formio-definition.java

private static final FormMapping<RegDate> regDateMapping = 
  Forms.basic(RegDate.class, "regDate").fields("month", "year").build();
private static final FormMapping<Registration> registrationForm =
	Forms.basic(Registration.class, "registration")
	  // whitelist of properties to bind
	  .fields("attendanceReasons", "cv", "interests", "email")
	  .nested(Forms.automatic(UploadedFileWrapper.class, "certificates", 
	    null, MappingType.LIST).build())
	  .nested(Forms.basic(Address.class, "contactAddress", 
	    Forms.factoryMethod(Address.class, "getInstance"))
	    .fields("street", "city", "zipCode").build())
	  .nested(Forms.basic(Collegue.class, "collegues", 
	    null, MappingType.LIST)
	    .fields("name", "email")
	    .nested(regDateMapping)
	    .build())
	  .nested(Forms.basic(NewCollegue.class, "newCollegue")
	    .fields("name", "email")
	    .nested(regDateMapping)
	    .build())
	  .build();