jsoup爬取百度瀑布流图片

       是的，Java也能够作网络爬虫，不只能够爬静态网页的图片，也能够爬动态网页的图片，好比采用Ajax技术进行异步加载的百度瀑布流。

      之前有写过用Java进行百度图片的抓取，但只能抓取到第一二页，本博文则对此问题进行了深刻研究，提出了另一种思路解决问题。个人思路是这样的：之前人们总认为既然百度瀑布流是采用Javascript进行异步加载的，那么爬取图片至少要有一个模拟浏览器，好比Java领域中的无界面浏览器工具HtmlUnit，但后来我发现其实Jsoup也是能够的，只要用Jsoup去向百度服务器发送Ajax请求就好了，幸运的是我在观察百度图片的ajax请求时还真发现有两个类型的请求方式：avatarjson和acjson，实验告诉咱们第一种请求方式已经几乎能够知足咱们的全部需求。

      本博文所实现的效果是：根据输入的多个关键字，能够按定制的页数把各自关键字的搜索结果下载到本地文件夹中。具体以下所示：

废话很少说，程序满上------->

package com.kendy.spider;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang3.StringEscapeUtils;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;

// 爬取百度图片
public class JsoupBaidu2 {
	
	public static void main(String[] args) throws Exception{
		String downloadPath = "C:\\Users\\Kendy\\Desktop\\中国明星图";
		List<String> list = nameList("凯莉·布鲁克 詹妮弗·洛佩兹 碧昂斯·诺里斯");
		getPictures(list,1,downloadPath); //1表明下载一页，一页通常有30张图片
	}
	
    public static void getPictures(List<String> keywordList, int max,String downloadPath) throws Exception{ // key为关键词,max做为爬取的页数
        String gsm=Integer.toHexString(max)+"";
        String finalURL = "";
        String tempPath = "";
       for(String keyword : keywordList){
    	   tempPath = downloadPath;
           if(!tempPath.endsWith("\\")){
           	tempPath = downloadPath+"\\";
           }
           tempPath = tempPath+keyword+"\\";
    	   File f = new File(tempPath);
    	   if(!f.exists()){
    		   f.mkdirs();
    	   }
    	   int picCount = 1;
	       for(int page=0;page<=max;page++) { 
	    	   sop("正在下载第"+page+"页面");
	            Document document = null;
	            try {
	            	String url ="http://image.baidu.com/search/avatarjson?tn=resultjsonavatarnew&ie=utf-8&word="+keyword+"&cg=star&pn="+page*30+"&rn=30&itg=0&z=0&fr=&width=&height=&lm=-1&ic=0&s=0&st=-1&gsm="+Integer.toHexString(page*30);
	            	sop(url);
	            	document = Jsoup.connect(url).data("query", "Java")//请求参数  
							 .userAgent("Mozilla/4.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)")//设置urer-agent  get();
							 .timeout(5000)
							 .get();
	                String xmlSource = document.toString();
	                xmlSource = StringEscapeUtils.unescapeHtml3(xmlSource);
	                sop(xmlSource);
	                String reg = "objURL\":\"http://.+?\\.jpg";
	        		Pattern pattern = Pattern.compile(reg);
	                Matcher m = pattern.matcher(xmlSource);
	                while (m.find()) {
	                	finalURL = m.group().substring(9);
	                	sop(keyword+picCount+++":"+finalURL);
	                	download(finalURL,tempPath);
	                	sop("             下载成功");
	                } 
	            } catch (IOException e) {
	                e.printStackTrace();
	            }
	        }
       }
       sop("下载完毕");
       delMultyFile(downloadPath);
       sop("已经删除全部空图");
    }
    public static void delMultyFile(String path){
		File file = new File(path);
		if(!file.exists())
			throw new RuntimeException("File \""+path+"\" NotFound when excute the method of delMultyFile()....");
		File[] fileList = file.listFiles();
		File tempFile=null;
		for(File f : fileList){
			if(f.isDirectory()){
				delMultyFile(f.getAbsolutePath());
			}else{
				if(f.length()==0)
					sop(f.delete()+"---"+f.getName());
			}
		}
	}
    public static List<String> nameList(String nameList){
    	List<String> arr = new ArrayList<>();
    	String[] list;
    	if(nameList.contains(","))
    		list= nameList.split(",");
    	else if(nameList.contains("、"))
    		list= nameList.split("、");
    	else if(nameList.contains(" "))
    		list= nameList.split(" ");
    	else{
    		arr.add(nameList);
    		return arr;
    	}
    	for(String s : list){
    		arr.add(s);
    	}
    	return arr;
    }
    public static void sop(Object obj){
    	System.out.println(obj);
    }
  //根据图片网络地址下载图片
  	public static void download(String url,String path){
  		//path = path.substring(0,path.length()-2);
  		File file= null;
  		File dirFile=null;
  		FileOutputStream fos=null;
  		HttpURLConnection httpCon = null;
  		URLConnection  con = null;
  		URL urlObj=null;
  		InputStream in =null;
  		byte[] size = new byte[1024];
  		int num=0;
  		try {
  			String downloadName= url.substring(url.lastIndexOf("/")+1);
  			dirFile = new File(path);
  			if(!dirFile.exists() && path.length()>0){
  				if(dirFile.mkdir()){
  					sop("creat document file \""+path.substring(0,path.length()-1)+"\" success...\n");
  				}
  			}else{
  				file = new File(path+downloadName);
  				fos = new FileOutputStream(file);
  				if(url.startsWith("http")){
  					urlObj = new URL(url);
  					con = urlObj.openConnection();
  					httpCon =(HttpURLConnection) con;
  					in = httpCon.getInputStream();
  					while((num=in.read(size)) != -1){
  						for(int i=0;i<num;i++)
  						   fos.write(size[i]);
  					}
  				}
  			}
  		}catch (FileNotFoundException notFoundE) {
  			sop("找不到该网络图片....");
  		}catch(NullPointerException nullPointerE){
  			sop("找不到该网络图片....");
  		}catch(IOException ioE){
  			sop("产生IO异常.....");
  		}catch (Exception e) {
  			e.printStackTrace();
  		}finally{
  			try {
  				fos.close();
  			} catch (Exception e) {
  				e.printStackTrace();
  			}
  		}
  	}
}