Spring Batch中的Hibernate会话（EntityManager）作用域？

Question

As I'm new to Spring and Spring Batch, I have a general question about Spring Batch and JPA using Hibernate as provider.

Please, I want to know when the Hibernate session (wrapped by the EntityManager) is flushed ? Between Reader, Processor and Writer? or for each commit interval? We can control it or not?

Answer 1

据我所知，何时提交Spring事务（在每个块之后）。

Answer 2

Please, I want to know when the Hibernate session (wrapped by the EntityManager) is flushed? Between Reader, Processor and Writer? or for each commit interval?

The session is flushed after writing a chunk of items, at each commit interval. For more details, take a look at:

• HibernateItemWriter : https://github.com/spring-projects/spring-batch/blob/master/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/HibernateItemWriter.java#L95

• JpaItemWriter : https://github.com/spring-projects/spring-batch/blob/master/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/JpaItemWriter.java#L84

We can control it or not?

If you use the HibernateItemWriter , you can set the clearSession flag to clear the session after each chunk.