download.jsp
<%@page import="java.io.*"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'download.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<jsp:include page="../res.jsp" />
</head>
<body>
<%
/*
File 文件，文件夹
InputStream 输入流
OutputStream 输出流
*/
InputStream is = null;
OutputStream os = null;
response.setContentType("application/octet-stream");
//attachment：附件
//inline：直接打开
response.setHeader("Content-Disposition","attachment;filename = test.txt");
try {
is = new FileInputStream(new File("D:/test.txt"));
os = response.getOutputStream();
byte[] bytes = new byte[1024];
int len = 0;
while((len = is.read(bytes)) != -1)
os.write(bytes,0,len);
os.flush();
//解决抛出异常
out.clear();
out = pageContext.pushBody();
} catch(Exception e) {
e.printStackTrace();
} finally {//无论发生什么，finally里的代码一定会执行
if(is != null) {
try {//如果is关闭失败，os必须也必须关闭掉
is.close();
} catch(Exception e) {
e.printStackTrace();
}
}
if(os != null) {
try {
os.close();
} catch(Exception e) {
e.printStackTrace();
}
}
}
%>
</body>
</html>
