JDBC SingletonHelper

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;

public class SingletonHelper {
	/*
	 *  if(dsn.equals("oracle")) {
				    Class.forName("oracle.jdbc.OracleDriver");
			  		conn = DriverManager.getConnection("jdbc:oracle:thin:@localhsot:1521:xe","사용자이름","암호");
			 }else if(dsn.equals("mysql")) {
				    Class.forName("com.mysql.cj.jdbc.Driver");
				    conn = DriverManager.getConnection("jdbc:mysql://@localhsot:3306/sampledb?characterEncoding=UTF-8&serverTimezone=UTC&useSSL=true","사용자이름","암호");
			 }
	 */
	private static Connection conn = null;
	private SingletonHelper() {}
	
	//항상 같은 연결을 (주소) return 목적
	
	public static Connection getConnection(String dsn) {
		if(conn != null ) {
			return conn;
		}
		
		try {
			if(dsn.equals("oracle")) {
				    Class.forName("oracle.jdbc.OracleDriver");
			  		conn = DriverManager.getConnection("jdbc:oracle:thin:@localhsot:1521:xe","사용자이름","암호");
			 }else if(dsn.equals("mysql")) {
				    Class.forName("com.mysql.cj.jdbc.Driver");
				    conn = DriverManager.getConnection("jdbc:mysql://@localhsot:3306/sampledb?characterEncoding=UTF-8&serverTimezone=UTC&useSSL=true","사용자이름","암호");
			 }
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
		return conn;
		
	}
	
	public static void close(Connection conn) {
		if(conn != null) {
			try {
				conn.close();
			} catch (Exception e) {

			}
		}
	}
	
	public static void close(Statement stmt) {
		if(stmt!= null) {
			try {
				stmt.close();
			} catch (Exception e) {

			}
		}
	}
	
	public static void close(PreparedStatement pstmt) {
		if(pstmt!= null) {
			try {
				pstmt.close();
			} catch (Exception e) {

			}
		}
	}
	
	public static void close(ResultSet rs) {
		if(rs!= null) {
			try {
				rs.close();
			} catch (Exception e) {

			}
		}
	}

}