Bidirectional Mapping

[Farouk Elabady]

Hello, 

I am trying the following scenario to map two sources (department , employee) to (destinationDepartment, destinationEmployee), with bidirectional relation between the two,

as shown in the below code

public class DepSource {
 
 private String name;
 
 private EmpSource employee;
       // getters and setters
}

public class EmpSource {
 
 private String name;
 
 private DepSource department;
     // getters and setters
}

public class DepDest {
 
 @JMap
 String name;
 
 @JMap("employee")
 EmpDest emp;


// getters and setters


}

public class EmpDest {
 
 @JMap
 String name;
 
 @JMap(value = "department")
 DepDest dep;


// getters and setters
}

 public static void main(String[] args) {
 DepSource depSource = new DepSource();
 depSource.setName("Department 1");
 EmpSource empSource = new EmpSource();
 empSource.setName("employee 1");
 depSource.setEmployee(empSource);
 empSource.setDepartment(depSource);
 JMapper<EmpDest, EmpSource> mapper = new JMapper<>(EmpDest.class, EmpSource.class);
 EmpDest des = mapper.getDestination(empSource,MappingType.ONLY_NULL_FIELDS);
 System.out.println(des.getName());
 System.out.println(" : " + des.getDep().getName());
 System.out.println(" : " + des.getDep().getEmp().getName());
 }

when trying to run the code , it gives stack overflow exception, so what is the correct way of doing such mapping 

Note: what I am trying to to do is to mimic the bidirectional relation like what can be found in JPA entities

Best regards

Farouk Elabady

[Alessandro Vurro]

Hi Farouk,

this is a case of infinite recursive mapping, EmpSource contains DepSource and viceversa, equal for other classes.

JMapper does not know when to stop mapping, the only solution is to stop the recursion.

I hope to be a help

[Farouk Elabady]

Hi Alessandro,

That is true, I managed though to stop the infinte recursive mapping using @JmapConversion method and mapping the object inside the method,

although the method is trivial, but I think it will be good if I can control the depth of the mapping to prevent infinite loop, 

also it will be much needed if for example there is tree of objects, and I want to just mad the first or second level of the tree, 

e.g @JMap(depth = 1)

and thanks for your help :)