Microsoft Graph Java Client调用接口后JVM无法退出的问题求助

环境配置 #

• Microsoft Graph Java Client v5.36.0
• azure-identity 1.6.0
• azure-core-http-okhttp 1.11.2
• 测试环境：Eclipse

问题现象 #

• 仅构建Graph客户端但不发起请求时，JVM可正常退出
• 发起任意Graph请求后，主线程执行完毕退出，但JVM始终处于活跃状态（Eclipse中显示红色运行图标）

核心复现代码 #

final ClientSecretCredential clientSecretCredential = new ClientSecretCredentialBuilder()
        .clientId("--------------------------------------------")
        .clientSecret("----------------------------------------")
        .tenantId("--------------------------------------------")
        .build();

List<String> scopes=new ArrayList<>();
scopes.add("https://graph.microsoft.com/.default");

final TokenCredentialAuthProvider tokenCredentialAuthProvider = 
        new TokenCredentialAuthProvider(scopes, clientSecretCredential);

GraphServiceClient graphClient = GraphServiceClient
                                    .builder()
                                    .authenticationProvider(tokenCredentialAuthProvider)
                                    .buildClient();

MessageCollectionRequest req=graphClient
                                    .users("--").messages()
                                    .buildRequest(queryUnread,queryNoOfMails,queryExpandAttachment);
MessageCollectionPage page=req.get();
List<Message> messageList=page.getCurrentPage();

排查尝试 #

自行创建独立OKHttp客户端并绑定到GraphClient，请求执行后手动清理资源：

自定义OKHttp客户端初始化代码 #

OkHttpClient httpClient=HttpClients.createDefault(tokenCredentialAuthProvider);

GraphServiceClient graphClient=GraphServiceClient
                                .builder()
                                .authenticationProvider(tokenCredentialAuthProvider)
                                .httpClient(httpClient)
                                .buildClient();

资源清理代码 #

System.out.println(httpClient.connectTimeoutMillis());//Prints 10000
System.out.println(httpClient.connectionPool().connectionCount());//prints 1
httpClient.connectionPool().evictAll();
System.out.println(httpClient.connectionPool().connectionCount());//prints 0
httpClient.dispatcher().executorService().shutdown();
System.out.println(httpClient.dispatcher().executorService().isShutdown());//prints true

执行上述清理后，OKHttp连接池已清空、调度器线程池已标记为关闭，但JVM仍无法正常退出，排除OKHttp连接池问题。

疑问 #

是代码中遗漏了必要的资源释放步骤，还是相关库本身存在未终止后台线程的问题？

内容的提问来源于stack exchange，提问作者Ironluca