org.osgi.service.monitor
Interface MonitoringJob

public interface MonitoringJob

A Monitoring Job is a request for scheduled or event based notifications on update of a set of StatusVariables. The job is a data structure that holds a non-empty list of StatusVariable names, an identification of the initiator of the job, and the sampling parameters. There are two kinds of monitoring jobs: time based and change based. Time based jobs take samples of all StatusVariables with a specified frequency. The number of samples to be taken before the job finishes may be specified. Change based jobs are only interested in the changes of the monitored StatusVariables. In this case, the number of changes that must take place between two notifications can be specified.

The job can be started on the MonitorAdmin interface. Running the job (querying the StatusVariables, listening to changes, and sending out notifications on updates) is the task of the MonitorAdmin implementation.

Whether a monitoring job keeps track dynamically of the StatusVariables it monitors is not specified. This means that if we monitor a StatusVariable of a Monitorable service which disappears and later reappears then it is implementation specific whether we still receive updates of the StatusVariable changes or not.

Method Summary

java.lang.String	getInitiator() Returns the identitifier of the principal who initiated the job.
int	getReportCount() Returns the number of times MonitorAdmin will query the StatusVariables (for time based jobs), or the number of changes of a StatusVariable between notifications (for change based jobs).
int	getSchedule() Returns the delay (in seconds) between two samples.
java.lang.String[]	getStatusVariableNames() Returns the list of StatusVariable names that are the targets of this measurement job.
boolean	isLocal() Returns whether the job was started locally or remotely.
boolean	isRunning() Returns whether the job is running.
void	stop() Stops a Monitoring Job.

Method Detail

stop

public void stop()

Stops a Monitoring Job. Note that a time based job can also stop automatically if the specified number of samples have been taken.

getInitiator

public java.lang.String getInitiator()

Returns the identitifier of the principal who initiated the job. This is set at the time when MonitorAdmin.startJob() method is called. This string holds the ServerID if the operation was initiated from a remote manager, or an arbitrary ID of the initiator entity in the local case (used for addressing notification events).

Returns:

the ID of the initiator, cannot be null

getStatusVariableNames

public java.lang.String[] getStatusVariableNames()

Returns the list of StatusVariable names that are the targets of this measurement job. For time based jobs, the MonitorAdmin will iterate through this list and query all StatusVariables when its timer set by the job's frequency rate expires.

Returns:

the target list of the measurement job in [Monitorable_ID]/[StatusVariable_ID] format, cannot be null

getSchedule

public int getSchedule()

Returns the delay (in seconds) between two samples. If this call returns N (greater than 0) then the MonitorAdmin queries each StatusVariable that belongs to this job every N seconds. The value 0 means that the job is not scheduled but event based: in this case instant notification on changes is requested (at every nth change of the value, as specified by the report count parameter).

Returns:

the delay (in seconds) between samples, or 0 for change based jobs

getReportCount

public int getReportCount()

Returns the number of times MonitorAdmin will query the StatusVariables (for time based jobs), or the number of changes of a StatusVariable between notifications (for change based jobs). Time based jobs with non-zero report count will take getReportCount()*getSchedule() time to finish. Time based jobs with 0 report count and change based jobs do not stop automatically, but all jobs can be stopped with the stop() method.

Returns:

the number of measurements to be taken, or the number of changes between notifications

isLocal

public boolean isLocal()

Returns whether the job was started locally or remotely. Jobs started by the clients of this API are always local, remote jobs can only be started using the Device Management Tree.

Returns:

true if the job was started from the local device, false if the job was initiated from a management server through the device management tree

isRunning

public boolean isRunning()

Returns whether the job is running. A job is running until it is explicitely stopped, or, in case of time based jobs with a finite report count, until the given number of measurements have been made.

Returns:

true if the job is still running, false if it has finished