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Now that the model/db exist, we will create the persistence and layer services. The projects have been designed using the pattern Data Access Object because it allows to change the implementation from a database type to another, between ORM very easily. Moreover interfaces are used as 'contract' between the services and the DAO. This offers the advantage to decouple objects in the application and as you will see later on it will allow us to deploy services, persistence as separate bundles in the OSGI server. 1)

Persistence project

First, we will create the interface declaring the methods that we would like to provide/expose. Create in the folder src/main/java/org/apache/camel/example/reportincident/dao, the java class "IncidentDAO" with the following code :

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This file is not complete but we will review later in the tutorial when we will cover specific OSGI stuffs and Spring transaction management. Now, we will design the Spring service part2)

Spring Service project

In term of design, the service project is very similar to the persistence because we will create an interface and its implementation. Why repeating the interface. The answer is evident; it is for decoupling the service from the DAO implentation to allow you to switch easily from one ORM to another, ...

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