java - HttpClient 4 静静地卡在 socketRead 上

Question

我有一个应用程序使用保持连接持续轮询远程 HTTP API。

很少但偶尔应用程序会在工作一段时间后静默挂起。
套接字仍处于打开状态，但远程 API 未返回任何数据。

Httpclient 有套接字超时和连接超时，但是我如何处理我们已经连接的超时，套接字仍然打开但服务器没有返回数据？

netstat -np 进程:

Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name
tcp        0      0 redactedlocalip:31136       redactedforeignip:80        ESTABLISHED 11145/java   

我的 http 客户端:

SocketConfig socketConfig = SocketConfig.copy(SocketConfig.DEFAULT).setSoTimeout(25000).build();
BasicHttpClientConnectionManager connectionManager = new BasicHttpClientConnectionManager();
connectionManager.setSocketConfig(socketConfig);
return HttpClients
        .custom()
        .setUserAgent(USER_AGENT)
        .setConnectionManager(connectionManager)
        .setRetryHandler(new DefaultHttpRequestRetryHandler())
        .build();

主线程转储:

"main" #11 prio=5 os_prio=0 tid=0x00007f6b802ce800 nid=0x2b9f runnable [0x00007f6b675ec000]
   java.lang.Thread.State: RUNNABLE
        at java.net.SocketInputStream.socketRead0(Native Method)
        at java.net.SocketInputStream.read(SocketInputStream.java:150)
        at java.net.SocketInputStream.read(SocketInputStream.java:121)
        at org.apache.http.impl.io.SessionInputBufferImpl.streamRead(SessionInputBufferImpl.java:139)
        at org.apache.http.impl.io.SessionInputBufferImpl.fillBuffer(SessionInputBufferImpl.java:155)
        at org.apache.http.impl.io.SessionInputBufferImpl.readLine(SessionInputBufferImpl.java:284)
        at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:140)
        at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:57)
        at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:261)
        at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:165)
        at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:272)
        at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:124)
        at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:271)
        at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
        at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
        at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
        at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
        at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
        at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:107)
        at redacted.app.code.executemyRequest(MyClass.java:117)

我使用的是 maven "org.apache.httpcomponents:httpclient:4.5"的最新版本

Answer 1

问题是一个行为不佳的 HTTP 服务器，它从未响应某些请求，但继续保持 TCP 连接并发送/接收保持 Activity 数据包。
Apache HTTPClient 没有任何内置超时来处理这些情况，解决方案是在指定的等待时间后手动调用 HTTPRequest$abort() 方法。
它当然需要从不同的线程调用，因为调用线程将被阻塞等待。