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這篇文章主要講解了springBoot+webMagic怎么實(shí)現(xiàn)網(wǎng)站爬蟲,內(nèi)容清晰明了,對(duì)此有興趣的小伙伴可以學(xué)習(xí)一下,相信大家閱讀完之后會(huì)有幫助。
前端時(shí)間公司項(xiàng)目需要抓取各類數(shù)據(jù),py玩的不6,只好研究Java爬蟲方案,做一個(gè)總結(jié)。
開(kāi)發(fā)環(huán)境:
springBoot 2.2.6、jdk1.8。
1、導(dǎo)入依賴
<!--WebMagic核心包--> <dependency> <groupId>us.codecraft</groupId> <artifactId>webmagic-core</artifactId> <version>0.7.3</version> <!--這里可以去掉WebMagic自帶的日志(因?yàn)榇蛴〉暮芏?。。。。?-> <!-- <exclusions>--> <!-- <exclusion>--> <!-- <groupId>org.slf4j</groupId>--> <!-- <artifactId>slf4j-log4j12</artifactId>--> <!-- </exclusion>--> <!-- </exclusions>--> </dependency> <!--WebMagic擴(kuò)展--> <dependency> <groupId>us.codecraft</groupId> <artifactId>webmagic-extension</artifactId> <version>0.7.3</version> </dependency> <!--WebMagic對(duì)布隆過(guò)濾器的支持--> <dependency> <groupId>com.google.guava</groupId> <artifactId>guava</artifactId> <version>16.0</version> </dependency>
話不多說(shuō),直接上代碼。
基礎(chǔ)案例
下面代碼說(shuō)明以一個(gè)類似列表的頁(yè)面為例
package com.crawler.project.proTask; import com.alibaba.fastjson.JSONObject; import org.springframework.scheduling.annotation.Scheduled; import us.codecraft.webmagic.Page; import us.codecraft.webmagic.Site; import us.codecraft.webmagic.Spider; import us.codecraft.webmagic.processor.PageProcessor; import us.codecraft.webmagic.scheduler.BloomFilterDuplicateRemover; import us.codecraft.webmagic.scheduler.QueueScheduler; import us.codecraft.webmagic.selector.Selectable; import java.util.List; public class TaskProcessor implements PageProcessor { /* * 此方法為爬蟲業(yè)務(wù)實(shí)現(xiàn) * */ @Override public void process(Page page) { //1、爬蟲任務(wù)獲取到一個(gè)page 解析page上的列表 List<Selectable> list = page.getHtml().css("css selector").nodes(); if (list.size() > 0){//說(shuō)明為列表頁(yè)面、需要解析列表中每個(gè)元素的鏈接,存入待獲取page隊(duì)列中 for (Selectable selectable : list) { //遍歷集合,將每個(gè)元素鏈接存入待獲取page隊(duì)列中 page.addTargetRequest(selectable.links().toString()); } //同時(shí)將下一頁(yè)的url存入隊(duì)列中 page.addTargetRequest("下一頁(yè)的url"); }else { //此時(shí)為列表中單個(gè)元素對(duì)應(yīng)的詳情頁(yè) //在自定義方法中處理詳細(xì)頁(yè),獲取需要的數(shù)據(jù)進(jìn)行處理。 handle(page); } } private void handle(Page page) { //例如 處理后的數(shù)據(jù)為一個(gè)JSONObject對(duì)象 JSONObject tmp = new JSONObject(); //將這個(gè)tmp交由自定義的TaskPipline類處理,若未自定義Pipline并設(shè)置到Spider參數(shù)中,框架會(huì)默認(rèn)將tmp打印到控制臺(tái)。 page.putField("obj",tmp); } /* * 此方法為配置爬蟲過(guò)程的一些參數(shù) * */ private Site site = Site.me() .setCharset("UTF-8") .setTimeOut(60 * 1000) .setRetrySleepTime(60 * 1000) .setCycleRetryTimes(5); @Override public Site getSite() { return site; } /* 設(shè)置定時(shí)任務(wù),執(zhí)行爬蟲任務(wù) * */ @Scheduled(initialDelay = 1 * 1000,fixedDelay = 2 * 1000) public void process(){ System.out.println("開(kāi)始執(zhí)行爬蟲抓取任務(wù)"); Spider.create(new TaskProcessor())//注意這里的類名要和當(dāng)前類名對(duì)應(yīng) .addUrl("起始頁(yè)url") .addPipeline(new TaskPipeline()) //此處課自定義 數(shù)據(jù)處理類 (在handle()方法中有); .setScheduler(new QueueScheduler().setDuplicateRemover(new BloomFilterDuplicateRemover(100000))) .thread(3)//此處設(shè)置線程數(shù)量(不宜過(guò)多,最好和列表頁(yè)中列表元素?cái)?shù)量一致) .run(); } }
package com.crawler.project.proTask; import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.JSONObject; import us.codecraft.webmagic.ResultItems; import us.codecraft.webmagic.Task; import us.codecraft.webmagic.pipeline.Pipeline; public class TaskPipeline implements Pipeline { @Override public void process(ResultItems resultItems, Task task) { if (resultItems.getAll() .size() > 0){ Object obj = resultItems.getAll().get("obj"); JSONObject jsonObject = JSON.parseObject(obj.toString()); //獲取到JSONObject對(duì)象下面可進(jìn)行自定義的業(yè)務(wù)處理。 } } }
特殊情況一
需根據(jù)鏈接下載圖片或文件
eg:在上面說(shuō)到的詳情頁(yè)中含有iframe。
1、首先獲取iframe的src
//獲得iframe的src (這里要注意獲得的src是絕對(duì)路徑還是相對(duì)路徑,相對(duì)路徑需要拼接主站點(diǎn)url) String src = html.css("css selector", "src").toString(); //采用jsoup解析 Document document = Jsoup.parse(new URL(src),1000); //獲得需要的元素 Element ele = document.select("css selector").last(); //獲取需要下載的文件的鏈接 String downUrl = ele.attr("href"); //根據(jù)鏈接下載文件 返回一個(gè)文件的名稱 String fileName = downloadFile(downUrl);
//通過(guò)url下載文件 public String downloadFile(String fileUrl) throws FileNotFoundException{ try{ URL httpUrl = new URL(fileUrl); String fileName = UUID.randomUUID().toString() + ".mp3"; File file = new File(this.STATIC_FILEPATH + fileName); System.out.println("============保存文件方法被調(diào)用==============="); FileUtils.copyURLToFile(httpUrl,file); return fileName; }catch (Exception e){ e.printStackTrace(); return null; } }
特殊情況二
有些https站點(diǎn) 無(wú)法直接使用WebMagic默認(rèn)的下載器下載,此時(shí)我們可以根據(jù)站點(diǎn)ssl類型修改下載器。
在項(xiàng)目中創(chuàng)建一個(gè)包用于存放自定義(修改)的下載器類
(?。。≌詗ebMagic框架中HttpClientDownloader,基于此類修改!?。。?/p>
/* 此方法中需要傳入一個(gè)自定義的生成器(HttpClientGenerator) */ package com.crawler.project.spider_download; import org.apache.commons.io.IOUtils; import org.apache.http.HttpResponse; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.util.EntityUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import us.codecraft.webmagic.Page; import us.codecraft.webmagic.Request; import us.codecraft.webmagic.Site; import us.codecraft.webmagic.Task; import us.codecraft.webmagic.downloader.AbstractDownloader; import us.codecraft.webmagic.downloader.HttpClientRequestContext; import us.codecraft.webmagic.downloader.HttpUriRequestConverter; import us.codecraft.webmagic.proxy.Proxy; import us.codecraft.webmagic.proxy.ProxyProvider; import us.codecraft.webmagic.selector.PlainText; import us.codecraft.webmagic.utils.CharsetUtils; import us.codecraft.webmagic.utils.HttpClientUtils; import java.io.IOException; import java.nio.charset.Charset; import java.util.HashMap; import java.util.Map; /** * The http downloader based on HttpClient. * * @author code4crafter@gmail.com <br> * @since 0.1.0 */ public class HttpClientDownloader extends AbstractDownloader { private Logger logger = LoggerFactory.getLogger(getClass()); private final Map<String, CloseableHttpClient> httpClients = new HashMap<String, CloseableHttpClient>(); //自定義的生成器(HttpClientGenerator)注意導(dǎo)入的應(yīng)為自定義的HttpClientGenerator類,而不是WebMagic依賴中的HttpClientGenerator類。 private HttpClientGenerator httpClientGenerator = new HttpClientGenerator(); private HttpUriRequestConverter httpUriRequestConverter = new HttpUriRequestConverter(); private ProxyProvider proxyProvider; private boolean responseHeader = true; public void setHttpUriRequestConverter(HttpUriRequestConverter httpUriRequestConverter) { this.httpUriRequestConverter = httpUriRequestConverter; } public void setProxyProvider(ProxyProvider proxyProvider) { this.proxyProvider = proxyProvider; } private CloseableHttpClient getHttpClient(Site site) { if (site == null) { return httpClientGenerator.getClient(null); } String domain = site.getDomain(); CloseableHttpClient httpClient = httpClients.get(domain); if (httpClient == null) { synchronized (this) { httpClient = httpClients.get(domain); if (httpClient == null) { httpClient = httpClientGenerator.getClient(site); httpClients.put(domain, httpClient); } } } return httpClient; } @Override public Page download(Request request, Task task) { if (task == null || task.getSite() == null) { throw new NullPointerException("task or site can not be null"); } CloseableHttpResponse httpResponse = null; CloseableHttpClient httpClient = getHttpClient(task.getSite()); Proxy proxy = proxyProvider != null ? proxyProvider.getProxy(task) : null; HttpClientRequestContext requestContext = httpUriRequestConverter.convert(request, task.getSite(), proxy); Page page = Page.fail(); try { httpResponse = httpClient.execute(requestContext.getHttpUriRequest(), requestContext.getHttpClientContext()); page = handleResponse(request, request.getCharset() != null ? request.getCharset() : task.getSite().getCharset(), httpResponse, task); onSuccess(request); logger.info("downloading page success {}", request.getUrl()); return page; } catch (IOException e) { logger.warn("download page {} error", request.getUrl(), e); onError(request); return page; } finally { if (httpResponse != null) { //ensure the connection is released back to pool EntityUtils.consumeQuietly(httpResponse.getEntity()); } if (proxyProvider != null && proxy != null) { proxyProvider.returnProxy(proxy, page, task); } } } @Override public void setThread(int thread) { httpClientGenerator.setPoolSize(thread); } protected Page handleResponse(Request request, String charset, HttpResponse httpResponse, Task task) throws IOException { byte[] bytes = IOUtils.toByteArray(httpResponse.getEntity().getContent()); String contentType = httpResponse.getEntity().getContentType() == null ? "" : httpResponse.getEntity().getContentType().getValue(); Page page = new Page(); page.setBytes(bytes); if (!request.isBinaryContent()){ if (charset == null) { charset = getHtmlCharset(contentType, bytes); } page.setCharset(charset); page.setRawText(new String(bytes, charset)); } page.setUrl(new PlainText(request.getUrl())); page.setRequest(request); page.setStatusCode(httpResponse.getStatusLine().getStatusCode()); page.setDownloadSuccess(true); if (responseHeader) { page.setHeaders(HttpClientUtils.convertHeaders(httpResponse.getAllHeaders())); } return page; } private String getHtmlCharset(String contentType, byte[] contentBytes) throws IOException { String charset = CharsetUtils.detectCharset(contentType, contentBytes); if (charset == null) { charset = Charset.defaultCharset().name(); logger.warn("Charset autodetect failed, use {} as charset. Please specify charset in Site.setCharset()", Charset.defaultCharset()); } return charset; } }
然后在自定義的HttpClientGenerator類中修改有關(guān)ssl的參數(shù)
(?。。≌詗ebMagic框架中HttpClientGenerator,基于此類修改?。。。?/p>
/* 自定義的HttpClientGenerator生成器 */ package com.sealion_crawler.project.spider_download; import org.apache.http.HttpException; import org.apache.http.HttpRequest; import org.apache.http.HttpRequestInterceptor; import org.apache.http.client.CookieStore; import org.apache.http.config.Registry; import org.apache.http.config.RegistryBuilder; import org.apache.http.config.SocketConfig; import org.apache.http.conn.socket.ConnectionSocketFactory; import org.apache.http.conn.socket.PlainConnectionSocketFactory; import org.apache.http.conn.ssl.DefaultHostnameVerifier; import org.apache.http.conn.ssl.SSLConnectionSocketFactory; import org.apache.http.impl.client.*; import org.apache.http.impl.conn.PoolingHttpClientConnectionManager; import org.apache.http.impl.cookie.BasicClientCookie; import org.apache.http.protocol.HttpContext; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import us.codecraft.webmagic.Site; import us.codecraft.webmagic.downloader.CustomRedirectStrategy; import javax.net.ssl.SSLContext; import javax.net.ssl.TrustManager; import javax.net.ssl.X509TrustManager; import java.io.IOException; import java.security.KeyManagementException; import java.security.NoSuchAlgorithmException; import java.security.cert.CertificateException; import java.security.cert.X509Certificate; import java.util.Map; /** * @author code4crafter@gmail.com <br> * @since 0.4.0 */ public class HttpClientGenerator { private transient Logger logger = LoggerFactory.getLogger(getClass()); private PoolingHttpClientConnectionManager connectionManager; public HttpClientGenerator() { Registry<ConnectionSocketFactory> reg = RegistryBuilder.<ConnectionSocketFactory>create() .register("http", PlainConnectionSocketFactory.INSTANCE) .register("https", buildSSLConnectionSocketFactory()) .build(); connectionManager = new PoolingHttpClientConnectionManager(reg); connectionManager.setDefaultMaxPerRoute(100); } /* 此方法中設(shè)置ssl有關(guān)參數(shù)。 */ private SSLConnectionSocketFactory buildSSLConnectionSocketFactory() { try { return new SSLConnectionSocketFactory(createIgnoreVerifySSL(), new String[]{"SSLv3", "TLSv1", "TLSv1.1", "TLSv1.2"}, null, new DefaultHostnameVerifier()); // 優(yōu)先繞過(guò)安全證書 } catch (KeyManagementException e) { logger.error("ssl connection fail", e); } catch (NoSuchAlgorithmException e) { logger.error("ssl connection fail", e); } return SSLConnectionSocketFactory.getSocketFactory(); } private SSLContext createIgnoreVerifySSL() throws NoSuchAlgorithmException, KeyManagementException { // 實(shí)現(xiàn)一個(gè)X509TrustManager接口,用于繞過(guò)驗(yàn)證,不用修改里面的方法 X509TrustManager trustManager = new X509TrustManager() { @Override public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException { } @Override public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException { } @Override public X509Certificate[] getAcceptedIssuers() { return null; } }; /* 下面為當(dāng)前框架默認(rèn)參數(shù) SSLContext sc = SSLContext.getInstance("SSLv3"); 可修改為需要的ssl參數(shù)類型 */ SSLContext sc = SSLContext.getInstance("TLS"); sc.init(null, new TrustManager[] { trustManager }, null); return sc; } public HttpClientGenerator setPoolSize(int poolSize) { connectionManager.setMaxTotal(poolSize); return this; } public CloseableHttpClient getClient(Site site) { return generateClient(site); } private CloseableHttpClient generateClient(Site site) { HttpClientBuilder httpClientBuilder = HttpClients.custom(); httpClientBuilder.setConnectionManager(connectionManager); if (site.getUserAgent() != null) { httpClientBuilder.setUserAgent(site.getUserAgent()); } else { httpClientBuilder.setUserAgent(""); } if (site.isUseGzip()) { httpClientBuilder.addInterceptorFirst(new HttpRequestInterceptor() { public void process( final HttpRequest request, final HttpContext context) throws HttpException, IOException { if (!request.containsHeader("Accept-Encoding")) { request.addHeader("Accept-Encoding", "gzip"); } } }); } //解決post/redirect/post 302跳轉(zhuǎn)問(wèn)題 httpClientBuilder.setRedirectStrategy(new CustomRedirectStrategy()); SocketConfig.Builder socketConfigBuilder = SocketConfig.custom(); socketConfigBuilder.setSoKeepAlive(true).setTcpNoDelay(true); socketConfigBuilder.setSoTimeout(site.getTimeOut()); SocketConfig socketConfig = socketConfigBuilder.build(); httpClientBuilder.setDefaultSocketConfig(socketConfig); connectionManager.setDefaultSocketConfig(socketConfig); httpClientBuilder.setRetryHandler(new DefaultHttpRequestRetryHandler(site.getRetryTimes(), true)); generateCookie(httpClientBuilder, site); return httpClientBuilder.build(); } private void generateCookie(HttpClientBuilder httpClientBuilder, Site site) { if (site.isDisableCookieManagement()) { httpClientBuilder.disableCookieManagement(); return; } CookieStore cookieStore = new BasicCookieStore(); for (Map.Entry<String, String> cookieEntry : site.getCookies().entrySet()) { BasicClientCookie cookie = new BasicClientCookie(cookieEntry.getKey(), cookieEntry.getValue()); cookie.setDomain(site.getDomain()); cookieStore.addCookie(cookie); } for (Map.Entry<String, Map<String, String>> domainEntry : site.getAllCookies().entrySet()) { for (Map.Entry<String, String> cookieEntry : domainEntry.getValue().entrySet()) { BasicClientCookie cookie = new BasicClientCookie(cookieEntry.getKey(), cookieEntry.getValue()); cookie.setDomain(domainEntry.getKey()); cookieStore.addCookie(cookie); } } httpClientBuilder.setDefaultCookieStore(cookieStore); } }
好了,到這里 基于WebMagic框架 實(shí)現(xiàn)爬蟲、包括jsoup的使用總結(jié)就到這里的。
看完上述內(nèi)容,是不是對(duì)springBoot+webMagic怎么實(shí)現(xiàn)網(wǎng)站爬蟲有進(jìn)一步的了解,如果還想學(xué)習(xí)更多內(nèi)容,歡迎關(guān)注億速云行業(yè)資訊頻道。
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