Running Java program in a Docker Image - java

So I have a Docker network that has a Docker file with a bunch of information. I have a java program that is going to bring up the enviorment and then produce several commands to run within this enviorment. To be clear, the first command I need to run is NOT inside the Docker enviorment. I am having some challenges with the Process and Runtime classes.
First, say I wanted my java program to launch a new gnome terminal and then run a command to get into the docker network. I have this command,
Process process = Runtime.getRuntime().exec(new String[]{"gnome-terminal"});
Gnome terminal sucessfully comes up but any additional arguments I give in this array are just ignored. For example,
Process process = Runtime.getRuntime().exec(new String[]{"gnome-terminal","ls"});
Does not work. The command I ultimatly want to run would look something like this,
Process process = Runtime.getRuntime().exec(new String[]{"gnome-terminal","sudo","docker","exec","-it","sawtooth-shell-default", "bash"});
Second, Once I have this running, will additional commmands I run work within the Docker enviorment? I have a python file with a Stream handler that specifies the correct commands to run.
Other documentation on related issues was limited.
I made sure my code was wrapped in a runtime exception try catch and that I was running the correct .class file. Any help on this would be great!
Edit: I have also tried to run this in another linux terminal like Hyper and Tilda
I also am able to get a sudo sign in when I run the command like so,
Process process = Runtime.getRuntime().exec(new String[]{"gnome-terminal","--","sudo","docker","exec","-it","sawtooth-shell-default", "bash"});
However it closes immediatly after authorizing.

Okay this is what I was attempting to do.
https://www.atlassian.com/blog/software-teams/deploy-java-apps-with-docker-awesome
This site is outdated and I had to use this link for getting that latest version of the java PPA.
This process basically installs java into the docker contatiner so that I can run a java program that uses Runtime.

Related

Run java process as background process in linux

I am running my project as jar using java -jar command in Linux machine. As soon as this program run , It produces logs in another directory. Running my program this way requires me to keep the shell open. Now If I have to see the logs , I can't do that in the same shell. I am forced to do that by either doing the duplicate session or new session. Is there any way I can run the jar as background process and see the logs in the same shell ?
If you don't care about it staying alive, something as simple as nohup java -jar myjar.jar & should work. If you need it to be automatically restarted if it crashes or start automatically at boot, you'll want to look into something like systemd or monit.

Run shell script from Java to send data via USB

Exactly as specified in the title, I'm trying to send data to my ODROID-Show external screen via USB. I'm running a shell script that sends such data. The problem is I can simply run the command through Terminal and it runs successfully and data is sent to my little screen through USB port. When I try to run the same command via Java, Nothing happens.
Process proc = Runtime.getRuntime().exec("/bin/bash -c /home/ahmed/ODROID-SHOW-master/example/linux/images.sh /");
The specified command should have root privileges to run. That, I've switched to root then ran the code and nothing happened. Any thoughts how to solve such problem?
Edit:
IF you can show a code that executes given command prefixed by sudo this will absolutely work.
I was able to run the program as root. but, corrupted data are sent to ODROIDscreen rather than valid images. while it transfers successfully when ran through Terminal, Any thoughts why that happens?
I would check if the script executed by the bash interpreter requires certain environment variables set before execution.
I'd add a debug line in the executed shell script to dump the environment like "env > my_dump_env.txt" then run the script both from command line as well as from Java and do a diff see what is missing or is different.

How to Run Commands through a already running Java?

I was wondering if it was possible to execute commands from PHP to a Java prompt which is already running?
I have tried the solution listed here:
How to run a shell command through PHP code?
and this provided no functionality
Let me explain
The java is running on one screen of the linux server
sudo apt-get install screen
and running the .jar file through the command line.
I am then running a webserver, which will have an admin accessibility to restricted areas, which will contain scrips to run specific commands through that already running .jar file?
You can implement some kind of IPC. The java file listens to a port and receives the commands. Or you can write the commands in a specific file which the java programm reads. I think under linux you can also use shared memory: http://www.php.net/manual/en/book.shmop.php
It is possible by sending the command to the screen session. I used this for a minecraft server once.
screen -S <sessionname> -X stuff "<command>\r"
This would (IIRC) provide the same output as if you where inside the screen, typed the command and pressed enter.
I hope this was what you wanted.

Java ProcessBuilder showing console of started java application?

I have a JAVA application that launches (using ProcessBuilder) another JAVA application like this:
String val = "something";
ProcessBuilder processBuilder = new ProcessBuilder("java", "-classpath", dir, appName, val);
Process p = processBuilder.start();
Now, this works fine, appName is launched with the parameter val and it runs and works ... great ... the problem is no Console Window appears ... appName does a LOT of outputting to the console and we need to see it ... how can I start the process with a console?
I am trying stuff like ("CMD.exe", "java", "-classpath", dir, appName, val), etc... but I can't get it right ...
Also, I can't redirect the streams, my program can actually start 5-10 of these appName's, each should have their own console window showing their own information.
Any help would be much appreciated.
Thanks,
console windows are generally not the most reliable form of logging. they only store a set amount of information (buffer) and can behave differently across platforms.
i strongly suggest logging to a file using something like log4j and if you need to see it real time use a tail like program (i see you're using windows).
in addition to this, seeing as you want the windows visible at all times and launching a tail program for each log might be annoying, i'd write my own log window in java swing.
the basic idea is to not rely on the OS too much.
Tried Runtime.getRuntime().exec("cscript java -classpath ..."); ?
Anyway, consider using a logging framwork (log4j, commons-logging), because opening 5 consoles is not the most clever thing to do.
I call a few shell scripts via Process to open a command line window and launch whatever I need. As long as the scripts don't detach - you can usually stop any shell command from doing this -java will still hold the running process.
I did it in linux but the concept should be similar.
#!/bin/bash
# To open a process in a new window.
gnome-terminal -x ./your-real-shell-script-here.sh "$#"
the real script will have your java execution in it, such as:
#!/bin/bash
java -jar your-jar-file.jar "$#"
I think you can use javaw to run on windows, so you might only need the one shell script.
A Console object only exists when you execute java.... from a console. Otherwise, the call to obtain one returns null.
If you want to see a console, you need to open a command shell console (e.g. windows cmd.exe or Unix bash shell window) and type:
java -classpath="..." com.example.appName arg1
If you want to run in a different manner, sorry to say, logging to Console is not for you. Instead, log using one of:
log4j
slf4j
logback

Launching jEdit From Java Swing App Using Runtime.getRuntime().exec()

I'm writing a Java Swing Application running on Red Hat Enterprise Linux 5 server that I would like to launch jEdit to view log files.
Here is some example code.
public static void main(String[] args) throws IOException, InterruptedException {
String cmd = "sh -c \"java -jar /tmp/jEdit/jedit.jar /tmp/test.txt\"";
System.out.println(cmd);
Runtime.getRuntime().exec(cmd);
}
The output is:
sh -c "java -jar /tmp/jEdit/jedit.jar /tmp/test.txt"
If I copy and paste the cmd output in a terminal window, it runs fine.
I have tried a bunch of cmd values, but I can never get the jEdit window to be visible.
With changes, this process works fine on Windows.
Is what I'm doing possible on Linux?
Thanks in advance!
As jEdit is implemented in Java, perhaps it would be easier to check the source for what the main method (in the class declared in the manifest file included in the jedit.jar) does and do the same thing without using Runtime.getRuntime().exec() at all.
If you do want to stick with it, you could try passing the individual commands as an array to exec(), this often solved such problems for me.
Linux uses the concept of display ports for its X-Windows system. This allows it to maintain a different desktop environment for each user. It also allows a user on remote machine to run a desktop app from the first machine but see the UI on the remote.
Windows, having only one available desktop environment at a time, does not.
First thing you definitely have to do is add the environment variable "DISPLAY=localhost:0" to the environment from which you are launching this. However, you may also need to run 'xhost +localhost' or this may not be allowed.
Double-check, too, that you didn't successfully launch a bunch of jEdit processes that are now zombies (using top) and kill them if necessary (using kill).
Runtime.exec() needs some special attention. The exec method that accepts a String uses the space character as a delimiter to break up the string into commands. You need to use the exec method that accepts a String[]. Read more here, specifically near the bottom.
I´ve done this once and I got the same problem
What I've done is to write the command line into a text file and then execute the text file as a shell script file.
It worked fine for me.
Jedit has a launcher script, /usr/bin/jedit I guess. Simply typing jedit in command prompt runs it, at least in current version, 4.5. Try that script instead of explicit java command.

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