一、介绍

WebMagic是一个简单灵活的Java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。

二、如何学习

1.查看官网

2.跑通hello world示例(具体可以参考官网，也可以参考博客)

我下面写的单元测试案例，可作为Hello World示例。

注意需要导入Maven依赖:

us.codecraft

webmagic-core

0.7.3

us.codecraft

webmagic-extension

0.7.3

3.带着一个目的

说说我的目的，最近我开发的博客系统，其中有个导入第三方博客的插件，这个插件比较简单就是一个搜索框，在对应的搜索框里面填写URL，点击搜索即可导入到自己的博客。

以导入博客园单篇文章为例:

下面是我的源代码(单篇文章导入,我已经将其封装成一个工具类):

import cn.hutool.core.date.DateUtil;

import com.blog.springboot.dto.CnBlogModelDTO;

import com.blog.springboot.entity.Posts;

import com.blog.springboot.service.PostsService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Component;

import us.codecraft.webmagic.Page;

import us.codecraft.webmagic.Site;

import us.codecraft.webmagic.Spider;

import us.codecraft.webmagic.pipeline.ConsolePipeline;

import us.codecraft.webmagic.processor.PageProcessor;

import us.codecraft.webmagic.selector.Selectable;

import javax.annotation.PostConstruct;

/**

* 导入博客园文章工具类

*/

@Component

public class WebMagicCnBlogUtils implements PageProcessor {

@Autowired

private PostsService postService;

public static WebMagicCnBlogUtils magicCnBlogUtils;

@PostConstruct

public void init() {

magicCnBlogUtils = this;

magicCnBlogUtils.postService = this.postService;

}

private Site site = Site.me()

.setDomain("https://www.cnblogs.com/")

.setSleepTime(1000)

.setUserAgent("Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36");

@Override

public void process(Page page) {

Selectable obj = page.getHtml().xpath("//div[@class='post']");

Selectable title = obj.xpath("//h1[@class='postTitle']//a");

Selectable content = obj.xpath("//div[@class='blogpost-body']");

System.out.println("title:" + title.replace("]*>", ""));

System.out.println("content:" + content);

CnBlogModelDTO blog = new CnBlogModelDTO();

blog.setTitle(title.toString());

blog.setContent(content.toString());

Posts post = new Posts();

String date = DateUtil.date().toString();

post.setPostAuthor(1L);

post.setPostTitle(title.replace("]*>", "").toString());

post.setPostContent(content.toString());

post.setPostExcerpt(content.replace("]*>", "").toString());

post.setPostDate(date);

post.setPostDate(date);

post.setPostModified(date);

boolean importPost = magicCnBlogUtils.postService.insert(post);

if (importPost) {

System.out.println("success");

} else {

System.out.println("fail");

}

}

@Override

public Site getSite() {

return site;

}

/**

* 导入单篇博客园文章数据

*

* @param url

*/

public static void importSinglePost(String url) {

Spider.create(new WebMagicCnBlogUtils())

.addUrl(url)

.addPipeline(new ConsolePipeline())

.run();

}

}

单元测试代码:

import com.blog.springboot.dto.CnBlogModelDTO;

import us.codecraft.webmagic.Page;

import us.codecraft.webmagic.Site;

import us.codecraft.webmagic.Spider;

import us.codecraft.webmagic.pipeline.ConsolePipeline;

import us.codecraft.webmagic.processor.PageProcessor;

import us.codecraft.webmagic.selector.Selectable;

public class WebMagicJunitTest implements PageProcessor {

private Site site = Site.me()

.setDomain("https://www.cnblogs.com/")

.setSleepTime(1000)

.setUserAgent("Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36");

@Override

public void process(Page page) {

Selectable obj = page.getHtml().xpath("//div[@class='post']");

Selectable title = obj.xpath("//h1[@class='postTitle']//a");

Selectable content = obj.xpath("//div[@class='blogpost-body']");

System.out.println("title:" + title.replace("]*>", ""));

System.out.println("content:" + content);

}

@Override

public Site getSite() {

return site;

}

public static void importSinglePost(String url) {

Spider.create(new WebMagicJunitTest())

.addUrl(url)

.addPipeline(new ConsolePipeline())

.run();

}

public static void main(String[] args) {

WebMagicJunitTest.importSinglePost("https://www.cnblogs.com/youcong/p/9404007.html");

}

另外我是怎么知道要爬取哪些数据呢?

需求第一，然后通过Chrome或Firefox浏览器检查元素，如图:

到此这篇关于Java爬虫框架之WebMagic实战的文章就介绍到这了,更多相关Java WebMagic内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！