图画（txt等一下）实施开放的默认下载的默认浏览器，而不是（Java文本）

在网络上，假设我们超链接地址对应于jpg档,txt档，点击链接，默认浏览器打开这些文件，而不是下载，那么，你如何实现竞争力的默认下载。

1.可通过自己写一个download.jsp来实现

<%@ page contentType="text/html; charset=UTF-8"%>
<%@ page import="java.net.*"%>
<%
//得到文件名称字和路径
String filename = request.getParameter("filename");
String filepath = request.getParameter("filepath");
String displayfilename = URLEncoder.encode(filename,"UTF-8");
try {
response.setContentType("application/x-download");
response.setHeader("Content-Disposition","attachment;filename=\"" + displayfilename + "\"");
//HttpServletContext httpServletContext = (HttpServletContext)application;
RequestDispatcher dis = application.getRequestDispatcher(filepath + filename);
//application.getRequestDispatcher(url)这里的url仅仅能是相对路径,如/upload/1.jpg
if (dis != null) {
dis.forward(request,response);
}
response.flushBuffer();
} catch (Exception e) {
e.printStackTrace();
System.out.println("下载取消：" + filepath + filename);
}
out.clear();
out = pageContext.pushBody();
%>

当我们要链接图片（或其它浏览器默认打开的格式，这里以图片为例）时。把相应的文件名称和地址传入download.jsp的filename和filepath參数里。详细写法例如以下

<a class="blue-line-a" href=" /PackTool/download.jsp?

filename=WinGUI.exe&filepath=/other/WinGUI.exe">/other/WinGUI.exe</a>

通过这样方式，我们就能实现文件的默认下载了，而不是浏览器的默认打开。

2.通过文件输出流方式（推荐）：

<%@ page language="java" contentType="application/x-msdownload"    pageEncoding="UTF-8"%>
<%@ page import="java.net.*"%>
<%@ page import="java.io.*"%>
<%@ page import="com.hikvision.modules.guide.util.*"%>
<%
//关于文件下载时採用文件流输出的方式处理：
//加上response.reset()，而且全部的％>后面不要换行。包含最后一个；
String filename = request.getParameter("filename");
String filepath = request.getParameter("filepath");
response.reset();//能够加也能够不加
response.setContentType("application/x-download");
//"想办法找到要提供下载的文件的物理路径＋文件名称";D:/PackTools/shareFolder
String filedownload = GetSharePathXml.getShareFolderPath() + filename;
//"给用户提供的下载文件名称"
String filedisplay = filename;
filedisplay = URLEncoder.encode(filedisplay,"UTF-8");
response.addHeader("Content-Disposition","attachment;filename=" + filedisplay);

OutputStream outp = null;
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();
}
catch(Exception e)
{
System.out.println("Error!");
e.printStackTrace();
}
finally
{
if(in != null)
{
in.close();
in = null;
}
if(outp != null)
{
outp.close();
out.clear();
outp = null;
}
}
%>