web中解决乱码问题&&重定向和请求转发区别

String ss = "珍珍";
String s8 = URLEncoder.encode(ss, "utf-8");
String so = URLDecoder.decode(s8, "iso8859-1");
byte[] bs = so.getBytes("iso-8859-1");
String _s = new String(bs, "utf-8");
System.out.println(s);

String username = request.getParameter("username");
username = new String(username.getBytes("iso8859-1"), "utf-8");

request.setCharacterEncoding("utf-8");

URLEncoder.encode(s,"utf-8");//指定编码
URLDecoder.decode(s8,"iso8859-1");//指定解码

//设置下载的头信息，将文件名称 是哟见你utf-8
response.setHeader("content-disposition", "attchment;filename="+URLEncoder.encode(filename,"utf-8"));

//文件下载的工具类
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

import sun.misc.BASE64Encoder;

public class DownLoadUtils {
public static String getName(String agent, String filename) throws UnsupportedEncodingException {
if (agent.contains("MSIE")) {
// IE浏览器
filename = URLEncoder.encode(filename, "utf-8");
filename = filename.replace("+", " ");
} else if (agent.contains("Firefox")) {
// 火狐浏览器
BASE64Encoder base64Encoder = new BASE64Encoder();
filename = "=?utf-8?B?" + base64Encoder.encode(filename.getBytes("utf-8")) + "?=";
} else {
// 其它浏览器
filename = URLEncoder.encode(filename, "utf-8");
}
return filename;
}

}

//通过工具类修改编码
String _filename=DownLoadUtils.getName(request.getHeader("user-agent"),filename);
response.setHeader("content.disposition","attchment;filename"+_filename);

response.setHeader("content-disposition","attachment;filename="+new String(filename.getBytesk("gbk"),"ios8859-1"));