@Component
@Slf4j
public class FTPTools {

  /**
   * 文件上传
   * @param hostname 域名地址
   * @param port 端口号
   * @param username 用户名
   * @param password 密码
   * @param fileInfo 待上传的文件
   * @param uploadPath 待上传到的路径
   * @param saveName 预保存的文件名
   * @return
   */
  public static boolean upload(String hostname,int port,String username,String password,String fileInfo,String uploadPath,String saveName){
    boolean flag = false;

    FTPClient ftpClient = null;
    try {
      ftpClient = new FTPClient();
      ftpClient.connect(hostname,port);
      //每次数据连接之前，ftp client告诉ftp server开通一个端口来传输数据
      ftpClient.enterLocalPassiveMode();
      //设置二进制传输
      ftpClient.setFileType(FTPClient.BINARY_FILE_TYPE);
      ftpClient.setControlEncoding("UTF-8");
      if(ftpClient.login(username,password)){//若连接成功
        log.info("成功登录到ftp服务端，开始文件上传");
        flag = sendFile(ftpClient,fileInfo,uploadPath,saveName);
      }else{
        log.error("登录到ftp服务端失败，请检查用户名和密码");
      }
      disconnect(ftpClient);
    }catch (SocketException e) {
      log.error("文件{}上传失败：{}",saveName,e.getMessage());
    } catch (IOException e) {
      log.error("文件{}上传失败：{}",saveName,e.getMessage());
    } finally {

    }
    return flag;
  }

  /**
   * 文件传输
   * @param fileInfo
   * @param uploadPath
   * @param saveName
   * @return
   */
  private static boolean sendFile(FTPClient ftpClient, String fileInfo, String uploadPath, String saveName) throws FileNotFoundException,IOException{
    boolean flag = false;
    try(FileInputStream fileInputStream = new FileInputStream(fileInfo)){
      //检查工作目录是否存在
      if(ftpClient.changeWorkingDirectory(uploadPath)){
        if(ftpClient.listFiles(saveName).length != 0){ //检查文件是否已经存在
          boolean deleteFlag = ftpClient.deleteFile(saveName);
          log.info(deleteFlag?"文件已存在，直接删除":"存在同名文件且无法删除，请检查权限");
        }
        flag = ftpClient.storeFile(saveName,fileInputStream);
        log.info(flag?"文件上传成功！":"文件上传失败！");
      }else{
        log.error("找不到要上传的目录");
      }
    }catch (FileNotFoundException e){
      log.error("找不到要上传的文件{}：{}",fileInfo,e.getMessage());
      throw e;
    }catch (IOException e){
      log.error("文件传输异常：{}",e.getMessage());
      throw e;
    }
    return flag;
  }

  /**
   * 断开ftp连接
   * @param ftpClient
   */
  private static void disconnect(FTPClient ftpClient) {
    if (ftpClient.isConnected()){
      try{
        ftpClient.disconnect();
        log.info("ftp连接已关闭，文件上传结束");
      }catch (IOException e){
        log.error("ftp连接关闭失败:{}",e);
      }
    }
  }

}