Java 通过 JSch shell 通道向服务器发送命令

Sending commands to server via JSch shell channel

提问by Nezzit

I can't figure it out how I can send commands via JSch shell channel.

我不知道如何通过 JSch shell 通道发送命令。

I do this, but it doesn't work:

我这样做，但它不起作用：

JSch shell = new JSch();
String command = "cd home/s/src";  
Session session = shell.getSession(username, host, port);  
MyUserInfo ui = new MyUserInfo();  
ui.setPassword(password);  
session.setUserInfo(ui);  
session.connect();  

channel = session.openChannel("shell");  
fromServer = new BufferedReader(new InputStreamReader(channel.getInputStream()));  
toServer = channel.getOutputStream();
channel.connect();  
toServer.write((command + "\r\n").getBytes());
toServer.flush();

and then I read input like this:

然后我读取这样的输入：

StringBuilder builder = new StringBuilder();  

int count = 0;  
String line = "";  

while(line != null) {  
    line = fromServer.readLine();
    builder.append(line).append("\n");

    if (line.endsWith(".") || line.endsWith(">")){
        break;
    }
}  
String result = builder.toString();  
ConsoleOut.println(result);

采纳答案by nilbot

If it hangs at readLine()that means either your "while" is never ending (might be unlikely considering your code), or, readLine()is waiting for its source, namely the IOstreamblocks the thread cause available()!=true.

如果它挂起readLine()，则意味着您的“while”永远不会结束（考虑到您的代码可能不太可能），或者readLine()正在等待其源，即IOstream线程导致的阻塞available()!=true。

I can't quite troubleshoot your code without seeing your debug info. But as an advice, have you tried PipedIntputStream? The idea is to pipe your console input to "your" output so that you can "write" it. To implement this, you need to initialize the in/out-put.

在没有看到您的调试信息的情况下，我无法对您的代码进行故障排除。但作为一个建议，你试过PipedIntputStream吗？这个想法是将您的控制台输入通过管道传输到“您的”输出，以便您可以“编写”它。要实现这一点，您需要初始化输入/输出。

InputStream in = new PipedInputStream();
PipedOutputStream pin = new PipedOutputStream((PipedInputStream) in);
/**...*/
channel.setInputStream(in);
channel.connect();
/** ...*/
pin.write(myScript.getBytes());

The same goes to your question, how to read console output.

您的问题也是如此，如何读取控制台输出。

PipedInputStream pout = new PipedInputStream((PipedOutputStream) out);
/**
* ...
*/
BufferedReader consoleOutput = new BufferedReader(new InputStreamReader(pout));
consoleOutput.readLine();

And again, if you are not sure how many lines to read and thus want to use "while", make sure you do something inside while to prevent 1) busy-waiting 2) ending-condition. Example:

同样，如果您不确定要读取多少行，因此想要使用“while”，请确保在 while 内执行某些操作以防止 1) 忙等待 2) 结束条件。例子：

while(!end)
{
   consoleOutput.mark(32);
   if (consoleOutput.read()==0x03) end = true;//End of Text
   else
   { 
     consoleOutput.reset();
     consoleOutput.readLine();
     end = false;
   }
}

回答by Pushpinder Rattan

try this code :

试试这个代码：

         JSch jsch=new JSch();

         System.out.println("Getting session");
         Session session=jsch.getSession("root","10.0.0.0",22);

          System.out.println("session is ::::"+session.getHost());
          // username and password will be given via UserInfo interface.
          UserInfo ui = new MyUserInfo("Lab@123", null);
          //UserInfo ui = new MyUserInfo(password, null);
          session.setUserInfo(ui);
          session.setPassword("Lab@123");
          Properties config = new java.util.Properties();
          config.put("StrictHostKeyChecking", "no");
          session.setConfig(config);
          session.connect(40000);


              Channel channel=session.openChannel("exec"); 
              ((ChannelExec)channel).setCommand("ls");

              channel.connect();
              channel.run();

              // get I/O streams for remote scp
              OutputStream out=channel.getOutputStream();
              InputStream in=channel.getInputStream(); 


          String output="";
          while (channel.isClosed()!=true) {

              try {
                output+=streamToString(in);

            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }

            System.out.println("Output is :::"+output);
            channel.disconnect();
            session.disconnect();
    }

    public static String streamToString(InputStream input)throws Exception 
    { String output = ""; while(input.available()>0) { output += ((char)(input.read())); } return output; }



    public static OutputStream stringToStream(String charset) throws IOException{

        byte[] bytes = charset.getBytes();
        /*ByteArrayInputStream bais = new ByteArrayInputStream(bytes);
        InputStreamReader isr = new InputStreamReader(bais);*/
        InputStream is = null;
        OutputStream os = null;
        try {
            is = new ByteArrayInputStream(charset.getBytes("UTF-8"));
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        //byte[] buf = new byte[1024];
        int numRead;

          while ( (numRead = is.read(bytes) ) >= 0) {
              os.write(bytes, 0, numRead);
          }        
        return os;      

回答by Michael Cheremuhin

Try this:

尝试这个：

JSch jsch = new JSch();

try
{
  Session session = jsch.getSession("root", "192.168.0.1", 22);
  java.util.Properties config = new java.util.Properties();
  config.put("StrictHostKeyChecking", "no");
  session.setConfig(config);

  session.connect();

  String command = "lsof -i :80";
  Channel channel = session.openChannel("exec");
  ((ChannelExec) channel).setCommand(command);
  channel.setInputStream(null);
  ((ChannelExec) channel).setErrStream(System.err);
  InputStream in = channel.getInputStream();

  channel.connect();

  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())
    {
      System.out.println("exit-status: " + channel.getExitStatus());
      break;
    }
    try
    {
      Thread.sleep(1000);
    }
    catch (Exception ee)
    {
    }
  }

  channel.disconnect();
  session.disconnect();
}
catch (Exception e)
{
  System.out.println(e.getMessage());
}

回答by neosab

Following was a quickly written code for my assignment. Not a well done program. But serves its purpose.

以下是为我的作业快速编写的代码。不是一个做得好的程序。但达到了它的目的。

1. Connects via SSH (using Jsch) to a server (using a Private Key File - mykey.pem)
2. Creates a shell script (to mount a volume and mkfs)
3. Runs on the remote machine
4. All the while you can see the output on your stdout

1. 通过 SSH（使用 Jsch）连接到服务器（使用私钥文件 - mykey.pem）
2. 创建一个 shell 脚本（安装一个卷和 mkfs）
3. 在远程机器上运行
4. 一直以来，您都可以在标准输出上看到输出

The code follows:

代码如下：

public class connectSSH {

public void connect(String dnsName, String privKey) throws IOException {
    JSch jSch = new JSch();

    try {

                    //Authenticate through Private Key File
        jSch.addIdentity(privKey);
                    //Give the user and dnsName
        Session session = jSch.getSession("root", dnsName, 22);
                    //Required if not a trusted host
        java.util.Properties config = new java.util.Properties(); 
        config.put("StrictHostKeyChecking", "no");
        session.setConfig(config);
        System.out.println("Connecting SSH to " + dnsName + " - Please wait for few minutes... ");
        session.connect();
            //Open a shell 
        Channel channel=session.openChannel("shell");
        channel.setOutputStream(System.out);
            //Create a Shell Script
        File shellScript = createShellScript();
            //Convert the shell script to byte stream
        FileInputStream fin = new FileInputStream(shellScript);
        byte fileContent[] = new byte[(int)shellScript.length()];
        fin.read(fileContent);
        InputStream in = new ByteArrayInputStream(fileContent);
            //Set the shell script to the channel as input stream
        channel.setInputStream(in);
            //Connect and have fun!
        channel.connect();          

    } catch (JSchException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

public File createShellScript() {
     String filename = "shellscript.sh";
     File fstream = new File(filename);

     try{
          // Create file 
         PrintStream out = new PrintStream(new FileOutputStream(fstream));
         out.println("#!/bin/bash");
         out.println("echo \"hi\" > /tmp/test.info");
         out.println("echo \"n\" > /tmp/fdisk.in");
         out.println("echo \"p\" >> /tmp/fdisk.in");
         out.println("echo \"1\" >> /tmp/fdisk.in");
         out.println("echo >> /tmp/fdisk.in");
         out.println("echo >> /tmp/fdisk.in");
         out.println("echo \"w\" >> /tmp/fdisk.in");

         out.println("/sbin/fdisk /dev/sdf < /tmp/fdisk.in");
         out.println("mkfs.ext3 /dev/sdf1");
         out.println("mkdir /usr/myebs");
         out.println("mount /dev/sdf1 /usr/myebs");
         out.println("partprobe /dev/sdf1");

         out.println("echo \"Success\"");

         //Close the output stream
         out.close();
     }catch (Exception e){//Catch exception if any
         System.err.println("Error: " + e.getMessage());
     }
     return fstream;

}

public static void main(String[] args) {
    connectSSH ssh = new connectSSH();
    String privKey = "/Users/neo/Desktop/mykey.pem";
    try {
        ssh.connect("yourexampleserver.com", privKey);
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

}

回答by audriusa

With piped input and output streams seems interesting:

使用管道输入和输出流似乎很有趣：

JSch jsch = new JSch();
jsch.addIdentity("/home/audrius/.ssh/blablabla", "blablablabla");

String user = "audrius";
String host = "ultrastudio.org";

Session session = jsch.getSession(user, host, 439);
session.setConfig("StrictHostKeyChecking", "no");           
session.connect();

Channel channel = session.openChannel("shell");

PipedInputStream pip = new PipedInputStream(40);
channel.setInputStream(pip);

PipedOutputStream pop = new PipedOutputStream(pip);
PrintStream print = new PrintStream(pop);           
channel.setOutputStream(System.out);

print.println("ls");

回答by krishna

try this

尝试这个

Channel channel=session.openChannel("shell");
            OutputStream ops = channel.getOutputStream();
        PrintStream ps = new PrintStream(ops, true);

         channel.connect();
         ps.println("mkdir folder"); 
         ps.println("dir");
 //give commands to be executed inside println.and can have any no of commands sent.
                      ps.close();

         InputStream in=channel.getInputStream();
         byte[] bt=new byte[1024];


         while(true)
         {

         while(in.available()>0)
         {
         int i=in.read(bt, 0, 1024);
         if(i<0)
          break;
            String str=new String(bt, 0, i);
          //displays the output of the command executed.
            System.out.print(str);


         }
         if(channel.isClosed())
         {

             break;
        }
         Thread.sleep(1000);
         channel.disconnect();
         session.disconnect();   
         }

回答by user1345691

private void executeRemoteCommandAsSudo(String sudoAs, String password,
            String command, int delayInSeconds) 
{
    logger.info("executeRemoteCommandAsSudo started....");
    logger.info("sudoAs=" + sudoAs);
    logger.info("command=" + command);
    logger.info("delayInSeconds=" + delayInSeconds);
    Session session = null;
    Channel channel = null;
    try {
        session = getSession();
        channel = session.openChannel("exec");
        String sudoCommand = "sudo su - " + sudoAs;
        ((ChannelExec) channel).setCommand(sudoCommand);
        ((ChannelExec) channel).setPty(true);
        channel.connect();
        InputStream inputStream = channel.getInputStream();
        OutputStream out = channel.getOutputStream();
        ((ChannelExec) channel).setErrStream(System.err);
        out.write((password + "\n").getBytes());
        out.flush();
        Thread.sleep(1000);
        out.write((command + "\n").getBytes());
        out.flush();
        Thread.sleep(1000 * delayInSeconds);
        out.write(("logout" + "\n").getBytes());
        out.flush();
        Thread.sleep(1000);
        logInfo(channel, inputStream);
        out.write(("exit" + "\n").getBytes());
        out.flush();
        out.close();
        Thread.sleep(1000);
    } catch (Exception ex) {
        logger.error(ex.getMessage());
    } finally {
        session.disconnect();
        channel.disconnect();
    }
    logger.info("executeRemoteCommandAsSudo completed....");
}
private void logInfo(Channel channel, InputStream in) 
{
    try {
        byte[] tmp = new byte[1024];
        while (true) {
            while (in.available() > 0) {
                int i = in.read(tmp, 0, 1024);
                if (i < 0)
                    break;
                logger.info(new String(tmp, 0, i));
            }
            if (channel.isClosed()) {
                logger.info("exit-status: " + channel.getExitStatus());
                break;
            }
        }
    } catch (Exception ex) {
        logger.error(ex);
    }
}

private Session getSession() throws JSchException 
{
    JSch jsch = new JSch();
    logger.info("ftpUser=" + ftpUser);
    logger.info("ftpHost=" + ftpHost);
    Session session = jsch.getSession(ftpUser, ftpHost, 22);
    session.setPassword(ftpPassword);
    java.util.Properties config = new java.util.Properties();
    config.put("StrictHostKeyChecking", "no");
    session.setConfig(config);
    session.connect();
    return session;
}

回答by Apokralipsa

I realize that this is an old thread, but I have struggled with a similar problem today. This is my solution.

我意识到这是一个旧线程，但我今天遇到了类似的问题。这是我的解决方案。

public class ChannelConsole {

// ================================================
// static fields
// ================================================

// ================================================
// instance fields
// ================================================

private Session session;

// ================================================
// constructors
// ================================================

public ChannelConsole(Session session) {
    this.session = session;
}

// ================================================
// getters and setters
// ================================================

// ================================================
// public methods
// ================================================

public String execute(String command) throws JSchException {
    command = command.trim() + "\n";

    ChannelExec channel = (ChannelExec) this.session.openChannel("exec");
    channel.setCommand(command);

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

    channel.connect();

    try {
        awaitChannelClosure(channel);
    } catch (InterruptedException e) {
        // no one cares
    }

    String result = responseStream.toString();
    closeQuietly(responseStream);
    return result;

}

// ================================================
// private methods
// ================================================

private void awaitChannelClosure(ChannelExec channel) throws InterruptedException {
    while (channel.isConnected()) {
        Thread.sleep(100);
    }
}

private static void closeQuietly(Closeable closeable) {
    if (closeable == null) {
        return;
    }

    try {
        closeable.close();
    } catch (IOException ignored) {
        ignored.printStackTrace();
    }
}

}

Using this class you can just do something like : shell = new ChannelConsole(this.session); String result = shell.execute("quota -v; echo; echo \"Disk storage information:\"; df -hk")

使用此类，您可以执行以下操作： shell = new ChannelConsole(this.session); String result = shell.execute("quota -v; echo; echo \"Disk storage information:\"; df -hk")

回答by Mykhaylo Adamovych

Usage:

用法：

String remoteCommandOutput = exec("ssh://user:pass@host/work/dir/path", "ls -t | head -n1");
String remoteShellOutput = shell("ssh://user:pass@host/work/dir/path", "ls")
shell("ssh://user:pass@host/work/dir/path", "ls", System.out)
shell("ssh://user:pass@host", System.in, System.out);

Implementation

执行