Downfile.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>
<%@page import="java.io.*" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'Downfile.jsp' starting page</title>
<style type="text/css">
a:hover{color:red;}
</style>
</head> <body>
<center>
<font color="#00008b" size="5" >文件下载站</font><br><br>
<table>
<%
path=request.getRealPath("");
File file=new File(path,"\\myfile");
String str[]=file.list();
for(int i=0;i<str.length;i++){
String s=str[i];
out.print("<tr><td>"+s+"</td><td><a href='file/Downfile1.jsp?name="+s+"'>下载</a></td></tr>");
}
%>
</table>
</center>
</body>
</html>
Downfile1.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>
<%@page import="java.io.*"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'Downfile1.jsp' starting page</title>
</head> <body>
<%
response.reset();
try {
String str = request.getParameter("name");
//第一个参数为要解码的字节字符,第二个参数为解码方法
//getBytes()里面的参数为str原来的编码方式
str = new String(str.getBytes("UTF-8"), "UTF-8"); path = request.getRealPath("");
out.print(path);
path = path.substring(0, path.lastIndexOf("\\"));
out.print(path);
path = path + "\\myfile\\"; //第一个参数为路径，第二个参数文件名
File fileLoad = new File(path, str);
response.reset(); OutputStream o = response.getOutputStream();
BufferedOutputStream bos = new BufferedOutputStream(o); //输出文件用的字节数组，每次发送500个字节到输出流
byte b[] = new byte[500]; //客户端使用保存文件的对话框
response.setHeader(
"Content-disposition",
"attachment;filename="
+ new String(str.getBytes("UTF-8"), "UTF-8"));
//通知客户文件的MIMIE类型
response.setContentType("application/x-tar");
long fileLength = fileLoad.length();
String length = String.valueOf(fileLength);
response.setHeader("Content_length", length);
FileInputStream in = new FileInputStream(fileLoad);
int n = 0;
while ((n = in.read(b)) != -1) {
bos.write(b, 0, n);
}
bos.close();
//java.lang.IllegalStateException: getOutputStream() has already been called for this response
//加入下面两句不会抛出异常，取消response.reset(),否则会抛出
//java.lang.IllegalStateException: Cannot call reset() after response has been committed
out.clear();
out=pageContext.pushBody();
} catch (Exception e) {
System.out.print(e);
}
//response.reset();
%>
</body>
</html>