java - 227进入被动模式(124,153,94,30,242,138)

Question

我正在使用 SimpleFTP.java 代码通过 FTP 上传图像。我收到标题中提到的错误并且无法上传图片。它只是将图像保存在数据库中，大小为 0KB。请帮我解决这个问题，因为我搜索了一整天但找不到正确的解决方案。

public class SimpleFTP {


    /**
     * Create an instance of SimpleFTP.
     */
    public SimpleFTP() {

    }


    /**
     * Connects to the default port of an FTP server and logs in as
     * anonymous/anonymous.
     */
    public synchronized void connect(String host) throws IOException {
        connect(host, 21);
    }


    /**
     * Connects to an FTP server and logs in as anonymous/anonymous.
     */
    public synchronized void connect(String host, int port) throws IOException {
        connect(host, port, "anonymous", "anonymous");
    }


    /**
     * Connects to an FTP server and logs in with the supplied username
     * and password.
     */
    public synchronized void connect(String host, int port, String user, String pass) throws IOException {
        if (socket != null) {
            throw new IOException("SimpleFTP is already connected. Disconnect first.");
        }
        socket = new Socket(host, port);
        reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));

        String response = readLine();
        if (!response.startsWith("220 ")) {
            throw new IOException("SimpleFTP received an unknown response when connecting to the FTP server: " + response);
        }

        sendLine("USER " + user);

        response = readLine();
        if (!response.startsWith("331 ")) {
            throw new IOException("SimpleFTP received an unknown response after sending the user: " + response);
        }

        sendLine("PASS " + pass);

        response = readLine();
        if (!response.startsWith("230 ")) {
            throw new IOException("SimpleFTP was unable to log in with the supplied password: " + response);
        }

    }
        /**
     * Disconnects from the FTP server.
     */
    public synchronized void disconnect() throws IOException {
        try {
            sendLine("QUIT");
        } finally {
            socket = null;
        }
    }


    /**
     * Returns the working directory of the FTP server it is connected to.
     */
    public synchronized String pwd() throws IOException {
        sendLine("PWD");
        String dir = null;
        String response = readLine();
        if (response.startsWith("257 ")) {
            int firstQuote = response.indexOf('\"');
            int secondQuote = response.indexOf('\"', firstQuote + 1);
            if (secondQuote > 0) {
                dir = response.substring(firstQuote + 1, secondQuote);
            }
        }
        return dir;
    }


    /**
     * Changes the working directory (like cd). Returns true if successful.
     */
    public synchronized boolean cwd(String dir) throws IOException {
        sendLine("CWD " + dir);
        String response = readLine();
        return (response.startsWith("250 "));
    }


    /**
     * Sends a file to be stored on the FTP server.
     * Returns true if the file transfer was successful.
     * The file is sent in passive mode to avoid NAT or firewall problems
     * at the client end.
     */
    public synchronized boolean stor(File file) throws IOException {
        if (file.isDirectory()) {
            throw new IOException("SimpleFTP cannot upload a directory.");
        }

        String filename = file.getName();

        return stor(new FileInputStream(file), filename);
    }


    /**
     * Sends a file to be stored on the FTP server.
     * Returns true if the file transfer was successful.
     * The file is sent in passive mode to avoid NAT or firewall problems
     * at the client end.
     */
    public synchronized boolean stor(InputStream inputStream, String filename) throws IOException {

        BufferedInputStream input = new BufferedInputStream(inputStream);

        sendLine("PASV");
        String response = readLine();//227
      Log.e("RESPONSE ", response);
        if (!response.startsWith("200 ") && !response.startsWith("227 ")) {
            throw new IOException("SimpleFTP could not request passive mode: " + response);
        }

        String ip = null;
        int port = -1;
        int opening = response.indexOf('(');
        int closing = response.indexOf(')', opening + 1);
        if (closing > 0) {
            String dataLink = response.substring(opening + 1, closing);
            StringTokenizer tokenizer = new StringTokenizer(dataLink, ",");
            try {
                ip = tokenizer.nextToken() + "." + tokenizer.nextToken() + "." + tokenizer.nextToken() + "." + tokenizer.nextToken();
                port = Integer.parseInt(tokenizer.nextToken()) * 256 + Integer.parseInt(tokenizer.nextToken());
                //Log.e("FTP ",String.valueOf(port)+" P "+String.valueOf(port));
            } catch (Exception e) {
                throw new IOException("SimpleFTP received bad data link information: " + response);
            }
        }

        sendLine("STOR " + filename);

        Socket dataSocket = new Socket(ip, port);

        response = readLine();
        if (!response.startsWith("150 ")) {
            throw new IOException("SimpleFTP was not allowed to send the file: " + response);
        }

        BufferedOutputStream output = new BufferedOutputStream(dataSocket.getOutputStream());
        byte[] buffer = new byte[4096];
        int bytesRead = 0;
        while ((bytesRead = input.read(buffer)) != -1) {
            output.write(buffer, 0, bytesRead);
        }
        output.flush();
        output.close();
        input.close();

        response = readLine();
        return response.startsWith("226 ");
    }


    /**
     * Enter binary mode for sending binary files.
     */
    public synchronized boolean bin() throws IOException {
        sendLine("TYPE I");
        String response = readLine();
        return (response.startsWith("200 "));
    }


    /**
     * Enter ASCII mode for sending text files. This is usually the default
     * mode. Make sure you use binary mode if you are sending images or
     * other binary data, as ASCII mode is likely to corrupt them.
     */
    public synchronized boolean ascii() throws IOException {
        sendLine("TYPE A");
        String response = readLine();
        return (response.startsWith("200 "));
    }


    /**
     * Sends a raw command to the FTP server.
     */
    private void sendLine(String line) throws IOException {
        if (socket == null) {
            throw new IOException("SimpleFTP is not connected.");
        }
        try {
            writer.write(line + "\r\n");
            writer.flush();
            if (DEBUG) {
                System.out.println("> " + line);
            }
        } catch (IOException e) {
            socket = null;
            throw e;
        }
    }

    private String readLine() throws IOException {
        String line = reader.readLine();
        if (DEBUG) {
            System.out.println("< " + line);
        }
        return line;
    }

    private Socket socket = null;
    private BufferedReader reader = null;
    private BufferedWriter writer = null;

    private static boolean DEBUG = false;


}

Answer 1

我得到了答案。它的格式是

227 Entering Passive Mode (h1,h2,h3,h4,p1,p2) 其中 h1 到 h4 是格式为 h1:h2:h3:h4 的主机 ID，p1 -p2 是它阻塞的端口格式 p1*256+p2