if (url == null) {
+                Validate.notNull(url, "ACTION_CANCEL_DOWNLOAD intent needs download url extra");
-                    throw new IllegalArgumentException(
+
-                            "ACTION_CANCEL_DOWNLOAD intent needs download url extra");
-                }
                 if (BuildConfig.DEBUG)
                     Log.d(TAG, "Cancelling download with url " + url);
                 Downloader d = getDownloader(url);
@@ -409,7 +408,7 @@ public class DownloadService extends Service {
                     Log.e(TAG, "Could not cancel download with url " + url);
                 }
 
-            } else if (intent.getAction().equals(ACTION_CANCEL_ALL_DOWNLOADS)) {
+            } else if (StringUtils.equals(intent.getAction(), ACTION_CANCEL_ALL_DOWNLOADS)) {
                 for (Downloader d : downloads) {
                     d.cancel();
                     if (BuildConfig.DEBUG)
@@ -1033,12 +1032,9 @@ public class DownloadService extends Service {
         private DownloadStatus status;
 
         public ImageHandlerThread(DownloadStatus status, DownloadRequest request) {
-            if (status == null) {
+            Validate.notNull(status);
-                throw new IllegalArgumentException("Status must not be null");
+            Validate.notNull(request);
-            }
+
-            if (request == null) {
-                throw new IllegalArgumentException("Request must not be null");
-            }
             this.status = status;
             this.request = request;
         }
@@ -1070,12 +1066,8 @@ public class DownloadService extends Service {
         private DownloadStatus status;
 
         public MediaHandlerThread(DownloadStatus status, DownloadRequest request) {
-            if (status == null) {
+            Validate.notNull(status);
-                throw new IllegalArgumentException("Status must not be null");
+            Validate.notNull(request);
-            }
-            if (request == null) {
-                throw new IllegalArgumentException("Request must not be null");
-            }
 
             this.status = status;
             this.request = request;

src/de/danoeh/antennapod/service/download/DownloadStatus.java

@@ -1,5 +1,7 @@
 package de.danoeh.antennapod.service.download;
 
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.feed.FeedFile;
 import de.danoeh.antennapod.util.DownloadError;
 
@@ -59,9 +61,8 @@ public class DownloadStatus {
 
 	public DownloadStatus(DownloadRequest request, DownloadError reason,
 			boolean successful, boolean cancelled, String reasonDetailed) {
-		if (request == null) {
+        Validate.notNull(request);
-			throw new IllegalArgumentException("request must not be null");
+
-		}
 		this.title = request.getTitle();
 		this.feedfileId = request.getFeedfileId();
 		this.feedfileType = request.getFeedfileType();
@@ -75,9 +76,7 @@ public class DownloadStatus {
 	/** Constructor for creating new completed downloads. */
 	public DownloadStatus(FeedFile feedfile, String title, DownloadError reason,
 			boolean successful, String reasonDetailed) {
-		if (feedfile == null) {
+		Validate.notNull(feedfile);
-			throw new IllegalArgumentException("feedfile must not be null");
-		}
 
 		this.title = title;
 		this.done = true;

src/de/danoeh/antennapod/service/playback/PlaybackService.java

@@ -23,6 +23,9 @@ import android.util.Pair;
 import android.view.KeyEvent;
 import android.view.SurfaceHolder;
 import android.widget.Toast;
+
+import org.apache.commons.lang3.StringUtils;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.PodcastApp;
 import de.danoeh.antennapod.R;
@@ -896,8 +899,7 @@ public class PlaybackService extends Service {
 
         @Override
         public void onReceive(Context context, Intent intent) {
-            if (intent.getAction() != null &&
+            if (StringUtils.equals(intent.getAction(), Intent.ACTION_HEADSET_PLUG)) {
-                    intent.getAction().equals(Intent.ACTION_HEADSET_PLUG)) {
                 int state = intent.getIntExtra("state", -1);
                 if (state != -1) {
                     if (BuildConfig.DEBUG)
@@ -939,8 +941,7 @@ public class PlaybackService extends Service {
 
         @Override
         public void onReceive(Context context, Intent intent) {
-            if (intent.getAction() != null &&
+            if (StringUtils.equals(intent.getAction(), ACTION_SHUTDOWN_PLAYBACK_SERVICE)) {
-                    intent.getAction().equals(ACTION_SHUTDOWN_PLAYBACK_SERVICE)) {
                 stopSelf();
             }
         }
@@ -950,8 +951,7 @@ public class PlaybackService extends Service {
     private BroadcastReceiver skipCurrentEpisodeReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
-            if (intent.getAction() != null &&
+            if (StringUtils.equals(intent.getAction(), ACTION_SKIP_CURRENT_EPISODE)) {
-                    intent.getAction().equals(ACTION_SKIP_CURRENT_EPISODE)) {
                 if (BuildConfig.DEBUG)
                     Log.d(TAG, "Received SKIP_CURRENT_EPISODE intent");
                 mediaPlayer.endPlayback();

src/de/danoeh/antennapod/service/playback/PlaybackServiceMediaPlayer.java

@@ -7,6 +7,9 @@ import android.media.RemoteControlClient;
 import android.util.Log;
 import android.util.Pair;
 import android.view.SurfaceHolder;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.feed.Chapter;
 import de.danoeh.antennapod.feed.MediaType;
@@ -61,10 +64,8 @@ public class PlaybackServiceMediaPlayer {
     private final ThreadPoolExecutor executor;
 
     public PlaybackServiceMediaPlayer(Context context, PSMPCallback callback) {
-        if (context == null)
+        Validate.notNull(context);
-            throw new IllegalArgumentException("context = null");
+        Validate.notNull(callback);
-        if (callback == null)
-            throw new IllegalArgumentException("callback = null");
 
         this.context = context;
         this.callback = callback;
@@ -115,8 +116,8 @@ public class PlaybackServiceMediaPlayer {
      * @param prepareImmediately Set to true if the method should also prepare the episode for playback.
      */
     public void playMediaObject(final Playable playable, final boolean stream, final boolean startWhenPrepared, final boolean prepareImmediately) {
-        if (playable == null)
+        Validate.notNull(playable);
-            throw new IllegalArgumentException("playable = null");
+
         if (BuildConfig.DEBUG) Log.d(TAG, "Play media object.");
         executor.submit(new Runnable() {
             @Override
@@ -142,8 +143,7 @@ public class PlaybackServiceMediaPlayer {
      * @see #playMediaObject(de.danoeh.antennapod.util.playback.Playable, boolean, boolean, boolean)
      */
     private void playMediaObject(final Playable playable, final boolean forceReset, final boolean stream, final boolean startWhenPrepared, final boolean prepareImmediately) {
-        if (playable == null)
+        Validate.notNull(playable);
-            throw new IllegalArgumentException("playable = null");
         if (!playerLock.isHeldByCurrentThread())
             throw new IllegalStateException("method requires playerLock");
 
@@ -458,8 +458,8 @@ public class PlaybackServiceMediaPlayer {
      * Seek to the start of the specified chapter.
      */
     public void seekToChapter(Chapter c) {
-        if (c == null)
+        Validate.notNull(c);
-            throw new IllegalArgumentException("c = null");
+
         seekTo((int) c.getStart());
     }
 
@@ -662,8 +662,8 @@ public class PlaybackServiceMediaPlayer {
      * @param newMedia  The new playable object of the PSMP object. This can be null.
      */
     private synchronized void setPlayerStatus(PlayerStatus newStatus, Playable newMedia) {
-        if (newStatus == null)
+        Validate.notNull(newStatus);
-            throw new IllegalArgumentException("newStatus = null");
+
         if (BuildConfig.DEBUG) Log.d(TAG, "Setting player status to " + newStatus);
 
         this.playerStatus = newStatus;

src/de/danoeh/antennapod/service/playback/PlaybackServiceTaskManager.java

@@ -2,6 +2,9 @@ package de.danoeh.antennapod.service.playback;
 
 import android.content.Context;
 import android.util.Log;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.feed.EventDistributor;
 import de.danoeh.antennapod.feed.FeedItem;
@@ -52,10 +55,8 @@ public class PlaybackServiceTaskManager {
      * @param callback A PSTMCallback object for notifying the user about updates. Must not be null.
      */
     public PlaybackServiceTaskManager(Context context, PSTMCallback callback) {
-        if (context == null)
+        Validate.notNull(context);
-            throw new IllegalArgumentException("context must not be null");
+        Validate.notNull(callback);
-        if (callback == null)
-            throw new IllegalArgumentException("callback must not be null");
 
         this.context = context;
         this.callback = callback;
@@ -195,8 +196,7 @@ public class PlaybackServiceTaskManager {
      * @throws java.lang.IllegalArgumentException if waitingTime <= 0
      */
     public synchronized void setSleepTimer(long waitingTime) {
-        if (waitingTime <= 0)
+        Validate.isTrue(waitingTime > 0, "Waiting time <= 0");
-            throw new IllegalArgumentException("waitingTime <= 0");
 
         if (BuildConfig.DEBUG)
             Log.d(TAG, "Setting sleep timer to " + Long.toString(waitingTime)
@@ -271,8 +271,7 @@ public class PlaybackServiceTaskManager {
      * On completion, the callback's onChapterLoaded method will be called.
      */
     public synchronized void startChapterLoader(final Playable media) {
-        if (media == null)
+        Validate.notNull(media);
-            throw new IllegalArgumentException("media = null");
 
         if (isChapterLoaderActive()) {
             cancelChapterLoader();

src/de/danoeh/antennapod/spa/SPAUtil.java

@@ -5,6 +5,9 @@ import android.content.Intent;
 import android.content.SharedPreferences;
 import android.preference.PreferenceManager;
 import android.util.Log;
+
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.receiver.SPAReceiver;
 
@@ -56,7 +59,7 @@ public class SPAUtil {
      */
     public static void resetSPAPreferences(Context c) {
         if (BuildConfig.DEBUG) {
-            if (c == null) throw new IllegalArgumentException("c = null");
+            Validate.notNull(c);
             SharedPreferences.Editor editor = PreferenceManager
                     .getDefaultSharedPreferences(c.getApplicationContext()).edit();
             editor.putBoolean(PREF_HAS_QUERIED_SP_APPS, false);

src/de/danoeh/antennapod/storage/DownloadRequester.java

@@ -14,6 +14,7 @@ import de.danoeh.antennapod.util.URLChecker;
 import org.apache.commons.io.FilenameUtils;
 import org.apache.commons.lang3.StringEscapeUtils;
 import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.Validate;
 
 import java.io.File;
 import java.util.Map;
@@ -57,8 +58,9 @@ public class DownloadRequester {
      * @return True if the download request was accepted, false otherwise.
      */
     public boolean download(Context context, DownloadRequest request) {
-        if (context == null) throw new IllegalArgumentException("context = null");
+        Validate.notNull(context);
-        if (request == null) throw new IllegalArgumentException("request = null");
+        Validate.notNull(request);
+
         if (downloads.containsKey(request.getSource())) {
             if (BuildConfig.DEBUG) Log.i(TAG, "DownloadRequest is already stored.");
             return false;

src/de/danoeh/antennapod/storage/PodDBAdapter.java

@@ -10,14 +10,23 @@ import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteDatabase.CursorFactory;
 import android.database.sqlite.SQLiteOpenHelper;
 import android.util.Log;
-import de.danoeh.antennapod.BuildConfig;
+
-import de.danoeh.antennapod.feed.*;
+import org.apache.commons.lang3.Validate;
-import de.danoeh.antennapod.service.download.DownloadStatus;
-import de.danoeh.antennapod.util.flattr.FlattrStatus;
 
 import java.util.Arrays;
 import java.util.List;
 
+import de.danoeh.antennapod.BuildConfig;
+import de.danoeh.antennapod.feed.Chapter;
+import de.danoeh.antennapod.feed.Feed;
+import de.danoeh.antennapod.feed.FeedComponent;
+import de.danoeh.antennapod.feed.FeedImage;
+import de.danoeh.antennapod.feed.FeedItem;
+import de.danoeh.antennapod.feed.FeedMedia;
+import de.danoeh.antennapod.feed.FeedPreferences;
+import de.danoeh.antennapod.service.download.DownloadStatus;
+import de.danoeh.antennapod.util.flattr.FlattrStatus;
+
 // TODO Remove media column from feeditem table
 
 /**
@@ -1024,9 +1033,8 @@ public class PodDBAdapter {
      * @throws IllegalArgumentException if limit < 0
      */
     public final Cursor getCompletedMediaCursor(int limit) {
-        if (limit < 0) {
+        Validate.isTrue(limit >= 0, "Limit must be >= 0");
-            throw new IllegalArgumentException("Limit must be >= 0");
+
-        }
         Cursor c = db.query(TABLE_NAME_FEED_MEDIA, null,
                 KEY_PLAYBACK_COMPLETION_DATE + " > 0 LIMIT " + limit, null, null,
                 null, null);

src/de/danoeh/antennapod/util/playback/Playable.java

@@ -12,6 +12,7 @@ import de.danoeh.antennapod.feed.MediaType;
 import de.danoeh.antennapod.storage.DBReader;
 import de.danoeh.antennapod.util.ShownotesProvider;
 import org.apache.commons.io.IOUtils;
+import org.apache.commons.lang3.Validate;
 
 import java.io.ByteArrayInputStream;
 import java.io.InputStream;
@@ -216,9 +217,8 @@ public interface Playable extends Parcelable,
         private Playable playable;
 
         public DefaultPlayableImageLoader(Playable playable) {
-            if (playable == null) {
+            Validate.notNull(playable);
-                throw new IllegalArgumentException("Playable must not be null");
+
-            }
             this.playable = playable;
         }
 

src/de/danoeh/antennapod/util/playback/PlaybackController.java

@@ -15,6 +15,10 @@ import android.view.View.OnClickListener;
 import android.widget.ImageButton;
 import android.widget.SeekBar;
 import android.widget.TextView;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.Validate;
+
 import de.danoeh.antennapod.BuildConfig;
 import de.danoeh.antennapod.R;
 import de.danoeh.antennapod.feed.Chapter;
@@ -62,8 +66,8 @@ public abstract class PlaybackController {
     private boolean reinitOnPause;
 
     public PlaybackController(Activity activity, boolean reinitOnPause) {
-        if (activity == null)
+        Validate.notNull(activity);
-            throw new IllegalArgumentException("activity = null");
+
         this.activity = activity;
         this.reinitOnPause = reinitOnPause;
         schedExecutor = new ScheduledThreadPoolExecutor(SCHED_EX_POOLSIZE,
@@ -360,7 +364,7 @@ public abstract class PlaybackController {
         @Override
         public void onReceive(Context context, Intent intent) {
             if (isConnectedToPlaybackService()) {
-                if (intent.getAction().equals(
+                if (StringUtils.equals(intent.getAction(),
                         PlaybackService.ACTION_SHUTDOWN_PLAYBACK_SERVICE)) {
                     release();
                     onShutdownNotification();

src/de/danoeh/antennapod/util/playback/Timeline.java

@@ -5,6 +5,7 @@ import android.content.res.TypedArray;
 import android.util.Log;
 import android.util.TypedValue;
 
+import org.apache.commons.lang3.Validate;
 import org.jsoup.Jsoup;
 import org.jsoup.nodes.Document;
 import org.jsoup.nodes.Element;
@@ -154,7 +155,7 @@ public class Timeline {
 
 
     public void setShownotesProvider(ShownotesProvider shownotesProvider) {
-        if (shownotesProvider == null) throw new IllegalArgumentException("shownotesProvider = null");
+        Validate.notNull(shownotesProvider);
         this.shownotesProvider = shownotesProvider;
     }
 }