How to skip a field during map stage? - modelmapper

Question

I'm having list of employee objects - List
I need to convert it into list of employee transfer objects - List
Assume a field "password" exist in both the classes.
In few cases i need the password needs to be included from Employee → EmployeeDTO
In few cases i don't need the password and want to be excluded from Employee - EmployeeDTO.
Sample Code Snippet:
List<Employee> employees = employeeRepository.findAll();
// Define the target type
Type targetListType = new TypeToken<List<EmployeeDTO>>() {}.getType();
List<EmployeeDTO> employeeDTOs = modelMapper.map(employees, targetListType);
Please let me know how to skip the fields on mapping/copying.

Answer 1

Take a look the official user manual of Conditional Mapping.
In brief:
You would need to add a new Mapping and use a Condition. Your source and destionation would be:
Source: Employee
Destination: EmployeeDto
First create and custom your Condition. It would be something like this:
Condition<?, ?> isNotZero = new Condition<PersonDTO, Employee>() {
public boolean applies(MappingContext<PersonDTO, Employee> context) {
//Your conidition
return context.getSource().getEmployeeId() != 0;
}
};
Then add Mapping and use the condition:
modelMapper.addMappings(new PropertyMap<PersonDTO, Person>() {
protected void configure() {
when(isNotZero).map(source).setEmployee(null);
}
});
You can find this examples in the ModelMapper GitHub repository. The author has done few more and are well explained:
Link to above example

Answer 2

Here is how I skip fields during the mapping stage:
ModelMapper modelMapper = new ModelMapper();
modelMapper.typeMap(EmployeeDTO.class,Employee.class).addMappings(mapper -> {
mapper.skip(Employee::setPassword);
});