webmagic/README.md

Readme in Chinese

User Manual (Chinese)

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>0.4.3</version>
</dependency>
<dependency>
    <groupId>us.codecraft</groupId>
    <artifactId>webmagic-extension</artifactId>
    <version>0.4.3</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：

public class OschinaBlogPageProcesser implements PageProcessor {

    private Site site = Site.me().setDomain("my.oschina.net");

    @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()).addUrl("http://my.oschina.net/flashsword/blog")
             .addPipeline(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(),
			new ConsolePageModelPipeline(), OschinaBlog.class).addUrl("http://my.oschina.net/flashsword/blog").run();
    }
}

Docs and samples:

The architecture of webmagic (refered to Scrapy)

Javadocs: http://code4craft.github.io/webmagic/docs/en/

There are some samples in webmagic-samples package.

Lisence:

Lisenced under Apache 2.0 lisence

Contributors:

Thanks these people for commiting source code, reporting bugs or suggesting for new feature:

• yuany
• yxssfxwzy
• linkerlin
• d0ngw
• xuchaoo
• supermicah
• SimpleExpress
• aruanruan
• l1z2g9
• zhegexiaohuozi
• ywooer
• yyw258520
• perfecking
• ccliangbo
• lidongyang

Thanks:

To write webmagic, I refered to the projects below :

• Scrapy

  A crawler framework in Python.

  http://scrapy.org/

• Spiderman

  Another crawler framework in Java.

  https://gitcafe.com/laiweiwei/Spiderman

Mail-list:

https://groups.google.com/forum/#!forum/webmagic-java