List<MultipartFile> not supported, while MultipartFile[] works on v2.1.6

My server api:

    /**
     * 接收上传文件并转移到服务器根目录下。
     *
     * @param file 客户端上传的文件
     * @throws IOException
     */
    @PostMapping(path = "/uploadWithInfo")
    UserInfo uploadWithInfo(@FormPart(name = "user") UserInfo userInfo,
                            @FormPart(name = "file") MultipartFile file,
                            @FormPart(name = "fileList", required = false) List<MultipartFile> fileList
    ) throws IOException {
        File localFile = FileUtils.createFile(file);
        file.transferTo(localFile);
        if (fileList != null) {
            userInfo.setUserName(userInfo.getUserId() + " | fileList: " + fileList.size());
        }
        return userInfo;
    }

My client calls:

        UserInfo userInfo = new UserInfo();
        userInfo.setUserId("yanzhenjie");
        userInfo.setUserName("YAN Zhenjie");

        FormBody formBody = FormBody.newBuilder()
                .param("user", JSON.toJSONString(userInfo))
                .build();

        // 传object和文件及多文件
        List<File> files = new ArrayList<>();
        files.add(new File("/sdcard/batteryInfo.json"));
        files.add(new File("/sdcard/userinfo.json"));
        // 第一次上传不带可选参数多个文件
        formBody = FormBody.newBuilder()
                .param("user", JSON.toJSONString(userInfo))
                .file("file", new File("/sdcard/Debug_Log_ST2303/loglist.txt"))
                .build();
        Kalle.post(UrlConfig.UPLOAD_WITH_INFO)
                .body(formBody)
                .perform(new SimpleCallback<UserInfo>(this) {
                    @Override
                    public void onResponse(SimpleResponse<UserInfo, String> response) {
                        Logger.i(UrlConfig.UPLOAD_WITH_INFO + " 第一次上传不带可选参数多个文件 responded form:" + response.succeed());
                    }
                });
        // 第二次上传带可选参数多个文件
        formBody = FormBody.newBuilder()
                .param("user", JSON.toJSONString(userInfo))
                .file("file", new File("/sdcard/Debug_Log_ST2303/loglist.txt"))
                .files("fileList", files)
                .build();
        Kalle.post(UrlConfig.UPLOAD_WITH_INFO)
                .body(formBody)
                .perform(new SimpleCallback<UserInfo>(this) {
                    @Override
                    public void onResponse(SimpleResponse<UserInfo, String> response) {
                        Logger.i(UrlConfig.UPLOAD_WITH_INFO + " 第二次上传带可选参数多个文件 responded form:" + response.succeed());
                    }
                });

The output from the server:

2021-01-23 14:40:04.173 24806-25118/com.yanzhenjie.andserver.sample I/AndServerSample: Path: /uploadWithInfo
2021-01-23 14:40:04.173 24806-25118/com.yanzhenjie.andserver.sample I/AndServerSample: Method: POST
2021-01-23 14:40:04.174 24806-25118/com.yanzhenjie.andserver.sample I/AndServerSample: Param: {"user":["{\"userId\":\"yanzhenjie\",\"userName\":\"YAN Zhenjie\"}"]}
2021-01-23 14:40:04.178 24806-25118/com.yanzhenjie.andserver.sample W/System.err: com.alibaba.fastjson.JSONException: exepct '[', but {, pos 1, json : {"capacityVoltage":0.471,"floatingCharging":false,"lineGatherCharging":0,"mcuAlarmType":0,"powerSourceVoltage":0,"sampleSecondsSinceEpoch":1611384001,"voltage":6.728,"workTemperature":20.0,"name":"BatteryInfo"}
2021-01-23 14:40:04.179 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.alibaba.fastjson.parser.DefaultJSONParser.parseArray(DefaultJSONParser.java:734)
2021-01-23 14:40:04.179 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.alibaba.fastjson.serializer.CollectionCodec.deserialze(CollectionCodec.java:171)
2021-01-23 14:40:04.179 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.alibaba.fastjson.parser.DefaultJSONParser.parseObject(DefaultJSONParser.java:704)
2021-01-23 14:40:04.179 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.alibaba.fastjson.parser.DefaultJSONParser.parseObject(DefaultJSONParser.java:677)
2021-01-23 14:40:04.190 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.alibaba.fastjson.JSON.parseObject(JSON.java:245)
2021-01-23 14:40:04.191 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.alibaba.fastjson.JSON.parseObject(JSON.java:217)
2021-01-23 14:40:04.191 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.alibaba.fastjson.JSON.parseObject(JSON.java:187)
2021-01-23 14:40:04.191 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.yanzhenjie.andserver.sample.util.JsonUtils.parseJson(JsonUtils.java:80)
2021-01-23 14:40:04.191 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.yanzhenjie.andserver.sample.component.AppMessageConverter.convert(AppMessageConverter.java:50)
2021-01-23 14:40:04.191 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.yanzhenjie.andserver.sample.controller.CentralControllerUploadWithInfoHandler.onHandle(CentralControllerUploadWithInfoHandler.java:106)
2021-01-23 14:40:04.195 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.yanzhenjie.andserver.framework.handler.MappingHandler.handle(MappingHandler.java:174)
2021-01-23 14:40:04.195 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.yanzhenjie.andserver.DispatcherHandler.handle(DispatcherHandler.java:159)
2021-01-23 14:40:04.195 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at com.yanzhenjie.andserver.DispatcherHandler.handle(DispatcherHandler.java:128)
2021-01-23 14:40:04.195 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at org.apache.httpcore.protocol.HttpService.doService(HttpService.java:437)
2021-01-23 14:40:04.195 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at org.apache.httpcore.protocol.HttpService.handleRequest(HttpService.java:342)
2021-01-23 14:40:04.195 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at org.apache.httpcore.impl.bootstrap.Worker.run(Worker.java:66)
2021-01-23 14:40:04.196 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
2021-01-23 14:40:04.200 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
2021-01-23 14:40:04.200 24806-25118/com.yanzhenjie.andserver.sample W/System.err:     at java.lang.Thread.run(Thread.java:761)

This is what generated code looks like:

package com.yanzhenjie.andserver.sample.controller;

import android.content.Context;
import android.text.TextUtils;
import com.yanzhenjie.andserver.error.ParamMissingException;
import com.yanzhenjie.andserver.framework.MessageConverter;
import com.yanzhenjie.andserver.framework.cross.CrossOrigin;
import com.yanzhenjie.andserver.framework.handler.MappingHandler;
import com.yanzhenjie.andserver.framework.mapping.Addition;
import com.yanzhenjie.andserver.framework.mapping.Mapping;
import com.yanzhenjie.andserver.framework.view.ObjectView;
import com.yanzhenjie.andserver.framework.view.View;
import com.yanzhenjie.andserver.http.HttpMethod;
import com.yanzhenjie.andserver.http.HttpRequest;
import com.yanzhenjie.andserver.http.HttpResponse;
import com.yanzhenjie.andserver.http.RequestBody;
import com.yanzhenjie.andserver.http.multipart.MultipartFile;
import com.yanzhenjie.andserver.http.multipart.MultipartRequest;
import com.yanzhenjie.andserver.sample.model.UserInfo;
import com.yanzhenjie.andserver.util.MediaType;
import com.yanzhenjie.andserver.util.TypeWrapper;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.lang.Object;
import java.lang.Override;
import java.lang.Throwable;
import java.lang.reflect.Type;
import java.util.List;
import java.util.Map;

/**
 * This file was generated by AndServer automatically and you should NOT edit it.
 */
public final class CentralControllerUploadWithInfoHandler extends MappingHandler {
  private Object mHost;

  public CentralControllerUploadWithInfoHandler(Object host, Mapping mapping, Addition addition,
      CrossOrigin crossOrigin) {
    super(host, mapping, addition, crossOrigin);
    this.mHost = host;
  }

  @Override
  protected View onHandle(HttpRequest request, HttpResponse response) throws Throwable {
    Context context = (Context)request.getAttribute(HttpRequest.ANDROID_CONTEXT);
    String httpPath = request.getPath();
    HttpMethod httpMethod = request.getMethod();

    Object converterObj = request.getAttribute(HttpRequest.HTTP_MESSAGE_CONVERTER);
    MessageConverter converter = null;
    if (converterObj != null && converterObj instanceof MessageConverter) {
      converter = (MessageConverter)converterObj;
    }

    MultipartRequest multiRequest = null;
    if (request instanceof MultipartRequest) {
      multiRequest = (MultipartRequest) request;
    }

    RequestBody requestBody = null;
    if (httpMethod.allowBody()) {
      requestBody = request.getBody();
    }

    Map<String, String> pathMap = getPathVariable(httpPath);

    /** ---------- Building Parameters ---------- **/ 

    UserInfo param0 = null;
    Type param0Type = new TypeWrapper<UserInfo>(){}.getType();
    if (converter != null && multiRequest != null) {
      MultipartFile param0File = multiRequest.getFile("user");
      if (param0File != null) {
        InputStream stream = param0File.getStream();
        MediaType mimeType = param0File.getContentType();
        param0 = converter.convert(stream, mimeType, param0Type);
      }
      if (param0 == null) {
        String param0Str = multiRequest.getParameter("user");
        if (!TextUtils.isEmpty(param0Str)) {
          InputStream stream = new ByteArrayInputStream(param0Str.getBytes());
          MediaType mimeType = MediaType.TEXT_PLAIN;
          param0 = converter.convert(stream, mimeType, param0Type);
        }
      }
    }
    if (param0 == null) {
      throw new ParamMissingException("user");
    }

    MultipartFile param1 = null;
    if (multiRequest != null) {
      param1 = multiRequest.getFile("file");
    }
    if (param1 == null) {
      throw new ParamMissingException("file");
    }

    List<MultipartFile> param2 = null;
    Type param2Type = new TypeWrapper<List<MultipartFile>>(){}.getType();
    if (converter != null && multiRequest != null) {
      MultipartFile param2File = multiRequest.getFile("fileList");
      if (param2File != null) {
        InputStream stream = param2File.getStream();
        MediaType mimeType = param2File.getContentType();
        param2 = converter.convert(stream, mimeType, param2Type);
      }
      if (param2 == null) {
        String param2Str = multiRequest.getParameter("fileList");
        if (!TextUtils.isEmpty(param2Str)) {
          InputStream stream = new ByteArrayInputStream(param2Str.getBytes());
          MediaType mimeType = MediaType.TEXT_PLAIN;
          param2 = converter.convert(stream, mimeType, param2Type);
        }
      }
    }
    Object o = ((CentralController)mHost).uploadWithInfo(param0, param1, param2);
    return new ObjectView(true, o);
  }
}