Oracle + Docker + OJDBC

package com.sistmng;

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

public class SQLConnection {
	//JDBC를 사용하기 위한 변수 선언.
	private static final String JDBC_DRIVER = "oracle.jdbc.driver.OracleDriver";
	private static final String DB_URL = "jdbc:oracle:thin:@127.0.0.1:59161:xe";
	//DB 접속 아이디, 비밀번호.
	private static final String USER = "system"; //아이디
	private static final String PASS = "oracle"; //비밀번호

	private static Connection conn;
	//DB 연결 메소드 선언.
	public static final Connection connect() throws ClassNotFoundException, SQLException{

		Class.forName(JDBC_DRIVER);

		conn = DriverManager.getConnection(DB_URL, USER, PASS);

		return conn;
	}
	//DB 연결 종료 메소드 선언.
	public static void close() throws SQLException{
		if(conn!=null) {
			conn.close();
		}
	}
}

package com.sistmng.student;

import java.util.*;

import com.sistmng.Current;
import com.sistmng.SQLConnection;
import java.sql.*;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;

public class StudentDAO {

	private LocalDate now = LocalDate.now();
	private DateTimeFormatter dateFormat = DateTimeFormatter.ofPattern("yyyy-MM-dd");

  //회원정보출력
  public Student menu_1() {
		//DTO 클래스인 Student 타입의 결과를 반환할 객체를 생성한다.
		Student student = new Student();
		/*
		 SELECT COUNT(sh.mid) AS count_, m.name_, m.ssn, m.phone
		 FROM studentHistory_ sh, member_ m, student_ s
		 WHERE sh.mid = s.mid
		 AND s.mid = m.mid
		 AND sh.mid = '?'
		 GROUP BY  m.name_, m.ssn, m.phone ;
		 */
		Connection conn = null;
		PreparedStatement pstmt = null;
		String sql = "SELECT COUNT(sh.mid) AS count_, m.name_, m.ssn, m.phone FROM studentHistory_ sh, member_ m, student_ s WHERE WHERE sh.mid = s.mid AND s.mid = m.mid AND sh.mid = ? GROUP BY  m.name_, m.ssn, m.phone";

		try {
			//앞서 설정한 DB를 연결하기 위한 변수를 선언한다.
			conn = SQLConnection.connect();
			//보안상의 이유로 prepareStatement 메소드를 사용해서 오라클에 쿼리를 한 번만 업로드 할 수 있도록 한다.
			pstmt = conn.prepareStatement(sql);
			//물음표 기호의 부분에 들어갈 값 설정. 각각 인자는 (인덱스, 값)
			pstmt.setString(1, Current.getInstance().getCurrent());

			//SELECT 쿼리의 결과를 반환한다.
			ResultSet rs = pstmt.executeQuery();
			while(rs.next()) {
				String name_ = rs.getString("name_");
				String ssn = rs.getString("ssn");
				String phone = rs.getString("phone");
				int courseNumber = rs.getInt("count");
				student.setName_(name_);
				student.setSsn(ssn);
				student.setPhone(phone);
				student.setCourseNumber(courseNumber);
			}
			//반복문을  통해 setter를 통해 student 객체의 값을 할당한다.
			rs.close();
		} catch (SQLException se) {
			se.printStackTrace();
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				if (pstmt != null)
					pstmt.close();
			} catch (SQLException se) {

			}
			try {
				SQLConnection.close();
			} catch (SQLException se) {
				se.printStackTrace();
			}
		}
		return student;
  }
}