Fixed imports

sink-connector/src/main/java/com/altinity/clickhouse/sink/connector/db/HikariDbSource.java

@@ -7,26 +7,37 @@
 import java.sql.Connection;
 import java.sql.SQLException;
 
-// Singleton class to manage the Hikari connection pool
+// Singleton class.
 public class HikariDbSource {
-
+    private static HikariDbSource instance;
+
     private HikariDataSource dataSource;
 
+    // private constructor
+    private HikariDbSource(ClickHouseDataSource dataSource) {
+        this.createConnectionPool(dataSource);
+    }
 
-    public HikariDbSource(HikariDataSource dataSource, String jdbcUrl, String username, String password) {
+    public Connection getConnection() throws SQLException {
+        return this.dataSource.getConnection();
+    }
 
-        this.dataSource = dataSource;
+    public static HikariDbSource getInstance(ClickHouseDataSource dataSource) {
+        if (instance == null) {
+            instance = new HikariDbSource(dataSource);
+        }
+        return instance;
+    }
+    public void createConnectionPool(ClickHouseDataSource dataSource) {
+        // pass the clickhouse config to create the datasource
 
+
         HikariConfig poolConfig = new HikariConfig();
         poolConfig.setConnectionTimeout(5000L);
         poolConfig.setMaximumPoolSize(20);
         poolConfig.setMaxLifetime(300_000L);
-        poolConfig.setDataSource(new ClickHouseDataSource(dataSource.getJdbcUrl(), dataSource.getUsername(), dataSource.getPassword()));
+        poolConfig.setDataSource(dataSource);
 
-        HikariDataSource ds = new HikariDataSource(poolConfig);
-    }
-
-    public Connection getConnection() throws SQLException {
-        return this.dataSource.getConnection();
-    }
+        this.dataSource = new HikariDataSource(poolConfig);
+    }   
 }