package cn.xiaohuionline.download;


import java.io.FileInputStream;
import java.io.IOException;


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


public class DownloadServlet extends HttpServlet {


public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//获取要下载的文件的名称(就跟get提交方式一样)
String filename = request.getParameter("filename");
//要下载的这个文件的类型----客户端通过文件的MIME类型去区分类型
response.setContentType(this.getServletContext().getMimeType(filename));
//告诉客户端该文件不是直接解析 而是以附件的形式打开（下载）
response.setHeader("Content-Disposition","attachment;filename=" + filename);
//获取文件的绝对路径
String path = this.getServletContext().getRealPath("download/" +filename);
//获得该文件的输入流
FileInputStream in = new FileInputStream(path);
//获的该文件的输出流
ServletOutputStream out = response.getOutputStream();
int len = -1;
byte[] buf = new byte[1024];
while((len = in.read(buf))!=-1){
out.write(buf, 0, len);
out.flush();
}
in.close();
}


public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}