java 从网络下载视屏简短小程序

package download;


import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;


import com.mysql.jdbc.Statement;








/** 
 * 从输入流中获取字节数组 
 * @param inputStream 
 * @return 
 * @throws IOException 
 */  




public class DownLoadMain {


/** 
* 从网络Url中下载文件 
* @param urlStr 
* @param fileName 
* @param savePath 
* @throws IOException 
*/  
public static void  downLoadFromUrl(String urlStr,String fileName,String savePath) throws IOException{  
   URL url = new URL(urlStr);    
   HttpURLConnection conn = (HttpURLConnection)url.openConnection();    
           //设置超时间为3秒  
   //conn.setConnectTimeout(3*1000);  
   //防止屏蔽程序抓取而返回403错误  
   conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");  


   //得到输入流  
   InputStream inputStream = conn.getInputStream();    
   //获取自己数组  
   byte[] getData = readInputStream(inputStream);      


   //文件保存位置  
   File saveDir = new File(savePath);  
   if(!saveDir.exists()){  
       saveDir.mkdir();  
   }  
   File file = new File(saveDir+File.separator+fileName);      
   FileOutputStream fos = new FileOutputStream(file);       
   fos.write(getData);   
   if(fos!=null){  
       fos.close();    
   }  
   if(inputStream!=null){  
       inputStream.close();  
   }  




   System.out.println("info:"+fileName+'：'+url+" download success");   


}  
/** 
     * 从输入流中获取字节数组 
     * @param inputStream 
     * @return 
     * @throws IOException 
     */ 
public static  byte[] readInputStream(InputStream inputStream) throws IOException {    
   byte[] buffer = new byte[1024];    
   int len = 0;    
   ByteArrayOutputStream bos = new ByteArrayOutputStream();    
   while((len = inputStream.read(buffer)) != -1) {    
       bos.write(buffer, 0, len);    
   }    
   bos.close();    
   return bos.toByteArray();    
}    

public static void main(String[] args) {
// TODO Auto-generated method stub
//FabricCommunicationException
//驱动器的名称
String driver="com.mysql.jdbc.Driver";
//url 只想数据的的数据库名
String url="jdbc:mysql://127.0.0.1:3306/foodnutrifrombh";
//Mysql 的用户名，密码
String user="root";
String password="root";
//System.out.println("ajizai");
try{
//加载驱动程序
//System.out.println("ajizai");
Class.forName(driver);
//lianjie shju ku
Connection connection=DriverManager.getConnection(url,user,password);
if(!connection.isClosed())
System.out.println(" sucesss conect database!");
//只想Sql语句
Statement statement=(Statement) connection.createStatement();
//执行Sql语句
String sql="select chinesename,downloadurl from download1 where id >16";
//结果集
ResultSet resultSet=statement.executeQuery(sql);
System.out.println("-----------------");
            System.out.println("执行结果如下所示:");
            System.out.println("-----------------");
            System.out.println(" 名称" + "\t" + " url");
            System.out.println("-----------------");
            String chinesename=null;
            int i=1;
            while(resultSet.next()){
            //选择chinsesename这一列数据
            chinesename=resultSet.getString("chinesename");
            //解码
            chinesename = new String(chinesename.getBytes("utf-8"),"utf-8");
            System.out.println(resultSet.getString("downloadurl") + "\t" +chinesename +"\t"+i++);
            downLoadFromUrl(resultSet.getString("downloadurl"),chinesename+".mp4","E:/shipin/");
           
           
            }
resultSet.close();
connection.close();


}
catch(ClassNotFoundException e) {




            System.out.println("Sorry,can`t find the Driver!"); 
            e.printStackTrace();




           } catch(SQLException e) {




            e.printStackTrace();




           }
catch(Exception e)
{
e.printStackTrace();
}


}


}