Java 使用 OPC UA的步骤详解

<dependency>
    <groupId>org.eclipse.milo</groupId>
    <artifactId>sdk-client</artifactId>
    <version>0.6.7</version>
</dependency>

implementation 'org.eclipse.milo:sdk-client:0.6.7'

import org.eclipse.milo.opcua.sdk.client.OpcUaClient;
import org.eclipse.milo.opcua.stack.core.types.builtin.unsigned.Unsigned;
import org.eclipse.milo.opcua.stack.core.types.structured.EndpointDescription;
import org.eclipse.milo.opcua.stack.core.types.structured.EndpointDescriptionArray;
import org.eclipse.milo.opcua.stack.core.util.EndpointUtil;
import java.util.concurrent.CompletableFuture;
public class OpcUaClientExample {
    public static void main(String[] args) throws Exception {
        String endpointUrl = "opc.tcp://localhost:4840";  // 替换为你的OPC UA服务器地址
        // 找到服务器的端点
        EndpointDescription[] endpoints = OpcUaClient.getEndpoints(endpointUrl).get();
        // 选择合适的端点
        EndpointDescription endpoint = EndpointUtil.select(endpoints, "None", "None").orElseThrow(() ->
                new Exception("没有找到合适的端点"));
        // 创建客户端
        OpcUaClient client = OpcUaClient.create(endpoint);
        // 连接到服务器
        CompletableFuture<Void> future = client.connect();
        future.whenComplete((result, ex) -> {
            if (ex != null) {
                ex.printStackTrace();
            } else {
                System.out.println("连接成功!");
                // 在此添加你的业务逻辑
            }
        });
        future.get(); // 等待连接完成
    }
}

import org.eclipse.milo.opcua.sdk.client.OpcUaClient;
import org.eclipse.milo.opcua.stack.core.types.builtin.DataValue;
import org.eclipse.milo.opcua.stack.core.types.builtin.NodeId;
import org.eclipse.milo.opcua.stack.core.types.builtin.Variant;
import java.util.concurrent.CompletableFuture;
public class ReadWriteExample {
    public static void main(String[] args) throws Exception {
        OpcUaClient client = OpcUaClient.create("opc.tcp://localhost:4840").get();
        client.connect().get();
        NodeId nodeId = new NodeId(2, "MyVariable");
        // 读取变量值
        CompletableFuture<DataValue> readFuture = client.readValue(0, null, nodeId);
        DataValue value = readFuture.get();
        System.out.println("读取到的值: " + value.getValue().getValue());
        // 写入变量值
        Variant variant = new Variant(42); // 替换为你要写入的值
        DataValue newValue = new DataValue(variant);
        CompletableFuture<Void> writeFuture = client.writeValue(nodeId, newValue);
        writeFuture.get();
        System.out.println("值已写入");
    }
}