Package org.uma.jmetal.util.measure.impl

Class MeasureFactory

java.lang.Object

org.uma.jmetal.util.measure.impl.MeasureFactory

public class MeasureFactory
extends Object

The MeasureFactory provides some useful methods to build specific Measures.

Author:

Matthieu Vergne

Constructor Summary

Constructors

Constructor	Description
MeasureFactory()

Method Summary

Modifier and Type	Method	Description
<Value> PullMeasure<Value>	createPullFromPush(PushMeasure<Value> push, Value initialValue)	Create a PullMeasure to backup the last MeasureFactory of a PushMeasure.
Map<String,PullMeasure<?>>	createPullsFromFields(Object object)	Create PullMeasures based on the fields available from an instance, whatever it is.
Map<String,PullMeasure<?>>	createPullsFromGetters(Object object)	Create PullMeasures based on the getters available from an instance, whatever it is.
<Value> PushMeasure<Value>	createPushFromPull(PullMeasure<Value> pull, long period)	Create a PushMeasure which checks at regular intervals the value of a PullMeasure.

Methods inherited from class java.lang.Object

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

Constructor Details

MeasureFactory

public MeasureFactory()

Method Details

createPullFromPush

public <Value> PullMeasure<Value> createPullFromPush(PushMeasure<Value> push,
 Value initialValue)

Create a PullMeasure to backup the last MeasureFactory of a PushMeasure. When the PushMeasure send a notification with a given MeasureFactory, this MeasureFactory is stored into a variable so that it can be retrieved at any time through the method PullMeasure.get().

Parameters:

push - a PushMeasure to backup

initialValue - the MeasureFactory to return before the next notification of the PushMeasure is sent

Returns:

a PullMeasure allowing to retrieve the last value sent by the PushMeasure, or the initial value if it did not send any

createPushFromPull

public <Value> PushMeasure<Value> createPushFromPull(PullMeasure<Value> pull,
 long period)

Create a PushMeasure which checks at regular intervals the value of a PullMeasure. If the value have changed since the last check (or since the creation of the PushMeasure), a notification will be generated by the PushMeasure with the new MeasureFactory.

Notice that if the period is two small, the checking process could have a significant impact on performances, because a Thread is run in parallel to check regularly the MeasureFactory modifications. If the period is too big, you could miss relevant notifications, especially if the PullMeasure change to a new MeasureFactory and change back to its previous MeasureFactory between two consecutive checks. In such a case, no notification will be sent because the MeasureFactory during the two checks is equal.

Parameters:

pull - the PullMeasure to cover

period - the number of milliseconds between each check

Returns:

a PushMeasure which will notify any change occurred on the PullMeasure at the given frequency

createPullsFromGetters

public Map<String,PullMeasure<?>> createPullsFromGetters(Object object)

Create PullMeasures based on the getters available from an instance, whatever it is. The Class of the instance is analyzed to retrieve its public methods and a PullMeasure is built for each method which use a getter-like signature. The name of the method is further exploited to identify the measure, such that the map returned use the name of the method (without "get") as a key which maps to the PullMeasure built from this method. The PullMeasure itself is named by using the name of the method.

Parameters:

object - the Object to cover

Returns:

the Map which contains the names of the getter methods and the corresponding PullMeasure built from them

createPullsFromFields

public Map<String,PullMeasure<?>> createPullsFromFields(Object object)

Create PullMeasures based on the fields available from an instance, whatever it is. The Class of the instance is analyzed to retrieve its public fields and a PullMeasure is built for each of them. The name of the field is further exploited to identify the measure, such that the map returned use the name of the field as a key which maps to the PullMeasure built from this field. The PullMeasure itself is named by using the name of the field.

Parameters:

object - the Object to cover

Returns:

the Map which contains the names of the getter methods and the corresponding PullMeasure built from them