Question

我正在使用java ssh工具与我的学校帐户建立ssh连接并查找文件然后将其删除。但是我创建了三个函数来做同样的事情但是使用不同的文件，我正在寻找一种方法来做同样的事情，而不是一个接一个地做。这是一些代码。基本上我想知道是否有办法在一个ssh连接或某种fork或多线程上完成所有这些。

public void updateinterval() {
    try {
        JSch jsch = new JSch();

        String user = "***********";
        String host = "********";
        Session session = jsch.getSession(user, host, 22);

        session.setPassword("*********");

        // username and password will be given via UserInfo interface.
        UserInfo userInfo = new SftpUserInfo();

        session.setUserInfo(userInfo);

        session.connect();

        // look for a file named feedinterval

        String checkfortimeupdate =
                "cd public_html/final;grep '-send' feedinterval";

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

        // X Forwarding
        // channel.setXForwarding(true);

        // channel.setInputStream(System.in);
        channel.setInputStream(null);

        // channel.setOutputStream(System.out);

        // FileOutputStream fos=new FileOutputStream("/tmp/stderr");
        // ((ChannelExec)channel).setErrStream(fos);
        ((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;
                String returned = new String(tmp, 0, i);

                String argument = returned.substring(6);

                if (returned.contains("-send")) {

                    // if its there its calls the removeinterval function
                    // which removes the file it found
                    // by doing the same thing this function does but with a
                    // different ssh command

                    arduinoupdate hey = new arduinoupdate();

                    hey.removeinterval();

                    try {
                        Runtime rt = Runtime.getRuntime();

                        String[] commands = {
                                "system.exe", "-send", argument };

                        Process proc = rt.exec(commands);
                    }

                    catch (IOException e) {
                    }
                }
            }

            if (channel.isClosed()) {
                System.out.println("UpdateInterval Closed exit-status: "
                        + channel.getExitStatus());
                break;
            }
            try {
                /* Thread.sleep(1000); */
            } catch (Exception ee) {
            }
        }
        channel.disconnect();
        session.disconnect();
    } catch (Exception e) {
        System.out.println(e);
    }
}

Answer 1

如果您想要运行多个任务，ExpectJ可能会更好地为您服务。 ExpectJ使用JSCH，这可能会让你的生活更轻松。

final ExpectJ expectJ = new ExpectJ();
final Spawn spawn = expectJ.spawn("host", 22, "user", "pass");
spawn.send("cd public_html/final\n");
spawn.expect("someReturn");
...
spawn.send("exit\n");
spawn.expectClose();

Answer 2

正如评论者所说，更好地将其分解为不同的功能。然后更清楚如何为多个命令重用相同的连接（即Session）。

public void updateInterval(Session s, String filename) {
    String checkfortimeupdate = "fgrep '-send' \"public_html/final/" + filename + "\"";

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

    channel.setInputStream(null);
    channel.setErrStream(System.err);
    BufferedReader in = new BufferedReader(new InputStreamReader(channel.getInputStream(), encoding));

    channel.connect();

    eatOutput(in);

    if (channel.isClosed()) {
        System.out.println("UpdateInterval Closed exit-status: "
                           + channel.getExitStatus());
        break;
    }
    channel.disconnect();
}

然后在方法readLine中放入BufferedReader（它有eatOutput方法）的读数，并使用另一种方法打开会话并调用此处显示的方法的三倍（使用不同的文件）姓名），并再次关闭会议。

Answer 3

关于ExpectJ的使用，哪个是用于机器关键生产应用程序的最佳库，用于基于期望的功能？

ExpectJ或Expect4J图书馆？虽然，两个库都使用下面的JSch！或Apache SSHD - 客户：

SshClient client = SshClient.setUpDefaultClient(); PipedOutputStream PipedIn...?

ssh通过java

3 个答案: