Group updating method, message sending method, and apparatuses

A method for sending a message, comprising:

• obtaining event notification decision criteria of a subscribed resource, and determining a target attribute to be monitored according to the event notification decision criteria;
• obtaining a changed attribute value of the target attribute when an attribute value of the target attribute is changed;
• constructing a differential notification message according to the changed attribute value when a notification manner is a differential notification manner;
• and
• sending the differential notification message.

An electronic device for group update, comprising:

• a memory, storing a computer program;
• and
• a processor, configured to execute the computer program to implement the operations including:
• obtaining a location group for a target area;
• obtaining dynamic update period of the location group;
• obtaining, at each time point determined according to the dynamic update period, a target location of a target group object in the location group, and querying whether a business object not belonging to the location group exists within the target area;
• and
• updating the target group object in the location group according to the obtained target location and a query result.