Reusing existing data_layer_to_persist_multi_f

Reusing existing data layer to persist multi-format data streams

Agenda
Reusing your existing data layer
Persistence cartridge and Scribe
Examples:
Using custom Data Access Objects
Using JPA / Hibernate
Using iBATIS
Scribe feature details
Persistence cartridge feature details
Future improvements
Q&A

Reusing your existing data layer
Reuse entity POJO's within Smooks
Persistence logic stays within the data layer
No code duplication
Refactoring is easier

Single cartridge for multiple persistence solutions:
Custom Data Access Objects (DAOs)
JPA
Hibernate
iBatis (MyBatis)
Any persistence framework, if you write an adapter for it (which is very easy)

Framework abstraction via Scribe
Smooks subproject.
Abstracts persistence actions like inserting, updating, deleting and querying.
Map persistence actions via annotations or by implementing interfaces

XML Configuration namespace:
http://www.milyn.org/xsd/smooks/persistence-1.2.xsd
Namespace prefix: dao
Smooks visitor resources:
Locator
Inserter
Updater
Deleter
Flusher

Examples
Data structure:

Example: Using custom D.A.O.s
Order entity:

OrderLine entity:

Product entity:

A DAO to store orders:

A DAO to locate products:

Smooks execution:

Smooks configuration part 1

Example: Using JPA / Hibernate
Same data model and same entities as previous example:

Example: Using JPA / Hibernate Product entity had an extra Named Query which can be used by the persistence cartridge.

Smooks execution

Comparison to the previous example with the custom DAO:

Using a named query

Example: Using iBatis (MyBatis)
Again the same data:

Example: Using iBatis (MyBatis)

Example: Using iBatis (MyBatis) iBatis query mapping configuration file

Example: Using iBatis (MyBatis) Smooks execution

Example: Using iBatis (MyBatis) Smooks config part 1

Example: Using iBatis (MyBatis) Smooks config part 2

Lookup parameters can be in a map (named) or in a array (by position).
Multiple insert, update, delete, flush and lookup methods possible per DAO. Each is named, by default with the method name.
Multipe DAO Registers can be used in one Smooks instance. e.g. Combining Hibernate with DAOs. DAO name: {repo id}.{dao name}
An insert or update DAO method doesn´t need to return an entity. The method must then be annotated with @ReturnsNoEntity.

DAO methods that require a query string are supported via the @LookupByQuery annotation.

Persistence cartridge feature details
The locator parameter mapping supports:
Value mapping
Wire mapping (mapping objects in the bean context)
Expression mapping
When the locator has no result then an exception can be thrown or the value in the bean context can be nullified. See onNoResult attribute.
The locator can force unique results.
The entity object resulting from an insert, update or delete can be stored under a different bean context id.

Future improvements
Write decent documentation!!!
Creating a Injection cartridge A Smooks Injection cartridge should make it possible to create a DaoRegister from within the Smooks configuration.
Create a Transaction cartridge Should make it possible to completely handle transactions within the Smooks configuration.
Provider XML configuration next to annotations
Replace reflection with runtime code generation.

Reusing existing data_layer_to_persist_multi_f

by Maurice Zeijen on Sep 09, 2010

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Reusing existing data_layer_to_persist_multi_f — Presentation Transcript