TwinCollection Class
- java.
lang. Object - java.
util. AbstractMap - java.
util. HashMap - com.
microsoft. azure. sdk. iot. deps. twin. TwinCollection
- com.
- java.
- java.
public class TwinCollection
extends java.util.HashMap<java.lang.String,java.lang.Object>
Representation of a single Twin collection.
The TwinCollection is an extension of a HashMap of String and Object that contain individual and general versioning mechanism.
By the Twin definition, the Object can contain types of Boolean, Number, String, Object, or a sub-TwinCollection, but it cannot be types defined by the user or arrays.
A TwinCollection can contain up to 5 levels of sub TwinCollections. Once the TwinCollection is a extension of the HashMap, both TwinCollection as well as its sub-TwinCollections can be casted to Map of String and Object.
The collection will be represented in the rest API as a JSON in the body. It can or cannot contain the metadata (identified by the $ character at the beginning of the key.
Because of the Twin metadata, the character $ is not allowed in the entry key.
For instance, the following JSON is a valid TwinCollection with its metadata.
{
"Color":"White",
"MaxSpeed":{
"Value":500,
"NewValue":300
},
"$metadata":{
"$lastUpdated":"2017-09-21T02:07:44.238Z",
"$lastUpdatedVersion":4,
"Color":{
"$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
}
This class exposes the Twin collection with or without metadata as a Map here user can gat both the value and the metadata. For instance, in the above TwinCollection, #get(Object) for Color will return White and the getTwinMetadataFinal(String key) for Color will return the Object TwinMetadata that contain getLastUpdated() that will returns the Date 2017-09-21T02:07:44.238Z and getLastUpdatedVersion() that will returns the Integer 4.
For the nested TwinCollection, you can do the same, for instance, the following code will return the value and metadata of the NewValue nested in MaxSpeed:
// Get the value of the MaxSpeed, which is a inner TwinCollection.
TwinCollection innerMaxSpeed = (TwinCollection) twinCollection.get("MaxSpeed");
// From the inner TwinCollection, get the value of the NewValue.
Long maxSpeedNewValue = innerMaxSpeed.get("NewValue");
// As in the root TwinCollection, the inner TwinCollection contain its own metadata.
// So, get the metadata information for the inner NewValue.
TwinMetadata maxSpeedNewValueMetadata = innerMaxSpeed.getTwinMetadataFinal("NewValue");
Date newValueLastUpdated = maxSpeedNewValueMetadata.getLastUpdated(); //Shall contain `2017-09-21T02:07:44.238Z`
Integer newValueLastUpdatedVersion = maxSpeedNewValueMetadata.getLastUpdatedVersion(); //Shall contain `4`
Constructor Summary
| Constructor | Description |
|---|---|
| TwinCollection() |
Constructor |
| TwinCollection(TwinCollection collection) |
Constructor |
| TwinCollection(Map<? extends String,Object> map) |
Constructor |
Method Summary
| Modifier and Type | Method and Description |
|---|---|
|
protected static
Twin |
createFromRawCollection(Map<? extends String,Object> rawCollection)
Internal Constructor from raw map. |
|
Twin |
getTwinMetadata()
Deprecated
as of Deps version 0.7.1, please use getTwinMetadataFinal()
Getter for the Twin |
|
Twin |
getTwinMetadata(String key)
Deprecated
as of Deps version 0.7.1, please use getTwinMetadataFinal(String key)
Getter for the entry metadata in the Twin |
|
final
Twin |
getTwinMetadataFinal()
Getter for the Twin |
|
final
Twin |
getTwinMetadataFinal(String key)
Getter for the entry metadata in the Twin |
| java.lang.Integer |
getVersion()
Deprecated
as of Deps version 0.7.1, please use getVersionFinal()
Getter for the version. |
| final java.lang.Integer |
getVersionFinal()
Getter for the version. |
| java.lang.Object |
put(String key, Object value)
Deprecated
as of Deps version 0.7.1, please use putFinal(String key, Object value)
Add a single new entry in the Twin |
| void |
putAll(Map<? extends String,?> map)
Deprecated
as of Deps version 0.7.1, please use putAllFinal(Map<? extends String,?> map)
Add all information in the provided Map to the Twin |
| final void |
putAllFinal(Map<? extends String,?> map)
Add all information in the provided Map to the Twin |
| final java.lang.Object |
putFinal(String key, Object value)
Add a single new entry in the Twin |
| com.google.gson.JsonElement |
toJsonElement()
Serializer |
| protected com.google.gson.JsonElement |
toJsonElementWithMetadata()
Serializer with metadata. |
| java.lang.String |
toString()
Creates a pretty print JSON with the content of this class and subclasses. |
Methods inherited from java.lang.Object
Methods inherited from java.util.AbstractMap
Methods inherited from java.util.HashMap
Constructor Details
TwinCollection
public TwinCollection()
Constructor
Creates an empty collection. Fill it with putFinal(String key, Object value) or putAllFinal(Map<? extends String,?> map).
TwinCollection
public TwinCollection(TwinCollection collection)
Constructor
Creates a new Twin collection coping the provided collection.
Parameters:
? extends String and Object with the Twin collection
TwinCollection
public TwinCollection(Map map)
Constructor
Creates a new Twin collection coping the provided Map.
Parameters:
? extends String and Object with the Twin collection
Method Details
createFromRawCollection
protected static TwinCollection createFromRawCollection(Map rawCollection)
Internal Constructor from raw map.
This internal constructor is used to the deserialization process.
During the deserialization process, the GSON will convert both tags and properties to a raw Map, which will includes the $version and $metadata as part of the collection. So, we need to reorganize this map using the TwinCollection format. This constructor will do that.
For instance, the following JSON is a valid TwinCollection with its metadata.
{
"Color":"White",
"MaxSpeed":{
"Value":500,
"NewValue":300
},
"$metadata":{
"$lastUpdated":"2017-09-21T02:07:44.238Z",
"$lastUpdatedVersion":4,
"Color":{
"$lastUpdated":"2017-09-21T02:07:44.238Z",
"$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
}
Parameters:
Map<? extends String, Object> with contain all TwinCollection information, without
any differentiation between each entity is the Twin information and each entity is part
of the Twin metadata.
Returns:
getTwinMetadata
public TwinMetadata getTwinMetadata()
Deprecated
Getter for the TwinCollection metadata
Returns:
null.getTwinMetadata
public TwinMetadata getTwinMetadata(String key)
Deprecated
Getter for the entry metadata in the TwinCollection.
Parameters:
String with the name of the entry to retrieve the metadata.
Returns:
null.getTwinMetadataFinal
public final TwinMetadata getTwinMetadataFinal()
Getter for the TwinCollection metadata
Returns:
null.getTwinMetadataFinal
public final TwinMetadata getTwinMetadataFinal(String key)
Getter for the entry metadata in the TwinCollection.
Parameters:
String with the name of the entry to retrieve the metadata.
Returns:
null.getVersion
public Integer getVersion()
Deprecated
Getter for the version.
Returns:
Integer with the version content. It can be null.getVersionFinal
public final Integer getVersionFinal()
Getter for the version.
Returns:
Integer with the version content. It can be null.put
public Object put(String key, Object value)
Deprecated
Add a single new entry in the TwinCollection.
Override HashMap.put(String, Object).
This function will add a single pair key value to the TwinCollection. By the Twin definition, the Object can contain types of Boolean, Number, String, Object, or up to 5 levels of sub-TwinCollection, but it cannot be types defined by the user or arrays.
Overrides:
TwinCollection.put(String key, Object value)Parameters:
String that represent the key of the new entry. It cannot be {#code null} or empty.
Object that represents the value of the new entry. It cannot be user defined type or array.
Returns:
Object that correspond to the last value of this key. It will be null if there is no previous value.putAll
public void putAll(Map map)
Deprecated
Add all information in the provided Map to the TwinCollection.
Override HashMap.putAll(Map).
This function will add all entries in the Map to the TwinCollection. If the provided key already exists, it will replace the value by the new one. This function will not delete or change the content of the other keys in the Map.
As defined by the Twin, the value of a entry can be an inner Map. TwinCollection will accept up to 5 levels of inner Maps.
Overrides:
TwinCollection.putAll(Map<? extends String,?> map)Parameters:
Map of entries to add to the TwinCollection.
putAllFinal
public final void putAllFinal(Map map)
Add all information in the provided Map to the TwinCollection.
This function will add all entries in the Map to the TwinCollection. If the provided key already exists, it will replace the value by the new one. This function will not delete or change the content of the other keys in the Map.
As defined by the Twin, the value of a entry can be an inner Map. TwinCollection will accept up to 5 levels of inner Maps.
Parameters:
Map of entries to add to the TwinCollection.
putFinal
public final Object putFinal(String key, Object value)
Add a single new entry in the TwinCollection.
This function will add a single pair key value to the TwinCollection. By the Twin definition, the Object can contain types of Boolean, Number, String, Object, or up to 5 levels of sub-TwinCollection, but it cannot be types defined by the user or arrays.
Parameters:
String that represent the key of the new entry. It cannot be {#code null} or empty.
Object that represents the value of the new entry. It cannot be user defined type or array.
Returns:
Object that correspond to the last value of this key. It will be null if there is no previous value.toJsonElement
public 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:
JsonElement with the content of this class.toJsonElementWithMetadata
protected JsonElement toJsonElementWithMetadata()
Serializer with metadata.
Return a JsonElement with the full content of this class, including the metadata.
Returns:
JsonElement with the full content of this class.toString
public String toString()
Creates a pretty print JSON with the content of this class and subclasses.
Overrides:
TwinCollection.toString()Returns:
String with the pretty print JSON.Applies to
Azure SDK for Java
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