Introduction

Java Persistence API comes with a thorough concurrency control mechanism, supporting both implicit and explicit locking. The implicit locking mechanism is straightforward and it relies on:

• Optimistic locking: Entity state changes can trigger a version incrementation
• Row-level locking: Based on the current running transaction isolation level, the INSERT/UPDATE/DELETE statements may acquire exclusive row locks

While implicit locking is suitable for many scenarios, an explicit locking mechanism can leverage a finer-grained concurrency control.

In my previous posts, I covered the explicit optimistic lock modes:

• OPTIMISTIC
• OPTIMISTIC_FORCE_INCREMENT
• PESSIMISTIC_FORCE_INCREMENT

In this post, I am going to unravel the explicit pessimistic lock modes:

• PESSIMISTIC_READ
• PESSIMISTIC_WRITE

Continue reading “How do LockModeType.PESSIMISTIC_READ and LockModeType.PESSIMISTIC_WRITE work in JPA and Hibernate” →