不能在 java.net.http.HttpClient 上发出多个请求，否则将收到：javax.net.ssl.SSLHandshakeException

Posted 2023-02-22

【中文标题】不能在 java.net.http.HttpClient 上发出多个请求，否则将收到：javax.net.ssl.SSLHandshakeException

【英文标题】：Can't make more than one request on java.net.http.HttpClient or will receive: javax.net.ssl.SSLHandshakeException

【发布时间】：2019-05-14 21:34:37

【问题描述】：

我正在测试 Java 11 中的新 HttpClient 并遇到以下行为：

我正在向公共 REST API 发出两个异步请求以进行测试，并使用一个客户端和两个单独的请求进行了尝试。这个过程没有抛出任何异常。

String singleCommentUrl = "https://jsonplaceholder.typicode.com/comments/1";
String commentsUrl = "https://jsonplaceholder.typicode.com/comments";

Consumer<String> handleOneComment = s -> 
    Gson gson = new Gson();
    Comment comment = gson.fromJson(s, Comment.class);
    System.out.println(comment);
;
Consumer<String> handleListOfComments = s -> 
    Gson gson = new Gson();
    Comment[] comments = gson.fromJson(s, Comment[].class);
    List<Comment> commentList = Arrays.asList(comments);
    commentList.forEach(System.out::println);
;

HttpClient client = HttpClient.newBuilder().build();

client.sendAsync(HttpRequest.newBuilder(URI.create(singleCommentUrl)).build(), HttpResponse.BodyHandlers.ofString())
        .thenApply(HttpResponse::body)
        .thenAccept(handleOneComment)
        .join();

client.sendAsync(HttpRequest.newBuilder(URI.create(commentsUrl)).build(), HttpResponse.BodyHandlers.ofString())
        .thenApply(HttpResponse::body)
        .thenAccept(handleListOfComments)
        .join();

然后我尝试将HttpClient 重构为一个方法，当它尝试发出第二个请求时出现以下异常：

public void run() 
    String singleCommentUrl = "https://jsonplaceholder.typicode.com/comments/1";
    String commentsUrl = "https://jsonplaceholder.typicode.com/comments";

    Consumer<String> handleOneComment = s -> 
        Gson gson = new Gson();
        Comment comment = gson.fromJson(s, Comment.class);
        System.out.println(comment);
    ;
    Consumer<String> handleListOfComments = s -> 
        Gson gson = new Gson();
        Comment[] comments = gson.fromJson(s, Comment[].class);
        List<Comment> commentList = Arrays.asList(comments);
        commentList.forEach(System.out::println);
    ;

    sendRequest(handleOneComment, singleCommentUrl);
    sendRequest(handleListOfComments, commentsUrl);


private void sendRequest(Consumer<String> onSucces, String url) 
    HttpClient client = HttpClient.newBuilder().build();
    HttpRequest request = HttpRequest.newBuilder(URI.create(url)).build();

    client.sendAsync(request, HttpResponse.BodyHandlers.ofString())
            .thenApply(HttpResponse::body)
            .thenAccept(onSucces)
            .join();

这会在成功执行第一个请求并在第二个请求失败后产生以下异常：

Exception in thread "main" java.util.concurrent.CompletionException: javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure
    at java.base/java.util.concurrent.CompletableFuture.encodeRelay(CompletableFuture.java:367)
    at java.base/java.util.concurrent.CompletableFuture.completeRelay(CompletableFuture.java:376)
    at java.base/java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:1074)
    at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506)
    at java.base/java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2088)
    at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate.handleError(SSLFlowDelegate.java:904)
    at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate$Reader.processData(SSLFlowDelegate.java:450)
    at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate$Reader$ReaderDownstreamPusher.run(SSLFlowDelegate.java:263)
    at java.net.http/jdk.internal.net.http.common.SequentialScheduler$SynchronizedRestartableTask.run(SequentialScheduler.java:175)
    at java.net.http/jdk.internal.net.http.common.SequentialScheduler$CompleteRestartableTask.run(SequentialScheduler.java:147)
    at java.net.http/jdk.internal.net.http.common.SequentialScheduler$SchedulableTask.run(SequentialScheduler.java:198)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure
    at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:128)
    at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:117)
    at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:308)
    at java.base/sun.security.ssl.Alert$AlertConsumer.consume(Alert.java:279)
    at java.base/sun.security.ssl.TransportContext.dispatch(TransportContext.java:181)
    at java.base/sun.security.ssl.SSLTransport.decode(SSLTransport.java:164)
    at java.base/sun.security.ssl.SSLEngineImpl.decode(SSLEngineImpl.java:672)
    at java.base/sun.security.ssl.SSLEngineImpl.readRecord(SSLEngineImpl.java:627)
    at java.base/sun.security.ssl.SSLEngineImpl.unwrap(SSLEngineImpl.java:443)
    at java.base/sun.security.ssl.SSLEngineImpl.unwrap(SSLEngineImpl.java:422)
    at java.base/javax.net.ssl.SSLEngine.unwrap(SSLEngine.java:634)
    at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate$Reader.unwrapBuffer(SSLFlowDelegate.java:480)
    at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate$Reader.processData(SSLFlowDelegate.java:389)
    ... 7 more

我也尝试通过方法中的参数传递单独的客户端和请求，但它产生了相同的结果。这是怎么回事？

【问题讨论】：

您的应用程序无法保留单个 HttpClient 实例并将其用于所有请求是否有原因？ （至少，所有需要相同 HttpClient 设置的请求。）

并非如此，这将是理想的行为。我刚刚从 java 11 测试了新的 HttpClient 并遇到了这个问题。如果它是一个实际的应用程序，我很可能会使用单个 HttpClient 作为服务。

【参考方案1】：

显然，SSLContext 对象不是线程安全的。 （假设合约没有明确保证线程安全的任何可变对象不是线程安全的，通常是正确的。）

HttpClients use the default SSLContext 如果没有明确给出上下文。因此，您的两个请求似乎正在尝试同时共享该默认上下文。

解决方案是为每个 HttpClient 指定一个全新的 SSLContext：

private void sendRequest(Consumer<String> onSucces, String url) 
    SSLContext context;
    try 
        context = SSLContext.getInstance("TLSv1.3");
        context.init(null, null, null);
     catch (GeneralSecurityException e) 
        throw new RuntimeException(e);
    

    HttpClient client = HttpClient.newBuilder().sslContext(context).build();
    HttpRequest request = HttpRequest.newBuilder(URI.create(url)).build();

    client.sendAsync(request, HttpResponse.BodyHandlers.ofString())
            .thenApply(HttpResponse::body)
            .thenAccept(onSucces)
            .join();

【讨论】：

您是否在线程安全上下文中测试了init，然后在并发上下文中使用客户端？可能只有init 方法不安全？当多个线程JDK-8197807 使用时，我遇到了与不安​​全init 相关的问题。

@NicolasHenneaux 我不确定你的意思。在上面的代码中，init 的使用是线程安全的，因为 SSLContext 对任何其他方法或线程都不可见。您是在谈论在默认 SSLContext 上调用 init 吗？

像问题中那样调用两次sendAsync，看看它是否有效？

@NicolasHenneaux 当我尝试它时它似乎工作。这是我所期望的，因为我希望 HttpClient 读取 SSLContext 的状态但不修改它。

我期待着同样的结果，但你能够确认真是太好了！