In the beginning I would like to warn that I removed getters and setters in order to make code concise.
I guess code will describe more precisely that many words
//Mapper is obviously as separate class
@Mapper
public interface TestMapper {
@Mapping(source = "x.field1", target="inner.field1")
@Mapping(source = "y.field2", target="inner.field2")
Target map(Source source);
}
class Source {
private X x;
private Y y;
}
class X {
private String field1;
}
class Y {
private String field2;
}
class Target {
private Inner inner;
}
class Inner {
private String field1;
private String field2;
}
public class Main {
public static void main(String[] args) {
Source source = new Source();
final X x = new X();
x.setField1("field1");
Y y = new Y();
y.setField2("field2");
source.setX(x);
source.setY(y);
final TestMapper mapper = Mappers.getMapper(TestMapper.class);
Target target = mapper.map(source);
System.out.println(source.getX().getField1().equals(target.getInner().getField1()));
System.out.println(source.getY().getField2().equals(target.getInner().getField2()));
}
}
Such code generate implementation like this:
public class TestMapperImpl implements TestMapper {
@Override
public Target map(Source source) {
if ( source == null ) {
return null;
}
Target target = new Target();
target.setInner( xToInner( source.getX() ) );
target.setInner( yToInner( source.getY() ) );
return target;
}
(...)
This obviously causes overriding value of Inner. Which is not what I've expected. Is there a way to make it work? Or is it some bug in mapstruct?
This is a known bug in MapStruct that was fixed with 1.3.1.Final release.
The relevant issue is mapstruct/mapstruct#1828.
In case you still have the same problem after you upgrade to 1.3.1.Final then please raise a new issue in the MapStruct bug tracker