DB 6일차 4(jdbc)

JDBC 만들고

 

세팅하고

 

 

package main.java.com.study.jdbc.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

import com.mysql.cj.jdbc.Driver;

public class DBConnection {
	
	private static DBConnection instance = null;
	
	private DBConnection() {}
	
	public static DBConnection getInstance() {
		if(instance == null) {
			instance = new DBConnection();
		}
		return instance;
	}
	
	public Connection getConnection() {
		Connection connection = null;
		String url = null;
		String username = null;
		String password = null;
		
		try {
			Class.forName(Driver.class.getName()); /*객체를 생성한다.*/ /*Driver.class.getName() 자동으로 이름을 가져온다.*/
			System.out.println("데이터베이스 드라이브 로딩 성공!");
			url = "jdbc:mysql://localhost:3306/subquery_study";
			username = "root";
			password = "root";
			
			
			connection = DriverManager.getConnection(url, username, password);
			
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
			System.out.println("드라이버 로딩 실패!");
		} catch (SQLException e) {			
			e.printStackTrace();
			System.out.println("데이터베이스 연결 실패!");
		}
		return connection;
	}

}

 

 

package main.java.com.study.jdbc.main;

import java.sql.Connection;

import main.java.com.study.jdbc.util.DBConnection;

public class jdbcTest1 {

	public static void main(String[] args) {
		Connection connection = DBConnection.getInstance().getConnection();
		
		System.out.println(connection);
	}

}

여기에다 쿼리를 씁니다

 

 

 

/*결과*/

데이터베이스 드라이브 로딩 성공!
com.mysql.cj.jdbc.ConnectionImpl@8462f31