通过JSch在java上运行linux命令 [英] Running linux commands on java through JSch

问题描述

我正在通过JSch在java上建立一个ssh连接，一切似乎工作正常，直到我试图运行这个.sh文件。 shell脚本的名称是 repoUpdate.sh ，它非常简单：

I'm establishing a ssh connection through JSch on java and everything seemed to be working fine, until I tried to run this .sh file. The shell script's name is repoUpdate.sh and it's very simple:

echo  ' ****Repository update****'
echo  ' Location: /home/cissys/repo/'
echo -e ' Command: svn update /home/cissys/repo/2.3.0'

svn update /home/cissys/repo/2.3.0

这是输出我通过命令的正确响应直接进入linux控制台：

This is the output I get directly on the linux console with the proper response of the command:

[cissys@dsatelnx5 ~]$ repoUpdate.sh
 ****Repository update****
 Location: /home/cissys/repo/
 Command: svn update /home/cissys/repo/2.3.0

At revision 9432.

现在，这是我的方法的java代码，其中ssh连接尝试调用同一个文件

Now, here's the java code of my method with the ssh connection that tries to call this same file

public void cmremove()
{
    try
    {
        JSch jsch = new JSch();
        Session session = jsch.getSession(user, host, port);
        UserInfo ui = new SUserInfo(pass, null);
        session.setUserInfo(ui);
        session.setPassword(pass);
        session.connect();

        ChannelExec channelExec = (ChannelExec)session.openChannel("exec");

        InputStream in = channelExec.getInputStream();

        channelExec.setCommand("./repoUpdate.sh");
        channelExec.connect();

        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        String line;
        int index = 0;

        while ((line = reader.readLine()) != null)
        {
            System.out.println(++index + " : " + line);
        }

        channelExec.disconnect();
        session.disconnect();

        System.out.println("Done!");
    }
    catch(Exception e)
    {
        System.err.println("Error: " + e);
    }
}

我得到的回应如下：

run:
1 :  ****Repository update****
2 :  Location: /home/cissys/repo/
3 :  Command: svn update /home/cissys/repo/2.3.0
Done!
BUILD SUCCESSFUL (total time: 2 seconds)

没有输出或执行迹象svn命令（修订版9432）无论如何。

with no output or signs of execution on the svn command (At revision 9432) whatsoever.

我认为它可能会在某个时刻关闭会话，而不是让命令正确执行。如果 updateRepo.sh 文件会有类似cp test.txt test_2.txt的内容，那么它会毫无问题地执行此操作。但我只对这个和其他一些特定的.sh文件有这个问题。

I'm thinking it may be closing the session at some point, not letting the command execute properly. If the updateRepo.sh file would've had something like "cp test.txt test_2.txt", it would do it with no problem. But i only have this problem with this and some other specific .sh files.

任何帮助都将不胜感激。

Any help would be appreciated.

推荐答案

所以这就是我所做的。

我在顶部添加了 exec 2>& 1 repoUpdate.sh 文件中添加了一段代码来读取@DanielMartin建议的输出错误，结果如下：

So here's what I did.
I added the exec 2>&1 at the top of the repoUpdate.sh file and added that piece of code to read the output error as @DanielMartin suggested, resulting on this:

public void cmremove()
{
    try
    {
        JSch jsch = new JSch();
        Session session = jsch.getSession(user, host, port);
        UserInfo ui = new SUserInfo(pass, null);
        session.setUserInfo(ui);
        session.setPassword(pass);
        session.connect();

        ChannelExec channelExec = (ChannelExec)session.openChannel("exec");

        InputStream in = channelExec.getInputStream();

        channelExec.setCommand("./repoUpdate.sh");
        channelExec.connect();

        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        String line;
        int index = 0;

        while ((line = reader.readLine()) != null)
        {
            System.out.println(++index + " : " + line);
        }

        int exitStatus = channelExec.getExitStatus();
        channelExec.disconnect();
        session.disconnect();
        if(exitStatus < 0){
            System.out.println("Done, but exit status not set!");
        }
        else if(exitStatus > 0){
            System.out.println("Done, but with error!");
        }
        else{
            System.out.println("Done!");
        }
    }
    catch(Exception e)
    {
        System.err.println("Error: " + e);
    }
}

所以这实际上帮了很多忙。它确认该命令实际上没有像我想象的那样正确执行。我在我的java输出上得到了这个：

So that actually helped a lot. It confirmed that the command was, in fact, not executing correctly as I thought. I was getting this on my java output:

run:
1 :  ****Repository update****
2 :  Location: /home/cissys/repo/
3 :  Command: svn update /home/cissys/repo/2.3.0
4 : ./repoUpdate.sh[6]: svn: not found [No such file or directory]
Done!
BUILD SUCCESSFUL (total time: 2 seconds)

然后我尝试修改 repoUpdate.sh 文件，添加svn命令的绝对路径（谢谢，@ mysnk）

Then I tried modifying the repoUpdate.sh file, adding the absolute path for the svn command (Thank you, @ymnk)

exec 2>&1
echo  ' ****Repository update****'
echo  ' Location: /home/cissys/repo/'
echo -e ' Command: svn update /home/cissys/repo/2.3.0'

/opt/subversion/bin/svn update /home/cissys/repo/2.3.0

对于我的java，我得到了我想要的东西：

For my java, I got just what I was looking for:

run:
1 :  ****Repository update****
2 :  Location: /home/cissys/repo/
3 :  Command: svn update /home/cissys/repo/2.3.0
4 : At revision 9443.
Done!
BUILD SUCCESSFUL (total time: 3 seconds)

我发现 $ PATH 我从会话中通过java得到的与我直接在linux控制台上得到的不一样。
所以添加svn路径实际上就可以了。非常感谢你的帮助！

I found out that the $PATH I get from the session through java is not the same that I get directly on the linux console. So adding the svn path actually did the trick. Thank you very much for your help!

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