使用带有JSch的"exec"通道运行命令不会返回任何输出

Question

我正在尝试使用来自Android和JS的SSH在Linux服务器上执行命令.

据我所知,我正在连接到服务器,但当我尝试检索命令的结果时,我什么都没得到.

连接到服务器:

public class SSHCommand {

    public static String executeRemoteCommand(
            String username,
            String password,
            String hostname,
            int port) throws Exception {

        JSch jsch = new JSch();
        Session session = jsch.getSession(username, hostname, port);
        session.setPassword(password);

        // Avoid asking for key confirmation
        Properties prop = new Properties();
        prop.put("StrictHostKeyChecking", "no");
        session.setConfig(prop);

        session.connect();

        // SSH Channel
        ChannelExec channelssh = (ChannelExec)
                session.openChannel("exec");
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        channelssh.setOutputStream(baos);

        // Execute command
        channelssh.setCommand("ls");
        channelssh.connect();
        channelssh.disconnect();

        return baos.toString();
    }
}

检索数据:

public class MainActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final String TAG = "TESTING";

        new AsyncTask<Integer, Void, Void>(){
            @Override
            protected Void doInBackground(Integer... params) {
                try {
                    Log.d(TAG, SSHCommand.executeRemoteCommand("username", "password", "192.168.0.1", 22));
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return null;
            }
        }.execute(1);
    }
}

我在这里错过了什么？

Answer 1

在返回任何输出之前,在启动命令后立即断开连接.

您必须等待"exec"通道关闭(它会在命令完成后关闭).

有关"exec"频道,请参阅官方JSch示例.

byte[] tmp=new byte[1024];
while(true){
  while(in.available()>0){
    int i=in.read(tmp, 0, 1024);
    if(i<0)break;
    System.out.print(new String(tmp, 0, i));
  }
  if(channel.isClosed()){
    if(in.available()>0) continue; 
    System.out.println("exit-status: "+channel.getExitStatus());
    break;
  }
  try{Thread.sleep(1000);}catch(Exception ee){}
}