What is the implementation principle of Spring transact…

The implementation of Spring transactions is mainly based on AOP (Aspect Oriented Programming) and the underlying database transaction management mechanism.

1. Spring uses AOP to separate transaction management logic from business logic. By applying transaction management logic before and after business methods, it achieves operations such as transaction initiation, submission, and rollback.
2. Proxy pattern: Spring utilizes dynamic proxy technology to implement transaction management. It dynamically creates proxy objects at runtime, weaving transaction management logic into the target object.
3. Transaction Manager: In Spring, a transaction manager is used to centrally manage transactions. The transaction manager is responsible for initiating, committing, and rolling back transactions, as well as managing transaction isolation levels and propagation behavior.
4. Transaction interception points: In Spring, transaction interception points are used to determine which methods need to apply transactions. By configuring interception point expressions, transactions can be selectively applied to specific business methods.
5. Database transaction management: The underlying database transaction management is provided by the database itself, such as the Connection object in JDBC. Spring manages database transactions by interacting with the database.

In general, the implementation principle of Spring transactions is to weave transaction management logic into business methods through AOP and proxy patterns, and manage operations such as transaction opening, committing, and rolling back through a transaction manager, ultimately calling the underlying database transaction management mechanism to achieve transaction consistency and isolation.