guice-transactional

Overview

Miss the convenience of @Transactional but have no interest in using JPA? Then guice-transactional is for you.

guice-transactional lets you annotate methods using the standard @javax.transaction.Transactional annotation and works as you expect; transactions will be started before the method is called and committed or rolled back after the method completes. It also implements all of the transaction types for more complicated use-cases.

guice-transactional just needs access to the underlying javax.sql.DataSource so it will work with any persistence framework, including jDBI, Hibernate, MyBatis, QueryRunner, or even raw JDBC.

Maven Dependency

To use on Maven-based projects, add the following dependency:

<dependency>
  <groupId>com.hubspot.guice</groupId>
  <artifactId>guice-transactional</artifactId>
  <version>0.2.3</version>
</dependency>

Usage

There are a few steps to get up and running with guice-transactional:

1. Install TransactionalModule when building your Guice injector, this sets up the necessary method interceptor

2. When configuring your persistence framework, wrap your DataSource in a TransactionalDataSource

3. Annotate methods with @javax.transaction.Transactional and profit! The only restriction is that these methods must be on objects that were created by Guice and they must not have private access

How Does it Work?

When you install TransactionalModule, an interceptor is added to methods annotated with @javax.transaction.Transactional. When a transactional method is entered, the interceptor stores this state in a ThreadLocal. The TransactionalDataSource checks the interceptor for this flag when a connection is requested. If the flag is set, it disables auto-commit and returns the same connection for the duration of the transactional method. Once the transactional method completes, the interceptor either commits or rolls back the transaction depending on the result of the method call and then clears the thread local state.