After_End/Load_Down_case/src/main/java/DownLoadUtils.java

import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Base64;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

public class DownLoadUtils {
    public static String getFileName(String agent, String filename) throws UnsupportedEncodingException {
        if (agent.contains("MSIE")) {
            //IE浏览器 -- utf-8编码
            filename = URLEncoder.encode(filename, "utf-8");
            filename = filename.replace("+"," ");

        } else if (agent.contains("Firefox")) {
            //火狐浏览器
            Base64.Encoder encoder = Base64.getEncoder();
            filename = "=?UTF-8?B?" + (new String(encoder.encode(filename.getBytes("UTF-8")))) + "?=";
        } else {
            //其他浏览器
            filename = URLEncoder.encode(filename,"utf-8");
        }
        return filename;
    }
}