java - HttpClient 连接被对等方重置 : socket write error

Question

我使用httpclient 4.4发送get和post请求。我刚刚创建了一个简单的 httpclient 包装器以方便使用:

    package com.u8.server.sdk;    import com.sun.net.httpserver.Headers;    import com.u8.server.log.Log;    import org.apache.http.Header;    import org.apache.http.HttpEntity;    import org.apache.http.HttpResponse;    import org.apache.http.NameValuePair;    import org.apache.http.client.ClientProtocolException;    import org.apache.http.client.HttpClient;    import org.apache.http.client.HttpRequestRetryHandler;    import org.apache.http.client.ResponseHandler;    import org.apache.http.client.config.RequestConfig;    import org.apache.http.client.entity.UrlEncodedFormEntity;    import org.apache.http.client.methods.HttpGet;    import org.apache.http.client.methods.HttpPost;    import org.apache.http.config.Registry;    import org.apache.http.config.RegistryBuilder;    import org.apache.http.conn.socket.ConnectionSocketFactory;    import org.apache.http.conn.socket.PlainConnectionSocketFactory;    import org.apache.http.conn.ssl.NoopHostnameVerifier;    import org.apache.http.conn.ssl.SSLConnectionSocketFactory;    import org.apache.http.conn.ssl.TrustStrategy;    import org.apache.http.entity.ByteArrayEntity;    import org.apache.http.impl.client.BasicCookieStore;    import org.apache.http.impl.client.CloseableHttpClient;    import org.apache.http.impl.client.HttpClientBuilder;    import org.apache.http.impl.client.HttpClients;    import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;    import org.apache.http.impl.cookie.BasicClientCookie;    import org.apache.http.message.BasicHeader;    import org.apache.http.message.BasicNameValuePair;    import org.apache.http.protocol.HttpContext;    import org.apache.http.ssl.SSLContextBuilder;    import org.apache.http.util.EntityUtils;    import org.springframework.util.StringUtils;    import javax.net.ssl.HostnameVerifier;    import javax.net.ssl.SSLContext;    import java.io.IOException;    import java.io.UnsupportedEncodingException;    import java.net.CookiePolicy;    import java.net.URLEncoder;    import java.nio.charset.Charset;    import java.security.cert.CertificateException;    import java.security.cert.X509Certificate;    import java.util.ArrayList;    import java.util.Iterator;    import java.util.List;    import java.util.Map;    /**     * Created by ant on 2015/10/12.     */    public class UHttpAgent {        private int connectTimeout = 5000;  //5s        private int socketTimeout = 5000;   //5s        private int maxTotalConnections = 200;         private static UHttpAgent instance;        private CloseableHttpClient httpClient;        private UHttpAgent(){        }        public static UHttpAgent getInstance(){            if(instance == null){                instance = new UHttpAgent();            }            return instance;        }        public static UHttpAgent newInstance(){            return new UHttpAgent();        }        public String get(String url, Map params){            return get(url, null, params, "UTF-8");        }        public String post(String url, Map params){            return post(url, null, params, "UTF-8");        }        public String get(String url , Map headers, Map params, String encoding){            if(this.httpClient == null){                init();            }            String fullUrl = url;            String urlParams = parseGetParams(params, encoding);            if (urlParams != null)            {                if (url.contains("?"))                {                    fullUrl = url + "&" + urlParams;                }                else                {                    fullUrl = url + "?" + urlParams;                }            }            Log.d("the full url is "+ fullUrl);            HttpGet getReq = new HttpGet(fullUrl.trim());            getReq.setHeaders(parseHeaders(headers));            ResponseHandler responseHandler = new ResponseHandler() {                @Override                public String handleResponse(HttpResponse httpResponse) throws IOException {                    HttpEntity entity = httpResponse.getEntity();                    return entity != null ? EntityUtils.toString(entity) : null;                }            };            try {                String res = httpClient.execute(getReq, responseHandler);                return res;            } catch (Exception e) {                e.printStackTrace();            }finally {                getReq.releaseConnection();            }            return null;        }        public String post(String url, Map headers, Map params, String encoding){            List pairs = new ArrayList();            if(params != null){                for(String key : params.keySet()){                    pairs.add(new BasicNameValuePair(key, params.get(key)));                }            }            return post(url, headers, new UrlEncodedFormEntity(pairs, Charset.forName(encoding)));        }        public String post(String url, Map headers, HttpEntity entity){            if(this.httpClient == null) {                init();            }            HttpPost httpPost = new HttpPost(url);            httpPost.setHeaders(parseHeaders(headers));            httpPost.setEntity(entity);            ResponseHandler responseHandler = new ResponseHandler() {                @Override                public String handleResponse(HttpResponse httpResponse) throws IOException {                    HttpEntity entity = httpResponse.getEntity();                    return entity != null ? EntityUtils.toString(entity) : null;                }            };            try {                String body = httpClient.execute(httpPost, responseHandler);                return body;            } catch (IOException e) {                e.printStackTrace();            }finally {                httpPost.releaseConnection();            }            return null;        }        private Header[] parseHeaders(Map headers){            if(null == headers || headers.isEmpty()){                return getDefaultHeaders();            }            Header[] hs = new BasicHeader[headers.size()];            int i = 0;            for(String key : headers.keySet()){                hs[i] = new BasicHeader(key, headers.get(key));                i++;            }            return hs;        }        private Header[] getDefaultHeaders(){            Header[] hs = new BasicHeader[2];            hs[0] = new BasicHeader("Content-Type", "application/x-www-form-urlencoded");            hs[1] = new BasicHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.146 Safari/537.36");            return hs;        }        private String parseGetParams(Map data, String encoding){            if(data == null || data.size()  keyItor = data.keySet().iterator();            while(keyItor.hasNext()){                String key = keyItor.next();                String val = data.get(key);                try {                    result.append(key).append("=").append(URLEncoder.encode(val, encoding).replace("+", "%2B")).append("&");                } catch (UnsupportedEncodingException e) {                    e.printStackTrace();                }            }            return result.deleteCharAt(result.length() - 1).toString();        }        private void init(){            RequestConfig requestConfig = RequestConfig.custom()                    .setConnectTimeout(connectTimeout)                    .setSocketTimeout(socketTimeout)                    .setExpectContinueEnabled(true)                    .setAuthenticationEnabled(true)                    .build();            HttpRequestRetryHandler retryHandler = new HttpRequestRetryHandler() {                @Override                public boolean retryRequest(IOException e, int retryNum, HttpContext httpContext) {                    if(retryNum >= 3){                        return false;                    }                    if(e instanceof org.apache.http.NoHttpResponseException                            || e instanceof org.apache.http.client.ClientProtocolException                            || e instanceof java.net.SocketException){                        return true;                    }                    return false;                }            };            try{                SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {                    @Override                    public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException {                        return true;                    }                }).build();                HostnameVerifier hostnameVerifier = NoopHostnameVerifier.INSTANCE;                SSLConnectionSocketFactory sslFactory = new SSLConnectionSocketFactory(sslContext, hostnameVerifier);                Registry socketFactoryRegistry = RegistryBuilder.create()                        .register("http", PlainConnectionSocketFactory.getSocketFactory())                        .register("https", sslFactory)                        .build();                PoolingHttpClientConnectionManager connMgr = new PoolingHttpClientConnectionManager( socketFactoryRegistry);                connMgr.setMaxTotal(maxTotalConnections);                connMgr.setDefaultMaxPerRoute((connMgr.getMaxTotal()));                HttpClientBuilder builder = HttpClients.custom()                        .setDefaultRequestConfig(requestConfig)                        .setSslcontext(sslContext)                        .setConnectionManager(connMgr)                        .setRetryHandler(retryHandler);                this.httpClient = builder.build();            }catch (Exception e){                e.printStackTrace();            }        }        public HttpClient getHttpClient(){            return this.httpClient;        }        public void destroy(){            if(this.httpClient != null){                try{                    this.httpClient.close();                    this.httpClient = null;                }catch (Exception e){                    e.printStackTrace();                }            }        }    }

当我使用这个类发送post请求时。发生了一些奇怪的事情:

第一次向服务器发送post请求，没问题一分钟后，我向服务器发送相同的请求，也可以。但几分钟后，我发送了相同的请求，出了问题:

    java.net.SocketException: Connection reset by peer: socket write error        at java.net.SocketOutputStream.socketWrite0(Native Method)        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)        at java.net.SocketOutputStream.write(SocketOutputStream.java:136)        at org.apache.http.impl.conn.LoggingOutputStream.write(LoggingOutputStream.java:77)        at org.apache.http.impl.io.SessionOutputBufferImpl.streamWrite(SessionOutputBufferImpl.java:126)        at org.apache.http.impl.io.SessionOutputBufferImpl.flushBuffer(SessionOutputBufferImpl.java:138)        at org.apache.http.impl.io.SessionOutputBufferImpl.flush(SessionOutputBufferImpl.java:146)        at org.apache.http.impl.BHttpConnectionBase.doFlush(BHttpConnectionBase.java:175)        at org.apache.http.impl.DefaultBHttpClientConnection.flush(DefaultBHttpClientConnection.java:185)        at org.apache.http.impl.conn.CPoolProxy.flush(CPoolProxy.java:177)        at org.apache.http.protocol.HttpRequestExecutor.doSendRequest(HttpRequestExecutor.java:215)        at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:122)        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:71)        at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:220)        at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:164)        at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:139)        at com.u8.server.sdk.UHttpAgent.post(UHttpAgent.java:259)        at com.u8.server.sdk.UHttpAgent.post(UHttpAgent.java:147)        at com.u8.server.sdk.baidu.BaiduSDK.verify(BaiduSDK.java:30)        at com.u8.server.web.UserAction.getLoginToken(UserAction.java:100)        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)        at java.lang.reflect.Method.invoke(Method.java:597)

但是，我仍然向服务器发送相同的请求，又没问题了。

每次我按照上述步骤尝试时，都会发生同样的事情。

有人可以帮助我吗？非常感谢。

Answer 1

客户端的对等点是服务器。所以“Connection Reset by Peer”意味着服务器重置了套接字。 Reset意味着强制关闭。

这可能是由于服务器中的错误造成的。如果您还编写了服务器或 servlet(自定义协议(protocol)就是这种情况)，则需要检查服务器的行为以检查其原因。服务器的日志文件可能会提供线索。

如果服务器具有针对行为不当或恶意客户端的保护，则服务器可能会重置套接字，因为它已将您的客户端归类为行为不当。如果您实现了客户端协议(protocol)代码，则可能是因为协议(protocol)实现中存在错误。如果您使用第三方代码来处理通信协议(protocol)，您可能仍然会滥用它；例如发送过大的请求。 HTTP 服务器通过强制 header 字段和正文的最大长度来保护自己免受拒绝服务攻击，并要求客户端以相当快的速率发送数据(无需长时间暂停)，这种情况并不罕见。您的客户可能违反了这些保护措施。