<dependency>
    <groupId>org.eclipse.milo</groupId>
    <artifactId>sdk-client</artifactId>
    <version>0.6.15</version> 
    <!-- 版本號(hào)可根據(jù)需要更新 -->
</dependency>
<dependency>
         <groupId>org.eclipse.milo</groupId>
         <artifactId>server-examples</artifactId>
         <version>0.6.15</version> 
     </dependency>

implementation 'org.eclipse.milo:sdk-client:0.6.15'

import org.eclipse.milo.opcua.sdk.client.OpcUaClient;
import org.eclipse.milo.opcua.stack.core.security.SecurityPolicy;
import org.eclipse.milo.opcua.sdk.client.api.config.OpcUaClientConfigBuilder;
import org.eclipse.milo.opcua.stack.core.types.structured.EndpointDescription;
import org.eclipse.milo.opcua.stack.core.types.structured.UserTokenPolicy;
import org.eclipse.milo.opcua.stack.core.types.enumerated.UserTokenType;
import org.eclipse.milo.opcua.sdk.client.api.identity.AnonymousProvider;
import java.util.List;
import java.util.concurrent.CompletableFuture;
public class OpcUaAnonymousExample {
    public static void main(String[] args) {
        try {
            // OPC UA 服務(wù)器地址，例如 "opc.tcp://localhost:49320"
            String url= "opc.tcp://127.0.0.1:49320";
            // 創(chuàng)建 client
                OpcUaClient client = OpcUaClient.create(url,
                        endpoints ->
                                endpoints.stream()
                                        .filter(e -> e.getSecurityPolicyUri().equals(SecurityPolicy.None.getUri()))
                                        .findFirst(),
                        configBuilder ->
                                configBuilder
                                        //訪問(wèn)方式
                                        .setIdentityProvider(new AnonymousProvider())
                                        .setRequestTimeout(UInteger.valueOf(5000))
                                        .build());
            }
            // 連接到服務(wù)器
            CompletableFuture<OpcUaClient> future = client.connect();
            future.get(); // 等待連接完成
            System.out.println("匿名連接成功！");
            // 在此處可以進(jìn)行讀寫(xiě)操作，例如讀取節(jié)點(diǎn)的值
            // client.readValue(0, TimestampsToReturn.Both, new ReadValueId(NodeId, ...));
            // ...
            // 最后斷開(kāi)連接
            client.disconnect().get();
            System.out.println("客戶端斷開(kāi)連接。");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    // 簡(jiǎn)單選擇一個(gè)安全策略為 None 的端點(diǎn)（匿名方式一般使用安全策略None，具體看服務(wù)器配置）
    private static EndpointDescription chooseSecureEndpoint(List<EndpointDescription> endpoints) {
        EndpointDescription result = null;
        for (EndpointDescription e : endpoints) {
            if (e.getSecurityPolicyUri().equals(SecurityPolicy.None.getUri())) {
                result = e;
                break;
            }
        }
        return result;
    }
}

import org.eclipse.milo.opcua.sdk.client.OpcUaClient;
import org.eclipse.milo.opcua.stack.core.security.SecurityPolicy;
import org.eclipse.milo.opcua.sdk.client.api.config.OpcUaClientConfigBuilder;
import org.eclipse.milo.opcua.stack.core.types.structured.EndpointDescription;
import org.eclipse.milo.opcua.stack.core.types.structured.UserTokenPolicy;
import org.eclipse.milo.opcua.stack.core.types.enumerated.UserTokenType;
import org.eclipse.milo.opcua.sdk.client.api.identity.UsernameProvider;
import java.util.List;
import java.util.concurrent.CompletableFuture;
public class OpcUaUsernamePasswordExample {
    public static void main(String[] args) {
        try {
            String endpointUrl = "opc.tcp://127.0.0.1:4840";
            List<EndpointDescription> endpoints = OpcUaClient
                    .getEndpoints(endpointUrl).get();
            EndpointDescription endpoint = chooseUserNameEndpoint(endpoints);
            OpcUaClientConfigBuilder configBuilder = new OpcUaClientConfigBuilder();
            configBuilder.setEndpoint(endpoint);
            // 假設(shè)用戶名為 "user", 密碼為 "password"
            configBuilder.setIdentityProvider(new UsernameProvider("user", "password"));
            OpcUaClient client = OpcUaClient.create(configBuilder.build());
            CompletableFuture<OpcUaClient> future = client.connect();
            future.get();
            System.out.println("用戶名密碼方式連接成功！");
            // 進(jìn)行后續(xù)讀寫(xiě)操作
            // ...
            client.disconnect().get();
            System.out.println("客戶端斷開(kāi)連接。");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    private static EndpointDescription chooseUserNameEndpoint(List<EndpointDescription> endpoints) {
        // 通常 OPC UA 服務(wù)器也支持 SecurityPolicy.None + UserName 方式
        // 也可能是 Basic128Rsa15, Basic256, etc. 具體看服務(wù)端配置
        for (EndpointDescription e : endpoints) {
            if (e.getSecurityPolicyUri().equals(SecurityPolicy.None.getUri())) {
                // 確保端點(diǎn)支持 UserName 類型的認(rèn)證
                for (UserTokenPolicy tokenPolicy : e.getUserIdentityTokens()) {
                    if (tokenPolicy.getTokenType() == UserTokenType.UserName) {
                        return e;
                    }
                }
            }
        }
        return null;
    }
}

import org.eclipse.milo.opcua.sdk.server.util.HostnameUtil;
import org.eclipse.milo.opcua.stack.core.util.SelfSignedCertificateBuilder;
import org.eclipse.milo.opcua.stack.core.util.SelfSignedCertificateGenerator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.security.*;
import java.security.cert.X509Certificate;
import java.util.regex.Pattern;
class KeyStoreLoader {
    private final Logger logger = LoggerFactory.getLogger(getClass());
    private static final Pattern IP_ADDR_PATTERN = Pattern.compile(
        "^(([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\.){3}([01]?\\d\\d?|2[0-4]\\d|25[0-5])$");
    // 證書(shū)別名
    private static final String CLIENT_ALIAS = "client-ai";
    // 獲取私鑰的密碼
    private static final char[] PASSWORD = "password".toCharArray();
    // 證書(shū)對(duì)象
    private X509Certificate clientCertificate;
    // 密鑰對(duì)對(duì)象
    private KeyPair clientKeyPair;
    KeyStoreLoader load(Path baseDir) throws Exception {
        // 創(chuàng)建一個(gè)使用`PKCS12`加密標(biāo)準(zhǔn)的KeyStore。KeyStore在后面將作為讀取和生成證書(shū)的對(duì)象。
        KeyStore keyStore = KeyStore.getInstance("PKCS12");
        // PKCS12的加密標(biāo)準(zhǔn)的文件后綴是.pfx，其中包含了公鑰和私鑰。
        // 而其他如.der等的格式只包含公鑰，私鑰在另外的文件中。
        Path serverKeyStore = baseDir.resolve("example-client.pfx");
        logger.info("Loading KeyStore at {}", serverKeyStore);
        // 如果文件不存在則創(chuàng)建.pfx證書(shū)文件。
        if (!Files.exists(serverKeyStore)) {
            keyStore.load(null, PASSWORD);
            // 用2048位的RAS算法。`SelfSignedCertificateGenerator`為Milo庫(kù)的對(duì)象。
            KeyPair keyPair = SelfSignedCertificateGenerator.generateRsaKeyPair(2048);
            // `SelfSignedCertificateBuilder`也是Milo庫(kù)的對(duì)象，用來(lái)生成證書(shū)。
            // 中間所設(shè)置的證書(shū)屬性可以自行修改。
            SelfSignedCertificateBuilder builder = new SelfSignedCertificateBuilder(keyPair)
                .setCommonName("Eclipse Milo Example Client")
                .setOrganization("digitalpetri")
                .setOrganizationalUnit("dev")
                .setLocalityName("Folsom")
                .setStateName("CA")
                .setCountryCode("US")
                .setApplicationUri("urn:eclipse:milo:examples:client")
                .addDnsName("localhost")
                .addIpAddress("127.0.0.1");
            // Get as many hostnames and IP addresses as we can listed in the certificate.
            for (String hostname : HostnameUtil.getHostnames("0.0.0.0")) {
                if (IP_ADDR_PATTERN.matcher(hostname).matches()) {
                    builder.addIpAddress(hostname);
                } else {
                    builder.addDnsName(hostname);
                }
            }
            // 創(chuàng)建證書(shū)
            X509Certificate certificate = builder.build();
            // 設(shè)置對(duì)應(yīng)私鑰的別名，密碼，證書(shū)鏈
            keyStore.setKeyEntry(CLIENT_ALIAS, keyPair.getPrivate(), PASSWORD, new X509Certificate[]{certificate});
            try (OutputStream out = Files.newOutputStream(serverKeyStore)) {
                // 保存證書(shū)到輸出流
                keyStore.store(out, PASSWORD);
            }
        } else {
            try (InputStream in = Files.newInputStream(serverKeyStore)) {
                // 如果文件存在則讀取
                keyStore.load(in, PASSWORD);
            }
        }
        // 用密碼獲取對(duì)應(yīng)別名的私鑰。
        Key serverPrivateKey = keyStore.getKey(CLIENT_ALIAS, PASSWORD);
        if (serverPrivateKey instanceof PrivateKey) {
            // 獲取對(duì)應(yīng)別名的證書(shū)對(duì)象。
            clientCertificate = (X509Certificate) keyStore.getCertificate(CLIENT_ALIAS);
            // 獲取公鑰
            PublicKey serverPublicKey = clientCertificate.getPublicKey();
            // 創(chuàng)建Keypair對(duì)象。
            clientKeyPair = new KeyPair(serverPublicKey, (PrivateKey) serverPrivateKey);
        }
        return this;
    }
    // 返回證書(shū)
    X509Certificate getClientCertificate() {
        return clientCertificate;
    }
    // 返回密鑰對(duì)
    KeyPair getClientKeyPair() {
        return clientKeyPair;
    }
}

public static OpcUaClient initClient(String url,SecurityPolicy securityPolicy) {
        try {
            if (securityPolicy.equals(SecurityPolicy.None)){
                return OpcUaClient.create(url,
                        endpoints ->
                                endpoints.stream()
                                        .filter(e -> e.getSecurityPolicyUri().equals(securityPolicy.getUri()))
                                        .findFirst(),
                        configBuilder ->
                                configBuilder
                                        //訪問(wèn)方式
                                        .setIdentityProvider(new AnonymousProvider())
                                        .setRequestTimeout(UInteger.valueOf(5000))
                                        .build());
            }
            Path securityTempDir = Paths.get(System.getProperty("java.io.tmpdir"), "security");
            Files.createDirectories(securityTempDir);
            if (!Files.exists(securityTempDir)) {
                throw new Exception("unable to create security dir: " + securityTempDir);
            }
            KeyStoreLoader loader = new KeyStoreLoader().load(securityTempDir);
            File pkiDir = securityTempDir.resolve("pki").toFile();
            DefaultTrustListManager trustListManager = new DefaultTrustListManager(pkiDir);
            DefaultClientCertificateValidator certificateValidator =
                    new DefaultClientCertificateValidator(trustListManager);
            String hostName = InetAddress.getLocalHost().getHostName();
            return OpcUaClient.create(url,
                    endpoints ->
                            endpoints.stream()
                                    .map(endpoint -> {
                                        // 構(gòu)建一個(gè)新的 EndpointDescription（可選修改某些字段）
                                        return new EndpointDescription(
                                                url,
                                                endpoint.getServer(),
                                                endpoint.getServerCertificate(),
                                                endpoint.getSecurityMode(), // 或者強(qiáng)制改為某種模式
                                                endpoint.getSecurityPolicyUri(),
                                                endpoint.getUserIdentityTokens(),
                                                endpoint.getTransportProfileUri(),
                                                endpoint.getSecurityLevel()
                                        );
                                    })
                                    .filter(e -> e.getSecurityPolicyUri().equals(securityPolicy.getUri()))
                                    .findFirst(),
                    configBuilder ->
                            configBuilder
                                    //訪問(wèn)方式
                                    .setApplicationName(LocalizedText.english("datacollector-driver"))
                                    .setApplicationUri(String.format("urn:%s:opcua-client", hostName))  // 必須與證書(shū)中的URI一致
                                    .setKeyPair(loader.getClientKeyPair())
                                    .setCertificate(loader.getClientCertificate())
                                    .setCertificateChain(loader.getClientCertificateChain())
                                    .setCertificateValidator(certificateValidator)
                                    .setIdentityProvider(new UsernameProvider("admin", "123456"))
                                    .setRequestTimeout(UInteger.valueOf(5000))
                                    .build());
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }