Java jsoup爬取图片

jsoup爬取百度瀑布流图片

是的，Java也可以做网络爬虫，不仅可以爬静态网页的图片，也可以爬动态网页的图片，比如采用Ajax技术进行异步加载的百度瀑布流。

      以前有写过用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入研究，提出了另外一种思路解决问题。我的思路是这样的：以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，比如Java领域中的无界面浏览器工具HtmlUnit，但后来我发现其实Jsoup也是可以的，只要用Jsoup去向百度服务器发送Ajax请求就行了，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，实验告诉我们第一种请求方式已经几乎可以满足我们的所有需求。

      本博文所实现的效果是：根据输入的多个关键字，可以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。具体如下所示：

废话不多说，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代表下载一页，一页一般有30张图片
    }

    public static void getPictures(List<String> keywordList, int max,String downloadPath) throws Exception{ // key为关键词,max作为爬取的页数
        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("已经删除所有空图");
    }
    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...
");
                }
            }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();
            }
        }
    }
}