public void close() {
		try {							//׽쳣
			if (rs != null) {				//ResultSetʵrsΪʱ
				rs.close();					//رResultSet
			}
			if (stmt != null) {				//StatementʵstmtΪʱ
				stmt.close();				//رStatement
			}
			if (conn != null) {				//ConnectionʵconnΪʱ
				conn.close();
				//رConnection
			}
			System.out.println("ɹرݿӣ");
		    } catch (Exception e) {
			System.out.println("رݿʧܣ");
			e.printStackTrace(System.err);	}//쳣Ϣ
	    }