Jsp file download, for example, txt

Download. jsp
<% @ Page import = "java. io. *" %>

<% @ Page language = "java" contentType = "text/html; charset = UTF-8"
PageEncoding = "UTF-8" %>
<%
String filename = request. getParameter ("filename"); // "tzhsymd.txt ";
String filepath = request. getParameter ("filepath"); // "path ";
Response. setContentType ("application/octet-stream ");
Response. setHeader ("Content-Disposition", "attachment; filename =" + filename );
BufferedReader br = new BufferedReader (new InputStreamReader (new FileInputStream (filepath + filename), "UTF-8 "));
BufferedWriter fos = new BufferedWriter (new OutputStreamWriter (response. getOutputStream (), "UTF-8 "));
String line;
While (line = br. readLine ())! = Null ){
Fos. write (line + "\ n \ r ");
}
Fos. flush ();
Fos. close ();
Br. close ();
Out. clear ();
Out = pageContext. pushBody ();
%>

// Out. clear ();
// Out = pageContext. pushBody ();

Both of them prevent getOutputStream () has already been called for this respons