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ORM / DataSource Extension

This page explains the current ORM and dynamic datasource extension surface and how a host application can override defaults without breaking the starter contract.

If you want to understand how the built-in dynamic datasource capability works before customizing it, read this first:

Current ORM Entry​

The current ORM auto-configuration entry is OrmAutoConfiguration, which mainly creates:

  • MetaCommandExecutor
  • SaveDefaultValueFiller

MetaCommandExecutor is created only when a Dao bean exists in the host application.

Which DAO Is Used​

The explicit ORM property is:

geelato.orm.dao-bean-name=dynamicDao

If the property is configured, ORM binds to the named Dao bean.

If it is not configured and multiple Dao beans exist, the current compatibility order is:

  1. dynamicDao
  2. primaryDao

Starter JDBC Defaults​

When spring.datasource.primary.jdbc-url exists, the starter creates:

  • primaryDataSource
  • primaryJdbcTemplate
  • primaryDao
  • dbGenerateDao

If spring.datasource.secondary.jdbc-url also exists, it additionally creates:

  • secondaryDataSource
  • secondaryJdbcTemplate
  • secondaryDao

Dynamic Datasource Extension Points​

The dynamic datasource property prefix is:

geelato.datasource.dynamic.*

Important defaults include:

  • delay-load-data-source=true
  • enable-jta-transaction=false
  • enable-seata-proxy=false
  • default pool settings and connection-test-query=SELECT 1

Default Definition Source​

The current default definition loader is:

  • PlatformDynamicDataSourceDefinitionLoader

It is created only when the host application does not provide its own DynamicDataSourceDefinitionLoader.

How To Replace It​

The host application only needs to provide its own:

  • DynamicDataSourceDefinitionLoader

Typical scenarios include reading datasource definitions from:

  • a configuration center
  • YAML or files
  • an external registry service

When JTA / Seata Is Enabled​

JTA and Seata are not enabled by default.

They are only activated after explicit configuration, for example:

geelato.datasource.dynamic.enable-jta-transaction=true

Suggested Reading​