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...\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();
}
}
}
}
