本文研究的主要是java網(wǎng)絡(luò)爬蟲連接超時的問題，具體如下。
在網(wǎng)絡(luò)爬蟲中，經(jīng)常會遇到如下報錯。即連接超時。針對此問題，一般解決思路為：將連接時間、請求時間設(shè)置長一下。如果出現(xiàn)連接超時的情況，則在重新請求【設(shè)置重新請求次數(shù)】。
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Exception in thread "main" java.net.ConnectException: Connection timed out: connect |
下面的代碼便是使用httpclient解決連接超時的樣例程序。直接上程序。
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package daili;import java.io.IOException;import java.net.URI;import org.apache.http.HttpRequest;import org.apache.http.HttpResponse;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.params.CookiePolicy;import org.apache.http.client.protocol.ClientContext;import org.apache.http.impl.client.BasicCookieStore;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.impl.client.DefaultHttpRequestRetryHandler;import org.apache.http.impl.client.HttpClients;import org.apache.http.impl.cookie.BasicClientCookie2;import org.apache.http.params.HttpConnectionParams;import org.apache.http.params.HttpParams;import org.apache.http.protocol.BasicHttpContext;import org.apache.http.protocol.ExecutionContext;import org.apache.http.protocol.HttpContext;import org.apache.http.util.EntityUtils;/* * author:合肥工業(yè)大學 管院學院 錢洋 */public class Test1 { public static void main(String[] args) throws ClientProtocolException, IOException, InterruptedException { getRawHTML("http://club.autohome.com.cn/bbs/forum-c-2098-1.html#pvareaid=103447"); } public static String getRawHTML ( String url ) throws ClientProtocolException, IOException, InterruptedException{ //初始化 DefaultHttpClient httpclient = new DefaultHttpClient(); httpclient.getParams().setParameter("http.protocol.cookie-policy", CookiePolicy.BROWSER_COMPATIBILITY); //設(shè)置參數(shù) HttpParams params = httpclient.getParams(); //連接時間 HttpConnectionParams.setConnectionTimeout(params, 6000); HttpConnectionParams.setSoTimeout(params, 6000*20); //超時重新請求次數(shù) DefaultHttpRequestRetryHandler dhr = new DefaultHttpRequestRetryHandler(5,true); HttpContext localContext = new BasicHttpContext(); HttpRequest request2 = (HttpRequest) localContext.getAttribute( ExecutionContext.HTTP_REQUEST); httpclient.setHttpRequestRetryHandler(dhr); BasicCookieStore cookieStore = new BasicCookieStore(); BasicClientCookie2 cookie = new BasicClientCookie2("Content-Type","text/html;charset=UTF-8"); BasicClientCookie2 cookie1 = new BasicClientCookie2("User-Agent","Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36"); cookieStore.addCookie(cookie); cookieStore.addCookie(cookie1); localContext.setAttribute(ClientContext.COOKIE_STORE, cookieStore); HttpGet request = new HttpGet(); request.setURI(URI.create(url)); HttpResponse response = null; String rawHTML = ""; response = httpclient.execute(request,localContext); int StatusCode = response.getStatusLine().getStatusCode(); //獲取響應(yīng)狀態(tài)碼 System.out.println(StatusCode); if(StatusCode == 200){ //狀態(tài)碼200表示響應(yīng)成功 //獲取實體內(nèi)容 rawHTML = EntityUtils.toString (response.getEntity()); System.out.println(rawHTML); //輸出實體內(nèi)容 EntityUtils.consume(response.getEntity()); //消耗實體 } else { //關(guān)閉HttpEntity的流實體 EntityUtils.consume(response.getEntity()); //消耗實體 Thread.sleep(20*60*1000); //如果報錯先休息30分鐘 } httpclient.close(); System.out.println(rawHTML); return rawHTML; }} |
結(jié)果：
總結(jié)
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原文鏈接：http://blog.csdn.net/qy20115549/article/details/54973952
