edu.berkeley.guir.ptk.input
Class CNNNewsInput

java.lang.Object
  edu.berkeley.guir.ptk.PTK
      edu.berkeley.guir.ptk.input.InputSource
          edu.berkeley.guir.ptk.input.CNNNewsInput

All Implemented Interfaces:

java.lang.Runnable

public class CNNNewsInput

extends InputSource

Gets news headlines from CNN.com and dispatches all the headlines in one event to the PTK Server. Extends the class InputSource and implements newInput() (an inherited, abstract method). This method is responsible for getting the actual input data from the CNN Web page. To do so, it uses the PTKWebParser.

This class sets the inherited Metadata mds field in the constructors. It is necessary to set the metadata because this is what identifies the events this input creates to outputs and to the PTK server. Outputs that want CNN news input, would subscribe to same metadata that is added to the event in the newInput method. Metadata is added using a Metadata object, which includes the ID of the metadata (which type of metadata it is) and the value of the metadata (the value that distinguishes it from other Events). Multiple Events can have Metadata with the same ID, but if it is important to tell them apart, their values should be different. For this CNN news input, the only Metadata in the event is the Event_TYPE_ID (the metadata ID), which is set to NewsConstants.NEWS (the metadata value). All events should have a Event_TYPE_ID.

To start the input, run this class as a Java application. The main class creates a new CNNNewsInput and starts it (which gets a new input and dispatches it to the PTK server). Events are dispatched in a loop with a sleeping time specified this.time_between_events. To customize the time between events, call setTimeBetweenEvents(long).

Field Summary

static java.lang.String

MY_ID The unique ID String for this input, found in NewsConstants, which is an application specific class.

Fields inherited from class edu.berkeley.guir.ptk.input.InputSource

history, mds, my_id, my_ip, time_between_events

Fields inherited from class edu.berkeley.guir.ptk.PTK

debug, MAX_DEBUG, MED_DEBUG, MIN_DEBUG, NO_DEBUG

Constructor Summary

CNNNewsInput()
Constructor for non-distributed applications.

CNNNewsInput(java.lang.String my_ip)
Constructor for distributed applications.

Method Summary

static void	main(java.lang.String[] argsv) This main method allows the input to run, continually getting new input and dispatching the data in events to the PTK server.
Events	newInput() Gets news headline input from the data source, CNN.com, and fills a Event with the headline strings.

Methods inherited from class edu.berkeley.guir.ptk.input.InputSource

addMetadata, addMetadataItem, addMyMetadataToEvent, dispatchEvent, finalize, getAbstractThenSendInputEvent, getMetadata, getMetadataItemsAsArray, getThenSendInputEvent, register, run, setMetadata, setTimeBetweenEvents, startInput

Methods inherited from class edu.berkeley.guir.ptk.PTK

getMAX, getMED, getMIN, getNO, printDebug, printDebug, printError

Methods inherited from class java.lang.Object

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

Field Detail

MY_ID

public static final java.lang.String MY_ID

The unique ID String for this input, found in NewsConstants, which is an application specific class. The ID must be unique per PTK server instance.

See Also:

Constant Field Values

Constructor Detail

CNNNewsInput

public CNNNewsInput()

Constructor for non-distributed applications. An input that uses this constructor cannot be part of an application on another machine.

CNNNewsInput

public CNNNewsInput(java.lang.String my_ip)

Constructor for distributed applications. An input that uses this constructor can send evets to remote applications.

Method Detail

newInput

public Events newInput()

Gets news headline input from the data source, CNN.com, and fills a Event with the headline strings. The Event is returned when it has NewsConstants.NUM_HEADLINES headline strings in it. This Event is what will be dispatched to the PTK server and eventually sent to outputs that subscribe to its metadata. Uses the PTKWebParser class to parse the CNN Web page.

Specified by:

newInput in class InputSource

Returns:

Events an Events object that contains a single Event with the news headlines. There are NewsConstants.NUM_HEADLINES DataString objects created and then added to the Event. Each DataString is given an ID in the array NewsConstants.ALL_IDS, which is an array of news headline IDs indexed by the number of the headline (i.e., the first headline is in the first position of the array, etc.).

main

public static void main(java.lang.String[] argsv)

This main method allows the input to run, continually getting new input and dispatching the data in events to the PTK server.

Parameters:

argsv -