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Simple way to run java classfile (Terminal)

I wanted to put a java classfile up for download recently, which people could run in Terminal. It's a Minecraft command generator, so the people downloading it won't necessarily have the greatest mental capacity (I'm referring to 8-year-olds who have no idea what they're doing, of course).
Anyway, I wanted to provide a simple, single command, both for the Mac / Linux terminal and the Windows command line, that ran the classfile without any complications. The problem is, I don't want to execute it by doing /cd path, and then doing java someFolder.someClass. I just want to have a single command to open the file. If anyone could provide these commands for me, both in Mac / Linux and Windows, that would be great.
Sorry for the super long explanation :P

A jar file with a main class in the manifest would probably be the easiest thing. Then the command is java -jar myjarfile.jar.
A swing application would probably be easier as the default way of running executable jars doesn't open a command prompt (it uses javaw instead of java).

You will have to first start a terminal and then run java in that terminal, which can be a bit tricky.
How to open a command terminal in Linux?
Why not create an interface (Swing) and pack everything in a jar?

Command-line options working in windows, but not Linux

I have a .bat file on Windows/shell script on Linux that starts a large Java application from the command line. It configures the classpath, environment variables, etc.
At one point, it uses RMID to configure a bunch of services which will run in their own JVMs. The problem is that it won't allow me to specify multiple JARs for the codebase property on Linux. It's allowing me to do so on Windows just fine, but I think my syntax/styling must be wrong for the .sh script and am hoping a more experienced Linux user could have some tip. On Windows, the working line looks like this:
SET RMID_OPTIONS=%RMID_VM%
-J-DINSTALL_DIR=%CONFIG_PATH%
-C-DINSTALL_DIR=%CONFIG_PATH%
-J-DINSTALL_DIR_LOCAL=%HOME_DIR%
-C-DINSTALL_DIR_LOCAL=%HOME_DIR%
-J-Djava.security.policy=%PL_HOME%\windows\system.policy
-C-Djava.rmi.server.codebase=
"file:/%HOME_DIR%\jar1.jar file:/%HOME_DIR%\jar2.jar"
-J-Djava.rmi.server.codebase=
"file:/%HOME_DIR%\jar1.jar file:/%HOME_DIR%\jar2.jar"
// more stuff here
The only important lines are the ones setting the rmi.server.codebase property. The above works 100% fine, however, when trying to set multiple JARs in the codebase in Linux, it causes a general failure and the whole RMID command is not executed. My shell script looks like the following:
export RMID_OPTIONS="${RMID_VM}
-J-DINSTALL_DIR=${CONFIG_PATH}
-C-DINSTALL_DIR=${CONFIG_PATH}
-J-DINSTALL_DIR_LOCAL=${HOME_DIR}
-C-DINSTALL_DIR_LOCAL=${HOME_DIR}
-J-Djava.security.policy=${PL_HOME}/linux/system.policy
-C-Djava.rmi.server.codebase=
""file:/${HOME_DIR}/jar1.jar file:/${PL_HOME_LOCAL}/jar2.jar""
-J-Djava.rmi.server.codebase=
""file:/${HOME_DIR}/jar1.jar file:/${PL_HOME_LOCAL}/jar2.jar""
// more stuff here
"
The shell script itself works perfectly fine if only one JAR is specified, but any more and I get a general failure. Any suggestions on what I'm doing wrong? I'm open to try new things to fix this as all my attempts so far have been fruitless.

Under Linux, escaping quotes is done differently. You are attempting to use the Windows specific syntax, which will result in the jar files being passed as separate arguments, instead of a single one, as it should be.
Instead of "" to produce a quote inside quotes, you have to use \" in Linux:
export RMID_OPTIONS="... -C-Djava.rmi.server.codebase=\"file:/${HOME_DIR}/jar1.jar file:/${PL_HOME_LOCAL}/jar2.jar\" ..."
Aside from that, I'm not sure that the file:/ syntax is correct. It's probably either file:// or the absolute file path without anything preceding it, but you'll have to try it out.

You're doing this wrong. You don't need to start rmid with arguments and system properties at all. All that stuff should be specified when you register the ActivationGroup(s) you're going to use, in your activation setup program. That in turn means that all command-line problems should just disappear.

Wrapping a jar file in a Windows service

Have you had experience with running a jar file using a command line, wrapped in a Windows service?
I'm trying to find a way to run a jar file without being logged into the machine, and since it allows command shell, I was wondering if it's a good idea.
Thanks!
Original Post:
I'm trying to run Associated Press's Web Feeds Manager, which is basically a jar file that can be run when logged in by double clicking it.
I'd like to run the same file but without being logged in to the machine. In their manual (http://wfm.ap.org/admin/content/help/Running_Agent_on_a_Remote_Server.htm) they write how to do that, using a commandline parameter.
Basically I'd like the jar to run as a Windows service, regardless of who's logged in, but Googling it showed it was problematic.
Have you had experience with remotely running jar files? What are the pitfalls?
Thanks!

On a google search, I came across this article -
Running Jar Applications as a Windows Service
It mentions about open source Java Service Wrapper project from Tanukisoftware.org for accomplishing this task.
Note: I've not used this personally.

If you are not interested in having the service started/stopped at boot/shutdown, but you just want the program to be started manually and keep running after logout, here is what you do:
$ nohup java -jar foobar.jar > foobar.log 2>&1 &
which means: start my foobar.jar (java -jar) and keep it running after I logout (nohup) redirect stdout to foobar.log (>) and also the stderr (2>&1), and make it running in background (& at the end).
Instead, if you are interested in installing a "service" in your linux box, there are many options, depending on what distribution you are using.
The most common are upstart (for ubuntu) and System V init scripts (Redhat or others). Also cron can be used to start/stop services at startup/shutdown.
You can find an example of installing a java app (hudson) on an init system here, or doing the same thing with upstart. Or, as I said, cron could be an option.
On Windows, there is Java Service Wrapper. And not much more.

For windows Java Service Wrapper is a better choice

My favourite is the upstart on linux, but it is Ubuntu only.
On Windows I see many alternatives according to this forum.

Execute shell command in Tomcat

So I have the following problem: I have a web service running inside a Tomcat7 server on Linux. The web service however has to execute some commands (mostly file operations such as copy and mount). Copy I've replaced with java.nio, but I don't think that there is a replacement for mount.
So I'm trying to execute shell commands out of my Tomcat Java process. Unfortunately it doesn't execute my commands. I've implemented the execution of shell commands in Java before. So my code should be correct:
Process pr = Runtime.getRuntime().exec("mount -o loop -t iso9660 <myimage> <mymountpoint>");
pr.waitFor();
<myimage> and <mymountpoint> are absolute paths, so no issues there either.
I've debugged my commands and they are working when executed on the console.
I've tried sending other commands. Simple commands such as id and pwd are working!
I've tried using /bin/bash -c "<command>", which didn't work.
I've tried executing a shell script, which executes the command, which didn't work.
I've tried escaping the spaces in my command, which didn't work.
So I've digged even deeper and now I'm suspecting some Tomcat security policy (Sandbox?), which prevents me from executing the command. Since security is no issue for me (it's an internal system, completely isolated from the outside world), I've tried a hack, which became quite popular just recently:
System.setSecurityManager(null);
This didn't work either. I'm using Java7 and Tomcat7 on RHEL6. Tomcat7 is just extracted! I don't have any files in /etc/.. or any other folder than /opt/tomcat/, where I've extracted the zip from the Tomcat home page. I've searched the /opt/tomcat/conf folder for security settings, but all I could find was the file catalina.policy, where it didn't seem like I could set some security level for shell commands.
Any ideas?

A few things:
System.setSecurityManager(null);
you have just killed the security of your application.
Yes, Tomcat is running as root. If I execute id I'm root as well.
Fix this immediately!
Now on to the question. You shouldnt have Tomcat executing anything, you need to defer this to a separate process whether that be a shell script or another Java program. This should also remove what (I hope) was a dependency on root running Tomcat. It should be possible to perform this command as a non-privileged user that cannot log into the system normally. You would do this by configuring /etc/fstab and supplying that same user the permissions to do this. From a pure security POV the process that mounts should not be owned by the tomcat user. Nor should the tomcat user ever be root. So to recap:
1) Stop running Tomcat as root
2) Create a separate process outside of the context of Tomcat to run this mount
3) Create a tomcat user, this user should not be able to log into the system nor should it be a privileged user (admin,super user, etc)
4) Create a process user, this user should be configured exactly as the tomcat user
5) Edit /etc/fstab giving the process user the necessary permissions to mount correctly.

It's generally a bad idea to use the single-string form of Runtime.exec. A better option is to use ProcessBuilder, and split up the arguments yourself rather than relying on Java to split them for you (which it does very naïvely).
ProcessBuilder pb = new ProcessBuilder("/bin/mount", "-o", "loop", /*...*/);
pb.redirectErrorStream(true); // equivalent of 2>&1
Process p = pb.start();
You say you're on RHEL so do you have selinux active? Check your logs and see if this is what's blocking you (I think it's audit.log you're looking for, it's been a few years since I've used selinux). If this does turn out to be the problem then you should probably ask on superuser or serverfault rather than SO...

I'm not sure if that's the problem you are having, but I've seen issues when Runtime.exec() is used without reading the associated output buffers. You can find a detailed explanation and potential solutions here. Reading the output and error streams can also help you figure out what's going on at the OS level when you run the command.

I've recently had to do something like this from a Swing app.
You'll probably be able to pull it off with ProcessBuilder, as in Ian's answer, but I found that once things start to get complex, it's easier to write a shell script that does what you want, enabling you to pass as few parameters as possible. Then use ProcessBuilder to invoke the shell script.
If you're invoking anything that has more than really minimal output, you'll also have to read the output and error streams to keep the process from blocking when the output buffers fill, as it seems you are already doing.

I use sudo -S before command and for the tomcat7 user: tomcat7 ALL=(ALL) NOPASSWD:ALL

Windows Registery: How to add a Java app to startup list?

I added a value at:
HKLM\Software\Microsoft\Windows\CurrentVersion\Run
That looks like this:
Value Name: LDE
Value Data: "java -jar C:\LDE\lde.jar"
Really with the quotes (Because all the others where also with quotes). After adding this, I restarted my computer, but it didn't start automatically.
Will wrapping my jar in an exe help?
I'm running Windows 7.
Any help?
Thanks in advance.
Update:
When I remove the quotes, it works. But now there is appears also a terminal, which I don't need...

A couple of things to note here, concerning the two different issues in the problem:
Format of Windows Run keys
From the Microsoft Windows XP knowledge base:
Run keys cause programs to
automatically run each time that a
user logs on. The Windows XP registry
includes the following four Run keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
Each of these keys has a series of
values. The values allow multiple
entries to exist without overwriting
one another. The data value for a
value is a command line.
Note the emphasis on the last line. The moment quotes are used, the command is bound to fail execution in the same manner it fails as if executed from a command prompt.
Also, note that the above approach is for Windows XP and does hold good for Windows 7. More details can be found in this Microsoft Technet article on the options available in Windows 7.
The javaw vs java application launcher
Once the java process can be initialized at Windows startup, one will get a console window that continues to stay around until the process is terminated. This occurs if the java executable is utilized to initialize the application.
From the technotes of the java application launcher:
The javaw command is identical to
java, except that with javaw there is
no associated console window. Use
javaw when you don't want a command
prompt window to appear. The javaw
launcher will, however, display a
dialog box with error information if a
launch fails for some reason.
Therefore, if you wish to avoid opening a console window for the Java process, you ought to use the javaw executable.

This is very simple. You will find the startup folder in the C:/Documents and Settings/AllUsers/YourUserName/StartUp. It will be on similar kind of path just check it. Then just paste your jar file in that folder and it will work nice. Remember that you put the jar file in the startup folder of your user name folder. You may find that this folders might be hidden so just check it out. If you find this answer useful vote it. Enjoy.....