org.cripac.isee.vpe.ctrl

Class MessageHandlingApp

java.lang.Object

org.cripac.isee.vpe.common.SparkStreamingApp

org.cripac.isee.vpe.ctrl.MessageHandlingApp

All Implemented Interfaces:

Serializable

public class MessageHandlingApp
extends SparkStreamingApp

The MessageHandlingApp class is a Spark Streaming application responsible for receiving commands from sources like web-UI, then producing appropriate command messages and sending to command-defined starting application.

Author:

Ken Yu, CRIPAC, 2016

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MessageHandlingApp.CommandType This class stores possible commands and the String expressions of them.
static class	MessageHandlingApp.Parameter The class Parameter contains a numeration of parameter types the MessageHandlingApp may use, as well as their keys.
static class	MessageHandlingApp.UnsupportedCommandException

Field Summary

Fields

Modifier and Type	Field and Description
static String	APP_NAME The name of this application.
private Singleton<HDFSReader>	hdfsReaderSingleton
private Singleton<ByteArrayProducer>	producerSingleton
private static long	serialVersionUID

Fields inherited from class org.cripac.isee.vpe.common.SparkStreamingApp

loggerSingleton

Constructor Summary

Constructors

Constructor and Description
MessageHandlingApp(SystemPropertyCenter propCenter) The constructor method.

Method Summary

Modifier and Type	Method and Description
void	addToContext() Add streaming actions directly to the global streaming context.
private void	handle(String cmd, Map<String,Serializable> param)
static void	main(String[] args)

Methods inherited from class org.cripac.isee.vpe.common.SparkStreamingApp

awaitTermination, buildDirectStream, buildDirectStream, finalize, initialize, registerStreams, start, stop

Methods inherited from class java.lang.Object

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

Field Detail

APP_NAME

public static final String APP_NAME

The name of this application.

See Also:

Constant Field Values

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

producerSingleton

private Singleton<ByteArrayProducer> producerSingleton

hdfsReaderSingleton

private Singleton<HDFSReader> hdfsReaderSingleton

Constructor Detail

MessageHandlingApp

public MessageHandlingApp(SystemPropertyCenter propCenter)
                   throws Exception

The constructor method. It sets the configurations, but does not run the contexts.

Parameters:

propCenter - The propCenter stores all the available configurations.

Throws:

Exception - Any exception that might occur during execution.

Method Detail

main

public static void main(String[] args)
                 throws Exception

Throws:

Exception

addToContext

public void addToContext()
                  throws org.apache.spark.SparkException

Description copied from class: SparkStreamingApp

Add streaming actions directly to the global streaming context. This is for applications that may take as input messages with types other than TaskData. Actions that take TaskData as input should be implemented in the Stream.addToGlobalStream(Map), in order to save time of deserialization. Note that existence of Kafka topics used in this method is not automatically checked.

Specified by:

addToContext in class SparkStreamingApp

Throws:

org.apache.spark.SparkException

handle

private void handle(String cmd,
                    Map<String,Serializable> param)
             throws Exception

Throws:

Exception