如何在java中仅获取Apache Mina SSHD的命令返回值？

Question

我在 Android 设备上使用以下 SSH 方法向本地服务器发送命令。

protected String sshConnect(String username, String password, String host, int port, long defaultTimeoutSeconds, String command) {
    ClientChannel channel;
    String responseString = null;
    // create a client instance
    try (SshClient client = SshClient.setUpDefaultClient()) {
        client.setForwardingFilter(AcceptAllForwardingFilter.INSTANCE); //?
        client.start();
        Log.d(TAG, "sshConnect(): client.start(): client started");

        // connection and authentication
        try (ClientSession session = client.connect(username, host, port).verify(TimeUnit.SECONDS.toMillis(defaultTimeoutSeconds)).getSession()) {
            Log.d(TAG, "ssh: client.connect()");
            session.addPasswordIdentity(password);
            session.auth().verify(TimeUnit.SECONDS.toMillis(defaultTimeoutSeconds));
            Log.d(TAG, "ssh: connection established");

            // create a channel to communicate
            channel = session.createChannel(Channel.CHANNEL_SHELL);
            Log.d(TAG, "ssh: starting shell");

            ByteArrayOutputStream responseStream = new ByteArrayOutputStream();
            channel.setOut(responseStream);


            // open channel
            channel.open().verify(5, TimeUnit.SECONDS);
            try (OutputStream pipedIn = channel.getInvertedIn()) {
                pipedIn.write(command.getBytes());
                pipedIn.flush();
            }

            // close channel
            channel.waitFor(EnumSet.of(ClientChannelEvent.CLOSED),
                    TimeUnit.SECONDS.toMillis(5));

            // output after converting to string type
            responseString = responseStream.toString();
            Log.d(TAG, "ssh: responseString == " + responseString);

        } catch (Exception e) {
            Log.d(TAG, "sshConnect(): client.connect(): Exception: " + e);
        }
    } catch (Exception e) {
        Log.d(TAG, "sshConnect(): client.start(): Exception: " + e);
    }
    return responseString;

}

问题是它似乎打开了一个虚拟终端，然后返回终端中的所有内容，包括欢迎消息、命令提示符、命令、结果以及一些有关成为“虚拟”终端的警告消息。打印出日志中的

responseString

，我得到..

debian raspbian buster 10 computer
touch test.file
'dummy': unknown terminal type.
username@computer:~$ touch test.file
username@computer:~$ 

我想要和我时一样的行为..

sss -p port username@host 'touch test.file'

，它不会打开虚拟终端，只是返回命令的返回值。

Answer 1

而不是..

channel = session.createChannel(Channel.CHANNEL_SHELL);

ByteArrayOutputStream responseStream = new ByteArrayOutputStream();
channel.setOut(responseStream);

// open channel
channel.open().verify(5, TimeUnit.SECONDS);
try (OutputStream pipedIn = channel.getInvertedIn()) {
    pipedIn.write(command.getBytes());
    pipedIn.flush();
}

做..

channel = session.createExecChannel(this.command);

ByteArrayOutputStream responseStream = new ByteArrayOutputStream();
channel.setOut(responseStream);

// open channel
channel.open().verify(5, TimeUnit.SECONDS);

// close channel
channel.waitFor(EnumSet.of(ClientChannelEvent.CLOSED),
        TimeUnit.SECONDS.toMillis(5));

// output after converting to string type
responseString = responseStream.toString();

它不是打开 shell 并发送回 shell 的所有内容，而是简单地发送命令并返回命令的结果。