Implement HikariCP for database

pom.xml

@@ -140,6 +140,16 @@
             <version>2.4.0</version>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>com.zaxxer</groupId>
+            <artifactId>HikariCP</artifactId>
+            <version>3.2.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-jdk14</artifactId>
+            <version>1.7.25</version>
+        </dependency>
     </dependencies>
 
     <build>

src/main/java/de/epiceric/shopchest/exceptions/WorldNotFoundException.java

@@ -2,8 +2,8 @@ package de.epiceric.shopchest.exceptions;
 
 public class WorldNotFoundException extends Exception {
 
-    public WorldNotFoundException(String message) {
+    public WorldNotFoundException(String worldName) {
-        super(message);
+        super("Could not find world with name \"" + worldName + "\"");
     }
 
 }

src/main/java/de/epiceric/shopchest/listeners/ShopInteractListener.java

@@ -1028,7 +1028,7 @@ public class ShopInteractListener implements Listener {
                                 return;
                             }
 
-                            database.logEconomy(executor, newProduct, shop.getVendor(), shop.getShopType(), shop.getLocation(), newPrice, ShopBuySellEvent.Type.BUY, null);
+                            database.logEconomy(executor, shop, newProduct, newPrice, ShopBuySellEvent.Type.BUY, null);
 
                             addToInventory(inventory, newProduct);
                             removeFromInventory(c.getInventory(), newProduct);
@@ -1072,7 +1072,7 @@ public class ShopInteractListener implements Listener {
                             return;
                         }
 
-                        database.logEconomy(executor, newProduct, shop.getVendor(), shop.getShopType(), shop.getLocation(), newPrice, ShopBuySellEvent.Type.BUY, null);
+                        database.logEconomy(executor, shop, newProduct, newPrice, ShopBuySellEvent.Type.BUY, null);
 
                         addToInventory(inventory, newProduct);
                         executor.updateInventory();
@@ -1192,7 +1192,7 @@ public class ShopInteractListener implements Listener {
                                 return;
                             }
 
-                            database.logEconomy(executor, newProduct, shop.getVendor(), shop.getShopType(), shop.getLocation(), newPrice, ShopBuySellEvent.Type.SELL, null);
+                            database.logEconomy(executor, shop, newProduct, newPrice, ShopBuySellEvent.Type.SELL, null);
 
                             addToInventory(inventory, newProduct);
                             removeFromInventory(executor.getInventory(), newProduct);
@@ -1237,7 +1237,7 @@ public class ShopInteractListener implements Listener {
                             return;
                         }
 
-                        database.logEconomy(executor, newProduct, shop.getVendor(), shop.getShopType(), shop.getLocation(), newPrice, ShopBuySellEvent.Type.SELL, null);
+                        database.logEconomy(executor, shop, newProduct, newPrice, ShopBuySellEvent.Type.SELL, null);
 
                         removeFromInventory(executor.getInventory(), newProduct);
                         executor.updateInventory();

src/main/java/de/epiceric/shopchest/sql/Database.java

@@ -3,6 +3,7 @@ package de.epiceric.shopchest.sql;
 import de.epiceric.shopchest.ShopChest;
 import de.epiceric.shopchest.config.Config;
 import de.epiceric.shopchest.event.ShopBuySellEvent;
+import de.epiceric.shopchest.event.ShopBuySellEvent.Type;
 import de.epiceric.shopchest.exceptions.WorldNotFoundException;
 import de.epiceric.shopchest.language.LanguageUtils;
 import de.epiceric.shopchest.shop.Shop;
@@ -28,86 +29,83 @@ import java.util.HashSet;
 import java.util.Set;
 import java.util.UUID;
 
+import com.zaxxer.hikari.HikariDataSource;
+
 public abstract class Database {
 
     private static Set<String> notFoundWorlds = new HashSet<>();
 
     ShopChest plugin;
-    Connection connection;
+    HikariDataSource dataSource;
 
-    Database(ShopChest plugin) {
+    protected Database(ShopChest plugin) {
         this.plugin = plugin;
     }
 
-    /**
+    abstract HikariDataSource getDataSource();
-     * @return New connection to the database
-     */
-    public abstract Connection getConnection();
 
     /**
      * (Re-)Connects to the the database and initializes it. <br>
      * Creates the table (if doesn't exist) and tests the connection
-     * @param callback Callback that - if succeeded - returns the amount of shops that were found (as {@code int})
+     * 
+     * @param callback Callback that - if succeeded - returns the amount of shops
+     *                 that were found (as {@code int})
      */
     public void connect(final Callback<Integer> callback) {
         new BukkitRunnable() {
             @Override
             public void run() {
+                disconnect();
+
+                dataSource = getDataSource();
+
+                String queryCreateTableShopList = 
+                        "CREATE TABLE IF NOT EXISTS shops ("
+                        + "id INTEGER PRIMARY KEY " + (Database.this instanceof SQLite ? "AUTOINCREMENT" : "AUTO_INCREMENT") + ","
+                        + "vendor TINYTEXT NOT NULL,"
+                        + "product TEXT NOT NULL,"
+                        + "world TINYTEXT NOT NULL,"
+                        + "x INTEGER NOT NULL,"
+                        + "y INTEGER NOT NULL,"
+                        + "z INTEGER NOT NULL,"
+                        + "buyprice FLOAT NOT NULL,"
+                        + "sellprice FLOAT NOT NULL,"
+                        + "shoptype TINYTEXT NOT NULL)";
+
+                String queryCreateTableShopLog = 
+                        "CREATE TABLE IF NOT EXISTS `shop_log` ("
+                        + "id INTEGER PRIMARY KEY " + (Database.this instanceof SQLite ? "AUTOINCREMENT" : "AUTO_INCREMENT") + ","
+                        + "timestamp TINYTEXT NOT NULL,"
+                        + "executor TINYTEXT NOT NULL,"
+                        + "product TINYTEXT NOT NULL,"
+                        + "vendor TINYTEXT NOT NULL,"
+                        + "world TINYTEXT NOT NULL,"
+                        + "x INTEGER NOT NULL,"
+                        + "y INTEGER NOT NULL,"
+                        + "z INTEGER NOT NULL,"
+                        + "price FLOAT NOT NULL,"
+                        + "type TINYTEXT NOT NULL)";
+
+                String queryCreateTablePlayerLogout = 
+                        "CREATE TABLE IF NOT EXISTS player_logout ("
+                        + "player VARCHAR(36) PRIMARY KEY NOT NULL,"
+                        + "time LONG NOT NULL)";
+
                 try {
-                    disconnect();
-
-                    plugin.debug("Connecting to database...");
-                    connection = getConnection();
-
-                    String queryCreateTableShopList =
-                            "CREATE TABLE IF NOT EXISTS shops (" +
-                                    "id INTEGER PRIMARY KEY " + (Database.this instanceof SQLite ? "AUTOINCREMENT" : "AUTO_INCREMENT") + "," +
-                                    "vendor TINYTEXT NOT NULL," +
-                                    "product TEXT NOT NULL," +
-                                    "world TINYTEXT NOT NULL," +
-                                    "x INTEGER NOT NULL," +
-                                    "y INTEGER NOT NULL," +
-                                    "z INTEGER NOT NULL," +
-                                    "buyprice FLOAT NOT NULL," +
-                                    "sellprice FLOAT NOT NULL," +
-                                    "shoptype TINYTEXT NOT NULL" +
-                                    ")";
-
-                    String queryCreateTableShopLog =
-                            "CREATE TABLE IF NOT EXISTS `shop_log` (" +
-                                    "id INTEGER PRIMARY KEY " + (Database.this instanceof SQLite ? "AUTOINCREMENT" : "AUTO_INCREMENT") + "," +
-                                    "timestamp TINYTEXT NOT NULL," +
-                                    "executor TINYTEXT NOT NULL," +
-                                    "product TINYTEXT NOT NULL," +
-                                    "vendor TINYTEXT NOT NULL," +
-                                    "world TINYTEXT NOT NULL," +
-                                    "x INTEGER NOT NULL," +
-                                    "y INTEGER NOT NULL," +
-                                    "z INTEGER NOT NULL," +
-                                    "price FLOAT NOT NULL," +
-                                    "type TINYTEXT NOT NULL" +
-                                    ")";
-
-                    String queryCreateTablePlayerLogout =
-                            "CREATE TABLE IF NOT EXISTS player_logout (" +
-                                    "player VARCHAR(36) PRIMARY KEY NOT NULL," +
-                                    "time LONG NOT NULL" +
-                                    ")";
-
                     // Create table "shops"
-                    Statement s = connection.createStatement();
+                    try (Connection con = dataSource.getConnection(); Statement s = con.createStatement()) {
-                    s.executeUpdate(queryCreateTableShopList);
+                        s.executeUpdate(queryCreateTableShopList);
-                    s.close();
+                    }
 
                     // Create table "shop_log"
-                    Statement s2 = connection.createStatement();
+                    try (Connection con = dataSource.getConnection(); Statement s = con.createStatement()) {
-                    s2.executeUpdate(queryCreateTableShopLog);
+                        s.executeUpdate(queryCreateTableShopLog);
-                    s2.close();
+                    }
 
                     // Create table "player_logout"
-                    Statement s3 = connection.createStatement();
+                    try (Connection con = dataSource.getConnection(); Statement s = con.createStatement()) {
-                    s3.executeUpdate(queryCreateTablePlayerLogout);
+                        s.executeUpdate(queryCreateTablePlayerLogout);
-                    s3.close();
+                    }
 
                     // Clean up economy log
                     if (Config.cleanupEconomyLogDays > 0) {
@@ -115,23 +113,28 @@ public abstract class Database {
                     }
 
                     // Count entries in table "shops"
-                    PreparedStatement ps = connection.prepareStatement("SELECT * FROM shops");
+                    try (Connection con = dataSource.getConnection(); Statement s = con.createStatement();) {
-                    ResultSet rs2 = ps.executeQuery();
+                        ResultSet rs = s.executeQuery("SELECT id FROM shops");
 
-                    int count = 0;
+                        int count = 0;
-                    while (rs2.next()) {
+                        while (rs.next()) {
-                        if (rs2.getString("vendor") != null) count++;
+                            count++;
+                        }
+
+                        plugin.debug("Initialized database with " + count + " entries");
+
+                        if (callback != null) {
+                            callback.callSyncResult(count);
+                        }
+                    }
+                } catch (SQLException e) {
+                    if (callback != null) {
+                        callback.callSyncError(e);
                     }
-                    plugin.debug("Initialized database with " + count + " entries");
                     
-                    close(ps, rs2);
-
-                    if (callback != null) callback.callSyncResult(count);
-                } catch (SQLException ex) {
-                    if (callback != null) callback.callSyncError(ex);
                     plugin.getLogger().severe("Failed to initialize database");
                     plugin.debug("Failed to initialize database");
-                    plugin.debug(ex);
+                    plugin.debug(e);
                 }
             }
         }.runTaskAsynchronously(plugin);
@@ -140,65 +143,70 @@ public abstract class Database {
     /**
      * Remove a shop from the database
      *
-     * @param shop Shop to remove
+     * @param shop     Shop to remove
      * @param callback Callback that - if succeeded - returns {@code null}
      */
     public void removeShop(final Shop shop, final Callback<Void> callback) {
         new BukkitRunnable() {
             @Override
             public void run() {
-                PreparedStatement ps = null;
+                try (Connection con = dataSource.getConnection();
-
+                        PreparedStatement ps = con.prepareStatement("DELETE FROM shops WHERE id = ?")) {
-                try {
-                    ps = connection.prepareStatement("DELETE FROM shops WHERE id = ?");
                     ps.setInt(1, shop.getID());
                     ps.executeUpdate();
 
                     plugin.debug("Removing shop from database (#" + shop.getID() + ")");
-                    if (callback != null) callback.callSyncResult(null);
+
+                    if (callback != null) {
+                        callback.callSyncResult(null);
+                    }
                 } catch (SQLException ex) {
-                    if (callback != null) callback.callSyncError(ex);
+                    if (callback != null) {
+                        callback.callSyncError(ex);
+                    }
+
                     plugin.getLogger().severe("Failed to access database");
                     plugin.debug("Failed to remove shop from database (#" + shop.getID() + ")");
                     plugin.debug(ex);
-                } finally {
-                    close(ps, null);
                 }
             }
         }.runTaskAsynchronously(plugin);
     }
 
     /**
-     * @param id ID of the shop
+     * @param id       ID of the shop
-     * @param callback Callback that - if succeeded - returns whether a shop with the given ID exists (as {@code boolean})
+     * @param callback Callback that - if succeeded - returns whether a shop with
+     *                 the given ID exists (as {@code boolean})
      */
     public void isShop(final int id, final Callback<Boolean> callback) {
         new BukkitRunnable() {
             @Override
             public void run() {
-                PreparedStatement ps = null;
+                try (Connection con = dataSource.getConnection();
-                ResultSet rs = null;
+                        PreparedStatement ps = con.prepareStatement("SELECT * FROM shops WHERE id = ?")) {
-
-                try {
-                    ps = connection.prepareStatement("SELECT * FROM shops WHERE id = ?");
                     ps.setInt(1, id);
-                    rs = ps.executeQuery();
+                    ResultSet rs = ps.executeQuery();
 
                     while (rs.next()) {
                         if (rs.getInt("id") == id) {
-                            if (callback != null) callback.callSyncResult(true);
+                            if (callback != null) {
+                                callback.callSyncResult(true);
+                            }
                             return;
                         }
                     }
 
-                    if (callback != null) callback.callSyncResult(false);
+                    if (callback != null) {
+                        callback.callSyncResult(false);
+                    }
                 } catch (SQLException ex) {
-                    if (callback != null) callback.callSyncError(ex);
+                    if (callback != null) {
+                        callback.callSyncError(ex);
+                    }
+
                     plugin.getLogger().severe("Failed to access database");
                     plugin.debug("Failed to check if shop with ID exists (#" + id + ")");
                     plugin.debug(ex);
-                } finally {
-                    close(ps, rs);
                 }
             }
         }.runTaskAsynchronously(plugin);
@@ -206,21 +214,22 @@ public abstract class Database {
 
     /**
      * Get all shops from the database
-     * @param callback Callback that - if succeeded - returns a read-only collection of all shops (as {@code Collection<Shop>})
+     * 
-     * @param showConsoleMessages Whether console messages (errors or warnings) should be shown
+     * @param callback            Callback that - if succeeded - returns a read-only
+     *                            collection of all shops (as
+     *                            {@code Collection<Shop>})
+     * @param showConsoleMessages Whether console messages (errors or warnings)
+     *                            should be shown
      */
     public void getShops(final boolean showConsoleMessages, final Callback<Collection<Shop>> callback) {
         new BukkitRunnable() {
             @Override
             public void run() {
-                PreparedStatement ps = null;
-                ResultSet rs = null;
-
                 ArrayList<Shop> shops = new ArrayList<>();
 
-                try {
+                try (Connection con = dataSource.getConnection();
-                    ps = connection.prepareStatement("SELECT * FROM shops");
+                        PreparedStatement ps = con.prepareStatement("SELECT * FROM shops")) {
-                    rs = ps.executeQuery();
+                    ResultSet rs = ps.executeQuery();
 
                     while (rs.next()) {
                         int id = rs.getInt("id");
@@ -234,9 +243,11 @@ public abstract class Database {
                         int z = rs.getInt("z");
 
                         if (world == null) {
-                            WorldNotFoundException ex = new WorldNotFoundException("Could not find world with name \"" + worldName + "\"");
+                            WorldNotFoundException ex = new WorldNotFoundException(worldName);
-                            if (showConsoleMessages && !notFoundWorlds.contains(worldName)) plugin.getLogger().warning(ex.getMessage());
+                            if (showConsoleMessages && !notFoundWorlds.contains(worldName)) {
-                            notFoundWorlds.add(worldName);
+                                plugin.getLogger().warning(ex.getMessage());
+                                notFoundWorlds.add(worldName);
+                            }
                             plugin.debug("Failed to get shop (#" + id + ")");
                             plugin.debug(ex);
                             continue;
@@ -255,80 +266,81 @@ public abstract class Database {
                         shops.add(new Shop(id, plugin, vendor, product, location, buyPrice, sellPrice, shopType));
                     }
 
-                    if (callback != null) callback.callSyncResult(Collections.unmodifiableCollection(shops));
+                    if (callback != null) {
+                        callback.callSyncResult(Collections.unmodifiableCollection(shops));
+                    }
                 } catch (SQLException ex) {
-                    if (callback != null) callback.callSyncError(ex);
+                    if (callback != null) {
+                        callback.callSyncError(ex);
+                    }
+
                     plugin.getLogger().severe("Failed to access database");
                     plugin.debug("Failed to get shops");
                     plugin.debug(ex);
-                } finally {
-                    close(ps, rs);
                 }
 
-
             }
         }.runTaskAsynchronously(plugin);
     }
 
     /**
      * Adds a shop to the database
-     * @param shop Shop to add
+     * 
-     * @param callback Callback that - if succeeded - returns the ID the shop was given (as {@code int})
+     * @param shop     Shop to add
+     * @param callback Callback that - if succeeded - returns the ID the shop was
+     *                 given (as {@code int})
      */
     public void addShop(final Shop shop, final Callback<Integer> callback) {
+        final String queryNoId = "REPLACE INTO shops (vendor,product,world,x,y,z,buyprice,sellprice,shoptype) VALUES(?,?,?,?,?,?,?,?,?)";
+        final String queryWithId = "REPLACE INTO shops (id,vendor,product,world,x,y,z,buyprice,sellprice,shoptype) VALUES(?,?,?,?,?,?,?,?,?,?)";
+
         new BukkitRunnable() {
             @Override
             public void run() {
-                PreparedStatement ps = null;
+                String query = shop.hasId() ? queryWithId : queryNoId;
-                ResultSet rs = null;
+
+                try (Connection con = dataSource.getConnection();
+                        PreparedStatement ps = con.prepareStatement(query, Statement.RETURN_GENERATED_KEYS)) {
+                    int i = 0;
+                    if (shop.hasId()) {
+                        i = 1;
+                        ps.setInt(1, shop.getID());
+                    }
+
+                    ps.setString(i+1, shop.getVendor().getUniqueId().toString());
+                    ps.setString(i+2, Utils.encode(shop.getProduct()));
+                    ps.setString(i+3, shop.getLocation().getWorld().getName());
+                    ps.setInt(i+4, shop.getLocation().getBlockX());
+                    ps.setInt(i+5, shop.getLocation().getBlockY());
+                    ps.setInt(i+6, shop.getLocation().getBlockZ());
+                    ps.setDouble(i+7, shop.getBuyPrice());
+                    ps.setDouble(i+8, shop.getSellPrice());
+                    ps.setString(i+9, shop.getShopType().toString());
+                    ps.executeUpdate();
 
-                try {
                     if (!shop.hasId()) {
-                        ps = connection.prepareStatement("REPLACE INTO shops (vendor,product,world,x,y,z,buyprice,sellprice,shoptype) VALUES(?,?,?,?,?,?,?,?,?)", Statement.RETURN_GENERATED_KEYS);
-
-                        ps.setString(1, shop.getVendor().getUniqueId().toString());
-                        ps.setString(2, Utils.encode(shop.getProduct()));
-                        ps.setString(3, shop.getLocation().getWorld().getName());
-                        ps.setInt(4, shop.getLocation().getBlockX());
-                        ps.setInt(5, shop.getLocation().getBlockY());
-                        ps.setInt(6, shop.getLocation().getBlockZ());
-                        ps.setDouble(7, shop.getBuyPrice());
-                        ps.setDouble(8, shop.getSellPrice());
-                        ps.setString(9, shop.getShopType().toString());
-                        ps.executeUpdate();
-
                         int shopId = -1;
-                        rs = ps.getGeneratedKeys();
+                        ResultSet rs = ps.getGeneratedKeys();
                         if (rs.next()) {
                             shopId = rs.getInt(1);
                         }
 
                         shop.setId(shopId);
-                    } else {
-                        ps = connection.prepareStatement("REPLACE INTO shops (id,vendor,product,world,x,y,z,buyprice,sellprice,shoptype) VALUES(?,?,?,?,?,?,?,?,?,?)");
-
-                        ps.setInt(1, shop.getID());
-                        ps.setString(2, shop.getVendor().getUniqueId().toString());
-                        ps.setString(3, Utils.encode(shop.getProduct()));
-                        ps.setString(4, shop.getLocation().getWorld().getName());
-                        ps.setInt(5, shop.getLocation().getBlockX());
-                        ps.setInt(6, shop.getLocation().getBlockY());
-                        ps.setInt(7, shop.getLocation().getBlockZ());
-                        ps.setDouble(8, shop.getBuyPrice());
-                        ps.setDouble(9, shop.getSellPrice());
-                        ps.setString(10, shop.getShopType().toString());
-                        ps.executeUpdate();
                     }
 
-                    if (callback != null) callback.callSyncResult(shop.getID());
+                    if (callback != null) {
+                        callback.callSyncResult(shop.getID());
+                    }
+
                     plugin.debug("Adding shop to database (#" + shop.getID() + ")");
                 } catch (SQLException ex) {
-                    if (callback != null) callback.callSyncError(ex);
+                    if (callback != null) {
+                        callback.callSyncError(ex);
+                    }
+
                     plugin.getLogger().severe("Failed to access database");
                     plugin.debug("Failed to add shop to database (#" + shop.getID() + ")");
                     plugin.debug(ex);
-                } finally {
-                    close(ps, rs);
                 }
             }
         }.runTaskAsynchronously(plugin);
@@ -336,65 +348,67 @@ public abstract class Database {
 
     /**
      * Log an economy transaction to the database
+     * 
      * @param executor Player who bought/sold something
-     * @param product {@link ItemStack} that was bought/sold
+     * @param shop The {@link Shop} the player bought from or sold to
-     * @param vendor Vendor of the shop
+     * @param product The {@link ItemStack} that was bought/sold
-     * @param shopType {@link ShopType} of the shop
+     * @param price The price the product was bought or sold for
-     * @param location Location of the shop
+     * @param type Whether the executor bought or sold
-     * @param price Price (buyprice or sellprice, depends on {@code type})
-     * @param type Whether the player bought or sold something
      * @param callback Callback that - if succeeded - returns {@code null}
      */
-    public void logEconomy(final Player executor, final ItemStack product, final OfflinePlayer vendor, final ShopType shopType, final Location location, final double price, final ShopBuySellEvent.Type type, final Callback<Void> callback) {
+    public void logEconomy(final Player executor, Shop shop, ItemStack product, double price, Type type, final Callback<Void> callback) {
+        final String query = "INSERT INTO shop_log (timestamp,executor,product,vendor,world,x,y,z,price,type) VALUES(?,?,?,?,?,?,?,?,?,?)";
         if (Config.enableEconomyLog) {
             new BukkitRunnable() {
                 @Override
                 public void run() {
-                    PreparedStatement ps = null;
+                    try (Connection con = dataSource.getConnection();
-
+                            PreparedStatement ps = con.prepareStatement(query)) {
-                    try {
-                        ps = connection.prepareStatement("INSERT INTO shop_log (timestamp,executor,product,vendor,world,x,y,z,price,type) VALUES(?,?,?,?,?,?,?,?,?,?)");
 
                         ps.setString(1, new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(Calendar.getInstance().getTime()));
                         ps.setString(2, executor.getUniqueId().toString() + " (" + executor.getName() + ")");
                         ps.setString(3, product.getAmount() + " x " + LanguageUtils.getItemName(product));
-                        ps.setString(4, vendor.getUniqueId().toString() + " (" + vendor.getName() + ")" + (shopType == ShopType.ADMIN ? " (ADMIN)" : ""));
+                        ps.setString(4, shop.getVendor().getUniqueId().toString() + " (" + shop.getVendor().getName() + ")" + (shop.getShopType() == ShopType.ADMIN ? " (ADMIN)" : ""));
-                        ps.setString(5, location.getWorld().getName());
+                        ps.setString(5, shop.getLocation().getWorld().getName());
-                        ps.setInt(6, location.getBlockX());
+                        ps.setInt(6, shop.getLocation().getBlockX());
-                        ps.setInt(7, location.getBlockY());
+                        ps.setInt(7, shop.getLocation().getBlockY());
-                        ps.setInt(8, location.getBlockZ());
+                        ps.setInt(8, shop.getLocation().getBlockZ());
                         ps.setDouble(9, price);
                         ps.setString(10, type.toString());
                         ps.executeUpdate();
 
-                        if (callback != null) callback.callSyncResult(null);
+                        if (callback != null) {
+                            callback.callSyncResult(null);
+                        }
+
                         plugin.debug("Logged economy transaction to database");
-                    } catch (final SQLException ex) {
+                    } catch (SQLException ex) {
-                        if (callback != null) callback.callSyncError(ex);
+                        if (callback != null) {
+                            callback.callSyncError(ex);
+                        }
+
                         plugin.getLogger().severe("Failed to access database");
                         plugin.debug("Failed to log economy transaction to database");
                         plugin.debug(ex);
-                    } finally {
-                        close(ps, null);
                     }
                 }
             }.runTaskAsynchronously(plugin);
         } else {
-            if (callback != null) callback.callSyncResult(null);
+            if (callback != null) {
+                callback.callSyncResult(null);
+            }
         }
     }
 
     /**
      * Cleans up the economy log to reduce file size
+     * 
      * @param async Whether the call should be executed asynchronously
      */
     public void cleanUpEconomy(boolean async) {
         BukkitRunnable runnable = new BukkitRunnable() {
             @Override
             public void run() {
-                Statement s = null;
-                Statement s2 = null;
-
                 Calendar cal = Calendar.getInstance();
                 long time = System.currentTimeMillis();
                 cal.add(Calendar.DATE, -Config.cleanupEconomyLogDays);
@@ -403,22 +417,18 @@ public abstract class Database {
                 String queryCleanUpLog = "DELETE FROM shop_log WHERE timestamp < '" + logPurgeLimit + "'";
                 String queryCleanUpPlayers = "DELETE FROM player_logout WHERE time < " + String.valueOf(time);
 
-                try {
+                try (Connection con = dataSource.getConnection();
-                    s = connection.createStatement();
+                        Statement s = con.createStatement();
+                        Statement s2 = con.createStatement()) {
                     s.executeUpdate(queryCleanUpLog);
-
-                    s2 = connection.createStatement();
                     s2.executeUpdate(queryCleanUpPlayers);
 
                     plugin.getLogger().info("Cleaned up economy log");
                     plugin.debug("Cleaned up economy log");
-                } catch (final SQLException ex) {
+                } catch (SQLException ex) {
                     plugin.getLogger().severe("Failed to clean up economy log");
                     plugin.debug("Failed to clean up economy log");
                     plugin.debug(ex);
-                } finally {
-                    close(s, null);
-                    close(s2, null);
                 }
             }
         };
@@ -432,32 +442,32 @@ public abstract class Database {
 
     /**
      * Get the revenue a player got while he was offline
-     * @param player Player whose revenue to get
+     * 
+     * @param player     Player whose revenue to get
      * @param logoutTime Time in milliseconds when he logged out the last time
-     * @param callback Callback that - if succeeded - returns the revenue the player made while offline (as {@code double})
+     * @param callback   Callback that - if succeeded - returns the revenue the
+     *                   player made while offline (as {@code double})
      */
     public void getRevenue(final Player player, final long logoutTime, final Callback<Double> callback) {
         new BukkitRunnable() {
             @Override
             public void run() {
-                PreparedStatement ps = null;
-                ResultSet rs = null;
-
                 String vendor = String.format("%s (%s)", player.getUniqueId().toString(), player.getName());
-
                 double revenue = 0;
 
-                try {
+                try (Connection con = dataSource.getConnection();
-                    ps = connection.prepareStatement("SELECT * FROM shop_log WHERE vendor = ?;");
+                        PreparedStatement ps = con.prepareStatement("SELECT * FROM shop_log WHERE vendor = ?")) {
                     ps.setString(1, vendor);
-                    rs = ps.executeQuery();
+                    ResultSet rs = ps.executeQuery();
 
                     while (rs.next()) {
                         if (rs.getString("vendor").equals(vendor)) {
                             double singleRevenue = rs.getDouble("price");
                             ShopBuySellEvent.Type type = ShopBuySellEvent.Type.valueOf(rs.getString("type"));
 
-                            if (type == ShopBuySellEvent.Type.SELL) singleRevenue = -singleRevenue;
+                            if (type == ShopBuySellEvent.Type.SELL) {
+                                singleRevenue = -singleRevenue;
+                            }
 
                             long timestamp;
 
@@ -475,14 +485,17 @@ public abstract class Database {
                         }
                     }
 
-                    if (callback != null) callback.callSyncResult(revenue);
+                    if (callback != null) {
+                        callback.callSyncResult(revenue);
+                    }
                 } catch (SQLException ex) {
-                    if (callback != null) callback.callSyncError(ex);
+                    if (callback != null) {
+                        callback.callSyncError(ex);
+                    }
+
                     plugin.getLogger().severe("Failed to access database");
                     plugin.debug("Failed to get revenue from player \"" + player.getUniqueId().toString() + "\"");
                     plugin.debug(ex);
-                } finally {
-                    close(ps, rs);
                 }
             }
         }.runTaskAsynchronously(plugin);
@@ -490,32 +503,35 @@ public abstract class Database {
 
     /**
      * Log a logout to the database
-     * @param player Player who logged out
+     * 
+     * @param player    Player who logged out
      * @param timestamp Time in milliseconds when the player logged out
-     * @param callback Callback that - if succeeded - returns {@code null}
+     * @param callback  Callback that - if succeeded - returns {@code null}
      */
     public void logLogout(final Player player, final long timestamp, final Callback<Void> callback) {
         new BukkitRunnable() {
             @Override
             public void run() {
-                PreparedStatement ps = null;
-
-                try {
-                    ps = connection.prepareStatement("REPLACE INTO player_logout (player,time) VALUES(?,?)");
 
+                try (Connection con = dataSource.getConnection();
+                        PreparedStatement ps = con.prepareStatement("REPLACE INTO player_logout (player,time) VALUES(?,?)")) {
                     ps.setString(1, player.getUniqueId().toString());
                     ps.setLong(2, timestamp);
                     ps.executeUpdate();
 
-                    if (callback != null) callback.callSyncResult(null);
+                    if (callback != null) {
+                        callback.callSyncResult(null);
+                    }
+
                     plugin.debug("Logged logout to database");
                 } catch (final SQLException ex) {
-                    if (callback != null) callback.callSyncError(ex);
+                    if (callback != null) {
+                        callback.callSyncError(ex);
+                    }
+
                     plugin.getLogger().severe("Failed to access database");
                     plugin.debug("Failed to log logout to database");
                     plugin.debug(ex);
-                } finally {
-                    close(ps, null);
                 }
             }
         }.runTaskAsynchronously(plugin);
@@ -523,78 +539,57 @@ public abstract class Database {
 
     /**
      * Get the last logout of a player
-     * @param player Player who logged out
+     * 
-     * @param callback Callback that - if succeeded - returns the time in milliseconds the player logged out (as {@code long})
+     * @param player   Player who logged out
+     * @param callback Callback that - if succeeded - returns the time in
+     *                 milliseconds the player logged out (as {@code long})
      */
     public void getLastLogout(final Player player, final Callback<Long> callback) {
         new BukkitRunnable() {
             @Override
             public void run() {
-                PreparedStatement ps = null;
+                String uuid = player.getUniqueId().toString();
-                ResultSet rs = null;
 
-                String playerUuid = player.getUniqueId().toString();
+                try (Connection con = dataSource.getConnection();
-
+                        PreparedStatement ps = con.prepareStatement("SELECT * FROM player_logout WHERE player = ?")) {
-                try {
+                    ps.setString(1, uuid);
-                    ps = connection.prepareStatement("SELECT * FROM player_logout WHERE player=?;");
+                    ResultSet rs = ps.executeQuery();
-                    ps.setString(1, playerUuid);
-                    rs = ps.executeQuery();
 
                     while (rs.next()) {
-                        if (rs.getString("player").equals(playerUuid)) {
+                        if (rs.getString("player").equals(uuid)) {
-                            if (callback != null) callback.callSyncResult(rs.getLong("time"));
+                            if (callback != null) {
+                                callback.callSyncResult(rs.getLong("time"));
+                            }
                             return;
                         }
                     }
 
-                    if (callback != null) callback.callSyncResult(-1L);
+                    if (callback != null) {
+                        callback.callSyncResult(-1L);
+                    }
                 } catch (SQLException ex) {
-                    if (callback != null) callback.callSyncError(ex);
+                    if (callback != null) {
+                        callback.callSyncError(ex);
+                    }
+
                     plugin.getLogger().severe("Failed to access database");
-                    plugin.debug("Failed to get last logout from player \"" + playerUuid + "\"");
+                    plugin.debug("Failed to get last logout from player \"" + player.getName() + "\"");
                     plugin.debug(ex);
-                } finally {
-                    close(ps, rs);
                 }
             }
         }.runTaskAsynchronously(plugin);
     }
 
     /**
-     * Closes a {@link Statement} and a {@link ResultSet}
+     * Closes the data source
-     * @param s {@link Statement} to close
-     * @param rs {@link ResultSet} to close
-     */
-    void close(Statement s, ResultSet rs) {
-        try {
-            if (s != null)
-                s.close();
-            if (rs != null)
-                rs.close();
-        } catch (SQLException ex) {
-            plugin.debug("Failed to close PreparedStatement/ResultSet");
-            plugin.debug(ex);
-        }
-    }
-
-    /**
-     * Closes the connection to the database
      */
     public void disconnect() {
-        try {
+        if (dataSource != null) {
-            if (connection != null && !connection.isClosed()) {
+            dataSource.close();
-                plugin.debug("Disconnecting from database...");
-                connection.close();
-            }
-        } catch (SQLException e) {
-            plugin.getLogger().severe("Failed to disconnect from database");
-            plugin.debug("Failed to disconnect from database");
-            plugin.debug(e);
         }
     }
 
     public enum DatabaseType {
-        SQLite,
+        SQLite, MySQL
-        MySQL
     }
 }

src/main/java/de/epiceric/shopchest/sql/MySQL.java

@@ -5,9 +5,11 @@ import de.epiceric.shopchest.config.Config;
 import org.bukkit.scheduler.BukkitRunnable;
 
 import java.sql.Connection;
-import java.sql.DriverManager;
-import java.sql.PreparedStatement;
 import java.sql.SQLException;
+import java.sql.Statement;
+
+import com.zaxxer.hikari.HikariConfig;
+import com.zaxxer.hikari.HikariDataSource;
 
 public class MySQL extends Database {
 
@@ -16,36 +18,27 @@ public class MySQL extends Database {
     }
 
     @Override
-    public Connection getConnection() {
+    HikariDataSource getDataSource() {
-        try {
+        HikariConfig config = new HikariConfig();
-            if (connection != null && !connection.isClosed()) {
+        config.setJdbcUrl(String.format("jdbc:mysql://%s:%d/%s?autoReconnect=true&useSSL=false",
-                return connection;
+                Config.databaseMySqlHost, Config.databaseMySqlPort, Config.databaseMySqlDatabase));
-            }
+        config.setUsername(Config.databaseMySqlUsername);
+        config.setPassword(Config.databaseMySqlPassword);
 
-            Class.forName("com.mysql.jdbc.Driver");
+        return new HikariDataSource(config);
-
-            String connectUrl = "jdbc:mysql://" + Config.databaseMySqlHost + ":" + Config.databaseMySqlPort + "/" + Config.databaseMySqlDatabase + "?autoReconnect=true&useSSL=false";
-            plugin.debug("Connecting to MySQL Server \"" + connectUrl + "\" as user \"" + Config.databaseMySqlUsername + "\"");
-
-            connection = DriverManager.getConnection(connectUrl, Config.databaseMySqlUsername, Config.databaseMySqlPassword);
-
-            return connection;
-        } catch (Exception ex) {
-            plugin.getLogger().severe("Failed to get database connection");
-            plugin.debug("Failed to get database connection");
-            plugin.debug(ex);
-        }
-
-        return null;
     }
 
+    /**
+     * Sends an asynchronous ping to the database
+     */
     public void ping() {
         new BukkitRunnable() {
             @Override
             public void run() {
-                try (PreparedStatement ps = connection.prepareStatement("/* ping */ SELECT 1")) {
+                try (Connection con = dataSource.getConnection();
+                        Statement s = con.createStatement()) {
                     plugin.debug("Pinging to MySQL server...");
-                    ps.executeQuery();
+                    s.execute("/* ping */ SELECT 1");
                 } catch (SQLException ex) {
                     plugin.getLogger().severe("Failed to ping to MySQL server. Trying to reconnect...");
                     plugin.debug("Failed to ping to MySQL server. Trying to reconnect...");

src/main/java/de/epiceric/shopchest/sql/SQLite.java

@@ -6,10 +6,12 @@ import org.bukkit.scheduler.BukkitRunnable;
 import java.io.File;
 import java.io.IOException;
 import java.sql.Connection;
-import java.sql.DriverManager;
 import java.sql.SQLException;
 import java.sql.Statement;
 
+import com.zaxxer.hikari.HikariConfig;
+import com.zaxxer.hikari.HikariDataSource;
+
 public class SQLite extends Database {
 
     public SQLite(ShopChest plugin) {
@@ -17,7 +19,7 @@ public class SQLite extends Database {
     }
 
     @Override
-    public Connection getConnection() {
+    HikariDataSource getDataSource() {
         File folder = plugin.getDataFolder();
         File dbFile = new File(folder, "shops.db");
 
@@ -31,36 +33,23 @@ public class SQLite extends Database {
             }
         }
         
-        try {
+        HikariConfig config = new HikariConfig();
-            if (connection != null && !connection.isClosed()) {
+        config.setJdbcUrl(String.format("jdbc:sqlite:" + dbFile));
-                return connection;
-            }
 
-            Class.forName("org.sqlite.JDBC");
+        return new HikariDataSource(config);
-            connection = DriverManager.getConnection("jdbc:sqlite:" + dbFile);
-
-            return connection;
-        } catch (ClassNotFoundException | SQLException ex) {
-            plugin.getLogger().severe("Failed to get database connection");
-            plugin.debug("Failed to get database connection");
-            plugin.debug(ex);
-        }
-
-        return null;
     }
 
     /**
      * Vacuums the database to reduce file size
+     * 
      * @param async Whether the call should be executed asynchronously
      */
     public void vacuum(boolean async) {
         BukkitRunnable runnable = new BukkitRunnable() {
             @Override
             public void run() {
-                Statement s = null;
+                try (Connection con = dataSource.getConnection();
-
+                        Statement s = con.createStatement()) {
-                try {
-                    s = connection.createStatement();
                     s.executeUpdate("VACUUM");
 
                     plugin.debug("Vacuumed SQLite database");
@@ -68,8 +57,6 @@ public class SQLite extends Database {
                     plugin.getLogger().severe("Failed to access database");
                     plugin.debug("Failed to vacuum database");
                     plugin.debug(ex);
-                } finally {
-                    close(s, null);
                 }
             }
         };