com.microsoft.azure.sdk.iot.device.twin

Class Twin

java.lang.Object

com.microsoft.azure.sdk.iot.device.twin.Twin

public class Twin
extends java.lang.Object

Representation of a single Twin.

The Twin can contain one TwinCollection of Tags, and one TwinCollection of properties.desired.

Each entity in the collections can contain a associated TwinMetadata.

These metadata are provided by the Service and contains information about the last updated date time, and version.

For instance, the following is a valid Twin, represented as initialTwin in the rest API.

     
      {
          "initialTwin": {
              "tags":{
                  "SpeedUnity":"MPH",
                  "$metadata":{
                      "$lastUpdated":"2017-09-21T02:07:44.238Z",
                      "$lastUpdatedVersion":4,
                      "SpeedUnity":{
                          "$lastUpdated":"2017-09-21T02:07:44.238Z",
                          "$lastUpdatedVersion":4
                      }
                  },
                  "$version":4
              },
              "properties":{
                  "desired": {
                      "MaxSpeed":{
                          "Value":500,
                          "NewValue":300
                      },
                      "$metadata":{
                          "$lastUpdated":"2017-09-21T02:07:44.238Z",
                          "$lastUpdatedVersion":4,
                          "MaxSpeed":{
                              "$lastUpdated":"2017-09-21T02:07:44.238Z",
                              "$lastUpdatedVersion":4,
                              "Value":{
                                  "$lastUpdated":"2017-09-21T02:07:44.238Z",
                                  "$lastUpdatedVersion":4
                              },
                              "NewValue":{
                                  "$lastUpdated":"2017-09-21T02:07:44.238Z",
                                  "$lastUpdatedVersion":4
                              }
                          }
                      },
                      "$version":4
                  },
                  "reported": {
                      "MaxSpeed":{
                          "Value":500,
                          "NewValue":300
                      },
                      "$metadata":{
                          "$lastUpdated":"2017-09-21T02:07:44.238Z",
                          "$lastUpdatedVersion":5,
                          "MaxSpeed":{
                              "$lastUpdated":"2017-09-21T02:07:44.238Z",
                              "$lastUpdatedVersion":4,
                              "Value":{
                                  "$lastUpdated":"2017-09-21T02:07:44.238Z",
                                  "$lastUpdatedVersion":5
                              },
                              "NewValue":{
                                  "$lastUpdated":"2017-09-21T02:07:44.238Z",
                                  "$lastUpdatedVersion":4
                              }
                          }
                      },
                      "$version":6
                  }
              }
          }
      }
     
 

See Also:

Understand and use device twins in IoT Hub, Device Twin Api

Constructor Summary

Constructors

Constructor and Description
Twin(TwinCollection desiredProperty, TwinCollection reportedProperty) CONSTRUCTOR

Method Summary

Modifier and Type	Method and Description
static Twin	createFromDesiredPropertyJson(java.lang.String json) Factory
static Twin	createFromPropertiesJson(java.lang.String json) Factory
static Twin	createFromReportedPropertyJson(java.lang.String json) Factory
static Twin	createFromTwinJson(java.lang.String json) Factory
TwinCollection	getDesiredProperties() Getter for the desired property.
TwinCollection	getReportedProperties() Getter for the reported property.
com.google.gson.JsonElement	toJsonElement() Serializer
java.lang.String	toString() Creates a pretty print JSON with the content of this class and subclasses.

Methods inherited from class java.lang.Object

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

Constructor Detail

Twin

public Twin(TwinCollection desiredProperty,
            TwinCollection reportedProperty)

CONSTRUCTOR

This constructor creates an instance of the Twin with the provided TwinCollection tags and desired properties.

When serialized, this class will looks like the following example:

     
          "initialTwin": {
              "tags":{
                  "SpeedUnity":"MPH",
                  "$version":4
              }
              "properties":{
                  "desired":{
                      "MaxSpeed":{
                          "Value":500,
                          "NewValue":300
                      },
                      "$version":4
                  }
              }
          }
      
     }
 

Parameters:

desiredProperty - the TwinCollection with the desired properties. It can be null.

reportedProperty - the TwinCollection with the reported properties. It can be null.

Method Detail

toJsonElement

public com.google.gson.JsonElement toJsonElement()

Serializer

Creates a JsonElement, which the content represents the information in this class and its subclasses in a JSON format. This is useful if the caller will integrate this JSON with JSON from other classes to generate a consolidated JSON.

Returns:

The JsonElement with the content of this class.

getDesiredProperties

public TwinCollection getDesiredProperties()

Getter for the desired property.

Returns:

The TwinCollection with the desired property content. It can be null.

getReportedProperties

public TwinCollection getReportedProperties()

Getter for the reported property.

Returns:

The TwinCollection with the reported property content. It can be null.

toString

public java.lang.String toString()

Creates a pretty print JSON with the content of this class and subclasses.

Overrides:

toString in class java.lang.Object

Returns:

The String with the pretty print JSON.

createFromTwinJson

public static Twin createFromTwinJson(java.lang.String json)

Factory

Create a new instance of the Twin parsing the provided string as a JSON with the full Twin information.

Parameters:

json - the String with the JSON received from the service. It cannot be null or empty.

Returns:

The new instance of the Twin.

createFromDesiredPropertyJson

public static Twin createFromDesiredPropertyJson(java.lang.String json)

Factory

Create a new instance of the Twin parsing the provided string as a JSON with only desired properties information.

Parameters:

json - the String with the JSON received from the service. It cannot be null or empty.

Returns:

The new instance of the Twin.

createFromReportedPropertyJson

public static Twin createFromReportedPropertyJson(java.lang.String json)

Factory

Create a new instance of the Twin parsing the provided string as a JSON with only reported properties information.

Parameters:

json - the String with the JSON received from the service. It cannot be null or empty.

Returns:

The new instance of the Twin.

createFromPropertiesJson

public static Twin createFromPropertiesJson(java.lang.String json)

Factory

Create a new instance of the Twin parsing the provided string as a JSON with only desired properties information.

Parameters:

json - the String with the JSON received from the service. It cannot be null or empty.

Returns:

The new instance of the Twin.