java 结合opc ua遍历所有节点代码

以下是使用Java结合OPC UA遍历所有节点的示例代码：

import java.util.List;
import java.util.concurrent.CompletableFuture;
import org.eclipse.milo.opcua.sdk.client.OpcUaClient;
import org.eclipse.milo.opcua.sdk.client.api.UaNode;
import org.eclipse.milo.opcua.sdk.client.nodes.UaNodeIterable;
import org.eclipse.milo.opcua.stack.core.Identifiers;
import org.eclipse.milo.opcua.stack.core.types.builtin.NodeId;
import org.eclipse.milo.opcua.stack.core.types.enumerated.NodeClass;

public class OPCUANodeTraversal {

    public static void main(String[] args) throws Exception {

        // create OPC UA client
        OpcUaClient client = OpcUaClient.create("opc.tcp://localhost:4840");

        // connect to server
        client.connect().get();

        // get root node
        NodeId rootNodeId = Identifiers.RootFolder;
        UaNode rootNode = client.getAddressSpace().getNode(rootNodeId);

        // traverse nodes recursively
        CompletableFuture<Void> future = traverseNodes(rootNode);

        // wait for traversal to complete
        future.get();

        // disconnect from server
        client.disconnect().get();
    }

    private static CompletableFuture<Void> traverseNodes(UaNode node) {

        // print node information
        System.out.println("Node: " + node.getBrowseName().get().getName());
        System.out.println("Class: " + node.getNodeClass().get().name());

        // get child nodes
        CompletableFuture<List<UaNode>> childrenFuture = node.getFolderElement().get();
        return childrenFuture.thenComposeAsync(children -> {

            // iterate over child nodes
            UaNodeIterable iterable = new UaNodeIterable(children);
            CompletableFuture<Void> traverseFuture = CompletableFuture.completedFuture(null);
            for (UaNode child : iterable) {

                // traverse child node recursively
                if (child.getNodeClass().get() == NodeClass.Object || child.getNodeClass().get() == NodeClass.Variable) {
                    traverseFuture = traverseFuture.thenComposeAsync(v -> traverseNodes(child));
                }
            }
            return traverseFuture;
        });
    }
}

该代码首先连接到OPC UA服务器，然后获取根节点，并使用递归方式遍历所有子节点。对于每个节点，它输出节点名称和节点类别，并检查它是否是对象或变量节点。如果是，它会递归遍历该节点的所有子节点。