Java下载网络压缩包及解压

       Java可以实现简单的网络爬虫，可以爬网络上的静态图和GIF图，也可以爬网络压缩包，如Zip压缩包和Rar压缩包，因为有些图片或者GIF图一张一张的下载比较麻烦，所以有的网址就提供一个本网页的文件压缩包，供用户下载，本文就以下载网络Zip压缩包的几点内容进行分享，主要内容是讲如何从某一网址批量下载Zip压缩包本地并把它们进行批量解压。

一、任务及效果

1，如下图是一个网页，该网页提供了很多Jar包的下载，我现在想用程序把它们全部下载到本地。

2：下载到本地，如下所示，现在我想用程序把本地的这些压缩文件全部解压到一个文件夹里

3：解压后最终效果如下图所示

二、代码实现

package com.kendy.spider;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.URL;import java.net.URLConnection;import java.util.ArrayList;import java.util.List;import java.util.zip.ZipEntry;import java.util.zip.ZipInputStream;import org.jsoup.Connection;import org.jsoup.Jsoup;import org.jsoup.nodes.Document;import org.jsoup.nodes.Element;import org.jsoup.select.Elements;public class ZipSpider {//根据网址返回网页源代码public static String getHtmlFromUrl(String url,String encoding){StringBuffer html = new StringBuffer();InputStreamReader isr=null;BufferedReader buf=null;String str = null;try {URL urlObj = new URL(url);URLConnection con = urlObj.openConnection();isr = new InputStreamReader(con.getInputStream(),encoding);buf = new BufferedReader(isr);while((str=buf.readLine()) != null){html.append(str+"\n");}//sop(html.toString());} catch (Exception e) {e.printStackTrace();}finally{if(isr != null){try {buf.close();isr.close();} catch (IOException e) {e.printStackTrace();}}}return html.toString();}//根据网址下载网络文件到硬盘，包括图片，Gif图，以及压缩包public static void download(String url,String path){File file= null;FileOutputStream fos=null;String downloadName= url.substring(url.lastIndexOf("/")+1);HttpURLConnection httpCon = null;URLConnection  con = null;URL urlObj=null;InputStream in =null;byte[] size = new byte[1024];int num=0;try {file = new File(path+downloadName);//if(!file.exists()){//file.mkdir();//}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 (Exception e) {e.printStackTrace();} finally{try {in.close();fos.close();} catch (Exception e) {e.printStackTrace();}}}//解压本地文件至目的文件路径public static void unzip(String fromFile,String toFile){ try {              ZipInputStream Zin=new ZipInputStream(new FileInputStream(fromFile));            BufferedInputStream Bin=new BufferedInputStream(Zin);              String Parent=toFile;             File Fout=null;              ZipEntry entry;              try {                  while((entry = Zin.getNextEntry())!=null && !entry.isDirectory()){                      Fout=new File(Parent,entry.getName());                      if(!Fout.exists()){                          (new File(Fout.getParent())).mkdirs();                      }                      FileOutputStream out=new FileOutputStream(Fout);                      BufferedOutputStream Bout=new BufferedOutputStream(out);                      int b;                      while((b=Bin.read())!=-1){                          Bout.write(b);                      }                      Bout.close();                      out.close();                      System.out.println(Fout+"解压成功");                      }                  Bin.close();                  Zin.close();              } catch (IOException e) {                  e.printStackTrace();              }          } catch (FileNotFoundException e) {              e.printStackTrace();          }  }//从总目录下解压文件里所有的压缩包至目的文件路径public static void unzipFromLoc(String filePath) throws Exception{File file = new File(filePath);File[] list = file.listFiles();String from = "";String to = "E:\\myDownload\\unzipFileFromWeb\\";for(File f : list){boolean bool = f.isFile();if(bool){from =  f.getAbsolutePath();from = from.replace("\\","\\\\");sop(from);unzip(from,to);}}}public static void sop(Object obj){System.out.println(obj);}public static void seperate(char c){for(int x=0;x<100;x++){System.out.print(c);}sop("");}/** * @author kendy * @version 1.0 */public static void main(String[] args) throws Exception{int i=0;String zipUrl=null;List<String> list = new ArrayList<>();String fromFile="";String locFile="E:\\myDownload\\unzipFileFromWeb\\";String url = "http://cn.jarfire.org/axis2.json.html";String encoding = "utf-8";String html = getHtmlFromUrl(url,encoding);Document doc = Jsoup.parse(html);Elements elements = doc.select("div.main ul li a[href]"); //带有href属性的a元素unzipFromLoc("E:\\myDownload\\zipFile");seperate('*');sop(list.size());}}