Overview

This guide shows you how to track a com.prosyst.mbs.services.da.DeviceAdmin service and how you can use the main functionality of this service of creating and removing devices and obtaining information about available protocol adapters.

General Principles

The DeviceAdmin is based on the Functional Item Management specification. You can learn more about it on the Developer Guide section. The DeviceAdmin extends FunctionalItemFactory and FunctionalItem. There are some additional restrictions related to them:

FunctionalItem UID is da:device:admin.
The supported classes in FunctionalItemFactory is only the class of Device. The DeviceAdmin creates only the Device functional items.
The DeviceAdmin provides only one attribute put as a registration property. The key of this attribute is supportedClasses and the value is set with one element – com.prosyst.mbs.services.da.Device.

The following table describes the functional property of the DeviceAdmin:

Property	Access	Property Class	Description
`DeviceAdmin.PROPERTY_ADAPTER_INFOS`	RE	`Set<AdapterInfo>`	Property for information for the protocol adapters.

The following table describes the operations of the DeviceAdmin:

Operation	Parameters	Description
`DeviceAdmin.OPERATION_GET_ADAPTER_INFO`	`String` – name of the adapter which is required.	Returns information for specific protocol adapter.
`DeviceAdmin.OPERATION_CREATE`	`String` – the only possible value can be `com.prosyst.mbs.services.da.Device` `Map<String, ?>` – a set of properties used for the functional item creation. The keys are the supported device creation properties while the values are the correct type for each property.	Creates and registers a `Device` with set of functional item creation properties. The `device items` are registered after the `Device` itself. The method finishes when the `Device` and its `device items` are created and registered in the system.
`DeviceAdmin.OPERATION_CREATE_DEVICE`	`DeviceItemDescriptor` – holds device properties to be used for the device creation.	Creates and registers `Device` using the creation data defined in the provided `com.prosyst.mbs.services.da.DeviceDescriptor` instance. The device items are registered after the Device itself. The method finishes when the `Device` and its `device items` are created and registered in the system.
`DeviceAdmin.OPERATION_REMOVE`	`String` – the UID of the `Device` to be removed.	Removes a `Device` with the given UID. The method finishes when the `Device` and its `device items` are removed and unregistered from the system.
`DeviceAdmin.OPERATION_REMOVE_DEVICE`	`String` – the UID of the `Device` to be removed. `RemoveArgument` – supported remove argument.	Removes the specified `Device` with remove operation argument, specified from the application. It is one of the provided values in `RemoveArgument`. The method finishes when the `Device` and its `device items` are removed and unregistered from the system.
`DeviceAdmin.OPERATION_CANCEL_REMOVE`	`String` – the UID of the removing `Device`.	Forces the adapter to cancel a device remove operation. This operation is executed if the method is supported by the protocol adapter.
`DeviceAdmin.OPERATION_RECREATE_DEVICE`	N/A	For this operation there is no defined operation method. Used only for `FunctionalItem` event operation name.

States of the DeviceAdmin

The lifecycle of the Device Admin starts when the service is registered and ends when the service is unregistered. The states of the DeviceAdmin are "Registered" and "Unregistered", as shown on the following diagram:

mbs_da_dev_guide2_v90

After Device Access is initialized it registers the DeviceAdmin as an OSGi service and after that all available Devices and their Device Items are registered as an OSGi services too. The "Unregistered" state can be achieved in two ways:

If the Device Access core is stopped – this is the end of the life-cycle of the DeviceAdmin.
If the protocol adapter is unregistered or registered. In this situation the DeviceAdmin changes the state to "Unregistered" and after that changes the state to "Registered" again.