CDM Java Library¶

• Table of contents
• CDM Java Library
  • Implementation
    • Maven, Seperation of Concerns
      • Maven repository
    • Domain Model - cdmlib-model
      • Property change support
      • Validation
      • XML binding
    • Persistence Layer - cdmlib-persistence
    • API - cdmlib-services
    • CDM Server - cdmlib-remote
    • Import/Export - cdmlib-io
  • Using the CDM Library
    • Eclipse setup
    • Spring applications with cdmlib
  • Background
    • Hibernate
    • Spring 2.0 Framework
    • Domain Models
    • Useful Patterns
    • Aspect Oriented Programming

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 serialsed 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 hope to develop this library in collaboration with the CATE project initially.

Implementation¶

Maven, Seperation of Concerns¶

We use http://maven.apache.org/ Maven 2 for this project.

The CDM library itself is devided into several maven subprojects which can be found here:

Maven Project Sites

• cdmlib-commons

• cdmlib-model

• cdmlib-persistence

• cdmlib-services

• cdmlib-remote

• cdmlib-io

Maven repository¶

To integrate the cdmlibray into your personal Maven project pelase add our Maven repository to your POM: http://wp5.e-taxonomy.eu/cdmlib/mavenrepo/

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.

• http://www.onjava.com/pub/a/onjava/2004/06/02/desktop.html

• http://www.javalobby.org/java/forums/t19476.html

Validation¶

Validation primarily in setter methods. Implement separate Rule classes too?

XML binding¶

using JAXB

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

Planned:

• TCS+DarwinCOre+SDD

• TaxonX

Using the CDM Library¶

Eclipse setup¶

• Maven: http://maven.apache.org/download.html (be sure to have JDK in your JAVA_HOME, jre is not enough !)

• Eclipse-IDE: http://m2eclipse.codehaus.org/index.html

• Sun's jars: http://maven.apache.org/guides/mini/guide-coping-with-sun-jars.html

After installing the jar to your local repository copy the local files to the javaLibrary folder in the svn just as they are

• AspectJ plugin: http://mojo.codehaus.org/aspectj-maven-plugin/usage.html

Spring applications with cdmlib¶

In your own applicationContext.xml you can simply import the cdm spring beans together with

a jdbc datasource bean that reads a property file. A basic mysql cdm store would look like this:

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans   http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

    <import resource="classpath:cdm-services.xml" />
    <import resource="classpath:cdm-jdbc-datasource.xml" />

</beans>

db.properties

hibernate.hbm2ddl.auto=update
hibernate.show_sql=true

hibernate.dialect=org.hibernate.dialect.MySQLDialect
db.driver_class=com.mysql.jdbc.Driver
db.url=jdbc:mysql://192.168.2.10/cdm_store
db.username=your_username
db.password=your_password

---

Background¶

Hibernate¶

• Hibernate works with most current RDBMS. See supported databases

Spring 2.0 Framework¶

We use the Spring 2.0 framework to develop the library and keep the coupling of components low.

• Spring2.0 Documentation

• Introduction to the Spring Framework

• Die Rückkehr der POJOs. Das Spring-Framework: leichtgewichtiges Komponentenmodell als Alternative zu EJB

Domain Models¶

• Domain Models and Validation. An Architectural Discussion

• Avoiding anemic domain models with Hibernate

• Business Object Pattern

• AnemicDomainModel Anti Pattern

Useful Patterns¶

• ApplicationService Pattern

Aspect Oriented Programming¶

We use AspectJ to implement the change property crosscutting concern:

• AspectJ

  • http://today.java.net/pub/a/today/2005/12/15/writing-mixins-with-aop.html

• JBoss AOP

  • http://www.damnhandy.com/javabean-aspect/

• Spring AOP

  • http://forum.springframework.org/archive/index.php/t-13293.html
  • http://forum.springframework.com/viewtopic.php?t=301