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.
Features:
- 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.
Install:
Add dependencies to your pom.xml:
<dependency>
<groupId>us.codecraft</groupId>
<artifactId>webmagic-core</artifactId>
<version>0.7.3</version>
</dependency>
<dependency>
<groupId>us.codecraft</groupId>
<artifactId>webmagic-extension</artifactId>
<version>0.7.3</version>
</dependency>
WebMagic use slf4j with slf4j-log4j12 implementation. If you customized your slf4j implementation, please exclude slf4j-log4j12.
<exclusions>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
</exclusions>
Get Started:
First crawler:
Write a class implements PageProcessor. For example, I wrote a crawler of github repository infomation.
public class GithubRepoPageProcessor implements PageProcessor {
private Site site = Site.me().setRetryTimes(3).setSleepTime(1000);
@Override
public void process(Page page) {
page.addTargetRequests(page.getHtml().links().regex("(https://github\\.com/\\w+/\\w+)").all());
page.putField("author", page.getUrl().regex("https://github\\.com/(\\w+)/.*").toString());
page.putField("name", page.getHtml().xpath("//h1[@class='public']/strong/a/text()").toString());
if (page.getResultItems().get("name")==null){
//skip this page
page.setSkip(true);
}
page.putField("readme", page.getHtml().xpath("//div[@id='readme']/tidyText()"));
}
@Override
public Site getSite() {
return site;
}
public static void main(String[] args) {
Spider.create(new GithubRepoPageProcessor()).addUrl("https://github.com/code4craft").thread(5).run();
}
}
-
page.addTargetRequests(links)Add urls for crawling.
You can also use annotation way:
@TargetUrl("https://github.com/\\w+/\\w+")
@HelpUrl("https://github.com/\\w+")
public class GithubRepo {
@ExtractBy(value = "//h1[@class='public']/strong/a/text()", notNull = true)
private String name;
@ExtractByUrl("https://github\\.com/(\\w+)/.*")
private String author;
@ExtractBy("//div[@id='readme']/tidyText()")
private String readme;
public static void main(String[] args) {
OOSpider.create(Site.me().setSleepTime(1000)
, new ConsolePageModelPipeline(), GithubRepo.class)
.addUrl("https://github.com/code4craft").thread(5).run();
}
}
Docs and samples:
Documents: http://webmagic.io/docs/
The architecture of webmagic (refered to Scrapy)
There are more examples in webmagic-samples package.
Lisence:
Lisenced under Apache 2.0 lisence
Thanks:
To write webmagic, I refered to the projects below :
-
Scrapy
A crawler framework in Python.
-
Spiderman
Another crawler framework in Java.
Mail-list:
https://groups.google.com/forum/#!forum/webmagic-java
http://list.qq.com/cgi-bin/qf_invite?id=023a01f505246785f77c5a5a9aff4e57ab20fcdde871e988
QQ Group: 373225642 542327088
Related Project
-
Gather Platform
A web console based on WebMagic for Spider configuration and management.