Added configurable ping interval to MySQL

src/main/java/de/epiceric/shopchest/ShopChest.java

@@ -219,6 +219,16 @@ public class ShopChest extends JavaPlugin {
             debug("Using database type: MySQL");
             getLogger().info("Using MySQL");
             database = new MySQL(this);
+            if (config.database_mysql_ping_interval > 0) {
+                Bukkit.getScheduler().runTaskTimer(this, new Runnable() {
+                    @Override
+                    public void run() {
+                        if (database instanceof MySQL) {
+                            ((MySQL) database).ping();
+                        }
+                    }
+                }, config.database_mysql_ping_interval * 20L, config.database_mysql_ping_interval * 20L);
+            }
         }
 
         if (config.auto_reload_time > 0) {

src/main/java/de/epiceric/shopchest/config/Config.java

@@ -40,6 +40,9 @@ public class Config {
     /** The database type used for ShopChest. **/
     public Database.DatabaseType database_type;
 
+    /** The interval in seconds, a ping is sent to the MySQL server **/
+    public int database_mysql_ping_interval;
+
     /**
      * <p>The minimum prices for certain items</p>
      * This returns a key set, which contains e.g "STONE", "STONE:1", of the <i>minimum-prices</i> section in ShopChest's config.
@@ -264,6 +267,7 @@ public class Config {
      * Reload the configuration values from config.yml
      */
     public void reload(boolean firstLoad, boolean langReload) {
+        database_mysql_ping_interval = plugin.getConfig().getInt("database.mysql.ping-interval");
         database_mysql_host = plugin.getConfig().getString("database.mysql.hostname");
         database_mysql_port = plugin.getConfig().getInt("database.mysql.port");
         database_mysql_database = plugin.getConfig().getString("database.mysql.database");
@@ -271,7 +275,7 @@ public class Config {
         database_mysql_password = plugin.getConfig().getString("database.mysql.password");
         database_type = Database.DatabaseType.valueOf(plugin.getConfig().getString("database.type"));
         minimum_prices = (plugin.getConfig().getConfigurationSection("minimum-prices") == null) ? new HashSet<String>() : plugin.getConfig().getConfigurationSection("minimum-prices").getKeys(true);
-        allow_broken_items = (plugin.getConfig().getBoolean("allow-broken-items"));
+        allow_broken_items = plugin.getConfig().getBoolean("allow-broken-items");
         shopLimits_group = (plugin.getConfig().getConfigurationSection("shop-limits.group") == null) ? new HashSet<String>() : plugin.getConfig().getConfigurationSection("shop-limits.group").getKeys(true);
         shopLimits_player = (plugin.getConfig().getConfigurationSection("shop-limits.player") == null) ? new HashSet<String>() : plugin.getConfig().getConfigurationSection("shop-limits.player").getKeys(true);
         blacklist = (plugin.getConfig().getStringList("blacklist") == null) ? new ArrayList<String>() : plugin.getConfig().getStringList("blacklist");

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

@@ -4,6 +4,8 @@ import de.epiceric.shopchest.ShopChest;
 
 import java.sql.Connection;
 import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
 
 public class MySQL extends Database {
 
@@ -20,7 +22,7 @@ public class MySQL extends Database {
 
             Class.forName("com.mysql.jdbc.Driver");
 
-            String connectUrl = "jdbc:mysql://" + plugin.getShopChestConfig().database_mysql_host + ":" + plugin.getShopChestConfig().database_mysql_port + "/" + plugin.getShopChestConfig().database_mysql_database + "?autoReconnect=true";
+            String connectUrl = "jdbc:mysql://" + plugin.getShopChestConfig().database_mysql_host + ":" + plugin.getShopChestConfig().database_mysql_port + "/" + plugin.getShopChestConfig().database_mysql_database;
             plugin.debug("Connecting to MySQL Server \"" + connectUrl + "\" as user \"" + plugin.getShopChestConfig().database_mysql_username + "\"");
 
             connection = DriverManager.getConnection(connectUrl, plugin.getShopChestConfig().database_mysql_username, plugin.getShopChestConfig().database_mysql_password);
@@ -34,4 +36,15 @@ public class MySQL extends Database {
 
         return null;
     }
+
+    public void ping() {
+        try (PreparedStatement ps = connection.prepareStatement("/* ping */ SELECT 1")) {
+            plugin.debug("Pinging to MySQL server...");
+            ps.executeQuery();
+        } 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...");
+            connect();
+        }
+    }
 }

src/main/resources/config.yml

@@ -98,6 +98,11 @@ database:
   # (You can leave this empty if you're using SQLite)
   mysql:
 
+    # ...interval in seconds, when the database should be pinged, to keep the connection alive
+    # This should be lower than the 'connect_timeout' variable in your MySQL server
+    # You can set this to '0' to disable the ping interval
+    ping-interval: 3600
+
     # ...hostname where the database is accessible
     hostname: ""