JSP编程

jsp文件上传与下载实例代码

互联网 2013-04-23JSP编程7748

文件上传与下载在javaWeb开发中还是比较常见的，于是分享下实用案例，感兴趣的朋友可以参考下哈，希望对你有所帮助

文件上传：

 
public class UploadServlet extends HttpServlet{ 
@Override 
protected void doGet(HttpServletRequest req, HttpServletResponse resp) 
throws ServletException, IOException { 
doPost(req, resp); 
} 
@Override 
protected void doPost(HttpServletRequest req, HttpServletResponse resp) 
throws ServletException, IOException { 
SmartUpload myupload = new SmartUpload(); 
ServletConfig config = getServletConfig(); 
myupload.initialize(config,req,resp); 
resp.setContentType("text/html"); 
resp.setCharacterEncoding("utf-8"); 
PrintWriter out = resp.getWriter(); 
out.println("<h2>处理上传的文件</h2>"); 
out.println("<hr>"); 

try { 
myupload.setMaxFileSize(1024*1024); 
myupload.setTotalMaxFileSize(5*1024*1024); 

myupload.setAllowedFilesList("doc,txt,jpg,gif"); 
myupload.setDeniedFilesList("exe,bat,jsp,htm,html"); 
myupload.upload();//上传文件，此项是必须的 
int count = myupload.getFiles().getCount(); 
Request myRequest = myupload.getRequest(); 
String rndFilename,fileExtName,fileName,filePathName; 
Date dt = null; 
SimpleDateFormat fmt = new SimpleDateFormat("yyyyMMdd"); 
//一一提取上传文件信息，同时可保持文件 
for(int i = 0; i < count; i++){ 
File file = myupload.getFiles().getFile(i); 
if(file.isMissing()) 
continue; 
fileName = new String(file.getFileName().getBytes(),"utf-8");//获取文件名 
filePathName = new String(file.getFilePathName().getBytes(),"utf-8"); 
fileExtName = file.getFileExt(); 
dt = new Date(System.currentTimeMillis()); 
Thread.sleep(100); 
rndFilename = fmt.format(dt)+i+"."+fileExtName; 
out.println("第"+(i+1)+"个文件的文件信息：<br>"); 
out.println(" 文件名为："+fileName+"<br>"); 
out.println(" 文件扩展名为："+fileExtName+"<br>"); 
out.println(" 文件全名："+filePathName+"<br>"); 
out.println(" 文件大小："+file.getSize()/1024+"kb<br>"); 
//创建文件保存位置 
ServletContext context = req.getServletContext(); 
String savePath = context.getRealPath("/upload/"); 
java.io.File folder = new java.io.File(savePath); 
if(!folder.exists()){ 
folder.mkdirs(); 
} 
out.println(" 文件保存路径："+savePath); 
file.saveAs(savePath+"/"+rndFilename,SmartUpload.SAVE_PHYSICAL); 
} 

} catch (Exception e) { 
out.println("文件上传失败！！！！"); 
e.printStackTrace(); 
} 
out.flush(); 
out.close(); 

} 
} 

复制代码代码如下:

 
<%@ page language="java" contentType="text/html; charset=UTF-8" 
pageEncoding="UTF-8"%> 
<%@ page import="com.jspsmart.upload.*" %> 
<% 
//设定请求编码方式，否则遇到中文就会乱码 
request.setCharacterEncoding("utf-8"); 
%> 
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 
<html> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 
<title>上传文件实例</title> 
<script type="text/javascript" src="js/jquery-1.8.1.js"></script> 
<script type="text/javascript"> 
$(function(){ 
$("#number").change(function(){ 
var number = $("#number").attr("value"); 
$("#files").html(""); 
for(var i = 0; i < number; i++){ 
$("#files").append("<input type='file' name='file''"+i+"'><br/>"); 
} 
}); 
}); 
</script> 
</head> 
<body> 
<h2>上传文件实例</h2> 
请选择上传文件数量： 
<select id="number"> 
<option value="1" selected="selected">1</option> 
<option value="2">2</option> 
<option value="3">3</option> 
<option value="4">4</option> 
<option value="5">5</option> 
</select> 
<form action="UploadServlet" method="post" enctype="multipart/form-data"> 
<div id="files"></div> 
<input type="submit" value="提交"/> 
</form> 
</body> 
</html> 

文件下载：

复制代码代码如下:

 
<% 
response.setContentType("application/x-download");//设置为下载application/x-download 
String filedownload = "/要下载的文件名";//即将下载的文件的相对路径 
String filedisplay = "最终要显示给用户的保存文件名";//下载文件时显示的文件保存名称 
String filenamedisplay = URLEncoder.encode(filedisplay,"UTF-8"); 
response.addHeader("Content-Disposition","attachment;filename=" + filedisplay); 
try 
{ 
RequestDispatcher dis = application.getRequestDispatcher(filedownload); 
if(dis!= null) 
{ 
dis.forward(request,response); 
} 
response.flushBuffer(); 
} 
catch(Exception e) 
{ 
e.printStackTrace(); 
} 
finally 
{ 
} 
%> 