Another example is that Alice and Bob write letters to each other, and the other receives them. In other words, Alice sends messages to Bob (push), and Bob receives them. This communication mode is SMTP.

When interacting with data within the Java team, there are several commonly used methods, such as Java native serialization method, JSON serialization method, ProtoBuf serialization method, etc. For comparative experiments, please refer to Performance Comparison of Several Serialization Methods.