Erasure error, while using generic types in methods with similar signature
The problem is that both map(D dto) and map(E entity), essentially have the same signature. being map(Object dto) and map(Object entity). And there is no way for java to determine which method is being called when you call entityMapper.map(something);
So, you need to define your method as follows:
public abstract class EntityMapper{
public abstract <E extends AbstractEntity, D extends AbstractDto> E map(D dto);
public abstract <E extends AbstractEntity, D extends AbstractDto> D map(E entity);
}