Try-Catch 자동 close

기존 try-catch 구문

try {
			Class.forName("com.mysql.jdbc.Driver");
			conn = DriverManager.getConnection(dburl, dbUser, dbpasswd);
			String sql = "SELECT description,role_id FROM role WHERE role_id = ?";
			ps = conn.prepareStatement(sql);
			ps.setInt(1, roleId);
			rs = ps.executeQuery();
			if (rs.next()) {
				String description = rs.getString(1);
				int id = rs.getInt("role_id");
				role = new Role(id, description);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (rs != null) {
				try {
					rs.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
			if (ps != null) {
				try {
					ps.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
			if (conn != null) {
				try {
					conn.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
		}

 

 

자동 close 구문

try (Connection conn = DriverManager.getConnection(dburl, dbUser, dbpasswd);
				PreparedStatement ps = conn.prepareStatement(sql)) {

			try (ResultSet rs = ps.executeQuery()) {

				while (rs.next()) {
					String description = rs.getString(1);
					int id = rs.getInt("role_id");
					Role role = new Role(id, description);
					list.add(role); // list에 반복할때마다 Role인스턴스를 생성하여 list에 추가한다.
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		} catch (Exception ex) {
			ex.printStackTrace();
		}

try 옆 ( ) 사이에 넣은 객체들은 finally를 사용할 필요 없이 자동으로 종료시 close 시켜준다