java.net.SocketException : No buffer space available (maximum connections reached? ): 连接

Question

您好，我正在使用 Apache HTTP Client 4.0 在基于 HTTPS 协议(protocol)的服务器上上传一些文件。上传的应用程序正在 24x7 运行。今天突然开始抛出这个异常-

java.net.SocketException: No buffer space available (maximum connections reached?): connect
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.PlainSocketImpl.doConnect(Unknown Source)
    at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.connect(Unknown Source)
    at org.apache.http.conn.ssl.SSLSocketFactory.connectSocket(SSLSocketFactory.java:333)
    at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:123)
    at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:147)
    at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:101)
    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:381)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:641)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:576)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:554)

谁能帮帮我？我完全不知道发生了什么事？

这是上传文件的源代码-

public File call() throws Exception {           
            HttpClient httpclient = new DefaultHttpClient();
        try{            
            httpclient.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);         
            /*
             * Create POST REQUEST
             */
            HttpPost httpPost = new HttpPost(this.URL);
            /*
             * Create MultipartRequestEntity
             */
            MultipartEntity multipartEntity = new MultipartEntity( HttpMultipartMode.BROWSER_COMPATIBLE );
            /*
             * Add POST Parameters
             */
            multipartEntity.addPart(parameters[0], this.fileBody);
            multipartEntity.addPart(parameters[1], new StringBody(this.TYPE));
            multipartEntity.addPart(parameters[2], new StringBody(this.MAAID));
            /*
             * Add this POST Method
             */
            httpPost.setEntity(multipartEntity);
            /*
             * Upload the file
             */
            HttpResponse response = httpclient.execute(httpPost);
            int responseCode = response.getStatusLine().getStatusCode();
            logger.info("Response Code of HTTP Connectivity ["+ responseCode + "], " +
                                                            "it means ["+ response.getStatusLine().getReasonPhrase()+"]");
            /*
             * Check the server Response
             */
            HttpEntity entity = response.getEntity();
            if(entity != null){
                String status = EntityUtils.toString(entity);
                logger.info("Status of file upload from Server >>"+ status+"<<");
                entity.consumeContent();
                if(status.equalsIgnoreCase("OK")){
                    return this.fileBody.getFile();
                }
            }else{
                logger.error("Unable to retrieve status of file upload from server");
            }           
        }catch(NoRouteToHostException e){
            logger.error("Internet connection to ["+ this.URL + "] is not available", e);
        }catch(SocketException e){
            logger.error("Unable to connect to "+ this.URL, e);
        }catch (Exception e) {          
            logger.error("Exception while uploading the file["+ this.fileBody.getFilename()+ "] on ["+ this.URL+"]", e);
        }finally{
            try{
                httpclient.getConnectionManager().shutdown();
            }catch(Exception e){
                // Ignore this exception
            }
        }
        return null;
    }

Answer 1

我的猜测:您的端口用完了，这个问题与您的代码没有直接关系，而是与您服务器的当前状态有关。与其他机器打开的连接太多，这会导致问题。

寻找什么:

• 您的服务器是否处于高负荷使用状态，可能会导致打开多个网络连接？
• HTTP client documentation建议只实例化一个 HttpClient 并重用这个实例。他们是cases其中实例化多个 HTTP 客户端并且未正确释放连接会导致网络连接堆叠并且永远不会关闭。尝试 httpPost.releaseConnection()。您可能还对 HTTP 客户端文档感兴趣，chapter 1.1.5, "Ensuring release of low level resources"