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;
impor
4000
t 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());

}
}