Package ch.hevs.cloudio.endpoint

Class CloudioAttribute<T>

java.lang.Object

ch.hevs.cloudio.endpoint.CloudioAttribute<T>

Type Parameters:

T - Data type of the attribute, must be one of the supported data types!

public class CloudioAttribute<T>
extends java.lang.Object

The leafs of a cloud.io data model consists of attributes. Attributes carry the actual information (not the structure) of a data model.

cloud.io supports multiple data types for attributes:

• Boolean
• Integers (Short, Integer, Long)
• Numbers (Float, Double)
• String

Example:

 class Switch extends ch.hevs.cloudio.endpoint.CloudioObject {
    @SetPoint
     public CloudioAttribute<boolean> state;

    @Status
     public CloudioAttribute<boolean> stateFeedback;
 }
 

Attributes are annotated with one of these constraints:

• Parameter
• Status
• SetPoint
• Measure

If the attribute does not have a constraint annotation, the object containing the attribute will throw a runtime exception, so ensure that every attribute has a constraint annotation. Attributes with a StaticAttribute annotation does not have to be of type Attribute, use rather native types for static attributes.

Method Summary

Modifier and Type	Method	Description
void	addListener(CloudioAttributeListener listener)	Adds the given listener to the list of listeners that will get informed about a change of the attribute.
java.lang.reflect.Type	getType()	Returns the actual type of the attribute.
T	getValue()	Returns the current value of the attribute.
void	removeListener(CloudioAttributeListener listener)	Removes the given listener from the list of listeners.
void	setInitialValue(T initialValue)	Tries to initialize the attribute with the given value.
void	setStringValue(java.lang.String value)	Tries to parse according to the type of the attribute the given string and sets the attribute's value to the result of the parsing process.
void	setStringValue(java.lang.String value, long timestamp)	Tries to parse according to the type of the attribute the given string and sets the attribute's value to the result of the parsing process.
void	setValue(T value)	Tries to change the attribute to the given value.
void	setValue(T value, java.lang.Long timestamp)	Tries to change the attribute to the given value and attributes the given timestamp to the new value.

Methods inherited from class java.lang.Object

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

Method Detail

getValue

public T getValue()

Returns the current value of the attribute.

Returns:

Attributes current value.

setValue

public void setValue(T value)
              throws CloudioAttributeConstraintException

Tries to change the attribute to the given value. This might fail if the attribute constraint is not suitable to change the value from the endpoint.

Parameters:

value - The new value for the attribute.

Throws:

CloudioAttributeConstraintException - If the endpoint can not change the attribute.

setValue

public void setValue(T value,
                     java.lang.Long timestamp)
              throws CloudioAttributeConstraintException

Tries to change the attribute to the given value and attributes the given timestamp to the new value. This might fail if the attribute constraint is not suitable to change the value from the endpoint.

Parameters:

value - The new value for the attribute.

timestamp - The timestamp in milliseconds since epoch to link with the new value.

Throws:

CloudioAttributeConstraintException - If the endpoint can not change the attribute.

setInitialValue

public void setInitialValue(T initialValue)
                     throws CloudioAttributeConstraintException,
                            CloudioAttributeInitializationException

Tries to initialize the attribute with the given value. You can not initialize an attribute with constraints Static and Parameter and you need to initialize the value only once and before the node has gone online. In all other cases, an exception will be thrown.

Parameters:

initialValue - The value to initialize the attribute with.

Throws:

CloudioAttributeConstraintException - If the endpoint can not change the attribute.

CloudioAttributeInitializationException - If the attribute is already initialized or the node is already online.

setStringValue

public void setStringValue(java.lang.String value)
                    throws java.lang.NumberFormatException,
                           CloudioAttributeConstraintException

Tries to parse according to the type of the attribute the given string and sets the attribute's value to the result of the parsing process.

Parameters:

value - String representation of the value to set.

Throws:

java.lang.NumberFormatException - In the case the attribute is a numeric data type and the parse failed.

CloudioAttributeConstraintException - If the endpoint can not change the attribute.

setStringValue

public void setStringValue(java.lang.String value,
                           long timestamp)
                    throws java.lang.NumberFormatException,
                           CloudioAttributeConstraintException

Tries to parse according to the type of the attribute the given string and sets the attribute's value to the result of the parsing process. Additionally this method links the parse result with the given timestamp.

Parameters:

value - String representation of the value to set.

timestamp - The timestamp in milliseconds since epoch to link with the new value.

Throws:

java.lang.NumberFormatException - In the case the attribute is a numeric data type and the parse failed.

CloudioAttributeConstraintException - If the endpoint can not change the attribute.

getType

public java.lang.reflect.Type getType()

Returns the actual type of the attribute.

Returns:

Attribute's type.

addListener

public void addListener(CloudioAttributeListener listener)

Adds the given listener to the list of listeners that will get informed about a change of the attribute.

Parameters:

listener - Reference to the object implementing the CloudioAttributeListener interface to add.

removeListener

public void removeListener(CloudioAttributeListener listener)

Removes the given listener from the list of listeners.

Parameters:

listener - Reference to the object implementing the CloudioAttributeListener interface to remove.