Java学习---下载文件并且对文件编码

import java.io.IOException;
import java.net.URLEncoder;
 
import sun.misc.BASE64Encoder;
 
public class FileUtils {
        /**
         * 下载文件时，针对不同浏览器，进行附件名的编码
         * 
         * @param filename
         *            下载文件名
         * @param agent
         *            客户端浏览器
         * @return 编码后的下载附件名
         * @throws IOException
         */
        public static String encodeDownloadFilename(String filename, String agent)
                throws IOException {
            if (agent.contains("Firefox")) { // 火狐浏览器
                filename = "=?UTF-8?B?"
                        + new BASE64Encoder().encode(filename.getBytes("utf-8"))
                        + "?=";
                filename = filename.replaceAll("\r\n", "");
            } else { // IE及其他浏览器
                filename = URLEncoder.encode(filename, "utf-8");
                filename = filename.replace("+"," ");
            }
            return filename;
        }
}