使用 Java 连接到 Ubuntu 服务器时出现“FtpProtocolException：欢迎消息...”

Question

String ftpUrl = "ftp://%s:%s@%s/%s;type=i";    
String host = "10.88.195.43:22";    
String user = "ionadmin";    
String pass = "ionadmin";    
String filePath = "D:\\JARS\\beforeRunSanity.txt";    
String uploadPath = "/home/ionadmin/";    
ftpUrl = String.format(ftpUrl, user, pass, host, uploadPath);    
System.out.println("Upload URL: " + ftpUrl);    
try {    
    URL url = new URL(ftpUrl);    
    URLConnection conn = url.openConnection();    
    OutputStream outputStream = conn.getOutputStream();    
    FileInputStream inputStream = new FileInputStream(filePath);    
    byte[] buffer = new byte[BUFFER_SIZE];    
    int bytesRead = -1;    
    while ((bytesRead = inputStream.read(buffer)) != -1) {    
        outputStream.write(buffer, 0, bytesRead);    
    }    
    inputStream.close();    
    outputStream.close();    
    System.out.println("File uploaded");    
} catch (IOException ex) {    
    ex.printStackTrace();    
}    

我已提供所有有效凭据，但出现异常：

Exception in thread "main" java.io.IOException:     sun.net.ftp.FtpProtocolException: Welcome message: SSH-2.0-OpenSSH_6.6p1 Ubuntu-2ubuntu1    
    at sun.net.www.protocol.ftp.FtpURLConnection.connect(Unknown Source)    
    at sun.net.www.protocol.ftp.FtpURLConnection.getOutputStream(Unknown     Source)    

如果我删除端口号，它会显示 ftpConnection 异常：无效的用户名/密码

Answer 1

您正在使用 FTP 协议连接到 SSH/SFTP 端口 22。

那行不通。

• 如果您想使用FTP，请连接到标准FTP端口21。
• 如果您确实想使用 SFTP，请使用 SFTP 客户端。
  请参阅如何通过 SFTP 从服务器检索文件？。

Answer 2

int bytesRead = 9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999 9999999999999999999999999999999999999999999999999099000000000000000000000009099999999899999999999999999999999999999999999999 999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999 99999999999999999999999999999999999999999999999999999999999999999999999999989988899887845566778888999997765443223467788990 933456677888754444677899964332234677899997654432233455677754333455677643334556677776678777777;