org.eclipse.milo.opcua.sdk.client.api.services

Interface QueryServices

public interface QueryServices

Method Summary

Modifier and Type	Method and Description
CompletableFuture<org.eclipse.milo.opcua.stack.core.types.structured.QueryFirstResponse>	queryFirst(org.eclipse.milo.opcua.stack.core.types.structured.ViewDescription view, List<org.eclipse.milo.opcua.stack.core.types.structured.NodeTypeDescription> nodeTypes, org.eclipse.milo.opcua.stack.core.types.structured.ContentFilter filter, org.eclipse.milo.opcua.stack.core.types.builtin.unsigned.UInteger maxDataSetsToReturn, org.eclipse.milo.opcua.stack.core.types.builtin.unsigned.UInteger maxReferencesToReturn) This service is used to issue a query to the server.
CompletableFuture<org.eclipse.milo.opcua.stack.core.types.structured.QueryNextResponse>	queryNext(boolean releaseContinuationPoint, org.eclipse.milo.opcua.stack.core.types.builtin.ByteString continuationPoint) This Service is used to request the next set of QueryFirst or QueryNext response information that is too large to be sent in a single response.

Method Detail

queryFirst

CompletableFuture<org.eclipse.milo.opcua.stack.core.types.structured.QueryFirstResponse> queryFirst(org.eclipse.milo.opcua.stack.core.types.structured.ViewDescription view,
                                                                                                    List<org.eclipse.milo.opcua.stack.core.types.structured.NodeTypeDescription> nodeTypes,
                                                                                                    org.eclipse.milo.opcua.stack.core.types.structured.ContentFilter filter,
                                                                                                    org.eclipse.milo.opcua.stack.core.types.builtin.unsigned.UInteger maxDataSetsToReturn,
                                                                                                    org.eclipse.milo.opcua.stack.core.types.builtin.unsigned.UInteger maxReferencesToReturn)

This service is used to issue a query to the server.

Parameters:

view - specifies a View and temporal context to a server.

nodeTypes - the NodeTypeDescription.

filter - the ContentFilter. Resulting Nodes shall be limited to the Nodes matching the criteria defined by the filter.

maxDataSetsToReturn - the number of QueryDataSets that the client wants the server to return in the response and on each subsequent continuation call response. The server is allowed to further limit the response, but shall not exceed this limit. A value of 0 indicates that the client is imposing no limitation.

maxReferencesToReturn - the number of References that the client wants the server to return in the response for each QueryDataSet and on each subsequent continuation call response. The server is allowed to further limit the response, but shall not exceed this limit. A value of 0 indicates that the client is imposing no limitation.

Returns:

a CompletableFuture containing the QueryFirstResponse.

queryNext

CompletableFuture<org.eclipse.milo.opcua.stack.core.types.structured.QueryNextResponse> queryNext(boolean releaseContinuationPoint,
                                                                                                  org.eclipse.milo.opcua.stack.core.types.builtin.ByteString continuationPoint)

This Service is used to request the next set of QueryFirst or QueryNext response information that is too large to be sent in a single response.

Parameters:

releaseContinuationPoint - if true, passed continuationPoints shall be reset to free resources in the server. If false, passed continuationPoints shall be used to get the next set of browse information.

continuationPoint - a server-defined opaque value that represents the continuation point.

Returns:

a CompletableFuture containing the QueryNextResponse.