Package com.cognite.client

Class Relationships

java.lang.Object

com.cognite.client.Relationships

public abstract class Relationships
extends Object

This class represents the Cognite relationships api endpoint. It provides methods for reading and writing Relationship.

Field Summary

Fields

Modifier and Type	Field	Description
protected static org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor	Description
Relationships()

Method Summary

Modifier and Type	Method	Description
protected Request	addAuthInfo(Request request)	Adds the required authentication information into the request object.
protected Aggregate	aggregate(ResourceType resourceType, Request requestParameters)	Performs an item aggregation request to Cognite Data Fusion.
protected List<String>	buildPartitionsList(int noPartitions)	Builds an array of partition specifications for parallel retrieval from the Cognite api.
protected List<Item>	deDuplicate(Collection<Item> itemList)	De-duplicates a collection of Item.
List<Item>	delete(List<Item> relationships)	Deletes a set of Relationships.
abstract CogniteClient	getClient()
protected Iterator<CompletableFuture<ResponseItems<String>>>	getListResponseIterator(ResourceType resourceType, Request requestParameters)
protected boolean	itemsHaveId(Collection<Item> items)	Returns true if all items contain either an externalId or id.
Iterator<List<Relationship>>	list(Request requestParameters)	Returns all Relationship objects that matches the filters set in the Request.
Iterator<List<Relationship>>	list(Request requestParameters, String... partitions)	Returns all Relationship objects that matches the filters set in the Request for the specified partitions.
protected Iterator<List<String>>	listJson(ResourceType resourceType, Request requestParameters, String... partitions)	Will return the results from a list / filter api endpoint.
protected Iterator<List<String>>	listJson(ResourceType resourceType, Request requestParameters, String partitionKey, String... partitions)	Will return the results from a list / filter api endpoint.
protected Map<String,Item>	mapItemToId(Collection<Item> items)	Maps all items to their externalId (primary) or id (secondary).
static Relationships	of(CogniteClient client)	Constructs a new Relationships object using the provided client configuration.
protected List<Item>	parseItems(List<String> input)	Parses a list of item object in json representation to typed objects.
protected String	parseName(String json)	Returns the name attribute value from a json input.
protected String	parseString(String itemJson, String fieldName)	Try parsing the specified Json path as a String.
List<Relationship>	retrieve(List<Item> items)	Retrieve Relationships by id.
protected List<String>	retrieveJson(ResourceType resourceType, Collection<Item> items)	Retrieve items by id.
protected List<Map<String,Object>>	toRequestItems(Collection<Item> itemList)	Converts a list of Item to a request object structure (that can later be parsed to Json).
List<Relationship>	upsert(List<Relationship> relationships)	Creates or updates a set of Relationship objects.

Methods inherited from class java.lang.Object

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

Field Detail

LOG

protected static final org.slf4j.Logger LOG

Constructor Detail

Relationships

public Relationships()

Method Detail

of

public static Relationships of(CogniteClient client)

Constructs a new Relationships object using the provided client configuration. This method is intended for internal use--SDK clients should always use CogniteClient as the entry point to this class.

Parameters:

client - The CogniteClient to use for configuration settings.

Returns:

the assets api object.

list

public Iterator<List<Relationship>> list(Request requestParameters)
                                  throws Exception

Returns all Relationship objects that matches the filters set in the Request. The results are paged through / iterated over via an Iterator--the entire results set is not buffered in memory, but streamed in "pages" from the Cognite api. If you need to buffer the entire results set, then you have to stream these results into your own data structure. The assets are retrieved using multiple, parallel request streams towards the Cognite api. The number of parallel streams are set in the ClientConfig.

Parameters:

requestParameters - the filters to use for retrieving the assets.

Returns:

an Iterator to page through the results set.

Throws:

Exception

list

public Iterator<List<Relationship>> list(Request requestParameters,
                                         String... partitions)
                                  throws Exception

Returns all Relationship objects that matches the filters set in the Request for the specified partitions. This is method is intended for advanced use cases where you need direct control over the individual partitions. For example, when using the SDK in a distributed computing environment. The results are paged through / iterated over via an Iterator--the entire results set is not buffered in memory, but streamed in "pages" from the Cognite api. If you need to buffer the entire results set, then you have to stream these results into your own data structure.

Parameters:

requestParameters - the filters to use for retrieving the assets.

partitions - the partitions to include.

Returns:

an Iterator to page through the results set.

Throws:

Exception

retrieve

public List<Relationship> retrieve(List<Item> items)
                            throws Exception

Retrieve Relationships by id.

Parameters:

items - The item(s) externalId / id to retrieve.

Returns:

The retrieved relationships.

Throws:

Exception

upsert

public List<Relationship> upsert(List<Relationship> relationships)
                          throws Exception

Creates or updates a set of Relationship objects. If it is a new Relationship object (based on id / externalId, then it will be created. If an Relationship object already exists in Cognite Data Fusion, it will be updated. The update behavior is specified via the update mode in the ClientConfig settings.

Parameters:

relationships - The relationships to upsert.

Returns:

The upserted relationships.

Throws:

Exception

delete

public List<Item> delete(List<Item> relationships)
                  throws Exception

Deletes a set of Relationships. The events to delete are identified via their externalId / id by submitting a list of Item.

Parameters:

relationships - a list of Item representing the events (externalId / id) to be deleted

Returns:

The deleted events via Item

Throws:

Exception

getClient

public abstract CogniteClient getClient()

buildPartitionsList

protected List<String> buildPartitionsList(int noPartitions)

Builds an array of partition specifications for parallel retrieval from the Cognite api. This specification is used as a parameter together with the filter / list endpoints. The number of partitions indicate the number of parallel read streams. Employ one partition specification per read stream.

Parameters:

noPartitions - The total number of partitions

Returns:

a List of partition specifications

listJson

protected Iterator<List<String>> listJson(ResourceType resourceType,
                                          Request requestParameters,
                                          String... partitions)
                                   throws Exception

Will return the results from a list / filter api endpoint. For example, the filter assets endpoint. The results are paged through / iterated over via an Iterator--the entire results set is not buffered in memory, but streamed in "pages" from the Cognite api. If you need to buffer the entire results set, then you have to stream these results into your own data structure. This method support parallel retrieval via a set of partition specifications. The specified partitions will be collected and merged together before being returned via the Iterator.

Parameters:

resourceType - The resource type to query / filter / list. Ex. event, asset, time series.

requestParameters - The query / filter specification. Follows the Cognite api request parameters.

partitions - An optional set of partitions to read via.

Returns:

an Iterator over the results set.

Throws:

Exception

listJson

protected Iterator<List<String>> listJson(ResourceType resourceType,
                                          Request requestParameters,
                                          String partitionKey,
                                          String... partitions)
                                   throws Exception

Will return the results from a list / filter api endpoint. For example, the filter assets endpoint. The results are paged through / iterated over via an Iterator--the entire results set is not buffered in memory, but streamed in "pages" from the Cognite api. If you need to buffer the entire results set, then you have to stream these results into your own data structure. This method support parallel retrieval via a set of partition specifications. The specified partitions will be collected and merged together before being returned via the Iterator.

Parameters:

resourceType - The resource type to query / filter / list. Ex. event, asset, time series.

requestParameters - The query / filter specification. Follows the Cognite api request parameters.

partitionKey - The key to use for the partitions in the read request. For example partition or cursor.

partitions - An optional set of partitions to read via.

Returns:

an Iterator over the results set.

Throws:

Exception

retrieveJson

protected List<String> retrieveJson(ResourceType resourceType,
                                    Collection<Item> items)
                             throws Exception

Retrieve items by id.

Parameters:

resourceType - The item resource type (Event, Asset, etc.) to retrieve.

items - The item(s) externalId / id to retrieve.

Returns:

The items in Json representation.

Throws:

Exception

aggregate

protected Aggregate aggregate(ResourceType resourceType,
                              Request requestParameters)
                       throws Exception

Performs an item aggregation request to Cognite Data Fusion. The default aggregation is a total item count based on the (optional) filters in the request. Some resource types, for example Event, supports multiple types of aggregation.

Parameters:

resourceType - The resource type to perform aggregation of.

requestParameters - The request containing filters.

Returns:

The aggregation result.

Throws:

Exception

See Also:

Cognite API v1 specification

addAuthInfo

protected Request addAuthInfo(Request request)
                       throws Exception

Adds the required authentication information into the request object. If the request object already have complete auth info nothing will be added. The following authentication schemes are supported: 1) API key. When using an api key, this service will look up the corresponding project/tenant to issue requests to.

Parameters:

request - The request to enrich with auth information.

Returns:

The request parameters with auth info added to it.

Throws:

Exception

getListResponseIterator

protected Iterator<CompletableFuture<ResponseItems<String>>> getListResponseIterator(ResourceType resourceType,
                                                                                     Request requestParameters)
                                                                              throws Exception

Throws:

Exception

parseItems

protected List<Item> parseItems(List<String> input)
                         throws Exception

Parses a list of item object in json representation to typed objects.

Parameters:

input - the item list in Json string representation

Returns:

the parsed item objects

Throws:

Exception

toRequestItems

protected List<Map<String,Object>> toRequestItems(Collection<Item> itemList)

Converts a list of Item to a request object structure (that can later be parsed to Json).

Parameters:

itemList - The items to parse.

Returns:

The items in request item object form.

deDuplicate

protected List<Item> deDuplicate(Collection<Item> itemList)

De-duplicates a collection of Item.

Parameters:

itemList -

Returns:

itemsHaveId

protected boolean itemsHaveId(Collection<Item> items)

Returns true if all items contain either an externalId or id.

Parameters:

items -

Returns:

mapItemToId

protected Map<String,Item> mapItemToId(Collection<Item> items)

Maps all items to their externalId (primary) or id (secondary). If the id function does not return any identity, the item will be mapped to the empty string. Via the identity mapping, this function will also perform deduplication of the input items.

Parameters:

items - the items to map to externalId / id.

Returns:

the Map with all items mapped to externalId / id.

parseString

protected String parseString(String itemJson,
                             String fieldName)

Try parsing the specified Json path as a String.

Parameters:

itemJson - The Json string

fieldName - The Json path to parse

Returns:

The Json path as a String.

parseName

protected String parseName(String json)

Returns the name attribute value from a json input.

Parameters:

json - the json to parse

Returns:

The name value