Merge pull request #1440 from mfietz/issue/1439-stupid-MIUI

Fix MIUI crash

30 files changed, 254 insertions, 274 deletions

diff --git a/core/src/main/java/de/danoeh/antennapod/core/asynctask/FlattrClickWorker.java b/core/src/main/java/de/danoeh/antennapod/core/asynctask/FlattrClickWorker.java
index 93b584677..ac032fcc0 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/asynctask/FlattrClickWorker.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/asynctask/FlattrClickWorker.java
@@ -6,11 +6,11 @@ import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.content.Context;
 import android.os.AsyncTask;
+import android.support.annotation.NonNull;
 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;
@@ -63,8 +63,7 @@ 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) {
-        Validate.notNull(context);
+    public FlattrClickWorker(@NonNull Context context) {
         this.context = context.getApplicationContext();
     }
 
diff --git a/core/src/main/java/de/danoeh/antennapod/core/feed/EventDistributor.java b/core/src/main/java/de/danoeh/antennapod/core/feed/EventDistributor.java
index 3425e8a8e..7ccb742fb 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/feed/EventDistributor.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/feed/EventDistributor.java
@@ -3,8 +3,6 @@ package de.danoeh.antennapod.core.feed;
 import android.os.Handler;
 import android.util.Log;
 
-import org.apache.commons.lang3.Validate;
-
 import java.util.AbstractQueue;
 import java.util.Observable;
 import java.util.Observer;
@@ -84,7 +82,6 @@ public class EventDistributor extends Observable {
 	@Override
 	public void addObserver(Observer observer) {
 		super.addObserver(observer);
-        Validate.isInstanceOf(EventListener.class, observer);
 	}
 
 	public void sendUnreadItemsUpdateBroadcast() {
diff --git a/core/src/main/java/de/danoeh/antennapod/core/feed/Feed.java b/core/src/main/java/de/danoeh/antennapod/core/feed/Feed.java
index 2acb7108d..0de046fe5 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/feed/Feed.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/feed/Feed.java
@@ -4,8 +4,7 @@ import android.content.Context;
 import android.database.Cursor;
 import android.net.Uri;
 import android.support.annotation.Nullable;
-
-import org.apache.commons.lang3.StringUtils;
+import android.text.TextUtils;
 
 import java.util.ArrayList;
 import java.util.Date;
@@ -367,7 +366,7 @@ public class Feed extends FeedFile implements FlattrThing, ImageResource {
         if (other.isPaged() && !this.isPaged()) {
             return true;
         }
-        if (!StringUtils.equals(other.getNextPageLink(), this.getNextPageLink())) {
+        if (!TextUtils.equals(other.getNextPageLink(), this.getNextPageLink())) {
             return true;
         }
         return false;
diff --git a/core/src/main/java/de/danoeh/antennapod/core/feed/FeedItemFilter.java b/core/src/main/java/de/danoeh/antennapod/core/feed/FeedItemFilter.java
index c1d21552e..d3d5dd0a1 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/feed/FeedItemFilter.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/feed/FeedItemFilter.java
@@ -1,8 +1,6 @@
 package de.danoeh.antennapod.core.feed;
 
-import android.content.Context;
-
-import org.apache.commons.lang3.StringUtils;
+import android.text.TextUtils;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -22,7 +20,7 @@ public class FeedItemFilter {
     private boolean hideNotDownloaded = false;
 
     public FeedItemFilter(String properties) {
-        this(StringUtils.split(properties, ','));
+        this(TextUtils.split(",", properties));
     }
 
     public FeedItemFilter(String[] properties) {
diff --git a/core/src/main/java/de/danoeh/antennapod/core/feed/FeedPreferences.java b/core/src/main/java/de/danoeh/antennapod/core/feed/FeedPreferences.java
index eb28a3185..ed568a6e5 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/feed/FeedPreferences.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/feed/FeedPreferences.java
@@ -2,8 +2,7 @@ package de.danoeh.antennapod.core.feed;
 
 import android.content.Context;
 import android.database.Cursor;
-
-import org.apache.commons.lang3.StringUtils;
+import android.text.TextUtils;
 
 import de.danoeh.antennapod.core.preferences.UserPreferences;
 import de.danoeh.antennapod.core.storage.DBWriter;
@@ -60,10 +59,10 @@ public class FeedPreferences {
     public boolean compareWithOther(FeedPreferences other) {
         if (other == null)
             return true;
-        if (!StringUtils.equals(username, other.username)) {
+        if (!TextUtils.equals(username, other.username)) {
             return true;
         }
-        if (!StringUtils.equals(password, other.password)) {
+        if (!TextUtils.equals(password, other.password)) {
             return true;
         }
         return false;
diff --git a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/GpodnetService.java b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/GpodnetService.java
index d8e07085d..d2a13f768 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/GpodnetService.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/GpodnetService.java
@@ -1,5 +1,7 @@
 package de.danoeh.antennapod.core.gpoddernet;
 
+import android.support.annotation.NonNull;
+
 import com.squareup.okhttp.Credentials;
 import com.squareup.okhttp.MediaType;
 import com.squareup.okhttp.OkHttpClient;
@@ -8,7 +10,6 @@ import com.squareup.okhttp.RequestBody;
 import com.squareup.okhttp.Response;
 import com.squareup.okhttp.ResponseBody;
 
-import org.apache.commons.lang3.Validate;
 import org.apache.http.HttpStatus;
 import org.apache.http.client.ClientProtocolException;
 import org.json.JSONArray;
@@ -101,10 +102,9 @@ public class GpodnetService {
      *
      * @throws IllegalArgumentException if tag is null
      */
-    public List<GpodnetPodcast> getPodcastsForTag(GpodnetTag tag, int count)
+    public List<GpodnetPodcast> getPodcastsForTag(@NonNull GpodnetTag tag,
+                                                  int count)
             throws GpodnetServiceException {
-        Validate.notNull(tag);
-
         try {
             URL url = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/api/2/tag/%s/%d.json", tag.getTag(), count), null).toURL();
@@ -128,7 +128,9 @@ public class GpodnetService {
      */
     public List<GpodnetPodcast> getPodcastToplist(int count)
             throws GpodnetServiceException {
-        Validate.isTrue(count >= 1 && count <= 100, "Count must be in range 1..100");
+        if(count < 1 || count > 100) {
+            throw new IllegalArgumentException("Count must be in range 1..100");
+        }
 
         try {
             URL url = new URI(BASE_SCHEME, BASE_HOST, String.format(
@@ -158,7 +160,9 @@ public class GpodnetService {
      * @throws GpodnetServiceAuthenticationException If there is an authentication error.
      */
     public List<GpodnetPodcast> getSuggestions(int count) throws GpodnetServiceException {
-        Validate.isTrue(count >= 1 && count <= 100, "Count must be in range 1..100");
+        if(count < 1 || count > 100) {
+            throw new IllegalArgumentException("Count must be in range 1..100");
+        }
 
         try {
             URL url = new URI(BASE_SCHEME, BASE_HOST, String.format(
@@ -215,10 +219,8 @@ public class GpodnetService {
      * @throws IllegalArgumentException              If username is null.
      * @throws GpodnetServiceAuthenticationException If there is an authentication error.
      */
-    public List<GpodnetDevice> getDevices(String username)
+    public List<GpodnetDevice> getDevices(@NonNull String username)
             throws GpodnetServiceException {
-        Validate.notNull(username);
-
         try {
             URL url = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/api/2/devices/%s.json", username), null).toURL();
@@ -243,12 +245,11 @@ public class GpodnetService {
      * @throws IllegalArgumentException              If username or deviceId is null.
      * @throws GpodnetServiceAuthenticationException If there is an authentication error.
      */
-    public void configureDevice(String username, String deviceId,
-                                String caption, GpodnetDevice.DeviceType type)
+    public void configureDevice(@NonNull String username,
+                                @NonNull String deviceId,
+                                String caption,
+                                GpodnetDevice.DeviceType type)
             throws GpodnetServiceException {
-        Validate.notNull(username);
-        Validate.notNull(deviceId);
-
         try {
             URL url = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/api/2/devices/%s/%s.json", username, deviceId), null).toURL();
@@ -286,11 +287,9 @@ public class GpodnetService {
      * @throws IllegalArgumentException              If username or deviceId is null.
      * @throws GpodnetServiceAuthenticationException If there is an authentication error.
      */
-    public String getSubscriptionsOfDevice(String username, String deviceId)
+    public String getSubscriptionsOfDevice(@NonNull String username,
+                                           @NonNull String deviceId)
             throws GpodnetServiceException {
-        Validate.notNull(username);
-        Validate.notNull(deviceId);
-
         try {
             URL url = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/subscriptions/%s/%s.opml", username, deviceId), null).toURL();
@@ -313,9 +312,8 @@ public class GpodnetService {
      * @throws IllegalArgumentException              If username is null.
      * @throws GpodnetServiceAuthenticationException If there is an authentication error.
      */
-    public String getSubscriptionsOfUser(String username)
+    public String getSubscriptionsOfUser(@NonNull String username)
             throws GpodnetServiceException {
-        Validate.notNull(username);
 
         try {
             URL url = new URI(BASE_SCHEME, BASE_HOST, String.format(
@@ -342,12 +340,11 @@ public class GpodnetService {
      * @throws IllegalArgumentException              If username, deviceId or subscriptions is null.
      * @throws GpodnetServiceAuthenticationException If there is an authentication error.
      */
-    public void uploadSubscriptions(String username, String deviceId,
-                                    List<String> subscriptions) throws GpodnetServiceException {
-        if (username == null || deviceId == null || subscriptions == null) {
-            throw new IllegalArgumentException(
-                    "Username, device ID and subscriptions must not be null");
-        }
+    public void uploadSubscriptions(@NonNull String username,
+                                    @NonNull String deviceId,
+                                    @NonNull List<String> subscriptions)
+            throws GpodnetServiceException {
+
         try {
             URL url = new URI(BASE_SCHEME, BASE_HOST, String.format(
                     "/subscriptions/%s/%s.txt", username, deviceId), null).toURL();
@@ -363,6 +360,7 @@ public class GpodnetService {
             e.printStackTrace();
             throw new GpodnetServiceException(e);
         }
+
     }
 
     /**
@@ -381,12 +379,11 @@ public class GpodnetService {
      * @throws de.danoeh.antennapod.core.gpoddernet.GpodnetServiceException if added or removed contain duplicates or if there
      *                                                                      is an authentication error.
      */
-    public GpodnetUploadChangesResponse uploadChanges(String username, String deviceId, Collection<String> added,
-                                                      Collection<String> removed) throws GpodnetServiceException {
-        Validate.notNull(username);
-        Validate.notNull(deviceId);
-        Validate.notNull(added);
-        Validate.notNull(removed);
+    public GpodnetUploadChangesResponse uploadChanges(@NonNull String username,
+                                                      @NonNull String deviceId,
+                                                      @NonNull Collection<String> added,
+                                                      @NonNull Collection<String> removed)
+            throws GpodnetServiceException {
 
         try {
             URL url = new URI(BASE_SCHEME, BASE_HOST, String.format(
@@ -422,10 +419,9 @@ public class GpodnetService {
      * @throws IllegalArgumentException              If username or deviceId is null.
      * @throws GpodnetServiceAuthenticationException If there is an authentication error.
      */
-    public GpodnetSubscriptionChange getSubscriptionChanges(String username,
-                                                            String deviceId, long timestamp) throws GpodnetServiceException {
-        Validate.notNull(username);
-        Validate.notNull(deviceId);
+    public GpodnetSubscriptionChange getSubscriptionChanges(@NonNull String username,
+                                                            @NonNull String deviceId,
+                                                            long timestamp) throws GpodnetServiceException {
 
         String params = String.format("since=%d", timestamp);
         String path = String.format("/api/2/subscriptions/%s/%s.json",
@@ -460,11 +456,9 @@ public class GpodnetService {
      * @throws de.danoeh.antennapod.core.gpoddernet.GpodnetServiceException if added or removed contain duplicates or if there
      *                                                                      is an authentication error.
      */
-    public GpodnetEpisodeActionPostResponse uploadEpisodeActions(Collection<GpodnetEpisodeAction> episodeActions)
+    public GpodnetEpisodeActionPostResponse uploadEpisodeActions(@NonNull Collection<GpodnetEpisodeAction> episodeActions)
             throws GpodnetServiceException {
 
-        Validate.notNull(episodeActions);
-
         String username = GpodnetPreferences.getUsername();
 
         try {
@@ -533,11 +527,9 @@ public class GpodnetService {
      *
      * @throws IllegalArgumentException If username or password is null.
      */
-    public void authenticate(String username, String password)
+    public void authenticate(@NonNull String username,
+                             @NonNull String password)
             throws GpodnetServiceException {
-        Validate.notNull(username);
-        Validate.notNull(password);
-
         URL url;
         try {
             url = new URI(BASE_SCHEME, BASE_HOST, String.format(
@@ -564,10 +556,8 @@ public class GpodnetService {
         }.start();
     }
 
-    private String executeRequest(Request.Builder requestB)
+    private String executeRequest(@NonNull Request.Builder requestB)
             throws GpodnetServiceException {
-        Validate.notNull(requestB);
-
         Request request = requestB.header("User-Agent", ClientConfig.USER_AGENT).build();
         String responseString = null;
         Response response = null;
@@ -631,10 +621,8 @@ public class GpodnetService {
         return result;
     }
 
-    private String getStringFromResponseBody(ResponseBody body)
+    private String getStringFromResponseBody(@NonNull ResponseBody body)
             throws GpodnetServiceException {
-        Validate.notNull(body);
-
         ByteArrayOutputStream outputStream;
         int contentLength = 0;
         try {
@@ -661,9 +649,8 @@ public class GpodnetService {
         return outputStream.toString();
     }
 
-    private void checkStatusCode(Response response)
+    private void checkStatusCode(@NonNull Response response)
             throws GpodnetServiceException {
-        Validate.notNull(response);
         int responseCode = response.code();
         if (responseCode != HttpStatus.SC_OK) {
             if (responseCode == HttpStatus.SC_UNAUTHORIZED) {
@@ -675,17 +662,14 @@ public class GpodnetService {
         }
     }
 
-    private List<GpodnetPodcast> readPodcastListFromJSONArray(JSONArray array)
+    private List<GpodnetPodcast> readPodcastListFromJSONArray(@NonNull JSONArray array)
             throws JSONException {
-        Validate.notNull(array);
-
         List<GpodnetPodcast> result = new ArrayList<GpodnetPodcast>(
                 array.length());
         for (int i = 0; i < array.length(); i++) {
             result.add(readPodcastFromJSONObject(array.getJSONObject(i)));
         }
         return result;
-
     }
 
     private GpodnetPodcast readPodcastFromJSONObject(JSONObject object)
@@ -730,10 +714,8 @@ public class GpodnetService {
                 logoUrl, website, mygpoLink);
     }
 
-    private List<GpodnetDevice> readDeviceListFromJSONArray(JSONArray array)
+    private List<GpodnetDevice> readDeviceListFromJSONArray(@NonNull JSONArray array)
             throws JSONException {
-        Validate.notNull(array);
-
         List<GpodnetDevice> result = new ArrayList<GpodnetDevice>(
                 array.length());
         for (int i = 0; i < array.length(); i++) {
@@ -752,8 +734,7 @@ public class GpodnetService {
     }
 
     private GpodnetSubscriptionChange readSubscriptionChangesFromJSONObject(
-            JSONObject object) throws JSONException {
-        Validate.notNull(object);
+            @NonNull JSONObject object) throws JSONException {
 
         List<String> added = new LinkedList<String>();
         JSONArray jsonAdded = object.getJSONArray("add");
@@ -772,8 +753,7 @@ public class GpodnetService {
     }
 
     private GpodnetEpisodeActionGetResponse readEpisodeActionsFromJSONObject(
-            JSONObject object) throws JSONException {
-        Validate.notNull(object);
+            @NonNull JSONObject object) throws JSONException {
 
         List<GpodnetEpisodeAction> episodeActions = new ArrayList<GpodnetEpisodeAction>();
 
@@ -789,5 +769,4 @@ public class GpodnetService {
         return new GpodnetEpisodeActionGetResponse(episodeActions, timestamp);
     }
 
-
 }
diff --git a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetDevice.java b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetDevice.java
index 4885a243a..2d49c170a 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetDevice.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetDevice.java
@@ -1,6 +1,6 @@
 package de.danoeh.antennapod.core.gpoddernet.model;
 
-import org.apache.commons.lang3.Validate;
+import android.support.annotation.NonNull;
 
 public class GpodnetDevice {
 
@@ -9,10 +9,10 @@ public class GpodnetDevice {
     private DeviceType type;
     private int subscriptions;
 
-    public GpodnetDevice(String id, String caption, String type,
+    public GpodnetDevice(@NonNull String id,
+                         String caption,
+                         String type,
                          int subscriptions) {
-        Validate.notNull(id);
-
         this.id = id;
         this.caption = caption;
         this.type = DeviceType.fromString(type);
diff --git a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetEpisodeAction.java b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetEpisodeAction.java
index efe39485e..2d174a6bc 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetEpisodeAction.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetEpisodeAction.java
@@ -1,13 +1,9 @@
 package de.danoeh.antennapod.core.gpoddernet.model;
 
 
+import android.text.TextUtils;
 import android.util.Log;
 
-import org.apache.commons.lang3.StringUtils;
-import org.apache.commons.lang3.builder.EqualsBuilder;
-import org.apache.commons.lang3.builder.HashCodeBuilder;
-import org.apache.commons.lang3.builder.ToStringBuilder;
-import org.apache.commons.lang3.builder.ToStringStyle;
 import org.json.JSONException;
 import org.json.JSONObject;
 
@@ -90,7 +86,7 @@ public class GpodnetEpisodeAction {
         String podcast = object.optString("podcast", null);
         String episode = object.optString("episode", null);
         String actionString = object.optString("action", null);
-        if(StringUtils.isEmpty(podcast) || StringUtils.isEmpty(episode) || StringUtils.isEmpty(actionString)) {
+        if(TextUtils.isEmpty(podcast) || TextUtils.isEmpty(episode) || TextUtils.isEmpty(actionString)) {
             return null;
         }
         GpodnetEpisodeAction.Action action;
@@ -103,7 +99,7 @@ public class GpodnetEpisodeAction {
         GpodnetEpisodeAction.Builder builder = new GpodnetEpisodeAction.Builder(podcast, episode, action)
                 .deviceId(deviceId);
         String utcTimestamp = object.optString("timestamp", null);
-        if(StringUtils.isNotEmpty(utcTimestamp)) {
+        if(!TextUtils.isEmpty(utcTimestamp)) {
             builder.timestamp(DateUtils.parse(utcTimestamp));
         }
         if(action == GpodnetEpisodeAction.Action.PLAY) {
@@ -173,34 +169,34 @@ public class GpodnetEpisodeAction {
 
     @Override
     public boolean equals(Object o) {
-        if(o == null) return false;
-        if(this == o) return true;
-        if(this.getClass() != o.getClass()) return false;
-        GpodnetEpisodeAction that = (GpodnetEpisodeAction)o;
-        return new EqualsBuilder()
-                .append(this.podcast, that.podcast)
-                .append(this.episode, that.episode)
-                .append(this.deviceId, that.deviceId)
-                .append(this.action, that.action)
-                .append(this.timestamp, that.timestamp)
-                .append(this.started, that.started)
-                .append(this.position, that.position)
-                .append(this.total, that.total)
-                .isEquals();
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        GpodnetEpisodeAction that = (GpodnetEpisodeAction) o;
+
+        if (started != that.started) return false;
+        if (position != that.position) return false;
+        if (total != that.total) return false;
+        if (podcast != null ? !podcast.equals(that.podcast) : that.podcast != null) return false;
+        if (episode != null ? !episode.equals(that.episode) : that.episode != null) return false;
+        if (deviceId != null ? !deviceId.equals(that.deviceId) : that.deviceId != null)
+            return false;
+        if (action != that.action) return false;
+        return !(timestamp != null ? !timestamp.equals(that.timestamp) : that.timestamp != null);
+
     }
 
     @Override
     public int hashCode() {
-        return new HashCodeBuilder()
-                .append(this.podcast)
-                .append(this.episode)
-                .append(this.deviceId)
-                .append(this.action)
-                .append(this.timestamp)
-                .append(this.started)
-                .append(this.position)
-                .append(this.total)
-                .toHashCode();
+        int result = podcast != null ? podcast.hashCode() : 0;
+        result = 31 * result + (episode != null ? episode.hashCode() : 0);
+        result = 31 * result + (deviceId != null ? deviceId.hashCode() : 0);
+        result = 31 * result + (action != null ? action.hashCode() : 0);
+        result = 31 * result + (timestamp != null ? timestamp.hashCode() : 0);
+        result = 31 * result + started;
+        result = 31 * result + position;
+        result = 31 * result + total;
+        return result;
     }
 
     public String writeToString() {
@@ -245,7 +241,16 @@ public class GpodnetEpisodeAction {
 
     @Override
     public String toString() {
-        return ToStringBuilder.reflectionToString(this, ToStringStyle.SHORT_PREFIX_STYLE);
+        return "GpodnetEpisodeAction{" +
+                "podcast='" + podcast + '\'' +
+                ", episode='" + episode + '\'' +
+                ", deviceId='" + deviceId + '\'' +
+                ", action=" + action +
+                ", timestamp=" + timestamp +
+                ", started=" + started +
+                ", position=" + position +
+                ", total=" + total +
+                '}';
     }
 
     public static class Builder {
diff --git a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetEpisodeActionGetResponse.java b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetEpisodeActionGetResponse.java
index 50420f0a3..1e21efcda 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetEpisodeActionGetResponse.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetEpisodeActionGetResponse.java
@@ -1,9 +1,7 @@
 package de.danoeh.antennapod.core.gpoddernet.model;
 
 
-import org.apache.commons.lang3.Validate;
-import org.apache.commons.lang3.builder.ToStringBuilder;
-import org.apache.commons.lang3.builder.ToStringStyle;
+import android.support.annotation.NonNull;
 
 import java.util.List;
 
@@ -12,8 +10,8 @@ public class GpodnetEpisodeActionGetResponse {
     private final List<GpodnetEpisodeAction> episodeActions;
     private final long timestamp;
 
-    public GpodnetEpisodeActionGetResponse(List<GpodnetEpisodeAction> episodeActions, long timestamp) {
-        Validate.notNull(episodeActions);
+    public GpodnetEpisodeActionGetResponse(@NonNull List<GpodnetEpisodeAction> episodeActions,
+                                           long timestamp) {
         this.episodeActions = episodeActions;
         this.timestamp = timestamp;
     }
@@ -28,7 +26,9 @@ public class GpodnetEpisodeActionGetResponse {
 
     @Override
     public String toString() {
-        return ToStringBuilder.reflectionToString(this, ToStringStyle.SHORT_PREFIX_STYLE);
+        return "GpodnetEpisodeActionGetResponse{" +
+                "episodeActions=" + episodeActions +
+                ", timestamp=" + timestamp +
+                '}';
     }
-
 }
diff --git a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetPodcast.java b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetPodcast.java
index afebf66ac..191c0fa39 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetPodcast.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetPodcast.java
@@ -1,6 +1,6 @@
 package de.danoeh.antennapod.core.gpoddernet.model;
 
-import org.apache.commons.lang3.Validate;
+import android.support.annotation.NonNull;
 
 public class GpodnetPodcast {
     private String url;
@@ -11,12 +11,13 @@ public class GpodnetPodcast {
     private String website;
     private String mygpoLink;
 
-    public GpodnetPodcast(String url, String title, String description,
-                          int subscribers, String logoUrl, String website, String mygpoLink) {
-        Validate.notNull(url);
-        Validate.notNull(title);
-        Validate.notNull(description);
-
+    public GpodnetPodcast(@NonNull String url,
+                          @NonNull String title,
+                          @NonNull String description,
+                          int subscribers,
+                          String logoUrl,
+                          String website,
+                          String mygpoLink) {
         this.url = url;
         this.title = title;
         this.description = description;
diff --git a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetSubscriptionChange.java b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetSubscriptionChange.java
index a5cb8c0f0..6cc9b79a3 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetSubscriptionChange.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetSubscriptionChange.java
@@ -1,6 +1,6 @@
 package de.danoeh.antennapod.core.gpoddernet.model;
 
-import org.apache.commons.lang3.Validate;
+import android.support.annotation.NonNull;
 
 import java.util.List;
 
@@ -9,11 +9,9 @@ public class GpodnetSubscriptionChange {
     private List<String> removed;
     private long timestamp;
 
-    public GpodnetSubscriptionChange(List<String> added, List<String> removed,
+    public GpodnetSubscriptionChange(@NonNull List<String> added,
+                                     @NonNull List<String> removed,
                                      long timestamp) {
-        Validate.notNull(added);
-        Validate.notNull(removed);
-
         this.added = added;
         this.removed = removed;
         this.timestamp = timestamp;
diff --git a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetTag.java b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetTag.java
index ee13bef25..42a31afc5 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetTag.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/gpoddernet/model/GpodnetTag.java
@@ -2,8 +2,7 @@ package de.danoeh.antennapod.core.gpoddernet.model;
 
 import android.os.Parcel;
 import android.os.Parcelable;
-
-import org.apache.commons.lang3.Validate;
+import android.support.annotation.NonNull;
 
 public class GpodnetTag implements Parcelable  {
 
@@ -11,10 +10,7 @@ public class GpodnetTag implements Parcelable  {
     private final String tag;
     private final int usage;
 
-    public GpodnetTag(String title, String tag, int usage) {
-        Validate.notNull(title);
-        Validate.notNull(tag);
-
+    public GpodnetTag(@NonNull String title, @NonNull String tag, int usage) {
         this.title = title;
         this.tag = tag;
         this.usage = usage;
diff --git a/core/src/main/java/de/danoeh/antennapod/core/preferences/GpodnetPreferences.java b/core/src/main/java/de/danoeh/antennapod/core/preferences/GpodnetPreferences.java
index 1401d5f39..edd7b807a 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/preferences/GpodnetPreferences.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/preferences/GpodnetPreferences.java
@@ -2,10 +2,9 @@ package de.danoeh.antennapod.core.preferences;
 
 import android.content.Context;
 import android.content.SharedPreferences;
+import android.text.TextUtils;
 import android.util.Log;
 
-import org.apache.commons.lang3.StringUtils;
-
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
@@ -293,7 +292,7 @@ public class GpodnetPreferences {
         String[] lines = s.split("\n");
         List<GpodnetEpisodeAction> result = new ArrayList<GpodnetEpisodeAction>(lines.length);
         for(String line : lines) {
-            if(StringUtils.isNotBlank(line)) {
+            if(TextUtils.isEmpty(line)) {
                 GpodnetEpisodeAction action = GpodnetEpisodeAction.readFromString(line);
                 if(action != null) {
                     result.add(GpodnetEpisodeAction.readFromString(line));
diff --git a/core/src/main/java/de/danoeh/antennapod/core/preferences/UserPreferences.java b/core/src/main/java/de/danoeh/antennapod/core/preferences/UserPreferences.java
index abb5f1f99..d6ac8496b 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/preferences/UserPreferences.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/preferences/UserPreferences.java
@@ -7,11 +7,11 @@ import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.SystemClock;
 import android.preference.PreferenceManager;
+import android.support.annotation.NonNull;
 import android.support.v4.app.NotificationCompat;
+import android.text.TextUtils;
 import android.util.Log;
 
-import org.apache.commons.lang3.StringUtils;
-import org.apache.commons.lang3.Validate;
 import org.json.JSONArray;
 import org.json.JSONException;
 
@@ -121,9 +121,8 @@ public class UserPreferences {
      *
      * @throws IllegalArgumentException if context is null
      */
-    public static void init(Context context) {
+    public static void init(@NonNull Context context) {
         Log.d(TAG, "Creating new instance of UserPreferences");
-        Validate.notNull(context);
 
         UserPreferences.context = context.getApplicationContext();
         UserPreferences.prefs = PreferenceManager.getDefaultSharedPreferences(context);
@@ -152,7 +151,7 @@ public class UserPreferences {
 
     public static List<String> getHiddenDrawerItems() {
         String hiddenItems = prefs.getString(PREF_HIDDEN_DRAWER_ITEMS, "");
-        return new ArrayList<String>(Arrays.asList(StringUtils.split(hiddenItems, ',')));
+        return new ArrayList<>(Arrays.asList(TextUtils.split(hiddenItems, ",")));
     }
 
     public static int getFeedOrder() {
@@ -347,7 +346,7 @@ public class UserPreferences {
 
     public static String[] getAutodownloadSelectedNetworks() {
         String selectedNetWorks = prefs.getString(PREF_AUTODL_SELECTED_NETWORKS, "");
-        return StringUtils.split(selectedNetWorks, ',');
+        return TextUtils.split(selectedNetWorks, ",");
     }
 
     public static boolean shouldResumeAfterCall() {
@@ -388,7 +387,7 @@ public class UserPreferences {
 
     public static void setAutodownloadSelectedNetworks(String[] value) {
         prefs.edit()
-             .putString(PREF_AUTODL_SELECTED_NETWORKS, StringUtils.join(value, ','))
+             .putString(PREF_AUTODL_SELECTED_NETWORKS, TextUtils.join(",", value))
              .apply();
     }
 
@@ -422,7 +421,9 @@ public class UserPreferences {
      *                            flattrd. Must be a value between 0 and 1 (inclusive)
      * */
     public static void setAutoFlattrSettings( boolean enabled, float autoFlattrThreshold) {
-        Validate.inclusiveBetween(0.0, 1.0, autoFlattrThreshold);
+        if(autoFlattrThreshold < 0.0 || autoFlattrThreshold > 1.0) {
+            throw new IllegalArgumentException("Flattr threshold must be in range [0.0, 1.0]");
+        }
         prefs.edit()
              .putBoolean(PREF_AUTO_FLATTR, enabled)
              .putFloat(PREF_AUTO_FLATTR_PLAYED_DURATION_THRESHOLD, autoFlattrThreshold)
@@ -430,7 +431,7 @@ public class UserPreferences {
     }
 
     public static void setHiddenDrawerItems(List<String> items) {
-        String str = StringUtils.join(items, ',');
+        String str = TextUtils.join(",", items);
         prefs.edit()
              .putString(PREF_HIDDEN_DRAWER_ITEMS, str)
              .apply();
diff --git a/core/src/main/java/de/danoeh/antennapod/core/receiver/AlarmUpdateReceiver.java b/core/src/main/java/de/danoeh/antennapod/core/receiver/AlarmUpdateReceiver.java
index 7fa92f30c..ce5004a98 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/receiver/AlarmUpdateReceiver.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/receiver/AlarmUpdateReceiver.java
@@ -3,10 +3,9 @@ package de.danoeh.antennapod.core.receiver;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
+import android.text.TextUtils;
 import android.util.Log;
 
-import org.apache.commons.lang3.StringUtils;
-
 import de.danoeh.antennapod.core.preferences.PlaybackPreferences;
 import de.danoeh.antennapod.core.preferences.UserPreferences;
 
@@ -18,9 +17,9 @@ public class AlarmUpdateReceiver extends BroadcastReceiver {
 	@Override
 	public void onReceive(Context context, Intent intent) {
 		Log.d(TAG, "Received intent");
-		if (StringUtils.equals(intent.getAction(), Intent.ACTION_BOOT_COMPLETED)) {
+		if (TextUtils.equals(intent.getAction(), Intent.ACTION_BOOT_COMPLETED)) {
 			Log.d(TAG, "Resetting update alarm after reboot");
-		} else if (StringUtils.equals(intent.getAction(), Intent.ACTION_PACKAGE_REPLACED)) {
+		} else if (TextUtils.equals(intent.getAction(), Intent.ACTION_PACKAGE_REPLACED)) {
 			Log.d(TAG, "Resetting update alarm after app upgrade");
 		}
         PlaybackPreferences.init(context);
diff --git a/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadRequest.java b/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadRequest.java
index 41bbd5ba6..bc3006eea 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadRequest.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadRequest.java
@@ -3,8 +3,7 @@ package de.danoeh.antennapod.core.service.download;
 import android.os.Bundle;
 import android.os.Parcel;
 import android.os.Parcelable;
-
-import org.apache.commons.lang3.Validate;
+import android.support.annotation.NonNull;
 
 import de.danoeh.antennapod.core.feed.FeedFile;
 import de.danoeh.antennapod.core.util.URLChecker;
@@ -27,11 +26,15 @@ public class DownloadRequest implements Parcelable {
     protected long size;
     protected int statusMsg;
 
-    public DownloadRequest(String destination, String source, String title,
-                           long feedfileId, int feedfileType, String username, String password, boolean deleteOnFailure, Bundle arguments) {
-        Validate.notNull(destination);
-        Validate.notNull(source);
-        Validate.notNull(title);
+    public DownloadRequest(@NonNull String destination,
+                           @NonNull String source,
+                           @NonNull String title,
+                           long feedfileId,
+                           int feedfileType,
+                           String username,
+                           String password,
+                           boolean deleteOnFailure,
+                           Bundle arguments) {
 
         this.destination = destination;
         this.source = source;
@@ -260,7 +263,7 @@ public class DownloadRequest implements Parcelable {
         private int feedfileType;
         private Bundle arguments;
 
-        public Builder(String destination, FeedFile item) {
+        public Builder(@NonNull String destination, @NonNull FeedFile item) {
             this.destination = destination;
             this.source = URLChecker.prepareURL(item.getDownload_url());
             this.title = item.getHumanReadableIdentifier();
@@ -285,9 +288,6 @@ public class DownloadRequest implements Parcelable {
         }
 
         public DownloadRequest build() {
-            Validate.notNull(destination);
-            Validate.notNull(source);
-            Validate.notNull(title);
             return new DownloadRequest(this);
         }
 
diff --git a/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadService.java b/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadService.java
index 677765e92..f7e084e20 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadService.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadService.java
@@ -14,14 +14,14 @@ import android.media.MediaMetadataRetriever;
 import android.os.Binder;
 import android.os.Handler;
 import android.os.IBinder;
+import android.support.annotation.NonNull;
 import android.support.v4.app.NotificationCompat;
 import android.support.v4.util.Pair;
+import android.text.TextUtils;
 import android.util.Log;
 import android.webkit.URLUtil;
 
 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;
 
@@ -407,9 +407,11 @@ public class DownloadService extends Service {
 
         @Override
         public void onReceive(Context context, Intent intent) {
-            if (StringUtils.equals(intent.getAction(), ACTION_CANCEL_DOWNLOAD)) {
+            if (TextUtils.equals(intent.getAction(), ACTION_CANCEL_DOWNLOAD)) {
                 String url = intent.getStringExtra(EXTRA_DOWNLOAD_URL);
-                Validate.notNull(url, "ACTION_CANCEL_DOWNLOAD intent needs download url extra");
+                if(url == null) {
+                    throw new IllegalArgumentException("ACTION_CANCEL_DOWNLOAD intent needs download url extra");
+                }
 
                 Log.d(TAG, "Cancelling download with url " + url);
                 Downloader d = getDownloader(url);
@@ -420,7 +422,7 @@ public class DownloadService extends Service {
                 }
                 postDownloaders();
 
-            } else if (StringUtils.equals(intent.getAction(), ACTION_CANCEL_ALL_DOWNLOADS)) {
+            } else if (TextUtils.equals(intent.getAction(), ACTION_CANCEL_ALL_DOWNLOADS)) {
                 for (Downloader d : downloads) {
                     d.cancel();
                     Log.d(TAG, "Cancelled all downloads");
@@ -909,7 +911,7 @@ public class DownloadService extends Service {
                     FeedItem item1 = feed.getItems().get(x);
                     FeedItem item2 = feed.getItems().get(y);
                     if (item1.hasItemImage() && item2.hasItemImage()) {
-                        if (StringUtils.equals(item1.getImage().getDownload_url(), item2.getImage().getDownload_url())) {
+                        if (TextUtils.equals(item1.getImage().getDownload_url(), item2.getImage().getDownload_url())) {
                             item2.setImage(null);
                         }
                     }
@@ -1017,10 +1019,8 @@ public class DownloadService extends Service {
         private DownloadRequest request;
         private DownloadStatus status;
 
-        public MediaHandlerThread(DownloadStatus status, DownloadRequest request) {
-            Validate.notNull(status);
-            Validate.notNull(request);
-
+        public MediaHandlerThread(@NonNull DownloadStatus status,
+                                  @NonNull DownloadRequest request) {
             this.status = status;
             this.request = request;
         }
diff --git a/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadStatus.java b/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadStatus.java
index 21928c94f..ed2b00dfe 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadStatus.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/service/download/DownloadStatus.java
@@ -1,8 +1,7 @@
 package de.danoeh.antennapod.core.service.download;
 
 import android.database.Cursor;
-
-import org.apache.commons.lang3.Validate;
+import android.support.annotation.NonNull;
 
 import java.util.Date;
 
@@ -62,10 +61,8 @@ public class DownloadStatus {
 		this.feedfileType = feedfileType;
 	}
 
-	public DownloadStatus(DownloadRequest request, DownloadError reason,
+	public DownloadStatus(@NonNull DownloadRequest request, DownloadError reason,
 			boolean successful, boolean cancelled, String reasonDetailed) {
-        Validate.notNull(request);
-
 		this.title = request.getTitle();
 		this.feedfileId = request.getFeedfileId();
 		this.feedfileType = request.getFeedfileType();
@@ -77,10 +74,8 @@ public class DownloadStatus {
 	}
 
 	/** Constructor for creating new completed downloads. */
-	public DownloadStatus(FeedFile feedfile, String title, DownloadError reason,
-			boolean successful, String reasonDetailed) {
-		Validate.notNull(feedfile);
-
+	public DownloadStatus(@NonNull FeedFile feedfile, String title, DownloadError reason,
+						  boolean successful, String reasonDetailed) {
 		this.title = title;
 		this.done = true;
 		this.feedfileId = feedfile.getId();
diff --git a/core/src/main/java/de/danoeh/antennapod/core/service/download/HttpDownloader.java b/core/src/main/java/de/danoeh/antennapod/core/service/download/HttpDownloader.java
index eda857bd5..9f54db477 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/service/download/HttpDownloader.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/service/download/HttpDownloader.java
@@ -1,5 +1,6 @@
 package de.danoeh.antennapod.core.service.download;
 
+import android.text.TextUtils;
 import android.util.Log;
 
 import com.squareup.okhttp.OkHttpClient;
@@ -10,7 +11,6 @@ import com.squareup.okhttp.ResponseBody;
 import com.squareup.okhttp.internal.http.HttpDate;
 
 import org.apache.commons.io.IOUtils;
-import org.apache.commons.lang3.StringUtils;
 import org.apache.http.HttpStatus;
 
 import java.io.BufferedInputStream;
@@ -86,7 +86,7 @@ public class HttpDownloader extends Downloader {
                     String credentials = encodeCredentials(parts[0], parts[1], "ISO-8859-1");
                     httpReq.header("Authorization", credentials);
                 }
-            } else if (!StringUtils.isEmpty(request.getUsername()) && request.getPassword() != null) {
+            } else if (!TextUtils.isEmpty(request.getUsername()) && request.getPassword() != null) {
                 String credentials = encodeCredentials(request.getUsername(), request.getPassword(),
                         "ISO-8859-1");
                 httpReq.header("Authorization", credentials);
@@ -114,7 +114,10 @@ public class HttpDownloader extends Downloader {
             }
             responseBody = response.body();
             String contentEncodingHeader = response.header("Content-Encoding");
-            boolean isGzip = StringUtils.equalsIgnoreCase(contentEncodingHeader, "gzip");
+            boolean isGzip = false;
+            if(!TextUtils.isEmpty(contentEncodingHeader)) {
+                isGzip = TextUtils.equals(contentEncodingHeader.toLowerCase(), "gzip");
+            }
 
             Log.d(TAG, "Response code is " + response.code());
 
@@ -126,7 +129,7 @@ public class HttpDownloader extends Downloader {
                         String credentials = encodeCredentials(parts[0], parts[1], "UTF-8");
                         httpReq.header("Authorization", credentials);
                     }
-                } else if (!StringUtils.isEmpty(request.getUsername()) && request.getPassword() != null) {
+                } else if (!TextUtils.isEmpty(request.getUsername()) && request.getPassword() != null) {
                     String credentials = encodeCredentials(request.getUsername(), request.getPassword(),
                             "UTF-8");
                     httpReq.header("Authorization", credentials);
@@ -134,7 +137,9 @@ public class HttpDownloader extends Downloader {
                 response = httpClient.newCall(httpReq.build()).execute();
                 responseBody = response.body();
                 contentEncodingHeader = response.header("Content-Encoding");
-                isGzip = StringUtils.equalsIgnoreCase(contentEncodingHeader, "gzip");
+                if(!TextUtils.isEmpty(contentEncodingHeader)) {
+                    isGzip = TextUtils.equals(contentEncodingHeader.toLowerCase(), "gzip");
+                }
             }
 
             if(!response.isSuccessful() && response.code() == HttpURLConnection.HTTP_NOT_MODIFIED) {
@@ -167,7 +172,7 @@ public class HttpDownloader extends Downloader {
             String contentRangeHeader = (fileExists) ? response.header("Content-Range") : null;
 
             if (fileExists && response.code() == HttpStatus.SC_PARTIAL_CONTENT
-                    && !StringUtils.isEmpty(contentRangeHeader)) {
+                    && !TextUtils.isEmpty(contentRangeHeader)) {
                 String start = contentRangeHeader.substring("bytes ".length(),
                         contentRangeHeader.indexOf("-"));
                 request.setSoFar(Long.valueOf(start));
diff --git a/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackService.java b/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackService.java
index 5e0738cb8..1313d9607 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackService.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackService.java
@@ -20,6 +20,7 @@ import android.os.IBinder;
 import android.os.Vibrator;
 import android.preference.PreferenceManager;
 import android.support.v4.app.NotificationCompat;
+import android.text.TextUtils;
 import android.util.Log;
 import android.util.Pair;
 import android.view.KeyEvent;
@@ -28,8 +29,6 @@ import android.widget.Toast;
 
 import com.bumptech.glide.Glide;
 
-import org.apache.commons.lang3.StringUtils;
-
 import java.util.List;
 import java.util.concurrent.ExecutionException;
 
@@ -1019,7 +1018,7 @@ public class PlaybackService extends Service {
 
         @Override
         public void onReceive(Context context, Intent intent) {
-            if (StringUtils.equals(intent.getAction(), Intent.ACTION_HEADSET_PLUG)) {
+            if (TextUtils.equals(intent.getAction(), Intent.ACTION_HEADSET_PLUG)) {
                 int state = intent.getIntExtra("state", -1);
                 if (state != -1) {
                     Log.d(TAG, "Headset plug event. State is " + state);
@@ -1041,7 +1040,7 @@ public class PlaybackService extends Service {
         @Override
         public void onReceive(Context context, Intent intent) {
             if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
-                if (StringUtils.equals(intent.getAction(), BluetoothA2dp.ACTION_CONNECTION_STATE_CHANGED)) {
+                if (TextUtils.equals(intent.getAction(), BluetoothA2dp.ACTION_CONNECTION_STATE_CHANGED)) {
                     int state = intent.getIntExtra(BluetoothA2dp.EXTRA_STATE, -1);
                     if (state == BluetoothA2dp.STATE_CONNECTED) {
                         Log.d(TAG, "Received bluetooth connection intent");
@@ -1102,7 +1101,7 @@ public class PlaybackService extends Service {
 
         @Override
         public void onReceive(Context context, Intent intent) {
-            if (StringUtils.equals(intent.getAction(), ACTION_SHUTDOWN_PLAYBACK_SERVICE)) {
+            if (TextUtils.equals(intent.getAction(), ACTION_SHUTDOWN_PLAYBACK_SERVICE)) {
                 stopSelf();
             }
         }
@@ -1112,7 +1111,7 @@ public class PlaybackService extends Service {
     private final BroadcastReceiver skipCurrentEpisodeReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
-            if (StringUtils.equals(intent.getAction(), ACTION_SKIP_CURRENT_EPISODE)) {
+            if (TextUtils.equals(intent.getAction(), ACTION_SKIP_CURRENT_EPISODE)) {
                 Log.d(TAG, "Received SKIP_CURRENT_EPISODE intent");
                 mediaPlayer.endPlayback(true);
             }
@@ -1122,7 +1121,7 @@ public class PlaybackService extends Service {
     private final BroadcastReceiver pauseResumeCurrentEpisodeReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
-            if (StringUtils.equals(intent.getAction(), ACTION_RESUME_PLAY_CURRENT_EPISODE)) {
+            if (TextUtils.equals(intent.getAction(), ACTION_RESUME_PLAY_CURRENT_EPISODE)) {
                 Log.d(TAG, "Received RESUME_PLAY_CURRENT_EPISODE intent");
                 mediaPlayer.resume();
             }
@@ -1132,7 +1131,7 @@ public class PlaybackService extends Service {
     private final BroadcastReceiver pausePlayCurrentEpisodeReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
-            if (StringUtils.equals(intent.getAction(), ACTION_PAUSE_PLAY_CURRENT_EPISODE)) {
+            if (TextUtils.equals(intent.getAction(), ACTION_PAUSE_PLAY_CURRENT_EPISODE)) {
                 Log.d(TAG, "Received PAUSE_PLAY_CURRENT_EPISODE intent");
                 mediaPlayer.pause(false, false);
             }
diff --git a/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceMediaPlayer.java b/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceMediaPlayer.java
index 7247c6bdf..6ad376bf0 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceMediaPlayer.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceMediaPlayer.java
@@ -10,6 +10,7 @@ import android.media.AudioManager;
 import android.net.wifi.WifiManager;
 import android.os.PowerManager;
 import android.preference.PreferenceManager;
+import android.support.annotation.NonNull;
 import android.support.v4.media.MediaMetadataCompat;
 import android.support.v4.media.session.MediaSessionCompat;
 import android.support.v4.media.session.PlaybackStateCompat;
@@ -23,8 +24,6 @@ import android.view.SurfaceHolder;
 import com.bumptech.glide.Glide;
 import com.bumptech.glide.request.target.Target;
 
-import org.apache.commons.lang3.Validate;
-
 import java.io.IOException;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.LinkedBlockingDeque;
@@ -92,10 +91,8 @@ public class PlaybackServiceMediaPlayer implements SharedPreferences.OnSharedPre
      */
     private WifiManager.WifiLock wifiLock;
 
-    public PlaybackServiceMediaPlayer(Context context, PSMPCallback callback) {
-        Validate.notNull(context);
-        Validate.notNull(callback);
-
+    public PlaybackServiceMediaPlayer(@NonNull Context context,
+                                      @NonNull PSMPCallback callback) {
         this.context = context;
         this.callback = callback;
         this.audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
@@ -175,9 +172,7 @@ public class PlaybackServiceMediaPlayer implements SharedPreferences.OnSharedPre
      *                           for playback immediately (see 'prepareImmediately' parameter for more details)
      * @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) {
-        Validate.notNull(playable);
-
+    public void playMediaObject(@NonNull final Playable playable, final boolean stream, final boolean startWhenPrepared, final boolean prepareImmediately) {
         Log.d(TAG, "playMediaObject(...)");
         executor.submit(new Runnable() {
             @Override
@@ -203,8 +198,7 @@ public class PlaybackServiceMediaPlayer implements SharedPreferences.OnSharedPre
      *
      * @see #playMediaObject(de.danoeh.antennapod.core.util.playback.Playable, boolean, boolean, boolean)
      */
-    private void playMediaObject(final Playable playable, final boolean forceReset, final boolean stream, final boolean startWhenPrepared, final boolean prepareImmediately) {
-        Validate.notNull(playable);
+    private void playMediaObject(@NonNull final Playable playable, final boolean forceReset, final boolean stream, final boolean startWhenPrepared, final boolean prepareImmediately) {
         if (!playerLock.isHeldByCurrentThread()) {
             throw new IllegalStateException("method requires playerLock");
         }
@@ -573,9 +567,7 @@ public class PlaybackServiceMediaPlayer implements SharedPreferences.OnSharedPre
     /**
      * Seek to the start of the specified chapter.
      */
-    public void seekToChapter(Chapter c) {
-        Validate.notNull(c);
-
+    public void seekToChapter(@NonNull Chapter c) {
         seekTo((int) c.getStart());
     }
 
@@ -840,9 +832,7 @@ public class PlaybackServiceMediaPlayer implements SharedPreferences.OnSharedPre
      * @param newStatus The new PlayerStatus. This must not be null.
      * @param newMedia  The new playable object of the PSMP object. This can be null.
      */
-    private synchronized void setPlayerStatus(PlayerStatus newStatus, Playable newMedia) {
-        Validate.notNull(newStatus);
-
+    private synchronized void setPlayerStatus(@NonNull PlayerStatus newStatus, Playable newMedia) {
         Log.d(TAG, "Setting player status to " + newStatus);
 
         this.playerStatus = newStatus;
diff --git a/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceTaskManager.java b/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceTaskManager.java
index 961f923e9..4e0c8a109 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceTaskManager.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/service/playback/PlaybackServiceTaskManager.java
@@ -2,10 +2,9 @@ package de.danoeh.antennapod.core.service.playback;
 
 import android.content.Context;
 import android.os.Vibrator;
+import android.support.annotation.NonNull;
 import android.util.Log;
 
-import org.apache.commons.lang3.Validate;
-
 import java.util.List;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
@@ -15,8 +14,8 @@ import java.util.concurrent.ScheduledThreadPoolExecutor;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.TimeUnit;
 
-import de.danoeh.antennapod.core.feed.FeedItem;
 import de.danoeh.antennapod.core.event.QueueEvent;
+import de.danoeh.antennapod.core.feed.FeedItem;
 import de.danoeh.antennapod.core.storage.DBReader;
 import de.danoeh.antennapod.core.util.playback.Playable;
 import de.greenrobot.event.EventBus;
@@ -62,10 +61,8 @@ public class PlaybackServiceTaskManager {
      * @param context
      * @param callback A PSTMCallback object for notifying the user about updates. Must not be null.
      */
-    public PlaybackServiceTaskManager(Context context, PSTMCallback callback) {
-        Validate.notNull(context);
-        Validate.notNull(callback);
-
+    public PlaybackServiceTaskManager(@NonNull Context context,
+                                      @NonNull PSTMCallback callback) {
         this.context = context;
         this.callback = callback;
         schedExecutor = new ScheduledThreadPoolExecutor(SCHED_EX_POOL_SIZE, new ThreadFactory() {
@@ -200,7 +197,9 @@ public class PlaybackServiceTaskManager {
      * @throws java.lang.IllegalArgumentException if waitingTime <= 0
      */
     public synchronized void setSleepTimer(long waitingTime, boolean shakeToReset, boolean vibrate) {
-        Validate.isTrue(waitingTime > 0, "Waiting time <= 0");
+        if(waitingTime <= 0) {
+            throw new IllegalArgumentException("Waiting time <= 0");
+        }
 
         Log.d(TAG, "Setting sleep timer to " + Long.toString(waitingTime) + " milliseconds");
         if (isSleepTimerActive()) {
@@ -275,9 +274,7 @@ public class PlaybackServiceTaskManager {
      * it will be cancelled first.
      * On completion, the callback's onChapterLoaded method will be called.
      */
-    public synchronized void startChapterLoader(final Playable media) {
-        Validate.notNull(media);
-
+    public synchronized void startChapterLoader(@NonNull final Playable media) {
         if (isChapterLoaderActive()) {
             cancelChapterLoader();
         }
diff --git a/core/src/main/java/de/danoeh/antennapod/core/storage/DBReader.java b/core/src/main/java/de/danoeh/antennapod/core/storage/DBReader.java
index c0a30f740..c34515118 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/storage/DBReader.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/storage/DBReader.java
@@ -225,12 +225,12 @@ public final class DBReader {
     private static Map<Long,FeedMedia> getFeedMedia(PodDBAdapter adapter,
                                                     long... itemIds) {
 
-        ArrayList<String> ids = new ArrayList<>(itemIds.length);
-        for(long itemId : itemIds) {
-            ids.add(String.valueOf(itemId));
+        String[] ids = new String[itemIds.length];
+        for(int i=0, len=itemIds.length; i < len; i++) {
+            ids[i] = String.valueOf(itemIds[i]);
         }
         Map<Long,FeedMedia> result = new HashMap<>(itemIds.length);
-        Cursor cursor = adapter.getFeedMediaCursor(ids.toArray(new String[0]));
+        Cursor cursor = adapter.getFeedMediaCursor(ids);
         try {
             if (cursor.moveToFirst()) {
                 do {
@@ -862,10 +862,14 @@ public final class DBReader {
     /**
      * Searches the DB for a FeedImage of the given id.
      *
-     * @param ids The id of the object
-     * @return The found object
+     * @param imageIds The ids of the images
+     * @return Map that associates the id of an image with the image itself
      */
-    private static Map<Long,FeedImage> getFeedImages(PodDBAdapter adapter, final long... ids) {
+    private static Map<Long,FeedImage> getFeedImages(PodDBAdapter adapter, final long... imageIds) {
+        String[] ids = new String[imageIds.length];
+        for(int i=0, len=imageIds.length; i < len; i++) {
+            ids[i] = String.valueOf(imageIds[i]);
+        }
         Cursor cursor = adapter.getImageCursor(ids);
         Map<Long, FeedImage> result = new HashMap<>(cursor.getCount());
         try {
diff --git a/core/src/main/java/de/danoeh/antennapod/core/storage/DownloadRequester.java b/core/src/main/java/de/danoeh/antennapod/core/storage/DownloadRequester.java
index ee079c068..0dc1dadeb 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/storage/DownloadRequester.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/storage/DownloadRequester.java
@@ -3,12 +3,12 @@ package de.danoeh.antennapod.core.storage;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.text.TextUtils;
 import android.util.Log;
 import android.webkit.URLUtil;
 
 import org.apache.commons.io.FilenameUtils;
-import org.apache.commons.lang3.StringUtils;
-import org.apache.commons.lang3.Validate;
 
 import java.io.File;
 import java.util.Map;
@@ -71,10 +71,8 @@ public class DownloadRequester {
      *                call will return false.
      * @return True if the download request was accepted, false otherwise.
      */
-    public synchronized boolean download(Context context, DownloadRequest request) {
-        Validate.notNull(context);
-        Validate.notNull(request);
-
+    public synchronized boolean download(@NonNull Context context,
+                                         @NonNull DownloadRequest request) {
         if (downloads.containsKey(request.getSource())) {
             if (BuildConfig.DEBUG) Log.i(TAG, "DownloadRequest is already stored.");
             return false;
@@ -145,7 +143,7 @@ public class DownloadRequester {
     private boolean isFilenameAvailable(String path) {
         for (String key : downloads.keySet()) {
             DownloadRequest r = downloads.get(key);
-            if (StringUtils.equals(r.getDestination(), path)) {
+            if (TextUtils.equals(r.getDestination(), path)) {
                 if (BuildConfig.DEBUG)
                     Log.d(TAG, path
                             + " is already used by another requested download");
diff --git a/core/src/main/java/de/danoeh/antennapod/core/storage/PodDBAdapter.java b/core/src/main/java/de/danoeh/antennapod/core/storage/PodDBAdapter.java
index bf324c9d1..97d91ccd3 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/storage/PodDBAdapter.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/storage/PodDBAdapter.java
@@ -14,9 +14,6 @@ import android.os.Build;
 import android.text.TextUtils;
 import android.util.Log;
 
-import org.apache.commons.lang3.StringUtils;
-import org.apache.commons.lang3.Validate;
-
 import java.util.Arrays;
 import java.util.List;
 
@@ -1018,15 +1015,42 @@ public class PodDBAdapter {
     /**
      * Returns a cursor for a DB query in the FeedImages table for given IDs.
      *
-     * @param ids IDs of the FeedImages
+     * @param imageIds IDs of the images
      * @return The cursor of the query
      */
-    public final Cursor getImageCursor(long... ids) {
-        String sql = "SELECT * FROM " + TABLE_NAME_FEED_IMAGES +
-                " WHERE " + KEY_ID + " IN (" + StringUtils.join(ids, ',') + ")";
-        Cursor c = db.rawQuery(sql, null);
+    public final Cursor getImageCursor(String... imageIds) {
+        int length = imageIds.length;
+        if (length > IN_OPERATOR_MAXIMUM) {
+            Log.w(TAG, "Length of id array is larger than "
+                    + IN_OPERATOR_MAXIMUM + ". Creating multiple cursors");
+            int numCursors = (int) (((double) length) / (IN_OPERATOR_MAXIMUM)) + 1;
+            Cursor[] cursors = new Cursor[numCursors];
+            for (int i = 0; i < numCursors; i++) {
+                int neededLength;
+                String[] parts;
+                final int elementsLeft = length - i * IN_OPERATOR_MAXIMUM;
 
-        return c;
+                if (elementsLeft >= IN_OPERATOR_MAXIMUM) {
+                    neededLength = IN_OPERATOR_MAXIMUM;
+                    parts = Arrays.copyOfRange(imageIds, i
+                            * IN_OPERATOR_MAXIMUM, (i + 1)
+                            * IN_OPERATOR_MAXIMUM);
+                } else {
+                    neededLength = elementsLeft;
+                    parts = Arrays.copyOfRange(imageIds, i
+                            * IN_OPERATOR_MAXIMUM, (i * IN_OPERATOR_MAXIMUM)
+                            + neededLength);
+                }
+
+                cursors[i] = db.rawQuery("SELECT * FROM "
+                        + TABLE_NAME_FEED_IMAGES + " WHERE " + KEY_ID + " IN "
+                        + buildInOperator(neededLength), parts);
+            }
+            return new MergeCursor(cursors);
+        } else {
+            return db.query(TABLE_NAME_FEED_IMAGES, null, KEY_ID + " IN "
+                    + buildInOperator(length), imageIds, null, null, null);
+        }
     }
 
     public final Cursor getSimpleChaptersOfFeedItemCursor(final FeedItem item) {
@@ -1154,7 +1178,9 @@ public class PodDBAdapter {
      * @throws IllegalArgumentException if limit < 0
      */
     public final Cursor getCompletedMediaCursor(int limit) {
-        Validate.isTrue(limit >= 0, "Limit must be >= 0");
+        if(limit < 0) {
+            throw new IllegalArgumentException("Limit must be >= 0");
+        }
 
         Cursor c = db.query(TABLE_NAME_FEED_MEDIA, null,
                 KEY_PLAYBACK_COMPLETION_DATE + " > 0", null, null,
diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/URLChecker.java b/core/src/main/java/de/danoeh/antennapod/core/util/URLChecker.java
index 4300556d2..415a1d3a2 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/util/URLChecker.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/util/URLChecker.java
@@ -3,8 +3,6 @@ package de.danoeh.antennapod.core.util;
 import android.net.Uri;
 import android.util.Log;
 
-import org.apache.commons.lang3.StringUtils;
-
 import de.danoeh.antennapod.core.BuildConfig;
 
 /**
@@ -32,19 +30,19 @@ public final class URLChecker {
      * @return The prepared url
      */
     public static String prepareURL(String url) {
-        url = StringUtils.trim(url);
+        url = url.trim();
         if (url.startsWith("feed://")) {
             if (BuildConfig.DEBUG) Log.d(TAG, "Replacing feed:// with http://");
             return url.replaceFirst("feed://", "http://");
         } else if (url.startsWith("pcast://")) {
             if (BuildConfig.DEBUG) Log.d(TAG, "Removing pcast://");
-            return prepareURL(StringUtils.removeStart(url, "pcast://"));
+            return prepareURL(url.substring("pcast://".length()));
         } else if (url.startsWith("itpc")) {
             if (BuildConfig.DEBUG) Log.d(TAG, "Replacing itpc:// with http://");
             return url.replaceFirst("itpc://", "http://");
         } else if (url.startsWith(AP_SUBSCRIBE)) {
             if (BuildConfig.DEBUG) Log.d(TAG, "Removing antennapod-subscribe://");
-            return prepareURL(StringUtils.removeStart(url, AP_SUBSCRIBE));
+            return prepareURL(url.substring(AP_SUBSCRIBE.length()));
         } else if (!(url.startsWith("http://") || url.startsWith("https://"))) {
             if (BuildConfig.DEBUG) Log.d(TAG, "Adding http:// at the beginning of the URL");
             return "http://" + url;
@@ -66,7 +64,7 @@ public final class URLChecker {
         if (base == null) {
             return prepareURL(url);
         }
-        url = StringUtils.trim(url);
+        url = url.trim();
         base = prepareURL(base);
         Uri urlUri = Uri.parse(url);
         Uri baseUri = Uri.parse(base);
diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/flattr/FlattrUtils.java b/core/src/main/java/de/danoeh/antennapod/core/util/flattr/FlattrUtils.java
index 318839e1d..6ddfb0366 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/util/flattr/FlattrUtils.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/util/flattr/FlattrUtils.java
@@ -8,9 +8,9 @@ import android.content.SharedPreferences;
 import android.net.Uri;
 import android.preference.PreferenceManager;
 import android.support.v7.app.AlertDialog;
+import android.text.TextUtils;
 import android.util.Log;
 
-import org.apache.commons.lang3.StringUtils;
 import org.shredzone.flattr4j.FlattrService;
 import org.shredzone.flattr4j.exception.FlattrException;
 import org.shredzone.flattr4j.model.Flattr;
@@ -78,8 +78,8 @@ public class FlattrUtils {
      * Returns true if FLATTR_APP_KEY and FLATTR_APP_SECRET in BuildConfig are not null and not empty
      */
     public static boolean hasAPICredentials() {
-        return StringUtils.isNotEmpty(ClientConfig.flattrCallbacks.getFlattrAppKey())
-                && StringUtils.isNotEmpty(ClientConfig.flattrCallbacks.getFlattrAppSecret());
+        return !TextUtils.isEmpty(ClientConfig.flattrCallbacks.getFlattrAppKey())
+                && !TextUtils.isEmpty(ClientConfig.flattrCallbacks.getFlattrAppSecret());
     }
 
     public static boolean hasToken() {
diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/playback/PlaybackController.java b/core/src/main/java/de/danoeh/antennapod/core/util/playback/PlaybackController.java
index 4eb955913..a519fb555 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/util/playback/PlaybackController.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/util/playback/PlaybackController.java
@@ -13,6 +13,8 @@ import android.media.MediaPlayer;
 import android.os.AsyncTask;
 import android.os.IBinder;
 import android.preference.PreferenceManager;
+import android.support.annotation.NonNull;
+import android.text.TextUtils;
 import android.util.Log;
 import android.util.Pair;
 import android.view.SurfaceHolder;
@@ -22,9 +24,6 @@ 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 java.util.concurrent.RejectedExecutionHandler;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
@@ -74,8 +73,7 @@ public abstract class PlaybackController {
      */
     private boolean reinitOnPause;
 
-    public PlaybackController(Activity activity, boolean reinitOnPause) {
-        Validate.notNull(activity);
+    public PlaybackController(@NonNull Activity activity, boolean reinitOnPause) {
 
         this.activity = activity;
         this.reinitOnPause = reinitOnPause;
@@ -360,7 +358,7 @@ public abstract class PlaybackController {
         @Override
         public void onReceive(Context context, Intent intent) {
             if (isConnectedToPlaybackService()) {
-                if (StringUtils.equals(intent.getAction(),
+                if (TextUtils.equals(intent.getAction(),
                         PlaybackService.ACTION_SHUTDOWN_PLAYBACK_SERVICE)) {
                     release();
                     onShutdownNotification();
diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/playback/Timeline.java b/core/src/main/java/de/danoeh/antennapod/core/util/playback/Timeline.java
index 0de9863e7..00f2e6f57 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/util/playback/Timeline.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/util/playback/Timeline.java
@@ -2,10 +2,10 @@ package de.danoeh.antennapod.core.util.playback;
 
 import android.content.Context;
 import android.content.res.TypedArray;
+import android.support.annotation.NonNull;
 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;
@@ -158,8 +158,7 @@ public class Timeline {
     }
 
 
-    public void setShownotesProvider(ShownotesProvider shownotesProvider) {
-        Validate.notNull(shownotesProvider);
+    public void setShownotesProvider(@NonNull ShownotesProvider shownotesProvider) {
         this.shownotesProvider = shownotesProvider;
     }
 }
diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/syndication/FeedDiscoverer.java b/core/src/main/java/de/danoeh/antennapod/core/util/syndication/FeedDiscoverer.java
index 9588265b8..d148419fd 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/util/syndication/FeedDiscoverer.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/util/syndication/FeedDiscoverer.java
@@ -1,7 +1,8 @@
 package de.danoeh.antennapod.core.util.syndication;
 
 import android.net.Uri;
-import org.apache.commons.lang3.StringUtils;
+import android.text.TextUtils;
+
 import org.jsoup.Jsoup;
 import org.jsoup.nodes.Document;
 import org.jsoup.nodes.Element;
@@ -50,7 +51,7 @@ public class FeedDiscoverer {
         for (Element link : links) {
             String rel = link.attr("rel");
             String href = link.attr("href");
-            if (!StringUtils.isEmpty(href) &&
+            if (!TextUtils.isEmpty(href) &&
                     (rel.equals("alternate") || rel.equals("feed"))) {
                 String type = link.attr("type");
                 if (type.equals(MIME_RSS) || type.equals(MIME_ATOM)) {
@@ -58,7 +59,7 @@ public class FeedDiscoverer {
                     String processedUrl = processURL(baseUrl, href);
                     if (processedUrl != null) {
                         res.put(processedUrl,
-                                (StringUtils.isEmpty(title)) ? href : title);
+                                (TextUtils.isEmpty(title)) ? href : title);
                     }
                 }
             }