Initialize SQLite driver before use

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

@@ -228,6 +228,11 @@ public abstract class Database {
 
                 dataSource = getDataSource();
 
+                if (dataSource == null) {
+                    callback.onError(new SQLException("Failed to get data source"));
+                    return;
+                }
+
                 try (Connection con = dataSource.getConnection()) {
                     // Update database structure if necessary
                     update();

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

@@ -20,6 +20,16 @@ public class SQLite extends Database {
 
     @Override
     HikariDataSource getDataSource() {
+        try {
+            // Initialize driver class so HikariCP can find it
+            Class.forName("org.sqlite.JDBC");
+        } catch (ClassNotFoundException e) {
+            plugin.getLogger().severe("Failed to initialize SQLite driver");
+            plugin.debug("Failed to initialize SQLite driver");
+            plugin.debug(e);
+            return null;
+        }
+
         File folder = plugin.getDataFolder();
         File dbFile = new File(folder, "shops.db");
 
@@ -30,6 +40,7 @@ public class SQLite extends Database {
                 plugin.getLogger().severe("Failed to create database file");
                 plugin.debug("Failed to create database file");
                 plugin.debug(ex);
+                return null;
             }
         }