downloadmusic.java

J2EE+jsp音乐网站,提供登录

package com.music;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class DownLoadMusic extends HttpServlet {

    private int len = 10 * 1024 * 1024; //定义字符数组长度，文件的最大长度
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		String MusicID=request.getParameter("MusicID");
		String MusicName="";
		if(MusicID!=null)
		{
		       Connection conn; 
		       Statement st; 
		       ResultSet rs; 
		       InputStream in;
		       String SelectStr = "select MusicName,MusicData from MusicInfor where MusicID = " + MusicID; 
		       try 
		       { 
		    	  
		    	   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
		    	   //这里是使用数据源进行连接的，数据源的名称是DataSoure。
				   conn = DriverManager.getConnection("jdbc:odbc:DataSoure","sa","yeguoxing");
		           st = conn.createStatement(); 
		           rs = st.executeQuery(SelectStr); 
		           rs.next();
		           { 
		        	   //MusicData为存放音乐文件的字段，自动类型是Image
		        	   MusicName=rs.getString("MusicName");
		        	   in = rs.getBinaryStream("MusicData");
		        	   //len=in.available(); 获取流的有效大小，使用时出了点问题，所以暂时屏蔽掉
		        	   //设置输出类型为音乐文件
		        	   response.reset(); 
		        	   response.setContentType("application/octet-stream;charset=ISO-8859-1");  
		        	   response.setHeader("Content-Disposition","attachment;filename=\""+MusicName+".mp3\"");
		        	   System.out.print(MusicName);
			   		   //response.reset(); 
			   		   OutputStream toClient = response.getOutputStream();
			   		   //FileOutputStream fos=new FileOutputStream("D:\\dddd.mp3");
			   		   byte[] P_Buf = new byte[len];
			   		   int i;
			   		   while ((i = in.read(P_Buf)) != -1)
			   		   {                    
			   			   toClient.write(P_Buf, 0, i);
			   			   //fos.write(P_Buf, 0, i); 
			   		   }                
			   		   in.close();
			   		   toClient.flush(); //强制清出缓冲区
			   		   toClient.close();
			   		   //fos.flush();
			   		   //fos.close();
			   		   
		           }
		           rs.close(); 
		           conn.close();
		           
		       }
		       catch (Exception ex) 
		       { 
		           System.out.print("Play Error:" + ex.toString()); 
		       } 

		}
	}
	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request,response);
		
	}

}