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。