Question

在我的Android应用程序中，我有一些代码：

         while(testCase){
            for(HttpPut put : httpPut){
                try {
                    httpclient.execute(put, responseHandler);
                } catch (ClientProtocolException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }

                try {
                    Thread.sleep(150);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }

我的目标是在一个永久循环中按顺序每隔150毫秒发出一个预先构建的HTTPPut请求列表（在这种情况下：“httpPut”），直到被告知中断（由“testCase”boolean打破）。它在技术上有效，但实际执行中有时会有很多延迟。在每个请求的接收端，它可能会在收到另一个HTTPPut之前滞后3-5秒。而手机的屏幕关闭甚至更糟。我在扩展的AsyncTask类中运行此代码。

我的问题是，在执行此代码时，我可以通过哪种方式更有效地以更精确的方式触发代码;准确地接近每150毫秒？谢谢你的阅读！

修改建议在另一个线程中运行，我尝试添加此代码：

...
                performOnBackgroundThread(new Runnable(){

                    @SuppressWarnings("unchecked")
                    @Override
                    public void run() {
                        try {
                            final DefaultHttpClient httpclient = new DefaultHttpClient();
                            final ResponseHandler responseHandler = new BasicResponseHandler();

                            httpclient.execute(put, responseHandler);
                        } catch (ClientProtocolException e1) {
                            // TODO Auto-generated catch block
                            e1.printStackTrace();
                        } catch (IOException e1) {
                            // TODO Auto-generated catch block
                            e1.printStackTrace();
                        }
                    }

                });
...

public static Thread performOnBackgroundThread(final Runnable runnable) {
    final Thread t = new Thread() {
        @Override
        public void run() {
            try {
                runnable.run();
            } finally {

            }
        }
    };
    t.start();
    return t;
}

但是我的应用程序很快崩溃了“I / Process（18762）：发送信号.PID：18762 SIG：9”我也得到了一堆这些错误。

02-10 00:14:58.639: W/SingleClientConnManager(18762): Invalid use of SingleClientConnManager: connection still allocated.
02-10 00:14:58.639: W/SingleClientConnManager(18762): Make sure to release the connection before allocating another one.
02-10 00:14:58.639: W/SingleClientConnManager(18762): Invalid use of SingleClientConnManager: connection still allocated.
02-10 00:14:58.639: W/SingleClientConnManager(18762): Make sure to release the connection before allocating another one.
02-10 00:14:58.647: W/System.err(18762): java.net.SocketException: Socket closed
02-10 00:14:58.647: W/System.err(18762):    at libcore.io.Posix.recvfromBytes(Native Method)
02-10 00:14:58.647: W/System.err(18762):    at libcore.io.Posix.recvfrom(Posix.java:131)
02-10 00:14:58.647: W/System.err(18762):    at libcore.io.BlockGuardOs.recvfrom(BlockGuardOs.java:164)
02-10 00:14:58.647: W/System.err(18762):    at libcore.io.IoBridge.recvfrom(IoBridge.java:513)
02-10 00:14:58.647: W/System.err(18762):    at java.net.PlainSocketImpl.read(PlainSocketImpl.java:488)
02-10 00:14:58.647: W/System.err(18762):    at java.net.PlainSocketImpl.access$000(PlainSocketImpl.java:46)
02-10 00:14:58.647: W/System.err(18762):    at java.net.PlainSocketImpl$PlainSocketInputStream.read(PlainSocketImpl.java:240)
02-10 00:14:58.647: W/System.err(18762):    at org.apache.http.impl.io.AbstractSessionInputBuffer.fillBuffer(AbstractSessionInputBuffer.java:103)
02-10 00:14:58.655: W/System.err(18762):    at org.apache.http.impl.io.AbstractSessionInputBuffer.readLine(AbstractSessionInputBuffer.java:191)
02-10 00:14:58.655: W/System.err(18762):    at org.apache.http.impl.conn.DefaultResponseParser.parseHead(DefaultResponseParser.java:82)
02-10 00:14:58.655: W/System.err(18762):    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:174)
02-10 00:14:58.655: W/System.err(18762):    at org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:180)
02-10 00:14:58.655: W/System.err(18762):    at org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:235)
02-10 00:14:58.663: W/System.err(18762):    at org.apache.http.impl.conn.AbstractClientConnAdapter.receiveResponseHeader(AbstractClientConnAdapter.java:259)
02-10 00:14:58.663: W/System.err(18762):    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:279)
02-10 00:14:58.663: W/System.err(18762):    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:121)
02-10 00:14:58.663: W/System.err(18762):    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:428)
02-10 00:14:58.663: W/System.err(18762):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
02-10 00:14:58.663: W/System.err(18762):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:653)
02-10 00:14:58.663: W/System.err(18762):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:627)
02-10 00:14:58.663: W/System.err(18762):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:616)
02-10 00:14:58.663: W/System.err(18762):    at com.<takenout>.<takenout>.<takenout>.run(MyFile.java:79)
02-10 00:14:58.663: W/System.err(18762):    at com.<takenout>.<takenout>.<takenout>.run(MyFile.java:116)
02-10 00:14:58.671: W/System.err(18762): java.net.SocketTimeoutException
02-10 00:14:58.671: W/System.err(18762):    at java.net.PlainSocketImpl.read(PlainSocketImpl.java:491)
02-10 00:14:58.671: W/System.err(18762):    at java.net.PlainSocketImpl.access$000(PlainSocketImpl.java:46)
02-10 00:14:58.671: W/dalvikvm(18762): threadid=17: thread exiting with uncaught exception (group=0x40d03300)

编辑＃2：

02-10 00:38:08.639: W/System.err(20100): java.net.SocketException: recvfrom failed: ECONNRESET (Connection reset by peer)
02-10 00:38:08.639: W/System.err(20100):    at libcore.io.IoBridge.maybeThrowAfterRecvfrom(IoBridge.java:552)
02-10 00:38:08.639: W/System.err(20100):    at libcore.io.IoBridge.recvfrom(IoBridge.java:516)
02-10 00:38:08.639: W/System.err(20100):    at java.net.PlainSocketImpl.read(PlainSocketImpl.java:488)
02-10 00:38:08.647: W/System.err(20100):    at java.net.PlainSocketImpl.access$000(PlainSocketImpl.java:46)
02-10 00:38:08.647: W/System.err(20100):    at java.net.PlainSocketImpl$PlainSocketInputStream.read(PlainSocketImpl.java:240)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.io.AbstractSessionInputBuffer.fillBuffer(AbstractSessionInputBuffer.java:103)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.io.AbstractSessionInputBuffer.readLine(AbstractSessionInputBuffer.java:191)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.conn.DefaultResponseParser.parseHead(DefaultResponseParser.java:82)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:174)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:180)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:235)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.conn.AbstractClientConnAdapter.receiveResponseHeader(AbstractClientConnAdapter.java:259)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:279)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:121)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:428)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:653)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:627)
02-10 00:38:08.647: W/System.err(20100):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:616)
02-10 00:38:08.647: W/System.err(20100):    at com.<takenout>.<takenout>.<takenout>.run(MyFile.java:79)
02-10 00:38:08.647: W/System.err(20100):    at com.<takenout>.<takenout>.<takenout>.run(MyFile.java:116)
02-10 00:38:08.647: W/System.err(20100): Caused by: libcore.io.ErrnoException: recvfrom failed: ECONNRESET (Connection reset by peer)
02-10 00:38:08.647: W/System.err(20100):    at libcore.io.Posix.recvfromBytes(Native Method)
02-10 00:38:08.647: W/System.err(20100):    at libcore.io.Posix.recvfrom(Posix.java:131)
02-10 00:38:08.647: W/System.err(20100):    at libcore.io.BlockGuardOs.recvfrom(BlockGuardOs.java:164)
02-10 00:38:08.647: W/System.err(20100):    at libcore.io.IoBridge.recvfrom(IoBridge.java:513)
02-10 00:38:08.647: W/System.err(20100):    ... 19 more

Answer 1

由于网络指标存在差异，您实际上无法100％保证您的服务器每150毫秒会更新一次。你最好的选择是尝试比你想要的更快的东西，例如：每隔100ms发送一个新请求，并希望服务器至少每100ms收到一次更新。此外，如果您要快速发送请求，请考虑使用UDP over TCP。由于确保数据包交付的开销，TCP请求在我的经验中花费的时间更长，但是如果您丢失了一两个，如果您的平均案例性能要好得多，那么对您来说并不是一件大事。 90％的情况下，您每100毫秒看到一次更新。

您可能会在服务器上看到延迟，因为您遇到了早先的请求，例如如果req1需要200ms，req2需要350ms，req3需要120ms，那么在服务器上你不会每隔150ms看到一次请求。对于前几个请求尤其如此，其中网络性能可能在5-10个请求之后显着更差（例如1-2秒）。

我建议您创建第二个AsyncTask类，您可以从第一个AsyncTask快速生成（请参阅this获取一些可能的指导）。但是，如果您如此快速地生成新的请求对象，这可能只会让您最终遇到一些线程限制。

最大的问题是你确定你做的是正确的吗？你不会让网络芯片组在请求之间有150毫秒的差距（这可能需要超过150毫秒才能完成执行！），所以为什么甚至打扰许多个别请求？为什么不使用像套接字一样保持开放的东西（例如google http long polling）？

Android：快速HTTP请求

1 个答案: