修复java.net.SocketTimeoutException: 读取超时错误

Question

我有一个RESTful服务器，它从客户端接收Http POST输入来对服务器上的歌曲进行投票。我已经在客户端中使用了Apache HTTPClient。

public boolean vote() {
        HttpClient client = new DefaultHttpClient(getHttpParameters());
        HttpConnectionParams.setConnectionTimeout(client.getParams(), 10000); // Timeout Limit                                                                              
        HttpResponse response;
        try {
            HttpPost post = new HttpPost("http://127.0.0.1:8080/ws/");
            StringEntity se = new StringEntity("{ \"song_id\" : \"2\" }");
            se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE,"application/json"));
            post.setEntity(se);
            response = client.execute(post);
            if (response != null) { 
                InputStream in = response.getEntity().getContent(); // Get the data in the Entity                                                               
                String result = convertStreamToString(in);
                return true;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        return false;
    }

    public static HttpParams getHttpParameters() {
        HttpParams httpParameters = new BasicHttpParams();
        int timeoutConnection = 30000;
        HttpConnectionParams.setConnectionTimeout(httpParameters,
                timeoutConnection);
        int timeoutSocket = 30000;
        HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
        return httpParameters;
    }

在投票过程中，当我点击继任按钮后，经过几次投票（比如7-8次），我会收到java.net.SocketTimeoutException: Read timed out异常提示。当我搜索原因时，发现是因为客户端在超时期间没有收到服务器响应。但问题是，当我使用其他应用程序（比如Chrome REST Console或JMeter）时，可以在相同的服务器上使用相同的参数和路径进行多次投票。是否我的Java代码有问题？请帮我解决这个问题。以下是我的堆栈跟踪：

java.net.SocketTimeoutException: Read timed out
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.read(Unknown Source)
    at org.apache.http.impl.io.AbstractSessionInputBuffer.fillBuffer(AbstractSessionInputBuffer.java:166)
    at org.apache.http.impl.io.SocketInputBuffer.fillBuffer(SocketInputBuffer.java:90)
    at org.apache.http.impl.io.AbstractSessionInputBuffer.readLine(AbstractSessionInputBuffer.java:281)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:92)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:62)
    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:254)
    at org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:289)
    at org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:252)
    at org.apache.http.impl.conn.ManagedClientConnectionImpl.receiveResponseHeader(ManagedClientConnectionImpl.java:191)
    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:300)
    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:127)
    at org.apache.http.impl.client.DefaultRequestDirector.tryExecute(DefaultRequestDirector.java:715)
    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:520)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:906)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:805)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:784)
    at notdefault.ServerStuffs.vote(ServerStuffs.java:72)
    at notdefault.MainClass.actionPerformed(MainClass.java:105)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$400(Unknown Source)
    at java.awt.EventQueue$2.run(Unknown Source)
    at java.awt.EventQueue$2.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)
java.net.SocketTimeoutException: Read timed out
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.read(Unknown Source)
    at org.apache.http.impl.io.AbstractSessionInputBuffer.fillBuffer(AbstractSessionInputBuffer.java:166)
    at org.apache.http.impl.io.SocketInputBuffer.fillBuffer(SocketInputBuffer.java:90)
    at org.apache.http.impl.io.AbstractSessionInputBuffer.readLine(AbstractSessionInputBuffer.java:281)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:92)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:62)
    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:254)
    at org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:289)
    at org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:252)
    at org.apache.http.impl.conn.ManagedClientConnectionImpl.receiveResponseHeader(ManagedClientConnectionImpl.java:191)
    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:300)
    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:127)
    at org.apache.http.impl.client.DefaultRequestDirector.tryExecute(DefaultRequestDirector.java:715)
    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:520)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:906)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:805)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:784)
    at notdefault.ServerStuffs.vote(ServerStuffs.java:72)
    at notdefault.MainClass.actionPerformed(MainClass.java:105)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$400(Unknown Source)
    at java.awt.EventQueue$2.run(Unknown Source)
    at java.awt.EventQueue$2.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

- asok Buzz

---

如果您设置了读取超时并且出现了读取超时，而您不想要读取超时，请增加读取超时时间。这只是因为您要求了它而发生的。如果您认为服务器应该比现在更快，请向他们提出。 - user207421

我也尝试过增加读取超时时间，但是迟早都会遇到这个问题。实际上，我忘记关闭连接，因此保持了想要的连接并消耗了服务器资源。下面Santosh的回答帮了很大的忙。 - asok Buzz

Answer 1

以下是调查的一些要点/建议：

1. 我发现每次投票时，您都会调用vote方法来创建一个新的HTTP连接。
2. 这可能是个问题。我建议使用单个HttpClient实例向服务器发送请求。这样就不会从客户端创建太多连接。
3. 最后，需要关闭HttpClient，因此调用httpclient.getConnectionManager().shutdown();以释放连接使用的资源。

- Santosh

---

谢谢，你让我感到非常开心。我在最后关闭了连接，这对我帮助很大。 - asok Buzz

Answer 2

我认为仅仅获得响应是不够的。我认为您需要阅读它（获取实体并通过EntityUtils.consume()来读取）。

例如（来自文档）

     System.out.println("<< Response: " + response.getStatusLine());
     System.out.println(EntityUtils.toString(response.getEntity()));

- Brian Agnew

---

实际上我已经有了，我只是想让问题简洁一些。我会编辑我的问题。谢谢。 - asok Buzz