EDIT

# CDM Java Library

{{>toc}}

The CDM Library is meant to be a shared library for the between several applications which can be of any kind, i.e. J2EE having an application container, simple command line tools or swing desktop applications.

The library defines a persistent domain model, EDITs [[CommonDataModel]], that can be serialised and read in XML. Business logic shared between applications should be part of this library as much as possible, while application specific logic has to stay out. We are developing this library in collaboration with the [CATE](http://www.cate-project.org/) project initially, but we seeking development collaboration with other projects like Key2Nature and PESI as well.

## Download

The latest version is available at the [[CdmLibraryDownload|CDM Library Download site]]

## Implementation

We use Wikipedia:Apache_Maven 2 for this project. The CDM library itself is devided into several maven subprojects, providing the following seperation of concerns:

* MavenSite:cdmlib-commons

* MavenSite:cdmlib-model

* MavenSite:cdmlib-persistence

* MavenSite:cdmlib-ext

* MavenSite:cdmlib-services

* MavenSite:cdmlib-remote

* MavenSite:cdmlib-io

### Current layers

![](cdmlib-arch2.png)

### Planned layers

Reuse service layer for all clients (Eclipse editor, CDM Server, CATE webapplication) and create DTOs made of preloaded domain classes instead of seperate classes.

![](cdmlib-arch3.png)

### Domain Model - _cdmlib-model_

Domain objects (also called business objects sometimes) are directly taken as POJOs from the [[CommonDataModel]]. The logic inherent to the domain objects are restricted to their own object graph, i.e. their own properties and related objects. But not unrelated objects available through DAOs only. Typical logic includes validation and calculations.

#### Property change support

We have implemented java.bean propertyChangeSupport methods for the entire cdm domain classes to send change events to registered listeners. 

The [[TaxonomicEditor]] makes use of these through a data binding framework. See wiki:JavaResources#DataBinding for more.

#### XML binding

For data exchange purposes, we want to serialize/deserialize the domain objects of the cdmlib-model to/from XML format using the [JAXB](https://jaxb.dev.java.net/) framework.

### Persistence Layer - _cdmlib-persistence_

we use Hibernate for persistence. We run unit and integration tests for [[MySQL]], Hypersonic, Postgres and MS SQL Server on a regular basis.

### API - _cdmlib-services_

Work in progress. see "CdmLibrary#Servicelayer" or wiki:CdmAPI for now.

### CDM Server - _cdmlib-remote_

That is the CdmServer community store.

### Import/Export - _cdmlib-io_

Supported import formats:

* [[BerlinModel]] database

* TCS

* ABCD

* SDD

* EDIT XML

Planned:

* DarwinCOre

* TaxonX

For more information about data conversion see [[SampleDataConversion]]

## Releases

Releases are currently in 2 flavours:

### Versioning strategy

Starting with the frozen [[CommonDataModel]] v1 we release minor upgrades for every model change in the library. Inferior version numbers (3rd level) are for bug-fixes and library extensions, which do not change the core model classes. This guarantees that all bug-fix releases are still working on the same database structure. 

For example: Svn:tags/cdmlib/rel_1.1.0 and rel_1.1.8 will work both on the same database structure as generated by hibernate. But for rel_1.2.0 you will have to update or better recreate your database, currently still losing all your data. In a later stage we will provide stable import/export formats to migrate your data to new versions.

### Change Log

All substantial changes to the library should be documented. This applies very strictly to all *model changes*. For them a separate changelog site has been setup at [[CdmChanges]].

All other changes should be documented at [[CdmLibraryChanges]].

Beside the model changes the highest priority for documentation have changes to signatures of visible methods and changes to semantics of existing methods.

If you just add some new functionality we highly appreciate it's documentation but documentation should not run into a unproductive overhead.

### Sourcecode via Subversion

The Maven project is available from our subversion server. For releases please see:

_http://dev.e-taxonomy.eu/svn/tags/cdmlib/_

### Eclipse plugin

For the cdmlib-service module we host an Eclipse plugin update site which is available here:

_http://wp5.e-taxonomy.eu/cdmlib/update/_