logger, diamond and arraylist refactoring

10 files changed, 244 insertions, 203 deletions

diff --git a/src/main/java/com/juick/server/AdsQueries.java b/src/main/java/com/juick/server/AdsQueries.java
index 0fb4c0a6..ad9b7149 100644
--- a/src/main/java/com/juick/server/AdsQueries.java
+++ b/src/main/java/com/juick/server/AdsQueries.java
@@ -20,6 +20,8 @@ package com.juick.server;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  *
@@ -27,6 +29,8 @@ import java.sql.SQLException;
  */
 public class AdsQueries {
 
+    private static final Logger logger = Logger.getLogger(AdsQueries.class.getName());
+
     public static int getAdMID(Connection sql, int uid) {
         if (uid > 0) {
             return SQLHelpers.getInt(sql, "SELECT message_id FROM ads_messages WHERE message_id NOT IN (SELECT message_id FROM ads_messages_log WHERE user_id=? AND ts>UNIX_TIMESTAMP()-60*60*24 GROUP BY message_id HAVING COUNT(*)>2) ORDER BY RAND() LIMIT 1", uid, 0);
@@ -43,7 +47,7 @@ public class AdsQueries {
             stmt.setInt(2, mid);
             stmt.executeUpdate();
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
diff --git a/src/main/java/com/juick/server/CrosspostQueries.java b/src/main/java/com/juick/server/CrosspostQueries.java
index fd677048..b44b6b59 100644
--- a/src/main/java/com/juick/server/CrosspostQueries.java
+++ b/src/main/java/com/juick/server/CrosspostQueries.java
@@ -21,6 +21,8 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  *
@@ -28,6 +30,8 @@ import java.sql.SQLException;
  */
 public class CrosspostQueries {
 
+    private static final Logger logger = Logger.getLogger(CrosspostQueries.class.getName());
+
     public static String[] getTwitterTokens(Connection sql, int uid) {
         String tokens[] = null;
 
@@ -43,7 +47,7 @@ public class CrosspostQueries {
                 tokens[1] = rs.getString(2);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -70,7 +74,7 @@ public class CrosspostQueries {
                 tokens[1] = rs.getString(2);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
diff --git a/src/main/java/com/juick/server/MessagesQueries.java b/src/main/java/com/juick/server/MessagesQueries.java
index 82fef672..4d5683bd 100644
--- a/src/main/java/com/juick/server/MessagesQueries.java
+++ b/src/main/java/com/juick/server/MessagesQueries.java
@@ -25,6 +25,9 @@ import java.sql.Statement;
 import java.sql.Types;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  *
@@ -32,11 +35,13 @@ import java.util.Collections;
  */
 public class MessagesQueries {
 
-    public static int createMessage(Connection sql, int uid, String txt, String attachment, ArrayList<com.juick.Tag> tags) {
+    private static final Logger logger = Logger.getLogger(MessagesQueries.class.getName());
+
+    public static int createMessage(Connection sql, int uid, String txt, String attachment, List<com.juick.Tag> tags) {
         int mid = 0;
 
         PreparedStatement stmt = null;
-        ResultSet rs = null;
+        ResultSet rs;
         try {
             stmt = sql.prepareStatement("INSERT INTO messages(user_id,attach) VALUES (?,?)", Statement.RETURN_GENERATED_KEYS);
             stmt.setInt(1, uid);
@@ -51,7 +56,7 @@ public class MessagesQueries {
                 mid = rs.getInt(1);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -73,7 +78,7 @@ public class MessagesQueries {
                 stmt = sql.prepareStatement("INSERT INTO messages_tags(message_id,tag_id) VALUES " + tagsIDs);
                 stmt.executeUpdate();
             } catch (SQLException e) {
-                System.err.println(e);
+                logger.log(Level.SEVERE, "sql exception", e);
             } finally {
                 Utils.finishSQL(null, stmt);
             }
@@ -81,7 +86,7 @@ public class MessagesQueries {
             try {
                 stmt = sql.prepareStatement("INSERT INTO messages_txt(message_id,tags,txt) VALUES (?,?,?)");
                 stmt.setInt(1, mid);
-                if (tagsNames == "") {
+                if (tagsNames.isEmpty()) {
                     stmt.setNull(2, Types.VARCHAR);
                 } else {
                     stmt.setString(2, tagsNames);
@@ -89,7 +94,7 @@ public class MessagesQueries {
                 stmt.setString(3, txt);
                 stmt.executeUpdate();
             } catch (SQLException e) {
-                System.err.println(e);
+                logger.log(Level.SEVERE, "sql exception", e);
             } finally {
                 Utils.finishSQL(null, stmt);
             }
@@ -118,7 +123,7 @@ public class MessagesQueries {
                 ridnew = 0;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -166,7 +171,7 @@ public class MessagesQueries {
                 privacy = rs.getInt(2);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -189,7 +194,7 @@ public class MessagesQueries {
                 ret = rs.getInt(1) == 1;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -210,7 +215,7 @@ public class MessagesQueries {
                 ret = rs.getInt(1) == 1;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -255,7 +260,7 @@ public class MessagesQueries {
                 msg.Hidden = rs.getBoolean(13);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -276,7 +281,7 @@ public class MessagesQueries {
                 msg.Text = rs.getString(3);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -307,7 +312,7 @@ public class MessagesQueries {
                 msg.Text = rs.getString(6);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -330,15 +335,15 @@ public class MessagesQueries {
                 user.UName = rs.getString(2);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return user;
     }
 
-    public static ArrayList<com.juick.Tag> getMessageTags(Connection sql, int mid) {
-        ArrayList<com.juick.Tag> tags = new ArrayList<com.juick.Tag>();
+    public static List<com.juick.Tag> getMessageTags(Connection sql, int mid) {
+        List<com.juick.Tag> tags = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -356,7 +361,7 @@ public class MessagesQueries {
                 tags.add(t);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -364,8 +369,8 @@ public class MessagesQueries {
         return tags;
     }
 
-    public static ArrayList<Integer> getMessageTagsIDs(Connection sql, int mid) {
-        ArrayList<Integer> tids = new ArrayList<Integer>();
+    public static List<Integer> getMessageTagsIDs(Connection sql, int mid) {
+        List<Integer> tids = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -378,7 +383,7 @@ public class MessagesQueries {
                 tids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -387,7 +392,7 @@ public class MessagesQueries {
     }
 
     public static ArrayList<String> getMessageRecommendations(Connection sql, int mid) {
-        ArrayList<String> users = new ArrayList<String>();
+        ArrayList<String> users = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -400,7 +405,7 @@ public class MessagesQueries {
                 users.add(rs.getString(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -408,8 +413,8 @@ public class MessagesQueries {
         return users;
     }
 
-    public static ArrayList<Integer> getAll(Connection sql, int visitor_uid, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getAll(Connection sql, int visitor_uid, int before) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -448,15 +453,15 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return mids;
     }
 
-    public static ArrayList<Integer> getTag(Connection sql, int tid, int visitor_uid, int before, int cnt) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getTag(Connection sql, int tid, int visitor_uid, int before, int cnt) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -483,15 +488,15 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return mids;
     }
 
-    public static ArrayList<Integer> getTags(Connection sql, String tids, int visitor_uid, int before, int cnt) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getTags(Connection sql, String tids, int visitor_uid, int before, int cnt) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -512,15 +517,15 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return mids;
     }
 
-    public static ArrayList<Integer> getPlace(Connection sql, int place_id, int visitor_uid, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getPlace(Connection sql, int place_id, int visitor_uid, int before) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -541,15 +546,15 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return mids;
     }
 
-    public static ArrayList<Integer> getMyFeed(Connection sql, int uid, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(40);
+    public static List<Integer> getMyFeed(Connection sql, int uid, int before) {
+        List<Integer> mids = new ArrayList<>(40);
         PreparedStatement stmt = null;
         ResultSet rs = null;
         try {
@@ -569,7 +574,7 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -589,7 +594,7 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -603,8 +608,8 @@ public class MessagesQueries {
         return mids;
     }
 
-    public static ArrayList<Integer> getPrivate(Connection sql, int uid, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getPrivate(Connection sql, int uid, int before) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -623,15 +628,15 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return mids;
     }
 
-    public static ArrayList<Integer> getDiscussions(Connection sql, int uid, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getDiscussions(Connection sql, int uid, int before) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -650,7 +655,7 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -658,8 +663,8 @@ public class MessagesQueries {
         return mids;
     }
 
-    public static ArrayList<Integer> getRecommended(Connection sql, int uid, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getRecommended(Connection sql, int uid, int before) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -678,7 +683,7 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -687,8 +692,8 @@ public class MessagesQueries {
         return mids;
     }
 
-    public static ArrayList<Integer> getPopular(Connection sql, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getPopular(Connection sql, int before) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -705,15 +710,15 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return mids;
     }
 
-    public static ArrayList<Integer> getPhotos(Connection sql, int visitor_uid, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getPhotos(Connection sql, int visitor_uid, int before) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -732,15 +737,15 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return mids;
     }
 
-    public static ArrayList<Integer> getSearch(Connection sql, Connection sqlSearch, String search, int before) {
-        ArrayList<Integer> mids0 = new ArrayList<Integer>(20);
+    public static List<Integer> getSearch(Connection sql, Connection sqlSearch, String search, int before) {
+        List<Integer> mids0 = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -760,12 +765,12 @@ public class MessagesQueries {
                 mids0.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
 
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+        List<Integer> mids = new ArrayList<>(20);
         if (mids0.size() > 0) {
             try {
                 stmt = sql.prepareStatement("SELECT message_id FROM messages WHERE message_id IN (" + Utils.convertArrayInt2String(mids0) + ") AND privacy>0 ORDER BY message_id DESC LIMIT 20");
@@ -775,7 +780,7 @@ public class MessagesQueries {
                     mids.add(rs.getInt(1));
                 }
             } catch (SQLException e) {
-                System.err.println(e);
+                logger.log(Level.SEVERE, "sql exception", e);
             } finally {
                 Utils.finishSQL(rs, stmt);
             }
@@ -784,8 +789,8 @@ public class MessagesQueries {
         return mids;
     }
 
-    public static ArrayList<Integer> getUserBlog(Connection sql, int UID, int privacy, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getUserBlog(Connection sql, int UID, int privacy, int before) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -804,15 +809,15 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return mids;
     }
 
-    public static ArrayList<Integer> getUserTag(Connection sql, int UID, int TID, int privacy, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getUserTag(Connection sql, int UID, int TID, int privacy, int before) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -833,15 +838,15 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return mids;
     }
 
-    public static ArrayList<Integer> getUserRecommendations(Connection sql, int UID, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getUserRecommendations(Connection sql, int UID, int before) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -860,15 +865,15 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return mids;
     }
 
-    public static ArrayList<Integer> getUserPhotos(Connection sql, int UID, int privacy, int before) {
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+    public static List<Integer> getUserPhotos(Connection sql, int UID, int privacy, int before) {
+        List<Integer> mids = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -887,15 +892,15 @@ public class MessagesQueries {
                 mids.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return mids;
     }
 
-    public static ArrayList<Integer> getUserSearch(Connection sql, Connection sqlSearch, int UID, String search, int privacy, int before) {
-        ArrayList<Integer> mids0 = new ArrayList<Integer>(20);
+    public static List<Integer> getUserSearch(Connection sql, Connection sqlSearch, int UID, String search, int privacy, int before) {
+        List<Integer> mids0 = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -916,12 +921,12 @@ public class MessagesQueries {
                 mids0.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
 
-        ArrayList<Integer> mids = new ArrayList<Integer>(20);
+        List<Integer> mids = new ArrayList<>(20);
         if (mids0.size() > 0) {
             try {
                 stmt = sql.prepareStatement("SELECT message_id FROM messages WHERE message_id IN (" + Utils.convertArrayInt2String(mids0) + ") AND privacy>=" + privacy + " ORDER BY message_id DESC");
@@ -931,7 +936,7 @@ public class MessagesQueries {
                     mids.add(rs.getInt(1));
                 }
             } catch (SQLException e) {
-                System.err.println(e);
+                logger.log(Level.SEVERE, "sql exception", e);
             } finally {
                 Utils.finishSQL(rs, stmt);
             }
@@ -940,8 +945,8 @@ public class MessagesQueries {
         return mids;
     }
 
-    public static ArrayList<com.juick.Message> getMessages(Connection sql, ArrayList<Integer> mids) {
-        ArrayList<com.juick.Message> msgs = new ArrayList<com.juick.Message>(20);
+    public static List<com.juick.Message> getMessages(Connection sql, List<Integer> mids) {
+        List<com.juick.Message> msgs = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -978,7 +983,7 @@ public class MessagesQueries {
                 msgs.add(msg);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -986,8 +991,8 @@ public class MessagesQueries {
         return msgs;
     }
 
-    public static ArrayList<com.juick.Message> getReplies(Connection sql, int mid) {
-        ArrayList<com.juick.Message> replies = new ArrayList<com.juick.Message>();
+    public static List<com.juick.Message> getReplies(Connection sql, int mid) {
+        List<com.juick.Message> replies = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -1013,7 +1018,7 @@ public class MessagesQueries {
                 replies.add(msg);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -1039,7 +1044,7 @@ public class MessagesQueries {
             }
             ret = stmt.executeUpdate() > 0;
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -1050,7 +1055,7 @@ public class MessagesQueries {
                 stmt.setInt(1, mid);
                 stmt.executeUpdate();
             } catch (SQLException e) {
-                System.err.println(e);
+                logger.log(Level.SEVERE, "sql exception", e);
             } finally {
                 Utils.finishSQL(null, stmt);
             }
@@ -1068,7 +1073,7 @@ public class MessagesQueries {
             stmt.setInt(1, mid);
             ret = stmt.executeUpdate() > 0;
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
diff --git a/src/main/java/com/juick/server/PMQueries.java b/src/main/java/com/juick/server/PMQueries.java
index 56b91abf..c4b4fa2d 100644
--- a/src/main/java/com/juick/server/PMQueries.java
+++ b/src/main/java/com/juick/server/PMQueries.java
@@ -17,11 +17,16 @@
  */
 package com.juick.server;
 
+import com.juick.User;
+
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  *
@@ -29,6 +34,8 @@ import java.util.ArrayList;
  */
 public class PMQueries {
 
+    private static final Logger logger = Logger.getLogger(PMQueries.class.getName());
+
     public static boolean createPM(Connection sql, int uid_from, int uid_to, String body) {
         boolean ret = false;
         PreparedStatement stmt = null;
@@ -39,7 +46,7 @@ public class PMQueries {
             stmt.setString(3, body);
             ret = stmt.executeUpdate() > 0;
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -52,7 +59,7 @@ public class PMQueries {
                 stmt2.setInt(2, uid_to);
                 stmt2.executeUpdate();
             } catch (SQLException e) {
-                System.err.println(e);
+                logger.log(Level.SEVERE, "sql exception", e);
             } finally {
                 Utils.finishSQL(null, stmt2);
             }
@@ -70,7 +77,7 @@ public class PMQueries {
             stmt.setString(2, jid);
             ret = stmt.executeUpdate() > 0;
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -86,7 +93,7 @@ public class PMQueries {
             stmt.setString(2, jid);
             ret = stmt.executeUpdate() > 0;
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -107,7 +114,7 @@ public class PMQueries {
                 ret = true;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -128,15 +135,15 @@ public class PMQueries {
                 ret = rs.getString(1);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return ret;
     }
 
-    public static ArrayList<com.juick.User> getPMLastConversationsUsers(Connection sql, int uid, int cnt) {
-        ArrayList<com.juick.User> users = new ArrayList<com.juick.User>();
+    public static List<com.juick.User> getPMLastConversationsUsers(Connection sql, int uid, int cnt) {
+        List<User> users = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -152,7 +159,7 @@ public class PMQueries {
                 users.add(u);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -177,7 +184,7 @@ public class PMQueries {
                     }
                 }
             } catch (SQLException e) {
-                System.err.println(e);
+                logger.log(Level.SEVERE, "sql exception", e);
             } finally {
                 Utils.finishSQL(rs, stmt);
             }
@@ -190,18 +197,17 @@ public class PMQueries {
         return users;
     }
 
-    public static boolean haveUserInArray(ArrayList<com.juick.User> arr, int uid) {
-        int s = arr.size();
-        for (int i = 0; i < s; i++) {
-            if (arr.get(i).UID == uid) {
+    public static boolean haveUserInArray(List<com.juick.User> arr, int uid) {
+        for (User user : arr) {
+            if (user.UID == uid) {
                 return true;
             }
         }
         return false;
     }
 
-    public static ArrayList<com.juick.Message> getPMMessages(Connection sql, int uid, int uid_to) {
-        ArrayList<com.juick.Message> msgs = new ArrayList<com.juick.Message>(20);
+    public static List<com.juick.Message> getPMMessages(Connection sql, int uid, int uid_to) {
+        List<com.juick.Message> msgs = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -223,7 +229,7 @@ public class PMQueries {
                 msgs.add(0, msg);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -235,7 +241,7 @@ public class PMQueries {
             stmt2.setInt(2, uid_to);
             stmt2.executeUpdate();
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt2);
         }
@@ -243,8 +249,8 @@ public class PMQueries {
         return msgs;
     }
 
-    public static ArrayList<com.juick.Message> getLastPMInbox(Connection sql, int uid) {
-        ArrayList<com.juick.Message> msgs = new ArrayList<com.juick.Message>(20);
+    public static List<com.juick.Message> getLastPMInbox(Connection sql, int uid) {
+        List<com.juick.Message> msgs = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -264,7 +270,7 @@ public class PMQueries {
                 msgs.add(0, msg);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -272,8 +278,8 @@ public class PMQueries {
         return msgs;
     }
 
-    public static ArrayList<com.juick.Message> getLastPMSent(Connection sql, int uid) {
-        ArrayList<com.juick.Message> msgs = new ArrayList<com.juick.Message>(20);
+    public static List<com.juick.Message> getLastPMSent(Connection sql, int uid) {
+        List<com.juick.Message> msgs = new ArrayList<>(20);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -293,7 +299,7 @@ public class PMQueries {
                 msgs.add(0, msg);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
diff --git a/src/main/java/com/juick/server/PushQueries.java b/src/main/java/com/juick/server/PushQueries.java
index bf7505ca..c17972b0 100644
--- a/src/main/java/com/juick/server/PushQueries.java
+++ b/src/main/java/com/juick/server/PushQueries.java
@@ -10,6 +10,8 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  *
@@ -17,12 +19,14 @@ import java.util.List;
  */
 public class PushQueries {
 
+    private static final Logger logger = Logger.getLogger(PushQueries.class.getName());
+
     public static String getAndroidRegID(Connection sql, int uid) {
         return SQLHelpers.getString(sql, "SELECT regid FROM android WHERE user_id=?", uid);
     }
 
-    public static ArrayList<String> getAndroidSubscribers(Connection sql, int uid) {
-        ArrayList<String> regids = new ArrayList<String>();
+    public static List<String> getAndroidSubscribers(Connection sql, int uid) {
+        List<String> regids = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -35,7 +39,7 @@ public class PushQueries {
                 regids.add(rs.getString(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -46,8 +50,8 @@ public class PushQueries {
         return SQLHelpers.getString(sql, "SELECT url FROM winphone WHERE user_id=?", uid);
     }
 
-    public static ArrayList<String> getWinPhoneSubscribers(Connection sql, int uid) {
-        ArrayList<String> urls = new ArrayList<String>();
+    public static List<String> getWinPhoneSubscribers(Connection sql, int uid) {
+        List<String> urls = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -60,7 +64,7 @@ public class PushQueries {
                 urls.add(rs.getString(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -72,7 +76,7 @@ public class PushQueries {
     }
 
     public static List<String> getAPNSSubscribers(Connection sql, int uid) {
-        List<String> urls = new ArrayList<String>();
+        List<String> urls = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -85,7 +89,7 @@ public class PushQueries {
                 urls.add(rs.getString(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
diff --git a/src/main/java/com/juick/server/SQLHelpers.java b/src/main/java/com/juick/server/SQLHelpers.java
index f5569993..13ebe98a 100644
--- a/src/main/java/com/juick/server/SQLHelpers.java
+++ b/src/main/java/com/juick/server/SQLHelpers.java
@@ -9,6 +9,9 @@ import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  *
@@ -16,6 +19,8 @@ import java.util.ArrayList;
  */
 public class SQLHelpers {
 
+    private static final Logger logger = Logger.getLogger(SQLHelpers.class.getName());
+
     public static int execute(Connection sql, String query) {
         int ret = -1;
         PreparedStatement stmt = null;
@@ -23,7 +28,7 @@ public class SQLHelpers {
             stmt = sql.prepareStatement(query);
             ret = stmt.executeUpdate();
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -38,7 +43,7 @@ public class SQLHelpers {
             stmt.setInt(1, param);
             ret = stmt.executeUpdate();
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -56,7 +61,7 @@ public class SQLHelpers {
                 ret = rs.getInt(1);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -75,7 +80,7 @@ public class SQLHelpers {
                 ret = rs.getInt(1);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -94,7 +99,7 @@ public class SQLHelpers {
                 ret = rs.getInt(1);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -113,7 +118,7 @@ public class SQLHelpers {
                 ret = rs.getString(1);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -132,15 +137,15 @@ public class SQLHelpers {
                 ret = rs.getString(1);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return ret;
     }
 
-    public static ArrayList<Integer> getArrayInteger(Connection sql, String query, int param) {
-        ArrayList<Integer> ret = new ArrayList<Integer>();
+    public static List<Integer> getArrayInteger(Connection sql, String query, int param) {
+        List<Integer> ret = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -153,7 +158,7 @@ public class SQLHelpers {
                 ret.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
diff --git a/src/main/java/com/juick/server/SubscriptionsQueries.java b/src/main/java/com/juick/server/SubscriptionsQueries.java
index d0f5f308..637c2bcf 100644
--- a/src/main/java/com/juick/server/SubscriptionsQueries.java
+++ b/src/main/java/com/juick/server/SubscriptionsQueries.java
@@ -9,6 +9,9 @@ import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  *
@@ -16,8 +19,10 @@ import java.util.ArrayList;
  */
 public class SubscriptionsQueries {
 
-    public static ArrayList<String> getJIDSubscribedToUser(Connection sql, int uid, boolean friendsonly) {
-        ArrayList<String> jids = new ArrayList<String>();
+    private static final Logger logger = Logger.getLogger(SubscriptionsQueries.class.getName());
+
+    public static List<String> getJIDSubscribedToUser(Connection sql, int uid, boolean friendsonly) {
+        List<String> jids = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -36,27 +41,27 @@ public class SubscriptionsQueries {
                 jids.add(rs.getString(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return jids;
     }
 
-    public static ArrayList<String> getJIDSubscribedToUserAndTags(Connection sql, int uid, int mid) {
-        ArrayList<String> jids = new ArrayList<String>();
+    public static List<String> getJIDSubscribedToUserAndTags(Connection sql, int uid, int mid) {
+        List<String> jids = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
 
         String tbl = "subscr_jids_" + mid;
-        ArrayList<Integer> tags = MessagesQueries.getMessageTagsIDs(sql, mid);
+        List<Integer> tags = MessagesQueries.getMessageTagsIDs(sql, mid);
 
         try {
             stmt = sql.prepareStatement("CREATE TEMPORARY TABLE " + tbl + "(user_id INT UNSIGNED NOT NULL) ENGINE=MEMORY");
             stmt.executeUpdate();
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -69,7 +74,7 @@ public class SubscriptionsQueries {
             stmt = sql.prepareStatement(query);
             stmt.executeUpdate();
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -87,7 +92,7 @@ public class SubscriptionsQueries {
                 jids.add(rs.getString(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -96,7 +101,7 @@ public class SubscriptionsQueries {
             stmt = sql.prepareStatement("DROP TABLE " + tbl);
             stmt.executeUpdate();
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -104,8 +109,8 @@ public class SubscriptionsQueries {
         return jids;
     }
 
-    public static ArrayList<String> getJIDSubscribedToComments(Connection sql, int mid, int ignore_uid) {
-        ArrayList<String> jids = new ArrayList<String>();
+    public static List<String> getJIDSubscribedToComments(Connection sql, int mid, int ignore_uid) {
+        List<String> jids = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -119,17 +124,17 @@ public class SubscriptionsQueries {
                 jids.add(rs.getString(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return jids;
     }
 
-    public static ArrayList<String> getJIDSubscribedToUserRecommendations(Connection sql, int uid, int mid, int muid) {
-        ArrayList<String> jids = new ArrayList<String>();
+    public static List<String> getJIDSubscribedToUserRecommendations(Connection sql, int uid, int mid, int muid) {
+        List<String> jids = new ArrayList<>();
 
-        ArrayList<Integer> tags = MessagesQueries.getMessageTagsIDs(sql, mid);
+        List<Integer> tags = MessagesQueries.getMessageTagsIDs(sql, mid);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -154,7 +159,7 @@ public class SubscriptionsQueries {
                 jids.add(rs.getString(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
diff --git a/src/main/java/com/juick/server/TagQueries.java b/src/main/java/com/juick/server/TagQueries.java
index 493e8675..1c5e27d1 100644
--- a/src/main/java/com/juick/server/TagQueries.java
+++ b/src/main/java/com/juick/server/TagQueries.java
@@ -17,12 +17,17 @@
  */
 package com.juick.server;
 
+import com.juick.Tag;
+
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  *
@@ -30,6 +35,8 @@ import java.util.ArrayList;
  */
 public class TagQueries {
 
+    private static final Logger logger = Logger.getLogger(TagQueries.class.getName());
+
     public static com.juick.Tag getTag(Connection sql, int tid) {
         com.juick.Tag ret = null;
 
@@ -46,7 +53,7 @@ public class TagQueries {
                 ret.Name = rs.getString(2);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -70,7 +77,7 @@ public class TagQueries {
                 ret.Name = rs.getString(3);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -84,12 +91,12 @@ public class TagQueries {
         return ret;
     }
 
-    public static ArrayList<com.juick.Tag> getTags(Connection sql, String[] tags, boolean autoCreate) {
-        ArrayList<com.juick.Tag> ret = new ArrayList<com.juick.Tag>();
+    public static List<com.juick.Tag> getTags(Connection sql, String[] tags, boolean autoCreate) {
+        List<Tag> ret = new ArrayList<>();
 
-        for (int i = 0; i < tags.length; i++) {
-            if (!tags[i].isEmpty()) {
-                com.juick.Tag t = getTag(sql, tags[i], autoCreate);
+        for (String tag : tags) {
+            if (!tag.isEmpty()) {
+                Tag t = getTag(sql, tag, autoCreate);
                 if (t != null) {
                     ret.add(t);
                 }
@@ -112,7 +119,7 @@ public class TagQueries {
                 ret = rs.getInt(1) == 1;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -134,7 +141,7 @@ public class TagQueries {
                 ret = rs.getInt(1);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -142,8 +149,8 @@ public class TagQueries {
         return ret;
     }
 
-    public static ArrayList<com.juick.Tag> getUserTagsAll(Connection sql, int uid) {
-        ArrayList<com.juick.Tag> tags = new ArrayList<com.juick.Tag>();
+    public static List<com.juick.Tag> getUserTagsAll(Connection sql, int uid) {
+        List<com.juick.Tag> tags = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -159,15 +166,15 @@ public class TagQueries {
                 tags.add(t);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return tags;
     }
 
-    public static ArrayList<String> getUserBLTags(Connection sql, int uid) {
-        ArrayList<String> tags = new ArrayList<String>();
+    public static List<String> getUserBLTags(Connection sql, int uid) {
+        List<String> tags = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -180,7 +187,7 @@ public class TagQueries {
                 tags.add(rs.getString(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
diff --git a/src/main/java/com/juick/server/UserQueries.java b/src/main/java/com/juick/server/UserQueries.java
index 767a68d2..98573bfb 100644
--- a/src/main/java/com/juick/server/UserQueries.java
+++ b/src/main/java/com/juick/server/UserQueries.java
@@ -25,6 +25,7 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.ArrayList;
+import java.util.List;
 import java.util.Random;
 import java.util.UUID;
 import java.util.logging.Level;
@@ -52,7 +53,7 @@ public class UserQueries {
                 stmt.setString(2, hash);
                 stmt.executeUpdate();
             } catch (SQLException e) {
-                System.err.println(e);
+                logger.log(Level.SEVERE, "sql exception", e);
             } finally {
                 Utils.finishSQL(null, stmt);
             }
@@ -76,7 +77,7 @@ public class UserQueries {
                 uid = rs.getInt(1);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -103,7 +104,7 @@ public class UserQueries {
                 user.Banned = rs.getBoolean(2);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -126,7 +127,7 @@ public class UserQueries {
                 user.Banned = rs.getBoolean(3);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -149,15 +150,15 @@ public class UserQueries {
                 user.JID = jid;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return user;
     }
 
-    public static ArrayList<com.juick.User> getUsersByName(Connection sql, ArrayList<String> unames) {
-        ArrayList<com.juick.User> users = new ArrayList<com.juick.User>();
+    public static List<com.juick.User> getUsersByName(Connection sql, List<String> unames) {
+        List<com.juick.User> users = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -172,15 +173,15 @@ public class UserQueries {
                 users.add(user);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return users;
     }
 
-    public static ArrayList<com.juick.User> getUsersByID(Connection sql, ArrayList<Integer> uids) {
-        ArrayList<com.juick.User> users = new ArrayList<com.juick.User>();
+    public static List<com.juick.User> getUsersByID(Connection sql, List<Integer> uids) {
+        List<com.juick.User> users = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -195,7 +196,7 @@ public class UserQueries {
                 users.add(u);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -203,7 +204,7 @@ public class UserQueries {
         return users;
     }
 
-    public static boolean fillUsersByID(Connection sql, ArrayList<com.juick.User> users) {
+    public static boolean fillUsersByID(Connection sql, List<com.juick.User> users) {
         boolean ret = false;
 
         String uids = "";
@@ -231,7 +232,7 @@ public class UserQueries {
                 }
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -239,8 +240,8 @@ public class UserQueries {
         return ret;
     }
 
-    public static ArrayList<com.juick.User> getUsersByJID(Connection sql, ArrayList<String> jids) {
-        ArrayList<com.juick.User> users = new ArrayList<com.juick.User>();
+    public static List<com.juick.User> getUsersByJID(Connection sql, List<String> jids) {
+        List<com.juick.User> users = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -256,7 +257,7 @@ public class UserQueries {
                 users.add(user);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -296,7 +297,7 @@ public class UserQueries {
                 user.AuthHash = hash;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -315,7 +316,7 @@ public class UserQueries {
                 stmt.setString(2, hash);
                 stmt.executeUpdate();
             } catch (SQLException e) {
-                System.err.println(e);
+                logger.log(Level.SEVERE, "sql exception", e);
             } finally {
                 Utils.finishSQL(null, stmt);
             }
@@ -353,7 +354,7 @@ public class UserQueries {
                 }
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -373,7 +374,7 @@ public class UserQueries {
                 ret = rs.getInt(1);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -388,7 +389,7 @@ public class UserQueries {
             stmt.setInt(2, uid);
             stmt.executeUpdate();
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(null, stmt);
         }
@@ -407,7 +408,7 @@ public class UserQueries {
                 ret = rs.getInt(1) < 3600;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -428,7 +429,7 @@ public class UserQueries {
                 ret = rs.getInt(1) == 1;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -449,7 +450,7 @@ public class UserQueries {
                 ret = rs.getInt(1) == 1;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -472,15 +473,15 @@ public class UserQueries {
                 ret = rs.getInt(1) == 1;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return ret;
     }
 
-    public static ArrayList<Integer> checkBL(Connection sql, int visitor, ArrayList<Integer> uids) {
-        ArrayList<Integer> ret = new ArrayList<Integer>();
+    public static List<Integer> checkBL(Connection sql, int visitor, List<Integer> uids) {
+        List<Integer> ret = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -493,7 +494,7 @@ public class UserQueries {
                 ret.add(rs.getInt(1));
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -515,19 +516,19 @@ public class UserQueries {
                 ret = rs.getInt(1) == 1;
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
         return ret;
     }
 
-    public static ArrayList<Integer> getUserRead(Connection sql, int uid) {
+    public static List<Integer> getUserRead(Connection sql, int uid) {
         return SQLHelpers.getArrayInteger(sql, "SELECT user_id FROM subscr_users WHERE suser_id=?", uid);
     }
 
-    public static ArrayList<com.juick.User> getUserReadLeastPopular(Connection sql, int uid, int cnt) {
-        ArrayList<com.juick.User> users = new ArrayList<com.juick.User>(cnt);
+    public static List<com.juick.User> getUserReadLeastPopular(Connection sql, int uid, int cnt) {
+        List<com.juick.User> users = new ArrayList<>(cnt);
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -544,7 +545,7 @@ public class UserQueries {
                 users.add(u);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -552,12 +553,12 @@ public class UserQueries {
         return users;
     }
 
-    public static ArrayList<Integer> getUserReaders(Connection sql, int uid) {
+    public static List<Integer> getUserReaders(Connection sql, int uid) {
         return SQLHelpers.getArrayInteger(sql, "SELECT suser_id FROM subscr_users WHERE user_id=?", uid);
     }
 
-    public static ArrayList<com.juick.User> getUserBLUsers(Connection sql, int uid) {
-        ArrayList<com.juick.User> users = new ArrayList<com.juick.User>();
+    public static List<com.juick.User> getUserBLUsers(Connection sql, int uid) {
+        List<com.juick.User> users = new ArrayList<>();
 
         PreparedStatement stmt = null;
         ResultSet rs = null;
@@ -573,7 +574,7 @@ public class UserQueries {
                 users.add(u);
             }
         } catch (SQLException e) {
-            System.err.println(e);
+            logger.log(Level.SEVERE, "sql exception", e);
         } finally {
             Utils.finishSQL(rs, stmt);
         }
@@ -603,7 +604,7 @@ public class UserQueries {
                 return stmt2.execute();
             }
         } catch (SQLException e) {
-            logger.throwing(UserQueries.class.getName(), "linkTwitterAccount", e);
+            logger.log(Level.SEVERE, "sql exception", e);
         }
         return false;
     }
@@ -642,7 +643,7 @@ public class UserQueries {
                 preparedStatement.setString(3, JID);
                 return preparedStatement.executeUpdate() >= 0;
             } catch (SQLException e) {
-                logger.log(Level.SEVERE, "sql error", e);
+                logger.log(Level.SEVERE, "sql exception", e);
             } finally {
                 Utils.finishSQL(null, preparedStatement);
             }
diff --git a/src/main/java/com/juick/server/Utils.java b/src/main/java/com/juick/server/Utils.java
index f97797d7..1968150e 100644
--- a/src/main/java/com/juick/server/Utils.java
+++ b/src/main/java/com/juick/server/Utils.java
@@ -21,7 +21,7 @@ import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
-import java.util.ArrayList;
+import java.util.List;
 
 /**
  *
@@ -29,7 +29,7 @@ import java.util.ArrayList;
  */
 public class Utils {
 
-    public static String convertArrayInt2String(ArrayList<Integer> mids) {
+    public static String convertArrayInt2String(List<Integer> mids) {
         String q = "";
         for (int i = 0; i < mids.size(); i++) {
             if (i > 0) {
@@ -40,7 +40,7 @@ public class Utils {
         return q;
     }
 
-    public static String convertArrayString2String(ArrayList<String> unames) {
+    public static String convertArrayString2String(List<String> unames) {
         String q = "";
         for (int i = 0; i < unames.size(); i++) {
             if (i > 0) {