jsp实现文件下载与中文文件名乱码问题解决

之前,写过一个Download.jsp文件,可以解决下载文件乱码问题(诸如:DOC,XSL文件等等).
后来发现,遇到中文名的文件的时候,文件下载将会报错~~~~
今天,通过改写原Download.jsp文件已经彻底解决了这个问题~
现在,把一整套的文件上传下载的方法给贴出来~~~以便大家借鉴!~!~!~!~!
作者:古埃及法老

download.jsp文件
---------------------------------------------------------

<%
java.io.BufferedInputStream bis=null;
java.io.BufferedOutputStream bos=null;
try{
String filename=request.getParameter("filename");
filename=new String(filename.getBytes("iso8859-1"),"gb2312");
response.setContentType("application/x-msdownload");
response.setHeader("Content-disposition","attachment; filename="+new String(filename.getBytes("gb2312"),"iso8859-1"));
bis =new java.io.BufferedInputStream(new java.io.FileInputStream(config.getServletContext().getRealPath("files/" + filename)));
bos=new java.io.BufferedOutputStream(response.getOutputStream());
byte[] buff = new byte[2048];
int bytesRead;
while(-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
bos.write(buff,0,bytesRead);
}
}
catch(Exception e){
e.printStackTrace();
}
finally {
if (bis != null)bis.close();
if (bos != null)bos.close();
}
%>

注意，关键就是setHeader里的filename需要重新编码,格式是ISO-8859-1就ＯＫ了

以下是我自己项目中用到的代码片断，供参考:

list.jsp: 显示附件名称的页面

<tr>
<td height="25" class="tdcor">附  件 </td>
<td colspan="3" height=50>
<%
if (null != publish.getAttatchFilename() &&
publish.getAttatchFilename().length() > 0) {
%>
<a href="publish_do.jsp?method=download&fileName=
<%=URLEncoder.encode(publish.getAttatchFilename(),"GBK")%>">
<%=URLDecoder.decode(publish.getAttatchFilename(),"GBK")%></a>
<%
}
%>
</td>
</tr>

download.jsp:下载页面
else if (null != method && method.equals("download")) {//下载附件

String fileName = request.getParameter("fileName");
File file = new File(Constants.PUBLISH_FILE_PATH + "/" + URLDecoder.decode(fileName,"GBK"));
response.reset();
response.setContentType("application/octet-stream; charset=GBK");
response.addHeader("Content-Disposition", "attachment; filename=" + CourseDetailBusiness.transfer(URLDecoder.decode(fileName,"GBK"),"GBK","ISO-8859-1"));
response.setContentLength((int) file.length());

byte[] buffer = new byte[4096];
BufferedOutputStream output = null;
BufferedInputStream input = null;

// 写缓冲区：
try {
output = new BufferedOutputStream(response.getOutputStream());
input = new BufferedInputStream(new FileInputStream(file));

int n = (-1);
while ((n = input.read(buffer, 0, 4096)) > -1) {
output.write(buffer, 0, n);
}
response.flushBuffer();
}
catch (Exception e) {
} // maybe user cancelled download
finally {
if (input != null) input.close();
if (output != null) output.close();
}

说明:
１。文件名在数据库中保存的编码为URLEncode
2.在list.jsp显示的时候多了一次encode,不知为什么，不encode一次还不行，实际上是第二次编码了