Defining the Class Model

In the following tutorial, we build a class model for a university. It uses the package name de.uniks.studyright, which you can replace according to your needs.

Create a class GenModel in the de.uniks.studyright package and put it in the src/gen/java source directory. The name GenModel is only a convention, you can also use a different one.

src/gen/java/de/uniks/studyright/GenModel.java:

package de.uniks.studyright;

import org.fulib.builder.ClassModelDecorator;
import org.fulib.builder.ClassModelManager;
import org.fulib.builder.reflect.Link;

import java.util.List;

public class GenModel implements ClassModelDecorator
{
   class University
   {
      String name;

      @Link("uni")
      List<Student> students;

      @Link("uni")
      List<Room> rooms;
   }

   class Student
   {
      String name;
      String studentId;
      int credits;
      double motivation;

      @Link("students")
      University uni;

      @Link("students")
      Room in;
   }

   class Room
   {
      String roomNo;
      String topic;
      int credits;

      @Link("rooms")
      University uni;

      @Link("in")
      List<Student> students;
   }

   @Override
   public void decorate(ClassModelManager mm)
   {
      mm.haveNestedClasses(GenModel.class);
   }
}

Within GenModel, we define our data model using a familiar yet shortened Java syntax. Every nested class is translated to a top-level class in the src/main/java source directory. The detailed docs describe this with more details and options. For now, we present a simple example in which we define three classes each with some attributes and associations.

Attributes are defined just like a normal field. Fulib takes care of generating getters and setters. It also ensures the correct access modifiers (private, public) are used in the generated code. We can simply omit them when defining the model within GenModel.

Associations are defined using the @Link annotation. You specify the name of the reverse role as the annotation argument. This way, fulib can generate setters that ensure referential integrity. To-many associations are specified by wrapping the target type in a collection, e.g. List<Student>. Instead of a setter, fulib will generate with and without methods for these associations.

For brevity, we do not show the generated code here. However, you can browse the generated files.