@Override
	public boolean add(Object item) {
		conn = new SQLconnect().getConnection();
		if(item instanceof Timenode)
		{
			Timenode newitem = new Timenode();
			newitem = (Timenode)item;
			try {  
	            String sql = String.format("INSERT INTO Timenodes(time_weight, time_description, time_owner, display)" +
			" VALUES ('%s', '%s', '%s','%s')",newitem.getTime_weight(),newitem.getTime_description(),newitem.getTime_owner(),"true"  );

	            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;
	}