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EclipseLink/Development/DBWS/RestfulComponent/UseCases
DBRS Use Cases
The DBRS utility starts by reading some initial configuration information:
(if command-line arg -builderFile not present, default to look in current working directory)
prompt > DBRSBuilder running, connected to port 8884 ... Press <Return> to finish
dbrsbuilder.properties:
# builder properties
builder.port=8884
#builder.mode=production
builder.mode=test
builder.test.port=8885
# project properties
project.name=projectname
project.entities=employee, other entities ...
# database properties
db.driver=com.mysql.jdbc.Driver
db.url=jdbc:mysql://localhost:3306/db
db.user=user
db.pwd=password
db.platform=org.eclipse.persistence.platform.database.MySQLPlatform
logging.level=info
There are three scenarios to consider:
- the database contains the specified entities: the typical scenario where the Project's entities are exposed via a RESTful CRUD application.
- the database does not contain the specified entities: the so-called greenfield scenario where the Project's entities do not yet exist on the database.
- meta-data describing the specified entities is provided through an alternative mechanism: the scenario where the Project's entities are described via a JPA .orm file.
Existing Entities
The DBRS utility will login in to the database using the given database credentials and 'scrape' the meta-data for the employee table: column names and datatypes, PKs, foreign-key relationships, etc. If the table name does not match the entity name, the user may specify an alias:
alias.employee.tablename=EMP
If the built-in pluralization does not generate acceptible URIs, the user can alias that as well - e.g. if the entity is person, the plural should be people, not persons:
alias.person.plural=people
The DBRS utility builds an in-memory representation of the required meta-data for the employee entity to be mapped to the database via a JPA entity and mapped to any REST-ful clients via JAXB (supporting both XML and JSON media representations). Initially the back-end generation will target EclipseLink JPA/JAXB + Jersey (1.9.1 at the time of this writing).