Spring - Mapping Objects

[Walter Gómez]

Hello,

Recently, I started a new job (4 months now) and I still have a lot to learn from Spring. One of the issues we're having is that when we bring objects from the DB and map them into (Repository -> Service -> Controller) a JSON, it brings a lot of unnecessary data - For example (small example):

We have an Employee class which has a Department object and it brings the following:

{
       'EmployeeId':1,
       'Name':'John',
       'Email':'[e-mail]'
       'Department': {
                'DepartmentId':1,
                'name':'Development',
                'location':'Somewhere',
       }
}

Class details:

@Entity
@Table(name = "Employees")
@NamedQuery(name = "Employee.findAll", query = "SELECT e FROM Employees e")
public class Employee implements Serializable {
	private static final long serialVersionUID = 1L;

	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	@Column(name = "EmployeeId")
	private long EmployeeId;

	@Column(name = "Email")
	private String email;

	@Column(name = "address")
	private String address;

    @ManyToOne
	@JoinColumn(name = "DepartmentId")
	@JsonBackReference(value = "department_employee")
	private Departament departament;
        
        // Other attributes, setters & getters

}

If I want to build a "custom" mapper, which is the best practice? Or how can I implement something that allows me to create a JSON that brings me something like this:

{
       'EmployeeId':'1',
       'Name':'John',
       'Email':'[e-mail]'
}

I've been doing some research and I stumbled across the following recommendations:

Jackson JSON Views
JSON Filter and JSON Views This one taken from another forum.

Also I've been thinking about using a generic object that contains a HashMap so I can include, on the Controller, the data that I want or need for an specific screen.

I really appreciate any help - hope the question is clear enough.

[Walter Gómez]

Question has been posted on other forum:

http://stackoverflow.com/questions/38905760/json-object-mapping-spring-data