Fixes many database issues and add scale for bigger propose

Bukkit/src/main/java/com/plotsquared/bukkit/uuid/SQLiteUUIDService.java

@@ -45,11 +45,6 @@ public class SQLiteUUIDService implements UUIDService, Consumer<List<UUIDMapping
     public SQLiteUUIDService(final String fileName) {
         this.sqlite =
                 new SQLite(FileUtils.getFile(PlotSquared.platform().getDirectory(), fileName));
-        try {
-            this.sqlite.openConnection();
-        } catch (ClassNotFoundException | SQLException e) {
-            e.printStackTrace();
-        }
 
         try (PreparedStatement stmt = getConnection().prepareStatement(
                 "CREATE TABLE IF NOT EXISTS `usercache` (uuid VARCHAR(32) NOT NULL, username VARCHAR(32) NOT NULL, PRIMARY KEY (uuid))")) {

Core/build.gradle.kts

@@ -44,6 +44,9 @@ dependencies {
     api(libs.arkitektonika)
     api(libs.paster)
     api(libs.informativeAnnotations)
+
+    // Database
+    implementation(libs.hikaricp)
 }
 
 tasks.processResources {

Core/src/main/java/com/plotsquared/core/database/Database.java

@@ -31,25 +31,6 @@
  */
 public abstract class Database {
 
-    public abstract Connection forceConnection() throws SQLException, ClassNotFoundException;
-
-    /**
-     * Opens a connection with the database.
-     *
-     * @return Opened connection
-     * @throws SQLException           if the connection can not be opened
-     * @throws ClassNotFoundException if the driver cannot be found
-     */
-    public abstract Connection openConnection() throws SQLException, ClassNotFoundException;
-
-    /**
-     * Checks if a connection is open with the database.
-     *
-     * @return {@code true} if the connection is open
-     * @throws SQLException if the connection cannot be checked
-     */
-    public abstract boolean checkConnection() throws SQLException;
-
     /**
      * Gets the connection with the database.
      *
@@ -72,7 +53,6 @@ public abstract class Database {
      * @param query Query to be run
      * @return the results of the query
      * @throws SQLException           If the query cannot be executed
-     * @throws ClassNotFoundException If the driver cannot be found; see {@link #openConnection()}
      */
     public abstract ResultSet querySQL(String query) throws SQLException, ClassNotFoundException;
 
@@ -84,7 +64,6 @@ public abstract class Database {
      * @param query Query to be run
      * @return Result Code, see {@link Statement#executeUpdate(String)}
      * @throws SQLException           If the query cannot be executed
-     * @throws ClassNotFoundException If the driver cannot be found; see {@link #openConnection()}
      */
     public abstract int updateSQL(String query) throws SQLException, ClassNotFoundException;
 

Core/src/main/java/com/plotsquared/core/database/MySQL.java

@@ -19,10 +19,10 @@
 package com.plotsquared.core.database;
 
 import com.plotsquared.core.configuration.Storage;
-import com.plotsquared.core.util.StringMan;
+import com.zaxxer.hikari.HikariConfig;
+import com.zaxxer.hikari.HikariDataSource;
 
 import java.sql.Connection;
-import java.sql.DriverManager;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
@@ -35,12 +35,7 @@
  */
 public class MySQL extends Database {
 
-    private final String user;
-    private final String database;
-    private final String password;
-    private final String port;
-    private final String hostname;
-    private Connection connection;
+    private final HikariDataSource hikariDataSource;
 
     /**
      * Creates a new MySQL instance.
@@ -52,66 +47,52 @@ public class MySQL extends Database {
      * @param password Password
      */
     public MySQL(String hostname, String port, String database, String username, String password) {
-        this.hostname = hostname;
-        this.port = port;
-        this.database = database;
-        this.user = username;
-        this.password = password;
-        this.connection = null;
-    }
-
-    @Override
-    public Connection forceConnection() throws SQLException {
-        this.connection = DriverManager.getConnection(
-                "jdbc:mysql://" + this.hostname + ':' + this.port + '/' + this.database + "?"
-                        + StringMan.join(Storage.MySQL.PROPERTIES, "&"), this.user, this.password);
-        return this.connection;
-    }
-
-    @Override
-    public Connection openConnection() throws SQLException {
-        if (checkConnection()) {
-            return this.connection;
+        HikariConfig config = new HikariConfig();
+        config.setJdbcUrl("jdbc:mysql://" + hostname + ':' + port + '/' + database);
+        config.setUsername(username);
+        config.setPassword(password);
+        for (final String property : Storage.MySQL.PROPERTIES) {
+            if (property.contains("=")) {
+                String[] splittedProperty = property.split("=");
+                if (splittedProperty.length != 2) {
+                    continue;
+                }
+                String key = splittedProperty[0];
+                String value = splittedProperty[1];
+                config.addDataSourceProperty(key,value);
+            }
         }
-        return forceConnection();
-    }
-
-    @Override
-    public boolean checkConnection() throws SQLException {
-        return (this.connection != null) && !this.connection.isClosed();
+        this.hikariDataSource = new HikariDataSource(config);
     }
 
     @Override
     public Connection getConnection() {
-        return this.connection;
+        try {
+            return this.hikariDataSource.getConnection();
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
     }
 
     @Override
     public boolean closeConnection() throws SQLException {
-        if (this.connection == null) {
+        if (this.hikariDataSource == null) {
             return false;
         }
-        this.connection.close();
-        this.connection = null;
+        this.hikariDataSource.close();
         return true;
     }
 
     @Override
     public ResultSet querySQL(String query) throws SQLException {
-        if (checkConnection()) {
-            openConnection();
-        }
-        try (Statement statement = this.connection.createStatement()) {
+        try (Statement statement = this.getConnection().createStatement()) {
             return statement.executeQuery(query);
         }
     }
 
     @Override
     public int updateSQL(String query) throws SQLException {
-        if (checkConnection()) {
-            openConnection();
-        }
-        try (Statement statement = this.connection.createStatement()) {
+        try (Statement statement = this.getConnection().createStatement()) {
             return statement.executeUpdate(query);
         }
     }