org.lsst.ccs.subsystem.shutter.statemachine

Class FutureReply

java.lang.Object

org.lsst.ccs.subsystem.shutter.statemachine.FutureReply

All Implemented Interfaces:

EventReply

public final class FutureReply
extends Object
implements EventReply

Response, possibly delayed, to an event. Similar to a Future but without cancellation, exception completion or ExecutionException, but with the additional restriction that put() may be called at most once per instance. Thread-safe.

Author:

tether

Constructor Summary

Constructors

Constructor and Description
FutureReply() Construct.

Method Summary

Modifier and Type	Method and Description
String	getMessage() Gets a short string describing the acceptance or rejection.
void	put(EventReply value) Posts a reply using an EventReply as the source of the message text.
String	toString() Gets the string form of the response.
boolean	wasAccepted() Gets a boolean flag, blocking if need be, which tells whether an event was accepted.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.lsst.ccs.subsystem.shutter.statemachine.EventReply

accepted

Constructor Detail

FutureReply

public FutureReply()

Construct.

Method Detail

wasAccepted

public boolean wasAccepted()
                    throws InterruptedException

Description copied from interface: EventReply

Gets a boolean flag, blocking if need be, which tells whether an event was accepted.

Specified by:

wasAccepted in interface EventReply

Returns:

true if the event was accepted, else false.

Throws:

InterruptedException

See Also:

EventReply.getMessage()

getMessage

public String getMessage()

Description copied from interface: EventReply

Gets a short string describing the acceptance or rejection.

Specified by:

getMessage in interface EventReply

Returns:

The string.

Throws:

IllegalStateException - if wasAccepted() wasn't called.

See Also:

#put(java.lang.String)

put

public void put(EventReply value)

Posts a reply using an EventReply as the source of the message text.

Parameters:

value - The source of the message text.

Throws:

IllegalStateException - if put() has already been called for this instance.

NullPointerException - if the argument is null.

See Also:

#get()

toString

public String toString()

Gets the string form of the response.

Overrides:

toString in class Object

Returns:

A string of the form FutureReply{message-text}. The message text will be empty if no reply has yet been posted.