我正在从java后端服务器向浏览器发送通知推送，最近我收到了很多连接关闭异常。我使用javawebpush库。
这个问题开始于2020年12月23日左右（从我的Angular 来看，这不是一个重要的日期，但可能有一些更新，我不知道…）
这是一个stacktrace示例，我希望我能对如何解决这个问题有一些想法。据我所知，如果注册无效或过期，我仍然会收到一个http状态码，我可以对此做出React。连接关闭是意外的，我不知道我的记录是否有效。
我认为这个错误不大可能与web推送库有关。任何帮助都将不胜感激。谢谢。

java.util.concurrent.ExecutionException: org.apache.http.ConnectionClosedException: Connection closed
     at org.apache.http.concurrent.BasicFuture.getResult(BasicFuture.java:71)
     at org.apache.http.concurrent.BasicFuture.get(BasicFuture.java:84)
     at org.apache.http.impl.nio.client.FutureWrapper.get(FutureWrapper.java:70)
     at nl.martijndwars.webpush.PushService.send(PushService.java:118)
     at my.package.MyClass.sendNotification(MyClass.java:xx)
     at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
     at java.util.concurrent.FutureTask.run(FutureTask.java:266)
     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
     at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.http.ConnectionClosedException: Connection closed
     at org.apache.http.nio.protocol.HttpAsyncRequestExecutor.endOfInput(HttpAsyncRequestExecutor.java:347)
     at org.apache.http.impl.nio.DefaultNHttpClientConnection.consumeInput(DefaultNHttpClientConnection.java:261)
     at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:81)
     at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:39)
     at org.apache.http.impl.nio.reactor.AbstractIODispatch.inputReady(AbstractIODispatch.java:121)
     at org.apache.http.impl.nio.reactor.BaseIOReactor.readable(BaseIOReactor.java:162)
     at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvent(AbstractIOReactor.java:337)
     at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvents(AbstractIOReactor.java:315)
     at org.apache.http.impl.nio.reactor.AbstractIOReactor.execute(AbstractIOReactor.java:276)
     at org.apache.http.impl.nio.reactor.BaseIOReactor.execute(BaseIOReactor.java:104)
     at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor$Worker.run(AbstractMultiworkerIOReactor.java:588)
     ... 1 more
Caused by:
org.apache.http.ConnectionClosedException: Connection closed
     at org.apache.http.nio.protocol.HttpAsyncRequestExecutor.endOfInput(HttpAsyncRequestExecutor.java:347)
     at org.apache.http.impl.nio.DefaultNHttpClientConnection.consumeInput(DefaultNHttpClientConnection.java:261)
     at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:81)
     at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:39)
     at org.apache.http.impl.nio.reactor.AbstractIODispatch.inputReady(AbstractIODispatch.java:121)
     at org.apache.http.impl.nio.reactor.BaseIOReactor.readable(BaseIOReactor.java:162)
     at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvent(AbstractIOReactor.java:337)
     at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvents(AbstractIOReactor.java:315)
     at org.apache.http.impl.nio.reactor.AbstractIOReactor.execute(AbstractIOReactor.java:276)
     at org.apache.http.impl.nio.reactor.BaseIOReactor.execute(BaseIOReactor.java:104)
     at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor$Worker.run(AbstractMultiworkerIOReactor.java:588)
     at java.lang.Thread.run(Thread.java:748)