爬虫框架webmagic与spring boot的结合使用

1. 爬虫框架webmagic

WebMagic是一个简单灵活的爬虫框架。基于WebMagic，你可以快速开发出一个高效、易维护的爬虫。

1.1 官网地址

官网文档写的比较清楚，建议大家直接阅读官方文档，也可以阅读下面的内容。地址如下：

官网：http://webmagic.io

中文文档地址: http://webmagic.io/docs/zh/

English: http://webmagic.io/docs/en

官网：www.fhadmin.org

2. webmagic与spring boot框架集成

spring boot与webmagic的结合主要有三个模块，分别为爬取模块Processor,入库模块Pipeline，向数据库存入爬取数据，和定时任务模块Scheduled,复制定时爬取网站数据。

2.1 maven添加

<dependency> 
    <groupId>us.codecraftgroupId> <artifactId>webmagic-coreartifactId> <version>0.5.3version> dependency> <dependency> <groupId>us.codecraftgroupId> <artifactId>webmagic-extensionartifactId> <version>0.5.3version> dependency>

2.2 爬取模块Processor

爬取简书首页Processor，分析简书首页的页面数据，获取响应的简书链接和标题，放入wegmagic的Page中，到入库模块取出添加到数据库。代码如下：

package com.shang.spray.common.processor;

import com.shang.spray.entity.News;
import com.shang.spray.entity.Sources;
import com.shang.spray.pipeline.NewsPipeline;
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.selector.Selectable; import java.util.List; /** * info:简书首页爬虫 * Created by shang on 16/9/9. */ public class JianShuProcessor implements PageProcessor { private Site site = Site.me() .setDomain("jianshu.com") .setSleepTime(100) .setUserAgent("Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36"); ; public static final String list = "http://www.jianshu.com"; @Override public void process(Page page) { if (page.getUrl().regex(list).match()) { List list=page.getHtml().xpath("//ul[@class=‘article-list thumbnails‘]/li").nodes(); for (Selectable s : list) { String title=s.xpath("//div/h4/a/text()").toString(); String link=s.xpath("//div/h4").links().toString(); News news=new News(); news.setTitle(title); news.setInfo(title); news.setLink(link); news.setSources(new Sources(5)); page.putField("news"+title, news); } } } @Override public Site getSite() { return site; } public static void main(String[] args) { Spider spider=Spider.create(new JianShuProcessor()); spider.addUrl("http://www.jianshu.com"); spider.addPipeline(new NewsPipeline()); spider.thread(5); spider.setExitWhenComplete(true); spider.start(); } }

2.3 入库模块Pipeline

官网：www.fhadmin.org 入库模块结合spring boot的Repository模块一起组合成入库方法，继承webmagic的Pipeline，然后实现方法，在process方法中获取爬虫模块的数据，然后调用spring boot的save方法。代码如下：

package com.shang.spray.pipeline;

import com.shang.spray.entity.News;
import com.shang.spray.entity.Sources;
import com.shang.spray.repository.NewsRepository;
import org.apache.commons.lang3.StringUtils; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.jpa.domain.Specification; import org.springframework.stereotype.Repository; import us.codecraft.webmagic.ResultItems; import us.codecraft.webmagic.Task; import us.codecraft.webmagic.pipeline.Pipeline; import javax.persistence.criteria.CriteriaBuilder; import javax.persistence.criteria.CriteriaQuery; import javax.persistence.criteria.Predicate; import javax.persistence.criteria.Root; import java.util.ArrayList; import java.util.Date; import java.util.List; import java.util.Map; /** * info:新闻 * Created by shang on 16/8/22. */ @Repository public class NewsPipeline implements Pipeline { @Autowired protected NewsRepository newsRepository; @Override public void process(ResultItems resultItems, Task task) { for (Map.Entry<String, Object> entry : resultItems.getAll().entrySet()) { if (entry.getKey().contains("news")) { News news=(News) entry.getValue(); Specification specification=new Specification() { @Override public Predicate toPredicate(Root root, CriteriaQuery criteriaQuery, CriteriaBuilder criteriaBuilder) { return criteriaBuilder.and(criteriaBuilder.equal(root.get("link"),news.getLink())); } }; if (newsRepository.findOne(specification) == null) {//检查链接是否已存在 news.setAuthor("水花"); news.setTypeId(1); news.setSort(1); news.setStatus(1); news.setExplicitLink(true); news.setCreateDate(new Date()); news.setModifyDate(new Date()); newsRepository.save(news); } } } } }

2.4 定时任务模块Scheduled

使用spring boot自带的定时任务注解@Scheduled(cron = "0 0 0/2 * * ? "),每天从0天开始，每两个小时执行一次爬取任务，在定时任务里调取webmagic的爬取模块Processor。代码如下：

package com.shang.spray.common.scheduled;

import com.shang.spray.common.processor.DevelopersProcessor;
import com.shang.spray.common.processor.JianShuProcessor;
import com.shang.spray.common.processor.ZhiHuProcessor;
import com.shang.spray.entity.Config;
import com.shang.spray.pipeline.NewsPipeline; import com.shang.spray.service.ConfigService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.jpa.domain.Specification; import org.springframework.scheduling.annotation.Scheduled; import org.springframework.stereotype.Component; import us.codecraft.webmagic.Spider; import javax.persistence.criteria.CriteriaBuilder; import javax.persistence.criteria.CriteriaQuery; import javax.persistence.criteria.Predicate; import javax.persistence.criteria.Root; /** * info:新闻定时任务 * Created by shang on 16/8/22. */ @Component public class NewsScheduled { @Autowired private NewsPipeline newsPipeline; /** * 简书 */ @Scheduled(cron = "0 0 0/2 * * ? ")//从0点开始,每2个小时执行一次 public void jianShuScheduled() { System.out.println("----开始执行简书定时任务"); Spider spider = Spider.create(new JianShuProcessor()); spider.addUrl("http://www.jianshu.com"); spider.addPipeline(newsPipeline); spider.thread(5); spider.setExitWhenComplete(true); spider.start(); spider.stop(); } }

2.5 spring boot启用定时任务

在spring boot的Application里启用定时任务注解，@EnableScheduling。代码如下：

package com.shang.spray;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.builder.SpringApplicationBuilder; import org.springframework.boot.context.web.SpringBootServletInitializer; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.scheduling.annotation.EnableScheduling; /** * info: * Created by shang on 16/7/8. */ @Configuration @EnableAutoConfiguration @ComponentScan @SpringBootApplication @EnableScheduling public class SprayApplication extends SpringBootServletInitializer{ @Override protected SpringApplicationBuilder configure(SpringApplicationBuilder application) { return application.sources(SprayApplication.class); } public static void main(String[] args) throws Exception { SpringApplication.run(SprayApplication.class, args); } }

3. 结束语

使用webmagic是我在水花一现项目中爬取网站数据时使用的的爬虫框架，在综合比较的其他几个爬虫框架后，选择了这个框架，这个框架比较简单易学，且功能强大，我这里只使用了基本的功能，还有许多强大的功能都没有使用。有兴趣的可以去看看官方文档！