A scalable crawler framework. It covers the whole lifecycle of crawler: downloading, url management, content extraction and persistent. It can simplify the development of a specific crawler.
- Simple core with high flexibility.
- Simple API for html extracting.
- Annotation with POJO to customize a crawler, no configuration.
- Multi-thread and Distribution support.
- Easy to be integrated.
Add dependencies to your pom.xml:
<dependency>
<groupId>us.codecraft</groupId>
<artifactId>webmagic-core</artifactId>
<version>0.4.0</version>
</dependency>
<dependency>
<groupId>us.codecraft</groupId>
<artifactId>webmagic-extension</artifactId>
<version>0.4.0</version>
</dependency>
Write a class implements PageProcessor:
public class OschinaBlogPageProcesser implements PageProcessor { private Site site = Site.me().setDomain("my.oschina.net") .addStartUrl("http://my.oschina.net/flashsword/blog"); @Override public void process(Page page) { List<String> links = page.getHtml().links().regex("http://my\\.oschina\\.net/flashsword/blog/\\d+").all(); page.addTargetRequests(links); page.putField("title", page.getHtml().xpath("//div[@class='BlogEntity']/div[@class='BlogTitle']/h1").toString()); page.putField("content", page.getHtml().$("div.content").toString()); page.putField("tags",page.getHtml().xpath("//div[@class='BlogTags']/a/text()").all()); } @Override public Site getSite() { return site; } public static void main(String[] args) { Spider.create(new OschinaBlogPageProcesser()) .pipeline(new ConsolePipeline()).run(); } }
-
page.addTargetRequests(links)Add urls for crawling.
You can also use annotation way:
@TargetUrl("http://my.oschina.net/flashsword/blog/\\d+") public class OschinaBlog { @ExtractBy("//title") private String title; @ExtractBy(value = "div.BlogContent",type = ExtractBy.Type.Css) private String content; @ExtractBy(value = "//div[@class='BlogTags']/a/text()", multi = true) private List<String> tags; public static void main(String[] args) { OOSpider.create( Site.me().addStartUrl("http://my.oschina.net/flashsword/blog"), new ConsolePageModelPipeline(), OschinaBlog.class).run(); } }
The architecture of webmagic (refered to Scrapy)
Javadocs: http://code4craft.github.io/webmagic/docs/en/
There are some samples in webmagic-samples package.
Lisenced under Apache 2.0 lisence
To write webmagic, I refered to the projects below :
-
Scrapy
A crawler framework in Python.
-
Spiderman
Another crawler framework in Java.