分享一个简单的java爬虫框架

反复给网站编写不同的爬虫逻辑太麻烦了,自己实现了一个小框架

可以自定义的部分有:

请求方式(默认为Getuser-agent为谷歌浏览器的设置),可以通过实现RequestSet接口来自定义请求方式

储存方式(默认储存在f盘的html文件夹下),可以通过SaveUtil接口来自定义保存方式

需要保存的资源(默认为整个html页面)

筛选方式(默认所有url都符合要求),通过实现ResourseChooser接口来自定义需要保存的url和资源页面

实现的部分有:

html页面的下载方式,通过HttpClient实现html页面的下载

html页面的解析部分,通过jsoup实现html页面的解析

HtmlDownloader类,用于根据一个url下载一个html页面

package DownloadPackage;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
/*
 * 根据一个url下载一个html页面
 */
public class HtmlDownloader {
	RequestSet requestset = null;
	public HtmlDownloader(RequestSet requestset){
		this.requestset = requestset;
	}
	public String downloadhtml(String url){
		String html = null;
		//创建一个客户端
		//创建一个读取流从entity读取html
		BufferedReader reader = null;
		CloseableHttpClient httpclient = HttpClients.createDefault();
		HttpResponse response = null;
		try {
			response = httpclient.execute(requestset.getMethod(url));
			HttpEntity entity = response.getEntity();
			reader = new BufferedReader(new InputStreamReader(entity.getContent()));
			StringBuilder sb = new StringBuilder();
			while((html = reader.readLine()) != null){
				sb.append(html);
			}
			html = sb.toString();
			System.out.println("一个html页面获取成功");
		}
		catch (IOException e) {
			System.out.println(url+"连接失败");
		}
		finally{
			if(reader != null){
				try {
					reader.close();
					httpclient.close();
				}
				catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		return html;
	}
}

UrlGet类,用于根据一个html页面获得所有的url连接

package DownloadPackage;
import java.util.LinkedList;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
public class UrlGet {
	public LinkedList<String> geturls(String html){
		LinkedList<String> urls = new LinkedList<String>();
		Document doc = Jsoup.parse(html);
		Elements links = doc.getElementsByTag("a");
		for (Element link:links){
			String url = link.attr("href");
			urls.add(url);
		}
		return urls;
	}
}

资源选择接口,需要实现三个方法,第一是isNeed方法,判断url是否为需要的,第二个是isResourse方法,判断url页面是不是需要的资源页面,第三个是process方法,

有时网页上的url是我们需要的但是格式不对,对url进行加工

package ChoosePackage;
public interface ResourseChooser {
	public Boolean isNeed(String url);
	public Boolean isResourse(String url);
	public String process(String url);
}

RequsetSet类,用于自定义请求方法的接口,实现getMethod方法获取请求方法

package DownloadPackage;
import org.apache.http.client.methods.HttpGet;
/*
 * 一个用于获得Request请求的接口
 * 实现getMethod方法获取Get方法
 */
public interface RequestSet {
	public HttpGet getMethod(String url);
}
Saveutil接口用于自定义保存方式,需要实现save方法
package SaveUtil;
/*
 * 数据储存的工具接口,必须实现保存方法
 */
public interface SaveUtil {
	public void save(String url,String html);
}

Spider类,有五中构造方法,可以实现多种自定义操作,其中实现了上述自定义接口的默认实现类

package Spider;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpGet;
import ChoosePackage.MyResourseChooser;
import ChoosePackage.ResourseChooser;
import DownloadPackage.HtmlDownloader;
import DownloadPackage.RequestSet;
import DownloadPackage.UrlGet;
import SaveUtil.MySaveUtil;
import SaveUtil.SaveUtil;
/*
 * 用于爬取资源的类
 */
public class Spider{
	public static void main(String[] args) {
		new Spider("http://www.bilibili.net").spiderstart();
	}
	//种子url
	String seed = null;
	//用于保存数据的类,需要自己实现
	private SaveUtil saveutil = null;
	//html下载类
	private HtmlDownloader downloader = null;
	//url下载类
	private UrlGet urldownloader = null;
	//资源选择工具
	private ResourseChooser resoursechooser = null;
	//用于保存未下载的网页
	LinkedList<String> unvisited = new LinkedList<String>();
	//用于保存已下载的网页
	HashSet<String> visited = new HashSet<String>();
	//自定义储存方式,请求方式,资源筛选方式的构造方法
	public Spider(SaveUtil saveutil,RequestSet request,ResourseChooser resoursechooser,String seed){
		this.saveutil = saveutil;
		this.downloader = new HtmlDownloader(request);
		this.urldownloader = new UrlGet();
		this.resoursechooser = resoursechooser;
		this.seed = seed;
		unvisited.add(seed);
	}
	//自定义储存方式,资源筛选方式的构造方法
	public Spider(SaveUtil saveutil,ResourseChooser resoursechooser,String seed){
		this.resoursechooser = resoursechooser;
		this.downloader = new HtmlDownloader(new getRequest());
		this.saveutil = saveutil;
		this.urldownloader = new UrlGet();
		this.seed = seed;
		unvisited.add(seed);
	}
	//自定义储存方式,请求的构造方法
	public Spider(SaveUtil saveutil,RequestSet requestset,String seed){
		this.saveutil = saveutil;
		this.downloader = new HtmlDownloader(requestset);
		this.resoursechooser = new MyResourseChooser();
		this.urldownloader = new UrlGet();
		this.seed = seed;
		unvisited.add(seed);
	}
	//自定义储存方式的构造方法
	public Spider(SaveUtil saveutil,String seed){
		this.saveutil = saveutil;
		this.downloader = new HtmlDownloader(new getRequest());
		this.resoursechooser = (new MyResourseChooser());
		this.urldownloader = new UrlGet();
		this.seed = seed;
		unvisited.add(seed);
	}
	//默认的爬虫构造方法
	public Spider(String seed){
		this.saveutil = new MySaveUtil();
		this.downloader = new HtmlDownloader(new getRequest());
		this.resoursechooser = (new MyResourseChooser());
		this.urldownloader = new UrlGet();
		this.seed = seed;
		unvisited.add(seed);
	}
	//开始爬取的方法
	private void spiderstart(){
		String html = null;
		while(!unvisited.isEmpty()){
			String url = unvisited.poll();
			System.out.println("开始获取"+url);
			if(resoursechooser.isNeed(url)){
				try{
					html = downloader.downloadhtml(url);
				}
				catch(RuntimeException e){
					System.out.println(url+"连接获取失败");
					continue;
				}
				visited.add(url);
				LinkedList<String> urls = new LinkedList<String>();
				try{
					urls = urldownloader.geturls(html);
				}
				catch(RuntimeException e){
					System.out.println(url+"的html页面为空");
					continue;
				}
				Iterator<String> it = urls.iterator();
				while(it.hasNext()){
					String newurl = it.next();
					if(resoursechooser.isNeed(newurl)&amp;&amp;!visited.contains(newurl)&amp;&amp;!unvisited.contains(newurl)){
						newurl = resoursechooser.process(newurl);
						unvisited.add(newurl);
						System.out.println(newurl+"加入页面");
					}
				}
				System.out.println("获取了"+url+"上的所有url");
				if(resoursechooser.isResourse(url)){
					saveutil.save(url,html);
				}
			}
		}
	}
	//默认资源筛选类
	private class MyResourseChooser implements ResourseChooser{
		@Override
		public Boolean isNeed(String url) {
			// TODO Auto-generated method stub
			if(!url.startsWith("/")&amp;&amp;!url.startsWith("http")){
				return false;
			}
			return true;
		}
		@Override
		public Boolean isResourse(String url) {
			// TODO Auto-generated method stub
			return true;
		}
		@Override
		public String process(String url) {
			// TODO Auto-generated method stub
			if(!url.startsWith("http")){
				url = seed+url;
			}
			return url;
		}
	}
	public class getRequest implements RequestSet{
		public HttpGet getMethod(String url) {
			// TODO Auto-generated method stub
			//创建一个get请求方法
			HttpGet getmethod = new HttpGet(url);
			//HttpHost proxy = new HttpHost("124.88.67.81",80);这里不设置代理IP
			//设置请求超时时间等 
			RequestConfig responseconfig = RequestConfig.custom().setConnectionRequestTimeout(10000).setConnectTimeout(10000).setSocketTimeout(10000).build();
			//设置请求头,主要是user-agent
			getmethod.addHeader("User-Agent","Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36");
			//设置请求参数
			getmethod.setConfig(responseconfig);
			return getmethod;
		}
	}
	//默认的存储类
	public class MySaveUtil implements SaveUtil{
		@Override
		public void save(String url, String html) {
			// TODO Auto-generated method stub
			String filename = getfilename(url);
			BufferedWriter writer = null;
			try{
				writer = new BufferedWriter(new FileWriter(filename));
				writer.write(html);
				writer.flush();
				System.out.println("文件写入成功");
			}
			catch(IOException e){
				System.out.println("文件写入失败");
			}
			finally{
				try {
					if(writer != null)
					writer.close();
				}
				catch (IOException e) {
					// TODO Auto-generated catch block
					System.out.println("流关闭失败");
				}
			}
		}
		private String getfilename(String url){
			String fileparentpath = "f://html";
			File file = new File(fileparentpath);
			if(!file.exists()){
				file.mkdir();
			}
			int last = url.lastIndexOf(".");
			int first = url.indexOf(".");
			url = url.substring(first,last);
			url = url.replaceAll("\\.", "");
			url = url.replaceAll("/", "");
			return fileparentpath+"/"+url+".txt";
		}
	}
}

总结

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