Java Web实现文件下载和乱码处理方法

/*
* 下载上传的文件
*/
function downloadFromUpload(fileName){
window.location.href = path + "/download?dir=upload&fileName="+encodeURI(encodeURI(fileName));
}
/*
* 普通下载
*/
function download(fileName){
window.location.href = path + "/download?dir=download&fileName="+encodeURI(encodeURI(fileName));
}

/**
* 文件下载(从上传路径下载)
* 
* @param request
* @param response
* @throws IOException
*/
@ResponseBody
@RequestMapping(value = "/download")
public void downloadFile(HttpServletRequest request,
HttpServletResponse response, FileModel model) throws Exception {
String fileName = URLDecoder.decode(model.getFileName(), "UTF-8");
/*
* 限制只有upload和download文件夹里的文件可以下载
*/
String folderName = "download";
if (!StringUtils.isEmpty(model.getDir())
&& model.getDir().equals("upload")) {
folderName = "upload";
} else {
folderName = "download";
}
String fileAbsolutePath = request.getSession().getServletContext()
.getRealPath("/")
+ "/WEB-INF/" + folderName + "/" + fileName;
FileTools.downloadFile(request, response, fileAbsolutePath);
log.warn("用户Id："
+ (Integer) (request.getSession().getAttribute("userId"))
+ ",用户名："
+ (String) (request.getSession().getAttribute("username"))
+ ",下载了文件:" + fileAbsolutePath);
}

/**
* 下载文件时指定下载名
* 
* @param request
* HttpServletRequest
* @param response
* HttpServletResponse
* @param filePath
* 文件全路径
* @param fileName
* 指定客户端下载时显示的文件名
* @throws IOException
*/
public static void downloadFile(HttpServletRequest request,
HttpServletResponse response, String filePath, String fileName)
throws IOException {
BufferedInputStream bis = null;
BufferedOutputStream bos = null;
bis = new BufferedInputStream(new FileInputStream(filePath));
bos = new BufferedOutputStream(response.getOutputStream());
long fileLength = new File(filePath).length();
response.setCharacterEncoding("UTF-8");
response.setContentType("multipart/form-data");
/*
* 解决各浏览器的中文乱码问题
*/
String userAgent = request.getHeader("User-Agent");
byte[] bytes = userAgent.contains("MSIE") ? fileName.getBytes()
: fileName.getBytes("UTF-8"); // fileName.getBytes("UTF-8")处理safari的乱码问题
fileName = new String(bytes, "ISO-8859-1"); // 各浏览器基本都支持ISO编码
response.setHeader("Content-disposition",
String.format("attachment; filename=\"%s\"", fileName));
response.setHeader("Content-Length", String.valueOf(fileLength));
byte[] buff = new byte[2048];
int bytesRead;
while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
bos.write(buff, 0, bytesRead);
}
bis.close();
bos.close();
}
/**
* 下载文件时不指定下载文件名称
* 
* @param request
* HttpServletRequest
* @param response
* HttpServletResponse
* @param filePath
* 文件全路径
* @throws IOException
*/
public static void downloadFile(HttpServletRequest request,
HttpServletResponse response, String filePath) throws IOException {
File file = new File(filePath);
downloadFile(request, response, filePath, file.getName());
}

response.setContentType("multipart/form-data");

/*
* 解决各浏览器的中文乱码问题
*/
String userAgent = request.getHeader("User-Agent");
byte[] bytes = userAgent.contains("MSIE") ? fileName.getBytes()
: fileName.getBytes("UTF-8"); // fileName.getBytes("UTF-8")处理safari的乱码问题
fileName = new String(bytes, "ISO-8859-1"); // 各浏览器基本都支持ISO编码
response.setHeader("Content-disposition",
String.format("attachment; filename=\"%s\"", fileName));