jsp_实现文件下载功能

package MyWeb.java;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.net.URLEncoder;import javax.imageio.stream.FileImageInputStream;import javax.servlet.ServletContext;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.xml.ws.Response;public class Download extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {//String path = this.getServletContext().getRealPath("/download/8.jpg"); //置入文件String path = this.getServletContext().getRealPath("/download/Dj舞曲 - 摇啊摇.mp3");//1 response.getWriter().print(path); 1打印出照片的详细地址 ////实行取得文件名称的工能int index = path.lastIndexOf(File.separator);String name= path.substring(index+1);//response.getWriter().print(name);//实行下载功能//response.setHeader("content-disposition", "attachment;filename = name");response.setHeader("content-disposition", "attachment;filename="+URLEncoder.encode(name, "utf-8"));//取得文件名的名字//实行图片下载InputStream in = new FileInputStream(path);OutputStream out = response.getOutputStream();byte[] b = new byte[1024];int len = 0;while((len=in.read(b))!=-1){out.write(b,0,len);}in.close();}  public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

新建一个文件夹：用以存放要本程序要运用的文件。