JavaEE 下载文件中文乱码兼容多浏览器

	public static String encodeFileName(HttpServletRequest request, String fileName) {
		
		String returnFileName = "";
		String agent = request.getHeader("User-Agent");
		boolean isMSIE = (agent != null && agent.indexOf("MSIE") != -1);
		try {
			
			if (isMSIE) {
				returnFileName = URLEncoder.encode(fileName, "UTF-8");  
			} else {
				returnFileName = new String(fileName.getBytes("UTF-8"), "ISO-8859-1");
			}
			
			if (returnFileName.length() > 150) {  
				returnFileName = new String(fileName.getBytes("GB2312"), "ISO8859-1");  	
				returnFileName = StringUtils.replace(returnFileName, " ", "%20");  
			} 
			
		} catch (Exception e) {
			logger.info("encodeFileName error...");
		}
		
		return returnFileName;
	}