Package ch.psi.wica.controlsystem.epics.io

Class EpicsChannelWriterService

java.lang.Object

ch.psi.wica.controlsystem.epics.io.EpicsChannelWriterService

All Implemented Interfaces:

AutoCloseable

@Service
@ThreadSafe
public class EpicsChannelWriterService
extends Object
implements AutoCloseable

A service which offers the possibility to write to a String value to an EPICS channel.

Implementation Note:

The current implementation uses PSI's CA EPICS client library to obtain a single shared EPICS CA Context per class instance. The EPICS CA context and all associated resources are disposed of when the service instance is closed.

Constructor Summary

Constructors

Constructor	Description
EpicsChannelWriterService(EpicsChannelAccessContextSupplier epicsChannelAccessContextSupplier)	Returns a new instance.

Method Summary

Modifier and Type	Method	Description
void	close()	Disposes of all resources associated with this class instance.
boolean	writeStringValue(EpicsChannelName epicsChannelName, String channelValue, long timeout, TimeUnit timeUnit)	Sets the value of a channel.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

EpicsChannelWriterService

public EpicsChannelWriterService(@Autowired
 EpicsChannelAccessContextSupplier epicsChannelAccessContextSupplier)

Returns a new instance.

Parameters:

epicsChannelAccessContextSupplier - an object which can be used to obtain a Channel-Access context.

Method Details

writeStringValue

public boolean writeStringValue(EpicsChannelName epicsChannelName,
 String channelValue,
 long timeout,
 TimeUnit timeUnit)

Sets the value of a channel. This method incurs the network cost of establishing a channel to the remote data source and performing a synchronous (= confirmed) PUT operation.

Parameters:

epicsChannelName - the channel name.

channelValue - the channel value.

timeout - the timeout to be applied when attempting to put the channel value to the underlying data source. If a timeout occurs the returned value will be false.

timeUnit - the time units to be used.

Returns:

boolean set true when the put completed successfully.

Throws:

NullPointerException - if any of the reference object arguments were null.

close

public void close()

Disposes of all resources associated with this class instance.

Specified by:

close in interface AutoCloseable