使用FTP从远程系统复制文件夹时出错

Question

Find the screen shot here about commands我试图在java中使用FTP从远程系统复制文件夹并收到此错误：

  

无法确定系统类型 - 响应：502命令未实现。

如何解决此问题？

这是获得502错误的代码：

ionViewDidLoad(): void {
  // Disable to give time for loading & scrolling
  this.infiniteScroll.enable(false);

  loadFirstTenChats().then(() => {
    // Fiddle with the timing depending on what you are doing.

    // If you have footers or other dynamic content to worry about.
    setTimeout( () => this.content.resize(), 100);

    // Scroll to the bottom once the size has been calculated:
    setTimeout( () => this.content.scrollToBottom(100), 200);

    // The scroll above has to be finished before enabling or
    // else the IS might think it needs to load the next batch.
    setTimeout( () => this.infiniteScroll.enable(true), 1000);
  });
}