ru.dz.mqtt_udp.config

Class Requester

java.lang.Object

ru.dz.mqtt_udp.config.Requester

All Implemented Interfaces:

Consumer<IPacket>

public class Requester
extends Object
implements Consumer<IPacket>

Active mode remote configuration. Application has no local config storage and requests config items on each start. Alternatively it has local config storage but updates it from time to time from central node.

Remote configuration requester.

See also Provider class.

Keeps set of topics, requests them from network, keeps replies. Usage:

 
 IPacketMultiSource ms = new PacketSourceMultiServer();
 ms.start();
 
 Requester r = Requester(ms);
 
 r.addTopic("$SYS/myinstancename/param"); // will request it from net

 r.startBackgroundRequests(); // start asking for topic values in loop
 
 if( !waitForAll(10*1000*1000) )
 {
                print("Can't get config from net"); System.Exit(1);
 }
 
 

Author:

dz

Constructor Summary

Constructors

Constructor and Description
Requester(IPacketMultiSource ms) Construct.

Method Summary

Modifier and Type	Method and Description
void	accept(IPacket t) Implementation of Consumer<IPacket> interface.
void	addTopic(String topicName) Add topic, which value is to be requested from MQTT/UDP network,
Set<String>	getAllEmpty() Get list of topics for which we do not have data yet.
long	getCheckLoopTime()
String	getValue(String topic) Get value for topic
boolean	isDone() Check if all items got values.
protected void	loop()
void	setCheckLoopTime(long checkLoopTime) Set time between repeated requests for items.
void	startBackgroundRequests() Start background process to poll net for topics we need.
boolean	waitForAll(long timeoutMsec) Wait for all topics to get content.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.function.Consumer

andThen

Constructor Detail

Requester

public Requester(IPacketMultiSource ms)

Construct.

Parameters:

ms - MQTT/UDP network listener which is able to serve multiple consumers.

Method Detail

addTopic

public void addTopic(String topicName)
              throws IOException

Add topic, which value is to be requested from MQTT/UDP network,

Parameters:

topicName - name of topic to request

Throws:

IOException - if network send is failed

getValue

public String getValue(String topic)

Get value for topic

Parameters:

topic - to get value for

Returns:

value or null if not yet received

accept

public void accept(IPacket t)

Implementation of Consumer<IPacket> interface. Sink to put received packets to.

Specified by:

accept in interface Consumer<IPacket>

startBackgroundRequests

public void startBackgroundRequests()

Start background process to poll net for topics we need.

setCheckLoopTime

public void setCheckLoopTime(long checkLoopTime)

Set time between repeated requests for items.

Parameters:

checkLoopTime - Time in milliseconds.

getCheckLoopTime

public long getCheckLoopTime()

loop

protected void loop()
             throws IOException

Throws:

IOException

getAllEmpty

public Set<String> getAllEmpty()

Get list of topics for which we do not have data yet.

Returns:

Set of topic strings

isDone

public boolean isDone()

Check if all items got values.

Returns:

true if we got all data.

waitForAll

public boolean waitForAll(long timeoutMsec)

Wait for all topics to get content. Returns when we have data for all topics we know about.

Parameters:

timeoutMsec - Max time to wait.

Returns:

true if success, false if timed out.