@Override
	public boolean update(Object item) {
		conn = SQLconnect.getConnection();
		String sql = "UPDATE `worlds` SET `name`='%s', `time_headnode`='%s' WHERE `id`='%s'";
		if (item instanceof Worldnode) {
			Worldnode newitem = (Worldnode) item;
			try {
					sql = String.format(sql, newitem.getName(),
						newitem.getTime_headnode(), newitem.getId());

				Statement st = (Statement) conn.createStatement(); // 创建用于执行静态sql语句的Statement对象

				System.out.println(sql);
				int count = st.executeUpdate(sql); // 执行插入操作的sql语句，并返回插入数据的个数
				System.out.println("insert " + count + " entries"); // 输出插入操作的处理结果
				conn.close(); // 关闭数据库连接
				return true;
			} catch (SQLException e) {
				System.out.println("插入数据失败 " + e.getMessage());
				return false;
			}
		}
		return false;
	}