Fix mysql connection #2

src/main/java/net/simplyvanilla/simplyrank/SimplyRankPlugin.java

@@ -3,6 +3,7 @@
 import com.google.common.reflect.TypeToken;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
+import io.papermc.paper.threadedregions.scheduler.ScheduledTask;
 import net.kyori.adventure.text.format.NamedTextColor;
 import net.kyori.adventure.text.format.TextColor;
 import net.simplyvanilla.simplyrank.addresswhitelist.AddressWhitelistService;
@@ -46,6 +47,8 @@ public class SimplyRankPlugin extends JavaPlugin {
 
     private MySqlClient mySqlClient = null;
 
+    private ScheduledTask cleanerTask;
+
 
     @Override
     public void onEnable() {
@@ -93,7 +96,7 @@ public void onEnable() {
         this.playerDataService =
             new PlayerDataService(mySqlRepository, mySqlRepository);
         proxyService = new ProxyService(mySqlRepository, new ProxyCheckProvider(this.getConfig().getString("proxycheck-api-url", "https://proxycheck.io/v2/%s&vpn=1")));
-        Bukkit.getAsyncScheduler().runAtFixedRate(this, new ProxyTtlCleanupTask(proxyService, this.getConfig().getInt("proxycache-ttl", 720)), 1, 10, TimeUnit.SECONDS);
+        this.cleanerTask = Bukkit.getAsyncScheduler().runAtFixedRate(this, new ProxyTtlCleanupTask(proxyService, this.getConfig().getInt("proxycache-ttl", 720)), 1, 10, TimeUnit.SECONDS);
 
         if (!this.playerDataService.groupExists("default")) {
             GroupData defaultData = new GroupData(NamedTextColor.GRAY, "Member ");
@@ -156,6 +159,7 @@ public void onEnable() {
     @Override
     public void onDisable() {
         instance = null;
+        if (this.cleanerTask != null) this.cleanerTask.cancel();
         if (this.mySqlClient != null) {
             this.mySqlClient.close();
         }

src/main/java/net/simplyvanilla/simplyrank/database/sql/MySqlClient.java

@@ -9,6 +9,9 @@ public class MySqlClient {
     public static final String TABLE_PLAYERS_NAME = "player";
     public static final String TABLE_GROUPS_NAME = "group";
 
+    private static final int MAX_TRIES = 10;
+    private static final long WAIT_TIME = 3000;
+
     private final String url;
     private final String username;
     private final String password;
@@ -24,6 +27,27 @@ public MySqlClient(String url, String user, String password) {
         initTables();
     }
 
+    public void testConnection() {
+        for (int i = 0; i < MAX_TRIES; i++) {
+            if (testConnectionSingle()) return;
+            try {
+                Thread.sleep(WAIT_TIME);
+            } catch (InterruptedException ignored) {
+                break;
+            }
+        }
+        throw new RuntimeException(String.format("It was not possible to recover Database connection after %s tries", MAX_TRIES));
+    }
+
+    private boolean testConnectionSingle() {
+        try {
+            connection = DriverManager.getConnection(url, username, password);
+            return connection.isValid(1);
+        } catch (SQLException e) {
+            return false;
+        }
+    }
+
     public void connect() {
         try {
             connection = DriverManager.getConnection(url, username, password);
@@ -41,11 +65,13 @@ public void close() {
     }
 
     public void update(PreparedStatement statement) throws SQLException {
+        testConnection();
         statement.executeUpdate();
         statement.close();
     }
 
     public ResultSet query(PreparedStatement statement) throws SQLException {
+        testConnection();
         ResultSet rs;
         rs = statement.executeQuery();
 
@@ -55,6 +81,7 @@ public ResultSet query(PreparedStatement statement) throws SQLException {
     }
 
     private void executeRawStatement(String cmd) throws SQLException {
+        testConnection();
         try (Statement st = connection.createStatement()) {
             st.execute(cmd);
         }
@@ -127,6 +154,7 @@ PRIMARY KEY (`id`),
     }
 
     public PreparedStatement prepareStatement(String qry) throws SQLException {
+        testConnection();
         return connection.prepareStatement(qry);
     }