修复不同浏览器下附件中文名乱码的bug

采用[RFC 6266]定义的标注写法，兼容市面上所有主流浏览器
详情请浏览本人原创文章：https://segmentfault.com/a/1190000023601065

ruoyi-common/src/main/java/com/ruoyi/common/utils/file/FileUtils.java

@@ -7,7 +7,9 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
 import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 
 /**
  * 文件处理工具类
@@ -139,4 +141,37 @@ public class FileUtils extends org.apache.commons.io.FileUtils
         }
         return filename;
     }
+
+    /**
+     * 下载文件名重新编码
+     *
+     * @param response 响应对象
+     * @param realFileName 真实文件名
+     * @return
+     */
+    public static void setAttachmentResponseHeader(HttpServletResponse response,String realFileName) throws UnsupportedEncodingException {
+        String percentEncodedFileName = percentEncode(realFileName);
+
+        StringBuilder contentDispositionValue = new StringBuilder();
+        contentDispositionValue.append("attachment; filename=")
+                .append(percentEncodedFileName)
+                .append(";")
+                .append("filename*=")
+                .append("utf-8''")
+                .append(percentEncodedFileName);
+
+        response.setHeader("Content-disposition",
+                contentDispositionValue.toString());
+    }
+
+    /**
+     * 百分号编码工具方法
+     *
+     * @param s 需要百分号编码的字符串
+     * @return 百分号编码后的字符串
+     */
+    public static String percentEncode(String s) throws UnsupportedEncodingException {
+        String encode = URLEncoder.encode(s, StandardCharsets.UTF_8.toString());
+        return encode .replaceAll("\\+", "%20");
+    }
 }