There are two enumerations that help the developer to simplify the work and are: NullPointerControl and MappingType. This enumerations allow to control the instances in input and apply a specific logical mapping. They are passed as input to getDestination, manyToOne and oneToMany methods.

This enumeration verifies that the objects passed in input are valued, if not, a null will be returned.
This enumeration allows to handle cases in which a field not valorized represents an error and where you want to avoid more controls to optimize performance.
The values of `NullPointerControl` are:

NullPointerControl.DESTINATION	only destination will be controlled
NullPointerControl.SOURCE	only source will be controlled
NullPointerControl.ALL	both instances will be checked
NullPointerControl.NOT_ANY	neither

This enumeration allows you to define which mode of mapping to apply.
This feature is useful when you want to enrich destination.
MappingType can be used for both instances.

IMPORTANT! JMapper not apply these mapping types to primitive variables, because they can not be null

The values of MappingType are:

MappingType.ALL_FIELDS	all fields will be included in the mapping
MappingType.ONLY_VALUED_FIELDS	only valued fields will be included in the mapping
MappingType.ONLY_NULL_FIELDS	only null fields will be included in the mapping

the possible combinations are summarized in the following table:

Destination MappingType	Source MappingType	Destination field
ALL_FIELDS	ALL_FIELDS	"SOURCE"
ONLY_VALUED_FIELDS	ALL_FIELDS	"SOURCE"
ONLY_NULL_FIELDS	ALL_FIELDS	"DESTINATION"
ALL_FIELDS	ONLY_VALUED_FIELDS	"SOURCE"
ONLY_VALUED_FIELDS	ONLY_VALUED_FIELDS	"SOURCE"
ONLY_NULL_FIELDS	ONLY_VALUED_FIELDS	"DESTINATION"
ALL_FIELDS	ONLY_NULL_FIELDS	"DESTINATION"
ONLY_VALUED_FIELDS	ONLY_NULL_FIELDS	"DESTINATION"
ONLY_NULL_FIELDS	ONLY_NULL_FIELDS	"DESTINATION"

Destination MappingType	Source MappingType	Destination field
ALL_FIELDS	ALL_FIELDS	"SOURCE"
ONLY_VALUED_FIELDS	ALL_FIELDS	null
ONLY_NULL_FIELDS	ALL_FIELDS	"SOURCE"
ALL_FIELDS	ONLY_VALUED_FIELDS	"SOURCE"
ONLY_VALUED_FIELDS	ONLY_VALUED_FIELDS	null
ONLY_NULL_FIELDS	ONLY_VALUED_FIELDS	"SOURCE"
ALL_FIELDS	ONLY_NULL_FIELDS	null
ONLY_VALUED_FIELDS	ONLY_NULL_FIELDS	null
ONLY_NULL_FIELDS	ONLY_NULL_FIELDS	null

Destination MappingType	Source MappingType	Destination field
ALL_FIELDS	ALL_FIELDS	null
ONLY_VALUED_FIELDS	ALL_FIELDS	null
ONLY_NULL_FIELDS	ALL_FIELDS	"DESTINATION"
ALL_FIELDS	ONLY_VALUED_FIELDS	"DESTINATION"
ONLY_VALUED_FIELDS	ONLY_VALUED_FIELDS	"DESTINATION"
ONLY_NULL_FIELDS	ONLY_VALUED_FIELDS	"DESTINATION"
ALL_FIELDS	ONLY_NULL_FIELDS	null
ONLY_VALUED_FIELDS	ONLY_NULL_FIELDS	null
ONLY_NULL_FIELDS	ONLY_NULL_FIELDS	"DESTINATION"

To better understand its use see the enumeration usage page.