Merge pull request 'Remove JDBC RAM leak + improve performance' (#237) from betterSQL into master

Reviewed-on: SteamWar/BungeeCore#237
Reviewed-by: YoyoNow <jwsteam@nidido.de>

src/de/steamwar/bungeecore/BungeeCore.java

@@ -24,11 +24,11 @@ import de.steamwar.bungeecore.bot.config.SteamwarDiscordBotConfig;
 import de.steamwar.bungeecore.commands.*;
 import de.steamwar.bungeecore.comms.SpigotReceiver;
 import de.steamwar.bungeecore.listeners.*;
-import de.steamwar.bungeecore.listeners.mods.ModLoaderBlocker;
 import de.steamwar.bungeecore.listeners.mods.Forge;
 import de.steamwar.bungeecore.listeners.mods.LabyMod;
+import de.steamwar.bungeecore.listeners.mods.ModLoaderBlocker;
 import de.steamwar.bungeecore.listeners.mods.WorldDownloader;
-import de.steamwar.bungeecore.sql.SQL;
+import de.steamwar.bungeecore.sql.Statement;
 import de.steamwar.bungeecore.sql.SteamwarUser;
 import de.steamwar.bungeecore.sql.Team;
 import net.dv8tion.jda.api.JDA;
@@ -145,19 +145,20 @@ public class BungeeCore extends Plugin {
         new EventStarter();
         new SessionManager();
         new SpigotReceiver();
-        new SteamwarDiscordBot();
         new TablistManager();
 
         getProxy().getScheduler().schedule(this, () -> {
             SteamwarUser.clearCache();
             Team.clearCache();
         }, 1, 1, TimeUnit.HOURS);
+
+        new SteamwarDiscordBot();
     }
 
     @Override
     public void onDisable(){
         ErrorLogger.stop();
-        SQL.close();
+        Statement.close();
         try {
             SteamwarDiscordBot.instance().getJda().shutdownNow();
             SteamwarDiscordBot.instance().getJda().awaitStatus(JDA.Status.SHUTDOWN);
@@ -258,7 +259,7 @@ public class BungeeCore extends Plugin {
         Persistent.setChatPrefix(CHAT_PREFIX);
         Persistent.setLobbyServer(LOBBY_SERVER);
 
-        SQL.connect(
+        Statement.connect(
                 config.getString("db.url"),
                 config.getString("db.username"),
                 config.getString("db.password")

src/de/steamwar/bungeecore/commands/PollresultCommand.java

@@ -46,7 +46,7 @@ public class PollresultCommand extends BasicCommand {
         ProxiedPlayer player = (ProxiedPlayer) sender;
 
         Map<String, Integer> voted = PollAnswer.getCurrentResults();
-        Message.send("POLLRESULT_HEADER", player, PollAnswer.getAllAnswered(), PollSystem.getQuestion());
+        Message.send("POLLRESULT_HEADER", player, voted.values().stream().reduce(Integer::sum), PollSystem.getQuestion());
         for (Map.Entry<String, Integer> e: voted.entrySet()) {
             Message.send("POLLRESULT_LIST", sender, e.getKey(), e.getValue());
         }

src/de/steamwar/bungeecore/commands/TeamCommand.java

@@ -177,7 +177,7 @@ public class TeamCommand extends BasicCommand {
         if(checkTeamName(player, team, args[2]))
             return;
 
-        Team.create(args[1], args[2], user);
+        Team.create(args[1], args[2]);
         user.setTeam(Team.get(args[1]).getTeamId());
         user.setLeader(true);
         Message.send("TEAM_CREATE_CREATED", player, args[2]);

src/de/steamwar/bungeecore/sql/BannedUserIPs.java

@@ -19,18 +19,18 @@
 
 package de.steamwar.bungeecore.sql;
 
-import de.steamwar.bungeecore.BungeeCore;
-
-import java.sql.ResultSet;
-import java.sql.SQLException;
 import java.sql.Timestamp;
 import java.util.ArrayList;
 import java.util.List;
 
 public class BannedUserIPs {
 
-    private int userID;
-    private Timestamp timestamp;
+    private static final Statement getByID = new Statement("SELECT * FROM BannedUserIPs WHERE UserID = ? ORDER BY Timestamp ASC");
+    private static final Statement getByIP = new Statement("SELECT * FROM BannedUserIPs WHERE IP = ? ORDER BY Timestamp DESC");
+    private static final Statement banIP = new Statement("INSERT INTO BannedUserIPs (UserID, Timestamp, IP) VALUES (?, NOW(), ?) ON DUPLICATE KEY UPDATE Timestamp=NOW()");
+
+    private final int userID;
+    private final Timestamp timestamp;
 
     private BannedUserIPs(int userID, Timestamp timestamp){
         this.userID = userID;
@@ -38,37 +38,31 @@ public class BannedUserIPs {
     }
 
     public static List<BannedUserIPs> get(int userID){
-        List<BannedUserIPs> userIPs = new ArrayList<>();
-        ResultSet dbentry = SQL.select("SELECT * FROM BannedUserIPs WHERE UserID = ? ORDER BY Timestamp ASC", userID);
-        try {
-            while(dbentry.next()){
+        return getByID.select(rs -> {
+            List<BannedUserIPs> userIPs = new ArrayList<>();
+            while(rs.next()) {
                 userIPs.add(new BannedUserIPs(
                         userID,
-                        dbentry.getTimestamp("Timestamp")));
+                        rs.getTimestamp("Timestamp")));
             }
-        } catch (SQLException e) {
-            BungeeCore.log("Get BannedUserIPs failed", e);
-        }
-        return userIPs;
+            return userIPs;
+        }, userID);
     }
 
     public static List<BannedUserIPs> get(String ip){
-        List<BannedUserIPs> userIDs = new ArrayList<>();
-        ResultSet dbentry = SQL.select("SELECT * FROM BannedUserIPs WHERE IP = ? ORDER BY Timestamp DESC", ip);
-        try {
-            while(dbentry.next()){
+        return getByIP.select(rs -> {
+            List<BannedUserIPs> userIDs = new ArrayList<>();
+            while(rs.next()) {
                 userIDs.add(new BannedUserIPs(
-                        dbentry.getInt("UserID"),
-                        dbentry.getTimestamp("Timestamp")));
+                        rs.getInt("UserID"),
+                        rs.getTimestamp("Timestamp")));
             }
-        } catch (SQLException e) {
-            BungeeCore.log("Get BannedUserIPs failed", e);
-        }
-        return userIDs;
+            return userIDs;
+        }, ip);
     }
 
     static void banIP(SteamwarUser user, String ip){
-        SQL.update("INSERT INTO BannedUserIPs (UserID, Timestamp, IP) VALUES (?, NOW(), ?) ON DUPLICATE KEY UPDATE Timestamp=NOW()", user.getId(), ip);
+        banIP.update(user.getId(), ip);
     }
 
     public int getUserID() {

src/de/steamwar/bungeecore/sql/BauweltMember.java

@@ -19,15 +19,17 @@
 
 package de.steamwar.bungeecore.sql;
 
-import de.steamwar.bungeecore.BungeeCore;
-
-import java.sql.ResultSet;
-import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.UUID;
 
 public class BauweltMember{
+
+    private static final Statement delete = new Statement("DELETE FROM BauweltMember WHERE BauweltID = ? AND MemberID = ?");
+    private static final Statement update = new Statement("INSERT INTO BauweltMember (BauweltID, MemberID, WorldEdit, World) VALUES (?, ?, ?, ?) ON DUPLICATE KEY UPDATE WorldEdit = VALUES(WorldEdit), World = VALUES(World)");
+    private static final Statement getMember = new Statement("SELECT * FROM BauweltMember WHERE BauweltID = ? AND MemberID = ?");
+    private static final Statement getMembers = new Statement("SELECT * FROM BauweltMember WHERE BauweltID = ?");
+
     private final int bauweltID;
     private final int memberID;
     private boolean worldEdit;
@@ -52,12 +54,11 @@ public class BauweltMember{
     }
 
     public void remove(){
-        SQL.update("DELETE FROM BauweltMember WHERE BauweltID = " + bauweltID + " AND MemberID = " + memberID);
+        delete.update(bauweltID, memberID);
     }
 
     private void updateDB(){
-        SQL.update("INSERT INTO BauweltMember (BauweltID, MemberID, WorldEdit, World) VALUES (?, ?, ?, ?) ON DUPLICATE KEY UPDATE WorldEdit = VALUES(WorldEdit), World = VALUES(World)",
-                bauweltID, memberID, worldEdit, world);
+        update.update(bauweltID, memberID, worldEdit, world);
     }
 
     public static BauweltMember getBauMember(UUID ownerID, UUID memberID){
@@ -65,18 +66,12 @@ public class BauweltMember{
     }
 
     public static BauweltMember getBauMember(int ownerID, int memberID){
-        ResultSet member = SQL.select("SELECT * FROM BauweltMember WHERE BauweltID = ? AND MemberID = ?", ownerID, memberID);
-        try {
-            if(member == null || !member.next()){
+        return getMember.select(rs -> {
+            if(!rs.next())
                 return null;
-            }
-            boolean worldEdit = member.getBoolean("WorldEdit");
-            boolean world = member.getBoolean("World");
-            return new BauweltMember(ownerID, memberID, worldEdit, world, false);
-        } catch (SQLException e) {
-            BungeeCore.log("Could not load BauweltMember", e);
-        }
-        return null;
+
+            return new BauweltMember(ownerID, memberID, rs.getBoolean("WorldEdit"), rs.getBoolean("World"), false);
+        }, ownerID, memberID);
     }
 
     public static List<BauweltMember> getMembers(UUID bauweltID){
@@ -84,20 +79,13 @@ public class BauweltMember{
     }
 
     public static List<BauweltMember> getMembers(int bauweltID){
-        try{
-            ResultSet memberlist = SQL.select("SELECT * FROM BauweltMember WHERE BauweltID = ?", bauweltID);
+        return getMembers.select(rs -> {
             List<BauweltMember> members = new ArrayList<>();
-            while(memberlist.next()){
-                int memberID = memberlist.getInt("MemberID");
-                boolean worldEdit = memberlist.getBoolean("WorldEdit");
-                boolean world = memberlist.getBoolean("World");
-                members.add(new BauweltMember(bauweltID, memberID, worldEdit, world, false));
+            while(rs.next()){
+                members.add(new BauweltMember(bauweltID, rs.getInt("MemberID"), rs.getBoolean("WorldEdit"), rs.getBoolean("World"), false));
             }
             return members;
-        }catch(SQLException e){
-            BungeeCore.log("Could not load BauweltMembers", e);
-        }
-        return new ArrayList<>();
+        }, bauweltID);
     }
 
     public int getBauweltID() {

src/de/steamwar/bungeecore/sql/CheckedSchematic.java

@@ -27,6 +27,9 @@ import java.util.List;
 
 public class CheckedSchematic {
 
+    private static final Statement create = new Statement("INSERT INTO CheckedSchematic (SchemName, SchemOwner, Validator, StartTime, EndTime, DeclineReason) VALUES (?, ?, ?, ?, ?, ?)");
+    private static final Statement previous = new Statement("SELECT * FROM CheckedSchematic WHERE SchemName = ? AND SchemOwner = ? ORDER BY EndTime ASC");
+
     private final String schemName;
     private final int schemOwner;
 
@@ -45,20 +48,16 @@ public class CheckedSchematic {
     }
 
     public static void create(String schemName, int schemOwner, int validator, Timestamp startTime, Timestamp endTime, String reason){
-        SQL.update("INSERT INTO CheckedSchematic (SchemName, SchemOwner, Validator, StartTime, EndTime, DeclineReason) VALUES (?, ?, ?, ?, ?, ?)",
-                schemName, schemOwner, validator, startTime, endTime, reason);
+        create.update(schemName, schemOwner, validator, startTime, endTime, reason);
     }
 
     public static List<CheckedSchematic> previousChecks(String schemName, int schemOwner){
-        ResultSet rs = SQL.select("SELECT * FROM CheckedSchematic WHERE SchemName = ? AND SchemOwner = ? ORDER BY EndTime ASC", schemName, schemOwner);
-        List<CheckedSchematic> schematics = new ArrayList<>();
-        try {
+        return previous.select(rs -> {
+            List<CheckedSchematic> schematics = new ArrayList<>();
             while(rs.next())
                 schematics.add(new CheckedSchematic(rs));
-        } catch (SQLException e) {
-            throw new SecurityException("Could not load previous checks", e);
-        }
-        return schematics;
+            return schematics;
+        }, schemName, schemOwner);
     }
 
     public int getValidator() {

src/de/steamwar/bungeecore/sql/Elo.java

@@ -19,33 +19,26 @@
 
 package de.steamwar.bungeecore.sql;
 
-import java.sql.ResultSet;
-import java.sql.SQLException;
-
 public class Elo {
+
+    private static final Statement elo = new Statement("SELECT Elo FROM Elo WHERE UserID = ? AND GameMode = ?");
+    private static final Statement place = new Statement("SELECT COUNT(*) AS Place FROM Elo WHERE GameMode = ? AND Elo > ?");
+
     private Elo(){}
 
     public static int getElo(int userID, String gameMode){
-        ResultSet rs = SQL.select("SELECT Elo FROM Elo WHERE UserID = ? AND GameMode = ?", userID, gameMode);
-        int elo = 1000;
-        try {
+        return elo.select(rs -> {
             if(rs.next())
-                elo = rs.getInt("Elo");
-        } catch (SQLException e) {
-            throw new SecurityException("Could not get Elo", e);
-        }
-        return elo;
+                return rs.getInt("Elo");
+            return 1000;
+        }, userID, gameMode);
     }
 
     public static int getPlacement(int elo, String gameMode){
-        ResultSet rs = SQL.select("SELECT COUNT(*) AS Place FROM Elo WHERE GameMode = ? AND Elo > ?", gameMode, elo);
-        try{
-            if(!rs.next())
-                return -1;
-
-            return rs.getInt("Place");
-        }catch(SQLException e){
-            throw new SecurityException("Could not get place", e);
-        }
+        return place.select(rs -> {
+            if(rs.next())
+                return rs.getInt("Place");
+            return -1;
+        }, gameMode, elo);
     }
 }

src/de/steamwar/bungeecore/sql/Event.java

@@ -19,17 +19,20 @@
 
 package de.steamwar.bungeecore.sql;
 
-import de.steamwar.bungeecore.BungeeCore;
-
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Timestamp;
 import java.time.Instant;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 
 public class Event {
 
+    private static final Statement byCurrent = new Statement("SELECT * FROM Event WHERE Start < now() AND End > now()");
+    private static final Statement byId = new Statement("SELECT * FROM Event WHERE EventID = ?");
+    private static final Statement byName = new Statement("SELECT * FROM Event WHERE lower(EventName) = ?");
+    private static final Statement byComing = new Statement("SELECT * FROM Event WHERE Start > now()");
+
     private final int eventID;
     private final String eventName;
     private final Timestamp start;
@@ -56,57 +59,39 @@ public class Event {
         if(current != null && current.now())
             return current;
 
-        ResultSet rs = SQL.select("SELECT * FROM Event WHERE Start < now() AND End > now()");
-        try{
-            if(!rs.next()){
+        return byCurrent.select(rs -> {
+            if(rs.next())
+                current = new Event(rs);
+            else
                 current = null;
-                return null;
-            }
-
-            current = new Event(rs);
             return current;
-        }catch (SQLException e){
-            BungeeCore.log("Failed to load current Event", e);
-            throw new SecurityException();
-        }
+        });
     }
 
     public static Event get(int eventID){
-        ResultSet rs = SQL.select("SELECT * FROM Event WHERE EventID = " + eventID);
-        try{
+        return byId.select(rs -> {
             if(!rs.next())
-                throw new IllegalArgumentException();
-
+                throw new SQLException("Couldn't find event " + eventID);
             return new Event(rs);
-        }catch (SQLException e){
-            BungeeCore.log("Failed to load Event", e);
-            throw new SecurityException();
-        }
+        }, eventID);
     }
 
     public static Event get(String eventName){
-        ResultSet rs = SQL.select("SELECT * FROM Event WHERE lower(EventName) = ?", eventName.toLowerCase());
-        try{
+        return byName.select(rs -> {
             if(!rs.next())
                 return null;
 
             return new Event(rs);
-        }catch (SQLException e){
-            BungeeCore.log("Failed to load Event by name", e);
-            throw new SecurityException();
-        }
+        }, eventName.toLowerCase());
     }
 
     public static List<Event> getComing(){
-        List<Event> events = new LinkedList<>();
-        ResultSet rs = SQL.select("SELECT * FROM Event WHERE Start > now()");
-        try{
+        return byComing.select(rs -> {
+            List<Event> events = new ArrayList<>();
             while(rs.next())
                 events.add(new Event(rs));
-        }catch (SQLException e){
-            BungeeCore.log("Failed to load Events", e);
-        }
-        return events;
+            return events;
+        });
     }
 
     private boolean now(){

src/de/steamwar/bungeecore/sql/EventFight.java

@@ -20,7 +20,6 @@
 package de.steamwar.bungeecore.sql;
 
 import de.steamwar.bungeecore.ArenaMode;
-import de.steamwar.bungeecore.BungeeCore;
 
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -31,7 +30,11 @@ import static java.time.temporal.ChronoUnit.SECONDS;
 
 public class EventFight implements Comparable<EventFight> {
 
-    private static Queue<EventFight> fights = new PriorityQueue<>();
+    private static final Statement reschedule = new Statement("UPDATE EventFight SET StartTime = ? WHERE EventID = ? AND FightID = ?");
+    private static final Statement allComing = new Statement("SELECT * FROM EventFight WHERE StartTime > now() ORDER BY `StartTime` ASC");
+    private static final Statement event = new Statement("SELECT * FROM EventFight WHERE EventID = ? ORDER BY `StartTime` ASC");
+
+    private static final Queue<EventFight> fights = new PriorityQueue<>();
 
     private final int eventID;
     private final int fightID;
@@ -57,31 +60,26 @@ public class EventFight implements Comparable<EventFight> {
 
     public void reschedule(){
         startTime = Timestamp.from(new Date().toInstant().plus(30, SECONDS));
-        SQL.update("UPDATE EventFight SET StartTime = ? WHERE EventID = ? AND FightID = ?", startTime, eventID, fightID);
+        reschedule.update(startTime, eventID, fightID);
     }
 
     public static void loadAllComingFights(){
-        ResultSet rs = SQL.select("SELECT * FROM EventFight WHERE StartTime > now() ORDER BY `StartTime` ASC");
-        fights.clear();
-        try{
+        allComing.select(rs -> {
+            fights.clear();
             while(rs.next()){
-                 fights.add(new EventFight(rs));
+                fights.add(new EventFight(rs));
             }
-        }catch (SQLException e){
-            BungeeCore.log("Failed to load EventFights", e);
-        }
+            return null;
+        });
     }
 
     public static List<EventFight> getEvent(int eventID){
-        ResultSet rs = SQL.select("SELECT * FROM EventFight WHERE EventID = ? ORDER BY `StartTime` ASC", eventID);
-        List<EventFight> fights = new LinkedList<>();
-        try{
+        return event.select(rs -> {
+            List<EventFight> fights = new LinkedList<>();
             while(rs.next())
                 fights.add(new EventFight(rs));
-        }catch (SQLException e){
-            BungeeCore.log("Failed to load EventFights", e);
-        }
-        return fights;
+            return fights;
+        }, eventID);
     }
 
     public static Queue<EventFight> getFights() {

src/de/steamwar/bungeecore/sql/IgnoreSystem.java

@@ -22,9 +22,13 @@ package de.steamwar.bungeecore.sql;
 import net.md_5.bungee.api.connection.ProxiedPlayer;
 
 import java.sql.ResultSet;
-import java.sql.SQLException;
 
 public class IgnoreSystem{
+
+    private static final Statement select = new Statement("SELECT COUNT(*) AS blocked FROM IgnoredPlayers WHERE Ignorer = ? AND Ignored = ?");
+    private static final Statement insert = new Statement("INSERT INTO IgnoredPlayers (Ignorer, Ignored) VALUES (?, ?)");
+    private static final Statement delete = new Statement("DELETE FROM IgnoredPlayers WHERE Ignorer = ? AND Ignored = ?");
+
     private IgnoreSystem(){}
 
     public static boolean isIgnored(ProxiedPlayer ignorer, ProxiedPlayer ignored){
@@ -34,22 +38,14 @@ public class IgnoreSystem{
     }
 
     public static boolean isIgnored(SteamwarUser ignorer, SteamwarUser ignored) {
-        try {
-            ResultSet rs = SQL.select("SELECT COUNT(*) AS blocked FROM IgnoredPlayers WHERE Ignorer = ? AND Ignored = ?", ignorer.getId(), ignored.getId());
-            if(!rs.next())
-                return false;
-
-            return rs.getInt("blocked") > 0;
-        } catch (SQLException e) {
-            throw new SecurityException("Could not check if ignored", e);
-        }
+        return select.select(ResultSet::next, ignorer.getId(), ignored.getId());
     }
 
     public static void ignore(SteamwarUser ignorer, SteamwarUser ignored) {
-        SQL.update("INSERT INTO IgnoredPlayers (Ignorer, Ignored) VALUES (?, ?)", ignorer.getId(), ignored.getId());
+        insert.update(ignorer.getId(), ignored.getId());
     }
 
     public static void unIgnore(SteamwarUser ignorer, SteamwarUser ignored) {
-        SQL.update("DELETE FROM IgnoredPlayers WHERE Ignorer = ? AND Ignored = ?", ignorer.getId(), ignored.getId());
+        delete.update(ignorer.getId(), ignored.getId());
     }
 }

src/de/steamwar/bungeecore/sql/Mod.java

@@ -19,12 +19,11 @@
 
 package de.steamwar.bungeecore.sql;
 
-import de.steamwar.bungeecore.BungeeCore;
-
-import java.sql.ResultSet;
-import java.sql.SQLException;
-
 public class Mod {
+
+    private static final Statement get = new Statement("SELECT * FROM Mods WHERE ModName = ? AND Platform = ?");
+    private static final Statement insert = new Statement("INSERT INTO Mods (ModName, Platform) VALUES (?, ?)");
+
     private final String modName;
     private final Platform platform;
     private final ModType modType;
@@ -36,15 +35,15 @@ public class Mod {
     }
 
     public static Mod get(String modName, Platform platform){
-        ResultSet rs = SQL.select("SELECT * FROM Mods WHERE ModName = ? AND Platform = ?", modName, platform.value);
-        try{
+        Mod mod = get.select(rs -> {
             if(rs.next())
                 return new Mod(modName, platform, ModType.valueOf(rs.getInt("ModType")));
-        }catch (SQLException e){
-            BungeeCore.log("Failed to load Mod", e);
-            throw new SecurityException();
-        }
-        SQL.update("INSERT INTO Mods (ModName, Platform) VALUES (?, ?)", modName, platform.value);
+            return null;
+        }, modName, platform.value);
+        if(mod != null)
+            return mod;
+
+        insert.update(modName, platform.value);
         return new Mod(modName, platform, ModType.UNKLASSIFIED);
     }
 

src/de/steamwar/bungeecore/sql/PollAnswer.java

@@ -19,7 +19,6 @@
 
 package de.steamwar.bungeecore.sql;
 
-import de.steamwar.bungeecore.BungeeCore;
 import de.steamwar.bungeecore.listeners.PollSystem;
 
 import java.sql.ResultSet;
@@ -29,6 +28,10 @@ import java.util.Map;
 
 public class PollAnswer {
 
+    private static final Statement get = new Statement("SELECT * FROM PollAnswer WHERE UserID = ? AND Question = ?");
+    private static final Statement getResults = new Statement("SELECT Count(UserID) AS Times, Answer FROM PollAnswer WHERE Question = ? GROUP BY Answer ORDER BY `Times` ASC");
+    private static final Statement insert = new Statement("INSERT INTO PollAnswer (UserID, Question, Answer) VALUES (?, ?, ?) ON DUPLICATE KEY UPDATE Answer = VALUES(Answer)");
+
     private final int userID;
     private final String question;
     private int answer;
@@ -44,38 +47,20 @@ public class PollAnswer {
     }
 
     public static PollAnswer get(int userID){
-        ResultSet rs = SQL.select("SELECT * FROM PollAnswer WHERE UserID = ? AND Question = ?", userID, PollSystem.getQuestion());
-        try {
-            if(!rs.next())
-                return new PollAnswer(userID, PollSystem.getQuestion());
-            return new PollAnswer(rs);
-        } catch (SQLException e) {
-            throw new SecurityException("Unable to get PollAnswer", e);
-        }
+        return get.select(rs -> {
+            if(rs.next())
+                return new PollAnswer(rs);
+            return new PollAnswer(userID, PollSystem.getQuestion());
+        }, userID, PollSystem.getQuestion());
     }
 
     public static Map<String, Integer> getCurrentResults() {
-        ResultSet set = SQL.select("SELECT Count(UserID) AS Times, Answer FROM PollAnswer WHERE Question = ? GROUP BY Answer ORDER BY `Times` ASC", PollSystem.getQuestion());
-        try {
+        return getResults.select(rs -> {
             Map<String, Integer> retMap = new HashMap<>();
-            while (set.next()) {
-                retMap.put(PollSystem.getAnswer(set.getInt("Answer")), set.getInt("Times"));
-            }
+            while (rs.next())
+                retMap.put(PollSystem.getAnswer(rs.getInt("Answer")), rs.getInt("Times"));
             return retMap;
-        }catch (SQLException e) {
-            throw new SecurityException("Unable to get PollAnswer", e);
-        }
-    }
-
-    public static Integer getAllAnswered() {
-        ResultSet set = SQL.select("SELECT Count(UserID) AS Times FROM PollAnswer WHERE Question = ?", PollSystem.getQuestion());
-        try {
-            if(!set.next())
-                throw new SecurityException("Could not get PollAnswers");
-            return set.getInt("Times");
-        }catch (SQLException e) {
-            throw new SecurityException("Unable to get PollAnswer", e);
-        }
+        }, PollSystem.getQuestion());
     }
 
     public boolean hasAnswered(){
@@ -84,6 +69,6 @@ public class PollAnswer {
 
     public void setAnswer(int answer){
         this.answer = answer;
-        SQL.update("INSERT INTO PollAnswer (UserID, Question, Answer) VALUES (?, ?, ?) ON DUPLICATE KEY UPDATE Answer = VALUES(Answer)", userID, question, answer);
+        insert.update(userID, question, answer);
     }
 }

src/de/steamwar/bungeecore/sql/Punishment.java

@@ -31,45 +31,40 @@ import java.util.*;
 
 public class Punishment {
 
+    private static final Statement getPunishment = new Statement("SELECT * FROM Punishments WHERE UserId = ? AND Type = ? ORDER BY PunishmentId DESC LIMIT 1");
+    private static final Statement getPunishments = new Statement("SELECT * FROM Punishments WHERE PunishmentId IN (SELECT MAX(PunishmentId) FROM Punishments WHERE UserId = ? GROUP BY Type)");
+    private static final Statement getAllPunishments = new Statement("SELECT * FROM Punishments WHERE UserId = ? ORDER BY `PunishmentId` DESC");
+    private static final Statement insert = new Statement("INSERT INTO Punishments (UserId, Punisher, Type, Reason, EndTime, Perma) VALUES (?, ?, ?, ?, ?, ?)");
+    private static final Statement update = new Statement("UPDATE Punishments SET EndTime = ?, Reason = ?, Perma = ? WHERE PunishmentId = ?");
+
     public static Punishment getPunishmentOfPlayer(int user, PunishmentType type) {
-        ResultSet set = SQL.select("SELECT * FROM Punishments WHERE UserId = ? AND Type = ? ORDER BY PunishmentId DESC LIMIT 1", user, type.name());
-        try {
-            if(!set.next())
-                return null;
-            return new Punishment(set);
-        } catch (SQLException e) {
-            throw new SecurityException("Could not Load Punishments", e);
-        }
+        return getPunishment.select(rs -> {
+            if(rs.next())
+                return new Punishment(rs);
+            return null;
+        }, user, type.name());
     }
 
     public static Map<PunishmentType, Punishment> getPunishmentsOfPlayer(int user) {
-        ResultSet set = SQL.select("SELECT * FROM Punishments WHERE PunishmentId IN (SELECT MAX(PunishmentId) FROM Punishments WHERE UserId = ? GROUP BY Type)", user);
-        try {
+        return getPunishments.select(rs -> {
             Map<PunishmentType, Punishment> punishments = new HashMap<>();
-            while (set.next())
-                punishments.put(PunishmentType.valueOf(set.getString("Type")), new Punishment(set));
+            while (rs.next())
+                punishments.put(PunishmentType.valueOf(rs.getString("Type")), new Punishment(rs));
             return punishments;
-        } catch (SQLException e) {
-            throw new SecurityException("Could not Load Punishments", e);
-        }
+        }, user);
     }
 
     public static List<Punishment> getAllPunishmentsOfPlayer(int user) {
-        ResultSet set = SQL.select("SELECT * FROM Punishments WHERE UserId = ? ORDER BY `PunishmentId` DESC", user);
-        try {
+        return getAllPunishments.select(rs -> {
             List<Punishment> punishments = new ArrayList<>();
-            while (set.next()) {
-                punishments.add(new Punishment(set));
-            }
+            while (rs.next())
+                punishments.add(new Punishment(rs));
             return punishments;
-        } catch (SQLException e) {
-            throw new SecurityException("Could not Load all Punishments", e);
-        }
+        }, user);
     }
 
     public static Punishment createPunishment(int user, int executor, PunishmentType type, String reason, Timestamp endTime, boolean perma) {
-        SQL.update("INSERT INTO Punishments (UserId, Punisher, Type, Reason, EndTime, Perma) VALUES (?, ?, ?, ?, ?, ?)",
-                user, executor, type.name(), reason, endTime, perma);
+        insert.update(user, executor, type.name(), reason, endTime, perma);
         return getPunishmentOfPlayer(user, type);
     }
 
@@ -122,7 +117,7 @@ public class Punishment {
     }
 
     public void updateEndTime(int from, String newreason, Timestamp newUpdate, boolean perma) {
-        if(newreason.equals(reason) && newUpdate.equals(endTime) && perma == perma)
+        if(newreason.equals(reason) && newUpdate.equals(endTime) && this.perma == perma)
             return;
         ProxiedPlayer player = BungeeCore.get().getProxy().getPlayer(SteamwarUser.get(from).getUuid());
         String newReason = Message.parse("BAN_CHANGED", player, reason,
@@ -131,7 +126,7 @@ public class Punishment {
                 getBantime(newUpdate, perma),
                 newreason);
 
-        SQL.update("UPDATE Punishments SET EndTime = ?, Reason = ?, Perma = ? WHERE PunishmentId = ?", newUpdate, newReason, perma, id);
+        update.update(newUpdate, newReason, perma, id);
         this.reason = newReason;
         this.perma = perma;
         this.endTime = newUpdate;

src/de/steamwar/bungeecore/sql/SQL.java

@@ -1,95 +0,0 @@
-/* 
-    This file is a part of the SteamWar software.
-    
-    Copyright (C) 2020  SteamWar.de-Serverteam
-
-    This program is free software: you can redistribute it and/or modify
-    it under the terms of the GNU Affero General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-    GNU Affero General Public License for more details.
-
-    You should have received a copy of the GNU Affero General Public License
-    along with this program.  If not, see <https://www.gnu.org/licenses/>.
-*/
-
-package de.steamwar.bungeecore.sql;
-
-import de.steamwar.bungeecore.BungeeCore;
-import net.md_5.bungee.api.ProxyServer;
-
-import java.sql.*;
-
-
-public class SQL {
-    private SQL(){}
-
-    private static Connection con;
-    private static String url;
-    private static String user;
-    private static String password;
-
-    public static void connect(String url, String user, String password) {
-        SQL.url = url;
-        SQL.user = user;
-        SQL.password = password;
-        try {
-            con = DriverManager.getConnection(url + "?autoreconnect=true", user, password);
-        }catch (SQLException e) {
-            ProxyServer.getInstance().stop();
-            throw new SecurityException("Could not start SQL-Exception", e);
-        }
-    }
-
-    public static void close() {
-        try {
-            if(con != null)
-                con.close();
-        }catch (SQLException e) {
-            BungeeCore.log("Could not close SQL-Connection", e);
-        }
-    }
-
-    static void update(String qry, Object... objects) {
-        try {
-            prepare(con, qry, objects).executeUpdate();
-        } catch (SQLException e) {
-            sqlException();
-            try (PreparedStatement st = con.prepareStatement(qry)) {
-                st.executeUpdate();
-            } catch (SQLException ex) {
-                throw new SecurityException("Could not execute update statement", ex);
-            }
-        }
-    }
-
-    static ResultSet select(String qry, Object... objects){
-        try{
-            return prepare(con, qry, objects).executeQuery();
-        } catch (SQLException e) {
-            sqlException();
-            try {
-                return prepare(con, qry, objects).executeQuery();
-            } catch (SQLException ex) {
-                throw new SecurityException("Could not run Select-Statement", ex);
-            }
-        }
-    }
-
-    private static PreparedStatement prepare(Connection connection, String qry, Object... objects) throws SQLException{
-        PreparedStatement st = connection.prepareStatement(qry);
-        for(int i = 0; i < objects.length; i++){
-            st.setObject(i+1, objects[i]);
-        }
-        return st;
-    }
-
-    private static void sqlException(){
-        close();
-        connect(url, user, password);
-    }
-}

src/de/steamwar/bungeecore/sql/SWException.java

@@ -22,7 +22,9 @@ package de.steamwar.bungeecore.sql;
 public class SWException {
     private SWException(){}
 
+    private static final Statement insert = new Statement("INSERT INTO Exception (server, message, stacktrace) VALUES (?, ?, ?)");
+
     public static void log(String server, String message, String stacktrace){
-        SQL.update("INSERT INTO Exception (server, message, stacktrace) VALUES (?, ?, ?)", server, message, stacktrace);
+        insert.update(server, message, stacktrace);
     }
 }

src/de/steamwar/bungeecore/sql/Schematic.java

@@ -23,14 +23,22 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.UUID;
 
 public class Schematic {
+
+    private static final Statement schemByName = new Statement("SELECT SchemID, SchemName, SchemOwner, SchemType, Item FROM Schematic WHERE SchemName = ? AND SchemOwner = ?");
+    private static final Statement schemById = new Statement("SELECT SchemID, SchemName, SchemOwner, SchemType, Item FROM Schematic WHERE SchemID = ?");
+    private static final Statement schemsByType = new Statement("SELECT SchemID, SchemName, SchemOwner, SchemType, Item FROM Schematic WHERE SchemType = ?");
+    private static final Statement schemsByUserType = new Statement("SELECT SchemID, SchemName, SchemOwner, SchemType, Item FROM Schematic WHERE SchemType = ? AND SchemOwner = ?");
+    private static final Statement schemsOfUser = new Statement("SELECT SchemID, SchemName, SchemOwner, Item, SchemType, Rank, SchemFormat, Item FROM Schematic WHERE SchemOwner = ? ORDER BY SchemName");
+    private static final Statement updateType = new Statement("UPDATE Schematic SET SchemType = ? WHERE SchemID = ?");
+    private static final Statement updateRank = new Statement("UPDATE Schematic SET Rank = ? WHERE SchemID = ?");
+
     private final int schemID;
     private final String schemName;
     private final int schemOwner;
     private SchematicType schemType;
-    private String schemItem;
+    private final String schemItem;
 
     private Schematic(ResultSet rs) throws SQLException {
         this.schemID = rs.getInt("SchemID");
@@ -40,74 +48,52 @@ public class Schematic {
         this.schemItem = rs.getString("Item");
     }
 
-    public static Schematic getSchemFromDB(String schemName, UUID schemOwner){
-        return getSchemFromDB(schemName, SteamwarUser.get(schemOwner).getId());
-    }
-
     public static Schematic getSchemFromDB(String schemName, int schemOwner){
-        ResultSet schematic = SQL.select("SELECT SchemID, SchemName, SchemOwner, SchemType, Item FROM Schematic WHERE SchemName = ? AND SchemOwner = ?", schemName, schemOwner);
-        try {
-            if(schematic == null || !schematic.next()){
-                return null;
-            }
-            return new Schematic(schematic);
-        } catch (SQLException e) {
-            throw new SecurityException("Failed loading schematic", e);
-        }
+        return schemByName.select(rs -> {
+            if(!rs.next())
+                return new Schematic(rs);
+            return null;
+        }, schemName, schemOwner);
     }
 
     public static Schematic getSchemFromDB(int schemID){
-        ResultSet schematic = SQL.select("SELECT SchemID, SchemName, SchemOwner, SchemType, Item FROM Schematic WHERE SchemID = ?", schemID);
-        try {
-            if(!schematic.next())
+        return schemById.select(rs -> {
+            if(!rs.next())
                 throw new SecurityException("Failed loading schematic " + schemID);
-            return new Schematic(schematic);
-        } catch (SQLException e) {
-            throw new SecurityException("Failed loading schematic", e);
-        }
+            return new Schematic(rs);
+        }, schemID);
     }
 
     public static List<Schematic> getAllSchemsOfType(SchematicType schemType){
-        try{
-            ResultSet schematic = SQL.select("SELECT SchemID, SchemName, SchemOwner, SchemType, Item FROM Schematic WHERE SchemType = ?", schemType.toDB());
+        return schemsByType.select(rs -> {
             List<Schematic> schematics = new ArrayList<>();
-            while(schematic.next()){
-                schematics.add(new Schematic(schematic));
-            }
+            while(rs.next())
+                schematics.add(new Schematic(rs));
             return schematics;
-        }catch(SQLException e){
-            throw new SecurityException("Failed loading all schems of type", e);
-        }
+        }, schemType.toDB());
     }
 
     public static List<Schematic> getSchemsOfType(int userId, SchematicType schemType){
-        try{
-            ResultSet schematic = SQL.select("SELECT SchemID, SchemName, SchemOwner, SchemType, Item FROM Schematic WHERE SchemType = ? AND SchemOwner = ?", schemType.toDB(), userId);
+        return schemsByUserType.select(rs -> {
             List<Schematic> schematics = new ArrayList<>();
-            while(schematic.next()){
-                schematics.add(new Schematic(schematic));
-            }
+            while(rs.next())
+                schematics.add(new Schematic(rs));
             return schematics;
-        }catch(SQLException e){
-            throw new SecurityException("Failed loading schems of type", e);
-        }
+        }, schemType.toDB(), userId);
     }
 
     public static List<Schematic> getSchemsAccessibleByUser(int schemOwner){
-        try{
-            ResultSet schematic = SQL.select("SELECT SchemID, SchemName, SchemOwner, Item, SchemType, Rank, SchemFormat, Item FROM Schematic WHERE SchemOwner = ? ORDER BY SchemName", schemOwner);
+        return schemsOfUser.select(rs -> {
             List<Schematic> schematics = new ArrayList<>();
-            while(schematic.next()){
-                schematics.add(new Schematic(schematic));
+            while(rs.next()){
+                schematics.add(new Schematic(rs));
             }
             List<SchematicMember> addedSchems = SchematicMember.getAccessibleSchems(schemOwner);
             for(SchematicMember schem : addedSchems){
                 schematics.add(getSchemFromDB(schem.getSchemName(), schem.getSchemOwner()));
             }
             return schematics;
-        }catch(SQLException e){
-            throw new SecurityException("Failed listing schematics", e);
-        }
+        }, schemOwner);
     }
 
     public int getSchemID() {
@@ -132,10 +118,10 @@ public class Schematic {
 
     public void setSchemType(SchematicType schemType) {
         this.schemType = schemType;
-        SQL.update("UPDATE Schematic SET SchemType = ? WHERE SchemID = ?", schemType.toDB(), schemID);
+        updateType.update(schemType.toDB(), schemID);
     }
 
     public void setRank(int rank) {
-        SQL.update("UPDATE Schematic SET Rank = ? WHERE SchemID = ?", rank, schemID);
+        updateRank.update(rank, schemID);
     }
 }

src/de/steamwar/bungeecore/sql/SchematicMember.java

@@ -19,13 +19,15 @@
 
 package de.steamwar.bungeecore.sql;
 
-import java.sql.ResultSet;
-import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.UUID;
 
 public class SchematicMember {
+
+    private static final Statement insert = new Statement("INSERT INTO SchemMember (SchemName, SchemOwner, Member) VALUES (?, ?, ?)");
+    private static final Statement selectSchems = new Statement("SELECT * FROM SchemMember WHERE Member = ?");
+    private static final Statement delete = new Statement("DELETE FROM SchemMember WHERE SchemOwner = ? AND SchemName = ? AND Member = ?");
+
     private final int schemOwner;
     private final String schemName;
     private final int member;
@@ -38,82 +40,17 @@ public class SchematicMember {
             updateDB();
     }
 
-    public SchematicMember(String schemName, int schemOwner, int schemMember){
-        this(schemName, schemOwner, schemMember, true);
-    }
-
-    public SchematicMember(String schemName, UUID schemOwner, UUID schemMember){
-        this(schemName, SteamwarUser.get(schemOwner).getId(), SteamwarUser.get(schemMember).getId(), true);
-    }
-
     private void updateDB(){
-        SQL.update("INSERT INTO SchemMember (SchemName, SchemOwner, Member) VALUES (?, ?, ?)", schemName, schemOwner, member);
-    }
-
-    public static SchematicMember getSchemMemberFromDB(String schemName, UUID schemOwner, UUID schemMember){
-        return getSchemMemberFromDB(schemName, SteamwarUser.get(schemOwner).getId(), SteamwarUser.get(schemMember).getId());
-    }
-
-    public static SchematicMember getSchemMemberFromDB(String schemName, int schemOwner, int schemMember){
-        ResultSet schematicMember = SQL.select("SELECT * FROM SchemMember WHERE SchemName = ? AND SchemOwner = ? AND Member = ?", schemName, schemOwner, schemMember);
-        try {
-            if(schematicMember == null || !schematicMember.next()){
-                return null;
-            }
-            return new SchematicMember(schemName, schemOwner, schemMember, false);
-        } catch (SQLException e) {
-            throw new SecurityException("Could not get schemmember", e);
-        }
-    }
-
-    public static SchematicMember getMemberBySchematic(String schemName, int schemMember){
-        ResultSet schematicMember = SQL.select("SELECT * FROM SchemMember WHERE SchemName = ? AND Member = ?", schemName, schemMember);
-        try {
-            if(schematicMember == null || !schematicMember.next()){
-                return null;
-            }
-            int schemOwner = schematicMember.getInt("SchemOwner");
-            return new SchematicMember(schemName, schemOwner, schemMember, false);
-        } catch (SQLException e) {
-            throw new SecurityException("Could not get member", e);
-        }
-    }
-
-    public static List<SchematicMember> getSchemMembers(String schemName, UUID schemOwner){
-        return getSchemMembers(schemName, SteamwarUser.get(schemOwner).getId());
-    }
-
-    public static List<SchematicMember> getSchemMembers(String schemName, int schemOwner){
-        ResultSet schematicMember = SQL.select("SELECT * FROM SchemMember WHERE SchemName = ? AND SchemOwner = ?", schemName, schemOwner);
-        try {
-            List<SchematicMember> schematicMembers = new ArrayList<>();
-            while(schematicMember.next()){
-                int schemMember = schematicMember.getInt("Member");
-                schematicMembers.add(new SchematicMember(schemName, schemOwner, schemMember, false));
-            }
-            return schematicMembers;
-        } catch (SQLException e) {
-            throw new SecurityException("Could not get schemmembers", e);
-        }
-    }
-
-    public static List<SchematicMember> getAccessibleSchems(UUID schemMember){
-        return getAccessibleSchems(SteamwarUser.get(schemMember).getId());
+        insert.update(schemName, schemOwner, member);
     }
 
     public static List<SchematicMember> getAccessibleSchems(int schemMember){
-        ResultSet schematicMember = SQL.select("SELECT * FROM SchemMember WHERE Member = ?", schemMember);
-        try {
+        return selectSchems.select(rs -> {
             List<SchematicMember> schematicMembers = new ArrayList<>();
-            while(schematicMember.next()){
-                String schemName = schematicMember.getString("SchemName");
-                int schemOwner = schematicMember.getInt("SchemOwner");
-                schematicMembers.add(new SchematicMember(schemName, schemOwner, schemMember, false));
-            }
+            while(rs.next())
+                schematicMembers.add(new SchematicMember(rs.getString("SchemName"), rs.getInt("SchemOwner"), schemMember, false));
             return schematicMembers;
-        } catch (SQLException e) {
-            throw new SecurityException("Could not get accessible schems", e);
-        }
+        }, schemMember);
     }
 
     public int getSchemOwner() {
@@ -129,6 +66,6 @@ public class SchematicMember {
     }
 
     public void remove(){
-        SQL.update("DELETE FROM SchemMember WHERE SchemOwner = ? AND SchemName = ? AND Member = ?", schemOwner, schemName, member);
+        delete.update(schemOwner, schemName, member);
     }
 }

src/de/steamwar/bungeecore/sql/Session.java

@@ -22,9 +22,12 @@ package de.steamwar.bungeecore.sql;
 import java.sql.Timestamp;
 
 public class Session {
+
+    private static final Statement insert = new Statement("INSERT INTO Session (UserID, StartTime, EndTime) VALUES (?, ?, NOW())");
+
     private Session(){}
 
     public static void insertSession(int userID, Timestamp startTime){
-        SQL.update("INSERT INTO Session (UserID, StartTime, EndTime) VALUES (?, ?, NOW())", userID, startTime);
+        insert.update(userID, startTime);
     }
 }

src/de/steamwar/bungeecore/sql/Statement.java

@@ -0,0 +1,137 @@
+/*
+    This file is a part of the SteamWar software.
+
+    Copyright (C) 2020  SteamWar.de-Serverteam
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.bungeecore.sql;
+
+import de.steamwar.bungeecore.BungeeCore;
+import net.md_5.bungee.api.ProxyServer;
+
+import java.sql.*;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Level;
+
+public class Statement {
+    private static final List<Statement> statements = new ArrayList<>();
+
+    private static Connection con;
+    private static String url;
+    private static String user;
+    private static String password;
+
+    public static void connect(String url, String user, String password) {
+        Statement.url = url;
+        Statement.user = user;
+        Statement.password = password;
+        try {
+            con = DriverManager.getConnection(url + "?autoreconnect=true", user, password);
+        } catch (SQLException e) {
+            ProxyServer.getInstance().stop();
+            throw new SecurityException("Could not start SQL-Connection", e);
+        }
+    }
+
+    private static void reset(SQLException e) {
+        BungeeCore.get().getLogger().log(Level.WARNING, "SQL Exception thrown", e);
+        close();
+        connect(url, user, password);
+        try {
+            for (Statement statement : statements) {
+                statement.init();
+            }
+        } catch (SQLException ex) {
+            throw new SecurityException("Could not reprepare SQL Statements", ex);
+        }
+    }
+
+    public static void close() {
+        for (Statement statement : statements) {
+            try {
+                statement.st.close();
+            } catch (SQLException e) {
+                BungeeCore.get().getLogger().log(Level.INFO, "Could not close statement", e);
+            }
+        }
+
+        try {
+            con.close();
+        } catch (SQLException e) {
+            BungeeCore.log("Could not close SQL-Connection", e);
+        }
+    }
+
+    private final String sql;
+    private PreparedStatement st;
+
+    Statement(String sql) {
+        this.sql = sql;
+        statements.add(this);
+        try {
+            init();
+        } catch (SQLException e) {
+            reset(e);
+        }
+    }
+
+    private synchronized void init() throws SQLException {
+        st = con.prepareStatement(sql);
+    }
+
+    <T> T select(ResultSetUser<T> user, Object... objects) {
+        return prepare(() -> {
+            ResultSet rs = st.executeQuery();
+            T result = user.use(rs);
+            rs.close();
+            return result;
+        }, objects);
+    }
+
+    void update(Object... objects) {
+        prepare(st::executeUpdate, objects);
+    }
+
+    private synchronized <T> T prepare(SQLRunnable<T> runnable, Object... objects) {
+        try {
+            setObjects(objects);
+            return runnable.run();
+        } catch (SQLException e) {
+            reset(e);
+            try {
+                setObjects(objects);
+                return runnable.run();
+            } catch (SQLException ex) {
+                throw new SecurityException("Could not execute SQL statement", ex);
+            }
+        }
+    }
+
+    private void setObjects(Object... objects) throws SQLException {
+        for (int i = 0; i < objects.length; i++) {
+            st.setObject(i + 1, objects[i]);
+        }
+    }
+
+    interface ResultSetUser<T> {
+        T use(ResultSet rs) throws SQLException;
+    }
+
+    private interface SQLRunnable<T> {
+        T run() throws SQLException;
+    }
+}

src/de/steamwar/bungeecore/sql/SteamwarUser.java

@@ -24,16 +24,14 @@ import de.steamwar.bungeecore.BungeeCore;
 import de.steamwar.bungeecore.Message;
 import de.steamwar.bungeecore.commands.WebregisterCommand;
 import de.steamwar.bungeecore.listeners.ConnectionListener;
-import java.io.IOException;
-import java.net.MalformedURLException;
-import java.net.URL;
-import java.util.Scanner;
 import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.api.chat.TextComponent;
 import net.md_5.bungee.api.connection.PendingConnection;
 import net.md_5.bungee.api.connection.ProxiedPlayer;
 
+import java.io.IOException;
 import java.net.InetAddress;
+import java.net.URL;
 import java.net.UnknownHostException;
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -41,18 +39,26 @@ import java.sql.Timestamp;
 import java.time.format.DateTimeFormatter;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Scanner;
 import java.util.UUID;
+import java.util.logging.Level;
 
 
 public class SteamwarUser {
-    private final int id;
-    private final UUID uuid;
-    private String userName;
-    private UserGroup userGroup;
-    private int team;
-    private boolean leader;
-    private Map<Punishment.PunishmentType, Punishment> punishments;
-    private String discordId;
+
+    private static final Statement updateName = new Statement("UPDATE UserData SET UserName = ? WHERE id = ?");
+    private static final Statement updateBedrock = new Statement("UPDATE UserData SET Bedrock = ? WHERE id = ?");
+    private static final Statement insert = new Statement("INSERT INTO UserData (UUID, UserName, UserGroup) VALUES (?, ?, 'Member')");
+    private static final Statement byUUID = new Statement("SELECT * FROM UserData WHERE UUID = ?");
+    private static final Statement byName = new Statement("SELECT * FROM UserData WHERE lower(UserName) = ?");
+    private static final Statement byID = new Statement("SELECT * FROM UserData WHERE id = ?");
+    private static final Statement byDiscord = new Statement("SELECT * FROM UserData WHERE DiscordId = ?");
+    private static final Statement updateTeam = new Statement("Update UserData SET Team = ? WHERE id = ?");
+    private static final Statement updateDiscord = new Statement("Update UserData SET DiscordId = ? WHERE id = ?");
+    private static final Statement deleteIPs = new Statement("DELETE FROM BannedUserIPs WHERE UserID = ?");
+    private static final Statement updateLeader = new Statement("Update UserData SET Leader = ? WHERE id = ?");
+    private static final Statement getPlaytime = new Statement("SELECT SUM(UNIX_TIMESTAMP(EndTime) - UNIX_TIMESTAMP(StartTime)) as Playtime FROM Session WHERE UserID = ?");
+    private static final Statement getFirstjoin = new Statement("SELECT MIN(StartTime) AS FirstJoin FROM Session WHERE UserID = ?");
 
     private static final Map<String, SteamwarUser> usersByName = new HashMap<>();
     private static final Map<UUID, SteamwarUser> usersByUUID = new HashMap<>();
@@ -62,6 +68,15 @@ public class SteamwarUser {
     private static final String API_URL = "https://api.mojang.com/users/profiles/minecraft/";
     private static final JsonParser jsonParser = new JsonParser();
 
+    private final int id;
+    private final UUID uuid;
+    private String userName;
+    private final UserGroup userGroup;
+    private int team;
+    private boolean leader;
+    private final Map<Punishment.PunishmentType, Punishment> punishments;
+    private String discordId;
+
     static {
         try {
             LIXFEL_DE = InetAddress.getByAddress(new byte[]{(byte) 195, (byte) 201, (byte) 242, 43});
@@ -93,7 +108,7 @@ public class SteamwarUser {
         if(user != null){
             String userName = connection.getName();
             if(!user.userName.equals(userName)){
-                SQL.update("UPDATE UserData SET UserName = ? WHERE id = ?", userName, user.id);
+                updateName.update(userName, user.id);
                 WebregisterCommand.changeUsername(user.userName, userName);
                 user.userName = userName;
             }
@@ -105,7 +120,7 @@ public class SteamwarUser {
         }
 
         boolean bedrock = connection.getAddress().getAddress().equals(LIXFEL_DE);
-        SQL.update("UPDATE UserData SET Bedrock = ? WHERE id = ?", bedrock, user.id);
+        updateBedrock.update(bedrock, user.id);
         return user;
     }
 
@@ -115,7 +130,7 @@ public class SteamwarUser {
             return user;
         }
 
-        UUID uuid = SteamwarUser.loadUUID(name);
+        UUID uuid = SteamwarUser.getUUIDofOfflinePlayer(name);
         if (uuid == null) {
             return null;
         }
@@ -124,21 +139,28 @@ public class SteamwarUser {
     }
 
     private static SteamwarUser createUserInDatabase(UUID uuid, String name) {
-        SQL.update("INSERT INTO UserData (UUID, UserName, UserGroup) VALUES (?, ?, 'Member')", uuid.toString(), name);
-        return dbInit(SQL.select("SELECT * FROM UserData WHERE UUID = ?", uuid.toString()));
+        insert.update(uuid.toString(), name);
+        return get(uuid);
     }
 
     public static SteamwarUser get(String userName){
         userName = userName.toLowerCase();
         if(usersByName.containsKey(userName))
             return usersByName.get(userName);
-        return dbInit(SQL.select("SELECT * FROM UserData WHERE lower(UserName) = ?", userName));
+        return byName.select(rs -> {
+            if(rs.next())
+                return new SteamwarUser(rs);
+            return null;
+        }, userName);
     }
 
     public static SteamwarUser get(UUID uuid){
         if(usersByUUID.containsKey(uuid))
             return usersByUUID.get(uuid);
-        return dbInit(SQL.select("SELECT * FROM UserData WHERE UUID = ?", uuid.toString()));
+        return byUUID.select(rs -> {
+            rs.next();
+            return new SteamwarUser(rs);
+        }, uuid.toString());
     }
 
     public static SteamwarUser get(ProxiedPlayer player){
@@ -148,13 +170,20 @@ public class SteamwarUser {
     public static SteamwarUser get(int id){
         if(usersById.containsKey(id))
             return usersById.get(id);
-        return dbInit(SQL.select("SELECT * FROM UserData WHERE id = ?", id));
+        return byID.select(rs -> {
+            rs.next();
+            return new SteamwarUser(rs);
+        }, id);
     }
 
     public static SteamwarUser get(Long discordId) {
         if(usersByDiscord.containsKey(discordId.toString()))
             return usersByDiscord.get(discordId.toString());
-        return dbInit(SQL.select("SELECT * FROM UserData WHERE DiscordId = ?", discordId));
+        return byDiscord.select(rs -> {
+            if(rs.next())
+                return new SteamwarUser(rs);
+            return null;
+        }, discordId);
     }
 
     public static void clearCache(){
@@ -164,25 +193,20 @@ public class SteamwarUser {
         usersByDiscord.clear();
     }
 
-    public static UUID loadUUID(String playerName) {
+    private static UUID getUUIDofOfflinePlayer(String playerName) {
         try {
             final URL url = new URL(API_URL + playerName);
-            return getUniqueIdFromString(jsonParser.parse(new Scanner(url.openConnection().getInputStream()).nextLine()).getAsJsonObject().get("id").getAsString());
-        } catch (MalformedURLException e) {
-            e.printStackTrace();
+            String uuid = jsonParser.parse(new Scanner(url.openConnection().getInputStream()).nextLine()).getAsJsonObject().get("id").getAsString();
+            return UUID.fromString(uuid.replaceFirst("(\\w{8})(\\w{4})(\\w{4})(\\w{4})(\\w{12})", "$1-$2-$3-$4-$5"));
         } catch (IOException e) {
-            e.printStackTrace();
+            BungeeCore.get().getLogger().log(Level.SEVERE, "Could not get offline player UUID", e);
+            return null;
         }
-        return null;
-    }
-
-    private static UUID getUniqueIdFromString(String uuid) {
-        return UUID.fromString(uuid.replaceFirst("(\\w{8})(\\w{4})(\\w{4})(\\w{4})(\\w{12})", "$1-$2-$3-$4-$5"));
     }
 
     public void setTeam(int team){
         this.team = team;
-        SQL.update("Update UserData SET Team = ? WHERE id = ?", team, id);
+        updateTeam.update(team, id);
         setLeader(false);
     }
 
@@ -217,7 +241,7 @@ public class SteamwarUser {
     public void setDiscordId(String discordId) {
         usersByDiscord.remove(this.discordId);
         this.discordId = discordId;
-        SQL.update("Update UserData SET DiscordId = ? WHERE id = ?", discordId, id);
+        updateDiscord.update(discordId, id);
         if(discordId != null) {
             usersByDiscord.put(discordId, this);
         }
@@ -227,7 +251,7 @@ public class SteamwarUser {
         if(!punishments.containsKey(Punishment.PunishmentType.Ban))
             return false;
         if(!punishments.get(Punishment.PunishmentType.Ban).isCurrent()) {
-            SQL.update("DELETE FROM BannedUserIPs WHERE UserID = ?", id);
+            deleteIPs.update(id);
             punishments.remove(Punishment.PunishmentType.Ban);
             return false;
         }
@@ -298,38 +322,20 @@ public class SteamwarUser {
         punishments.put(Punishment.PunishmentType.Mute, Punishment.createPunishment(id, from, Punishment.PunishmentType.Mute, muteReason, time, perma));
     }
 
-    private static SteamwarUser dbInit(ResultSet rs){
-        try {
-            if(!rs.next())
-                return null;
-            return new SteamwarUser(rs);
-        } catch (SQLException e) {
-            throw new SecurityException(e);
-        }
-    }
-
     public double getOnlinetime() {
-        ResultSet set = SQL.select("SELECT SUM(UNIX_TIMESTAMP(EndTime) - UNIX_TIMESTAMP(StartTime)) as Playtime FROM Session WHERE UserID = ?", id);
-        try {
-            if(!set.next())
-                return 0;
-            return set.getBigDecimal("Playtime").doubleValue();
-        } catch (SQLException throwables) {
-            throw new SecurityException("Could not load Online Time", throwables);
-        } catch (NullPointerException e) { //When no Sessions are recorded
-            return 0;
-        }
+        return getPlaytime.select(rs -> {
+            if(rs.next())
+                return rs.getBigDecimal("Playtime").doubleValue();
+            return 0.0;
+        }, id);
     }
 
     public Timestamp getFirstjoin() {
-        ResultSet set = SQL.select("SELECT MIN(StartTime) AS FirstJoin FROM Session WHERE UserID = ?", id);
-        try {
-            if(!set.next())
-                return null;
-            return set.getTimestamp("FirstJoin");
-        } catch (SQLException throwables) {
-            throw new SecurityException("Could not load First Join");
-        }
+        return getFirstjoin.select(rs -> {
+            if(rs.next())
+                return rs.getTimestamp("FirstJoin");
+            return null;
+        }, id);
     }
 
     public boolean isLeader() {
@@ -338,6 +344,6 @@ public class SteamwarUser {
 
     public void setLeader(boolean leader) {
         this.leader = leader;
-        SQL.update("Update UserData SET Leader = ? WHERE id = ?", leader, id);
+        updateLeader.update(leader, id);
     }
 }

src/de/steamwar/bungeecore/sql/Team.java

@@ -19,25 +19,31 @@
 
 package de.steamwar.bungeecore.sql;
 
-import de.steamwar.bungeecore.BungeeCore;
-
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 
-import static de.steamwar.bungeecore.sql.SQL.select;
-
 public class Team {
+
+    private static final Statement insert = new Statement("INSERT INTO Team (TeamKuerzel, TeamName) VALUES (?, ?)");
+    private static final Statement delete = new Statement("UPDATE Team SET TeamDeleted = 1 WHERE TeamID = ?");
+    private static final Statement update = new Statement("INSERT INTO Team (TeamID, TeamKuerzel, TeamName, TeamColor) VALUES (?, ?, ?, ?) ON DUPLICATE KEY UPDATE TeamName = VALUES(TeamName), TeamKuerzel = VALUES(TeamKuerzel), TeamColor = VALUES(TeamColor)");
+    private static final Statement getSize = new Statement("SELECT COUNT(id) FROM UserData WHERE Team = ?");
+    private static final Statement getMembers = new Statement("SELECT id FROM UserData WHERE Team = ?");
+    private static final Statement byId = new Statement("SELECT * FROM Team WHERE TeamID = ?");
+    private static final Statement byName = new Statement("SELECT * FROM Team WHERE (lower(TeamName) = ? OR lower(TeamKuerzel) = ?) AND NOT TeamDeleted");
+    private static final Statement all = new Statement("SELECT * FROM Team WHERE NOT TeamDeleted");
+
+    private static final List<Team> teamCache = new LinkedList<>();
+    private static final Team pub = new Team(0, "PUB", "Öffentlich", "8");
+
     private final int teamId;
     private String teamKuerzel;
     private String teamName;
     private String teamColor;
 
-    private static final List<Team> teamCache = new LinkedList<>();
-    private static final Team pub = new Team(0, "PUB", "Öffentlich", "8");
-
     private Team(int id, String kuerzel, String name, String color){
         teamId = id;
         teamKuerzel = kuerzel;
@@ -52,8 +58,8 @@ public class Team {
         this(rs.getInt("TeamID"), rs.getString("TeamKuerzel"), rs.getString("TeamName"), rs.getString("TeamColor"));
     }
 
-    public static void create(String kuerzel, String name, SteamwarUser user){
-        SQL.update("INSERT INTO Team (TeamKuerzel, TeamName) VALUES (?, ?)", kuerzel, name);
+    public static void create(String kuerzel, String name){
+        insert.update(kuerzel, name);
     }
 
     public static Team get(int id){
@@ -64,51 +70,38 @@ public class Team {
         for(Team team : teamCache)
             if(team.teamId == id)
                 return team;
-        return load(select("SELECT * FROM Team WHERE TeamID = ?", id));
+        return byId.select(rs -> {
+            rs.next();
+            return new Team(rs);
+        }, id);
     }
 
     public static Team get(String name){
         for(Team team : teamCache)
-            if(team.teamName.equalsIgnoreCase(name))
+            if(team.teamName.equalsIgnoreCase(name) || team.teamKuerzel.equalsIgnoreCase(name))
                 return team;
-        for(Team team : teamCache)
-            if(team.teamKuerzel.equalsIgnoreCase(name))
-                return team;
-        return load(select("SELECT * FROM Team WHERE (lower(TeamName) = ? OR lower(TeamKuerzel) = ?) AND NOT TeamDeleted", name.toLowerCase(), name.toLowerCase()));
+        return byName.select(rs -> {
+            if(rs.next())
+                return new Team(rs);
+            return null;
+        }, name.toLowerCase(), name.toLowerCase());
     }
 
     public static List<Team> getAll(){
         clearCache();
-        try{
-            ResultSet rs = select("SELECT * FROM Team WHERE NOT TeamDeleted");
-            if(rs == null)
-                return teamCache;
-
+        return all.select(rs -> {
             while(rs.next())
                 new Team(rs);
-        } catch (SQLException e) {
-            BungeeCore.log("Could not get all Teams", e);
-        }
-        return teamCache;
+            return teamCache;
+        });
     }
 
     public static void clearCache(){
         teamCache.clear();
     }
 
-    private static Team load(ResultSet dbteam){
-        try {
-            if(!dbteam.next())
-                return null;
-            return new Team(dbteam);
-        } catch (SQLException e) {
-            BungeeCore.log("Could not load Team", e);
-            return null;
-        }
-    }
-
     private void updateDB(){
-        SQL.update("INSERT INTO Team (TeamID, TeamKuerzel, TeamName, TeamColor) VALUES (?, ?, ?, ?) ON DUPLICATE KEY UPDATE TeamName = VALUES(TeamName), TeamKuerzel = VALUES(TeamKuerzel), TeamColor = VALUES(TeamColor)", teamId, teamKuerzel, teamName, teamColor);
+        update.update(teamId, teamKuerzel, teamName, teamColor);
     }
 
     public int getTeamId() {
@@ -143,33 +136,24 @@ public class Team {
     }
 
     public int size(){
-        ResultSet rs = select("SELECT COUNT(id) FROM UserData WHERE Team = ?", teamId);
-        try {
+        return getSize.select(rs -> {
             rs.next();
             return rs.getInt("COUNT(id)");
-        }catch (SQLException e) {
-            BungeeCore.log("Could not get Teamsize", e);
-            return 1000;
-        }
+        }, teamId);
     }
 
     public void disband(SteamwarUser user){
         user.setLeader(false);
-        SQL.update("UPDATE Team SET TeamDeleted = 1 WHERE TeamID = ?", teamId);
+        delete.update(teamId);
         teamCache.remove(this);
     }
 
     public List<Integer> getMembers(){
-        try{
-            ResultSet memberlist = select("SELECT id FROM UserData WHERE Team = ?", teamId);
+        return getMembers.select(rs -> {
             List<Integer> members = new ArrayList<>();
-            while(memberlist.next()){
-                members.add(memberlist.getInt("id"));
-            }
+            while(rs.next())
+                members.add(rs.getInt("id"));
             return members;
-        }catch(SQLException e){
-            BungeeCore.log("Could not get Teammembers", e);
-        }
-        return new ArrayList<>();
+        }, teamId);
     }
 }

src/de/steamwar/bungeecore/sql/TeamTeilnahme.java

@@ -19,55 +19,46 @@
 
 package de.steamwar.bungeecore.sql;
 
-import de.steamwar.bungeecore.BungeeCore;
-
 import java.sql.ResultSet;
-import java.sql.SQLException;
 import java.util.HashSet;
 import java.util.Set;
 
 public class TeamTeilnahme {
     private TeamTeilnahme(){}
 
+    private static final Statement insert = new Statement("INSERT INTO TeamTeilnahme (TeamID, EventID) VALUES (?, ?)");
+    private static final Statement delete = new Statement("DELETE FROM TeamTeilnahme WHERE TeamID = ? AND EventID = ?");
+    private static final Statement byEventTeam = new Statement("SELECT * FROM TeamTeilnahme WHERE TeamID = ? AND EventID = ?");
+    private static final Statement byEvent = new Statement("SELECT * FROM TeamTeilnahme WHERE EventID = ?");
+    private static final Statement byTeam = new Statement("SELECT * FROM TeamTeilnahme WHERE TeamID = ?");
+
     public static void teilnehmen(int teamID, int eventID){
-        SQL.update("INSERT INTO TeamTeilnahme (TeamID, EventID) VALUES (?, ?)", teamID, eventID);
+        insert.update(teamID, eventID);
     }
 
     public static void notTeilnehmen(int teamID, int eventID){
-        SQL.update("DELETE FROM TeamTeilnahme WHERE TeamID = ? AND EventID = ?", teamID, eventID);
+        delete.update(teamID, eventID);
     }
 
     public static boolean nimmtTeil(int teamID, int eventID){
-        ResultSet rs = SQL.select("SELECT * FROM TeamTeilnahme WHERE TeamID = ? AND EventID = ?", teamID, eventID);
-        try{
-            return rs.next();
-        }catch (SQLException e){
-            BungeeCore.log("Failed to load TeamTeilnahme", e);
-            throw new SecurityException();
-        }
+        return byEventTeam.select(ResultSet::next, teamID, eventID);
     }
 
     public static Set<Team> getTeams(int eventID){
-        Set<Team> teams = new HashSet<>();
-        ResultSet rs = SQL.select("SELECT * FROM TeamTeilnahme WHERE EventID = ?", eventID);
-        try{
+        return byEvent.select(rs -> {
+            Set<Team> teams = new HashSet<>();
             while(rs.next())
                 teams.add(Team.get(rs.getInt("TeamID")));
-        }catch (SQLException e){
-            BungeeCore.log("Failed to load TeamTeilnahmen", e);
-        }
-        return teams;
+            return teams;
+        }, eventID);
     }
 
     public static Set<Event> getEvents(int teamID){
-        Set<Event> events = new HashSet<>();
-        ResultSet rs = SQL.select("SELECT * FROM TeamTeilnahme WHERE TeamID = ?", teamID);
-        try{
+        return byTeam.select(rs -> {
+            Set<Event> events = new HashSet<>();
             while(rs.next())
                 events.add(Event.get(rs.getInt("EventID")));
-        }catch (SQLException e){
-            BungeeCore.log("Failed to load TeamTeilnahmen", e);
-        }
-        return events;
+            return events;
+        }, teamID);
     }
 }