Question

嘿，我使用的是Tomcat 7和HttpClient 4.3.3。我正在尝试使用多个线程连接到我的Servlet，但我经常收到java.net.SocketException: Connection reset。当我在第一行暂停Servlet的线程时，我仍然在我的客户端上收到异常。我的问题：这个问题的原因可能与最小活动连接数量太少有关吗？如果没有，请任何人帮我解决这个问题？

try{

        // create new httpPost request with url of his class
        HttpPost httpPost = new HttpPost( "http://192.168.1.229:8080/test/test" );

        // create params and add it to httpPost
        List<NameValuePair> paramList = new ArrayList<NameValuePair>();
        paramList.add( new BasicNameValuePair( "json_req", format ) );
        UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity( paramList );
        httpPost.setEntity( formEntity );

        // execute request and save response
        CloseableHttpResponse response = httpclient.execute( httpPost, context );

        HttpEntity entity = response.getEntity();
        InputStream content = entity.getContent();
        resp = content.available() > 0;

        content.close();
        response.close();
        // return the response
    }
    catch( Exception e ){
        e.printStackTrace();
    }

例外：

java.net.SocketException: Connection reset
    at java.net.SocketInputStream.read(SocketInputStream.java:168)
    at org.apache.http.impl.io.SessionInputBufferImpl.streamRead(SessionInputBufferImpl.java:136)
    at org.apache.http.impl.io.SessionInputBufferImpl.fillBuffer(SessionInputBufferImpl.java:152)
    at org.apache.http.impl.io.SessionInputBufferImpl.readLine(SessionInputBufferImpl.java:270)
    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:260)
    at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:161)
    at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.apache.http.impl.conn.CPoolProxy.invoke(CPoolProxy.java:138)
    at $Proxy0.receiveResponseHeader(Unknown Source)
    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:271)
    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:123)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:254)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:195)
    at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:86)
    at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:108)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:186)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
    at com.pribas.flightcacheservlet.servlet.HTTPThread.run(HTTPThread.java:69)
    at java.lang.Thread.run(Thread.java:662)

启动线程的代码：

public static void main( String[] args ) throws Exception{
    FileUtil.init();

    PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
    cm.setMaxTotal( 1000 );
    cm.setDefaultMaxPerRoute( 1000 );
    cm.setDefaultSocketConfig( SocketConfig.custom().setSoKeepAlive( true ).setSoReuseAddress( true ).setSoTimeout( 3000 ).build() );
    CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager( cm ).build();

    HTTPThread.THREAD_COUNT = 300;
    HTTPThread.start = new CountDownLatch( HTTPThread.THREAD_COUNT );

    Thread[] threads = new Thread[ HTTPThread.THREAD_COUNT ];

    for( int i = 0; i < HTTPThread.THREAD_COUNT; i++ ){
        threads[ i ] = new Thread( new HTTPThread( httpClient ) );
    }

    for( Thread thread : threads ){
        thread.start();
    }

    for( Thread thread : threads ){
        thread.join();
    }

    httpClient.close();

    System.out.println( "Average response time: " + calAverage( HTTPThread.times ) + " milliseconds." );
}

Answer 1

以下是JavaDoc对所述异常的说法：

抛出以指示底层协议中存在错误，例如TCP错误

根据我的个人经验，我遇到过这样的情况，似乎不是其他连接端（服务器）关闭连接而是你的客户端。否则，您会收到另一条消息：Connection reset by peer

这可能由于多种原因而发生，在您的情况下，我猜这与您在工作单元末端没有收集HttpClient实例的事实有关;因此，请尝试在try语句的finally块中添加以下行：

try
{
  ...
}
catch( Exception e )
{
  e.printStackTrace();
}
finally 
{
  httpClient.close(); //close the underlying client.
}

更新

您可能还需要启用SO_KEEPALIVE以使套接字保持活动状态：

    cm.setDefaultSocketConfig( 
        SocketConfig.custom().setSoKeepAlive(true)
          .setSoReuseAddress(true)
          .setSoTimeout(3000)
          .build());

Tomcat 7 - 连接重置

1 个答案:

更新