core

Class ModuleCommunicationBus

java.lang.Object

core.ModuleCommunicationBus

public class ModuleCommunicationBus
extends java.lang.Object

Intermodule communication bus. Works as a blackboard where modules can post data, subscribe to data changes and also poll for data values. This is fairly similar to Message class' property interface, but these values are shared for a node instead of message.

Constructor Summary

Constructors

Constructor and Description
ModuleCommunicationBus() Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	addProperty(java.lang.String key, java.lang.Object value) Adds a new property for this node.
boolean	containsProperty(java.lang.String key) Returns true if the bus contains a value for the given key
double	getDouble(java.lang.String key, double naValue) Returns a double value from the communication bus.
int	getInt(java.lang.String key, int naValue) Returns an integer value from the communication bus.
java.lang.Object	getProperty(java.lang.String key) Returns an object that was stored using the given key.
void	subscribe(java.lang.String key, ModuleCommunicationListener module) Subscribes a module to changes of a certain value.
java.lang.String	toString()
void	unsubscribe(java.lang.String key, ModuleCommunicationListener module) Removes a notification subscription
double	updateDouble(java.lang.String key, double delta) Changes the Double value with given key with the value delta
void	updateProperty(java.lang.String key, java.lang.Object value) Updates a value for an existing property.

Methods inherited from class java.lang.Object

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

Constructor Detail

ModuleCommunicationBus

public ModuleCommunicationBus()

Constructor.

Method Detail

addProperty

public void addProperty(java.lang.String key,
               java.lang.Object value)
                 throws SimError

Adds a new property for this node. The key can be any string but it should be such that no other class accidently uses the same value. Note that, unless the value is immutable, it can be changed by any object that can call getProperty(java.lang.String).

Parameters:

key - The key which is used to lookup the value

value - The value to store

Throws:

SimError - if there is already a value for the given key

getProperty

public java.lang.Object getProperty(java.lang.String key)

Returns an object that was stored using the given key. If such object is not found, null is returned.

Parameters:

key - The key used to lookup the object

Returns:

The stored object or null if it isn't found

containsProperty

public boolean containsProperty(java.lang.String key)

Returns true if the bus contains a value for the given key

Parameters:

key - The key for which a value's existence is checked

Returns:

true if the value exists, false if not

updateProperty

public void updateProperty(java.lang.String key,
                  java.lang.Object value)
                    throws SimError

Updates a value for an existing property. For storing the value first time, addProperty(String, Object) should be used which checks for name space clashes.

Parameters:

key - The key which is used to lookup the value

value - The new value to store

Throws:

SimError

updateDouble

public double updateDouble(java.lang.String key,
                  double delta)
                    throws SimError

Changes the Double value with given key with the value delta

Parameters:

key - The key of variable to update

delta - Value added to the old value

Returns:

The new value

Throws:

SimError - if the value with the given key was not a Double

getDouble

public double getDouble(java.lang.String key,
               double naValue)
                 throws SimError

Returns a double value from the communication bus.

Parameters:

key - The key of the variable

naValue - The value to return if there is no value for the key

Returns:

The value of the key, or the naValue if they key was not found

Throws:

SimError - if the value with the given key was not a Double

getInt

public int getInt(java.lang.String key,
         int naValue)
           throws SimError

Returns an integer value from the communication bus.

Parameters:

key - The key of the variable

naValue - The value to return if there is no value for the key

Returns:

The value of the key, or the naValue if they key was not found

Throws:

SimError - if the value with the given key was not an Integer

subscribe

public void subscribe(java.lang.String key,
             ModuleCommunicationListener module)

Subscribes a module to changes of a certain value.

Parameters:

key - The key of the value whose changes the module is interested of

module - The module to subscribe.

unsubscribe

public void unsubscribe(java.lang.String key,
               ModuleCommunicationListener module)

Removes a notification subscription

Parameters:

key - The key for which the subscription should be removed

module - The module to whose subscription is removed

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object