JSP 下载文件

JSP 下载文件的方法：
方法一：RequestDispatcher的方式
           String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
response.setContentType("application/x-download");//设置为下载application/x-download
String filedownload = path+"/point/LGVideoOcxSetup.msi";//即将下载的文件的相对路径
String filedisplay = "LGVideoOcxSetup.msi";//下载文件时显示的文件保存名称
filedisplay = 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 {
}
方法二：文件流方式
//关于文件下载时采用文件流输出的方式处理： 
//加上response.reset()，并且所有的％>后面不要换行，包括最后一个； 
response.reset();//可以加也可以不加 
response.setContentType("application/x-download");
String filedownload=application.getRealPath("/point/LGVideoOcxSetup.msi"); //获取的物理路径 
String filedisplay = "LGVideoOcxSetup.msi";
    filedisplay = URLEncoder.encode(filedisplay, "UTF-8");
response.addHeader("Content-Disposition", "attachment;filename="
+ filedisplay);
java.io.OutputStream outp = null;
java.io.FileInputStream in = null;
try {
outp = response.getOutputStream();
in = new FileInputStream(filedownload);
byte[] b = new byte[1024];
int i = 0;
while ((i = in.read(b)) > 0) {
outp.write(b, 0, i);
}
outp.flush();  
out.clear();
out = pageContext.pushBody();
} catch (Exception e) {
System.out.println("Error!");
e.printStackTrace();
} finally {
if (in != null) {
in.close();
in = null;
}
}