使用multipart打造rest粗接口

粗接口设计是实现微服务的关键。不论二进制还是rest接口，都可以设计“粗接口”。

 使用multipart，可以方便地打造REST粗接口。粗接口设计后的REST API，在各服务间有且只有一个接口。

function restfunc(const AReq: TBytes; const ABoundary: string): TBytes;
begin
  var parts: THttpMultiPartFormData := THttpMultiPartFormData.Create;
  try
    try
      parts.InitWithBoundary(ABoundary);      
      parts.Decode(AReq, Length(AReq));
      case StrToIntDef(parts.Fields['cmd'].AsString, 0) of
        cmd_query: Result := query(parts);
      end;
    except
      on e: Exception do
        WriteLog('yn.restfunc.restfunc ' + E.Message);
    end;
  finally
    parts.Free;
  end;
end;

　　

procedure TForm2.Button2Click(Sender: TObject);
//rest query
begin
  var req: TIdMultiPartFormDataStream := TIdMultiPartFormDataStream.Create;
  req.AddFormField('cmd', IntToStr(cmd_query));
  req.AddFormField('accountno', '1');
  req.AddFormField('sql', 'select * from tgoods');
  Memo1.Text := IdHTTP1.Post(FUrl + '/rest', req);
  req.Free;
end;