从Java执行SSH命令会发送状态代码255，但如果有效，则会在终端中发送

Question

我正在尝试开发一个小应用程序，它允许我通过SSH将某些命令发送到远程服务器。如果我在Linux终端或Windows命令提示符下尝试，它可以正常工作，但当我在Java应用程序中尝试时，它总是以255的状态代码响应

我禁用了防火墙，并将服务器上侦听SSH的端口更改为22，因为我使用了另一个端口，但没有任何功能。它不会抛出异常或任何东西，如果连接没有问题。有什么想法吗

我试过使用sshj和JSch库，但两者都有相同的问题

货运代理已关闭

sshj示例

private void sshj() throws Exception {
    SSHClient ssh = new SSHClient();
    ssh.addHostKeyVerifier((s, i, publicKey) -> true);
    ssh.connect("host", 22);
    Session session = null;
    try {
        ssh.authPassword("username", "password");
        session = ssh.startSession();
        Session.Command cmd = session.exec("command");
        System.out.println(IOUtils.readFully(cmd.getInputStream()).toString());
        cmd.join(5, TimeUnit.SECONDS);
        System.out.println("Exit status: " + cmd.getExitStatus());
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (session != null) {
            session.close();
        }

        ssh.disconnect();
    }
}

JSch示例

private static void jsch() throws Exception {
    JSch js = new JSch();
    Session s = js.getSession("username", "host", 22);
    s.setPassword("password");
    Properties config = new Properties();
    config.put("StrictHostKeyChecking", "no");
    s.setConfig(config);
    s.connect();

    Channel c = s.openChannel("exec");
    ChannelExec ce = (ChannelExec) c;
    ce.setCommand("command");
    ce.connect();

    BufferedReader reader = new BufferedReader(new InputStreamReader(ce.getInputStream()));
    String line;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }

    ce.disconnect();
    s.disconnect();

    System.out.println("Exit status: " + ce.getExitStatus());
}

Answer 1

更改为代码，以便在执行connect之前获得inputStream

InputStream in = ce.getInputStream();
ce.connect();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));

而且getSession本应是错误的

public Session getSession(String username,
                      String host,
                      int port)

编辑

下面的代码适用于我

JSch js = new JSch();
Session s = js.getSession("username", "127.0.0.1", 22);
s.setPassword("password");
Properties config = new Properties();
config.put("StrictHostKeyChecking", "no");
s.setConfig(config);
s.connect();

Channel c = s.openChannel("exec");
ChannelExec ce = (ChannelExec) c;
ce.setCommand("uptime");

InputStream in = ce.getInputStream();
ce.connect();

BufferedReader reader = new BufferedReader(new InputStreamReader(in));
String line;
while ((line = reader.readLine()) != null) {
      System.out.println(line);
}

ce.disconnect();
s.disconnect();

System.out.println("Exit status: " + ce.getExitStatus());

输出

 10:26:08 up 149 days, 58 min,  3 users,  load average: 0.61, 0.68, 0.68
Exit status: 0