jsp文件下载功能实现代码
本文实例为大家分享了jsp实现文件下载功能的3种方法，供大家参考，具体内容如下
第一种、采用转发的方式：
packagecn.jbit.download.servlet;
importjava.io.IOException;
importjavax.servlet.RequestDispatcher;
importjavax.servlet.ServletException;
importjavax.servlet.http.HttpServlet;
importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;
publicclassDownloadServletextendsHttpServlet{
privatestaticfinallongserialVersionUID=6765085208899952414L;
publicvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse)
throwsServletException,IOException{
doPost(request,response);
}
publicvoiddoPost(HttpServletRequestrequest,HttpServletResponseresponse)
throwsServletException,IOException{
Stringfiledownload="/upload/1/10213.jpg";//即将下载的文件的相对路径
Stringfiledisplay="10213.jpg";//下载文件时显示的文件保存名称
response.setContentType("application/x-download");//设置为下载application/x-download
//response.setContentType("application/x-msdownload");//设置为下载application/x-msdownload
//response.setContentType("application/octet-stream");//设置为下载application/octet-stream
response.addHeader("Content-Disposition","attachment;filename="
+filedisplay);
try{
RequestDispatcherrd=request.getRequestDispatcher(filedownload);
if(rd!=null)
{
rd.forward(request,response);
}
response.flushBuffer();
}catch(Exceptione){
e.printStackTrace();
}
}
}
二、通过输出流的方式：
packagecn.jbit.download.servlet;
importjava.io.BufferedInputStream;
importjava.io.BufferedOutputStream;
importjava.io.File;
importjava.io.FileInputStream;
importjava.io.IOException;
importjava.io.InputStream;
importjava.io.OutputStream;
importjavax.servlet.ServletException;
importjavax.servlet.http.HttpServlet;
importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;
publicclassDownloadOfIOServletextendsHttpServlet{
publicvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse)
throwsServletException,IOException{
doPost(request,response);
}
publicvoiddoPost(HttpServletRequestrequest,HttpServletResponseresponse)
throwsServletException,IOException{
StringbasePath=request.getSession().getServletContext().getRealPath("/upload");
Stringfiledisplay="helloworld.jpg";
Stringfiledownload=basePath+File.separator+"helloworld.jpg";
response.setContentType("applicaiton/x-download");
response.addHeader("Content-Disposition","attachment;filename="+filedisplay);
InputStreamis=null;
OutputStreamos=null;
BufferedInputStreambis=null;
BufferedOutputStreambos=null;
is=newFileInputStream(newFile(filedownload));
bis=newBufferedInputStream(is);
os=response.getOutputStream();
bos=newBufferedOutputStream(os);
byte[]b=newbyte[1024];
intlen=0;
while((len=bis.read(b))!=-1){
bos.write(b,0,len);
}
bis.close();
is.close();
bos.close();
os.close();
}
}
第三种、通过超链接的方式(注意不推荐，因为会暴露下载文件的位置)
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持毛票票。