org.eclipse.milo.opcua.sdk.client.BrowseHelper Maven / Gradle / Ivy
/*
* Copyright (c) 2019 the Eclipse Milo Authors
*
* This program and the accompanying materials are made
* available under the terms of the Eclipse Public License 2.0
* which is available at https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*/
package org.eclipse.milo.opcua.sdk.client;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import org.eclipse.milo.opcua.stack.client.UaStackClient;
import org.eclipse.milo.opcua.stack.core.types.builtin.ByteString;
import org.eclipse.milo.opcua.stack.core.types.builtin.DateTime;
import org.eclipse.milo.opcua.stack.core.types.builtin.NodeId;
import org.eclipse.milo.opcua.stack.core.types.structured.BrowseDescription;
import org.eclipse.milo.opcua.stack.core.types.structured.BrowseNextRequest;
import org.eclipse.milo.opcua.stack.core.types.structured.BrowseNextResponse;
import org.eclipse.milo.opcua.stack.core.types.structured.BrowseRequest;
import org.eclipse.milo.opcua.stack.core.types.structured.BrowseResponse;
import org.eclipse.milo.opcua.stack.core.types.structured.BrowseResult;
import org.eclipse.milo.opcua.stack.core.types.structured.ReferenceDescription;
import org.eclipse.milo.opcua.stack.core.types.structured.ViewDescription;
import static org.eclipse.milo.opcua.stack.core.types.builtin.unsigned.Unsigned.uint;
import static org.eclipse.milo.opcua.stack.core.util.ConversionUtil.l;
/**
* "Helper" functions for doing a Browse followed by as many BrowseNext calls as are necessary
* to retrieve all the references.
*/
public class BrowseHelper {
private BrowseHelper() {}
public static CompletableFuture> browse(
OpcUaClient client,
BrowseDescription browseDescription
) {
return client.getSession().thenCompose(
session ->
browse(client.getStackClient(), session, browseDescription)
);
}
public static CompletableFuture> browse(
UaStackClient client,
OpcUaSession session,
BrowseDescription browseDescription
) {
BrowseRequest browseRequest = new BrowseRequest(
client.newRequestHeader(
session.getAuthenticationToken(),
client.getConfig().getRequestTimeout()
),
new ViewDescription(
NodeId.NULL_VALUE,
DateTime.MIN_VALUE,
uint(0)
),
uint(0),
new BrowseDescription[]{browseDescription}
);
return client.sendRequest(browseRequest).thenApply(BrowseResponse.class::cast).thenCompose(response -> {
BrowseResult result = response.getResults()[0];
List references =
Collections.synchronizedList(new ArrayList<>());
return maybeBrowseNext(client, session, references, result);
});
}
private static CompletableFuture> maybeBrowseNext(
UaStackClient client,
OpcUaSession session,
List references,
BrowseResult result
) {
if (result.getStatusCode().isGood()) {
references.addAll(l(result.getReferences()));
ByteString nextContinuationPoint = result.getContinuationPoint();
if (nextContinuationPoint == null || nextContinuationPoint.isNull()) {
return CompletableFuture.completedFuture(references);
} else {
return browseNext(client, session, nextContinuationPoint, references);
}
} else {
return CompletableFuture.completedFuture(references);
}
}
private static CompletableFuture> browseNext(
UaStackClient client,
OpcUaSession session,
ByteString continuationPoint,
List references
) {
BrowseNextRequest browseNextRequest = new BrowseNextRequest(
client.newRequestHeader(
session.getAuthenticationToken(),
client.getConfig().getRequestTimeout()
),
false,
new ByteString[]{continuationPoint}
);
return client.sendRequest(browseNextRequest).thenApply(BrowseNextResponse.class::cast).thenCompose(response -> {
BrowseResult result = response.getResults()[0];
return maybeBrowseNext(client, session, references, result);
});
}
}