org.apache.sling.junit.jupiter.osgi

Enum ServiceCardinality

java.lang.Object

java.lang.Enum<ServiceCardinality>

org.apache.sling.junit.jupiter.osgi.ServiceCardinality

All Implemented Interfaces:

Serializable, Comparable<ServiceCardinality>

public enum ServiceCardinality
extends Enum<ServiceCardinality>

The cardinality of a service being injected is controlled via the type of the injected parameter and additionally via the @Service annotation's cardinality attribute.
The cardinality can be either OPTIONAL or MANDATORY. OPTIONAL does not require the presence of a service, whereas MANDATORY requires at least one service to be present, otherwise an exception is thrown.
The other aspect of cardinality, namely whether a single service or multiple services should be injected, is controlled via the type of the annotated field. For single service injection, the field's type is expected to be the type of the injected service. For multiple service injection, the field's type is expected to be a Collection or List with the type of the injected service as its generic type-argument.
Any further constraints, i.e. checking for an exact number or a range of services must be done via assertions.

See Also:

Service.cardinality()

Enum Constant Summary

Enum Constants

Enum Constant and Description
AUTO For unary service injection, AUTO defaults to MANDATORY.
MANDATORY At least one service must be present, otherwise a ParameterResolutionException is thrown.
OPTIONAL If no service is present, null is injected for unary service injection, and an empty List is injected for multiple service injection.

Method Summary

Modifier and Type	Method and Description
static ServiceCardinality	valueOf(String name) Returns the enum constant of this type with the specified name.
static ServiceCardinality[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

AUTO

public static final ServiceCardinality AUTO

For unary service injection, AUTO defaults to MANDATORY. Whereas for multiple service injection, AUTO defaults to OPTIONAL.

OPTIONAL

public static final ServiceCardinality OPTIONAL

If no service is present, null is injected for unary service injection, and an empty List is injected for multiple service injection.

MANDATORY

public static final ServiceCardinality MANDATORY

At least one service must be present, otherwise a ParameterResolutionException is thrown.

Method Detail

values

public static ServiceCardinality[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ServiceCardinality c : ServiceCardinality.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static ServiceCardinality valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null