import java.nio.file.Files;
import java.nio.file.Paths;

public class ServiceAccountTokenReader {
    public static String readToken() {
        try {
            // Token文件路径
            String tokenPath = "/var/run/secrets/kubernetes.io/serviceaccount/token";
            
            // 读取文件内容
            byte[] encoded = Files.readAllBytes(Paths.get(tokenPath));
            return new String(encoded);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public static void main(String[] args) {
        String token = readToken();
        System.out.println("ServiceAccount Token: " + token);
    }
}

import io.kubernetes.client.openapi.ApiClient;
import io.kubernetes.client.openapi.Configuration;
import io.kubernetes.client.openapi.apis.CoreV1Api;
import io.kubernetes.client.openapi.models.V1Secret;
import io.kubernetes.client.util.Config;

public class K8sServiceAccountToken {
    public static void main(String[] args) {
        try {
            // 创建API客户端
            ApiClient client = Config.defaultClient();
            Configuration.setDefaultApiClient(client);
            
            CoreV1Api api = new CoreV1Api();
            
            // 获取default命名空间下的default服务账号关联的secret
            // 注意：实际使用时需要根据你的服务账号名称和命名空间调整
            V1Secret secret = api.readNamespacedSecret(
                "default-token-xxxxx",  // secret名称通常为<serviceaccount-name>-token-xxxx
                "default",              // 命名空间
                null);
                
            // 从secret中获取token
            String token = new String(
                secret.getData().get("token").decode(),
                "UTF-8");
                
            System.out.println("Token: " + token);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

<dependency>
    <groupId>io.kubernetes</groupId>
    <artifactId>client-java</artifactId>
    <version>12.0.0</version>
</dependency>