org.mmbase.util

Class CommandServer

java.lang.Object

org.mmbase.util.CommandServer

public class CommandServer
extends Object

Java command server. Especially targeted at executing imagemagick 'convert' in a system call.

It can work in two ways. The first way is as a stand-alone server. You start it up with a port-number argument then (or with a host-name and port-number argument, if you don't want it to listen on localhost). A server socket will be created and communication can happen via tcp.

~$ /usr/bin/java -jar mmbase-commandserver.jar michiel.omroep.nl 1679
Started ServerSocket[addr=michiel.omroep.nl/145.58.67.10,port=0,localport=1679]

If no arguments are provided, it will listen on stdin and return the result on stdout. This means that it can be installed as a inetd daemon (in UNIX systems). This boils down to placing something like

commandserver 1679/tcp
 

In /etc/services. And

commandserver   stream  tcp             nowait  nobody  /usr/bin/java java -jar /home/michiel/mmbase/head/applications/commandserver/build/mmbase-commandserver.jar
 

in /etc/inetd.conf. The result is the same (you can communicate with TCP), but avoids the hassle of having to keep the process alive.

The input for this server are 2 serialized String[] arrays (which will be the arguments for Runtime.exec(String[], String[])), followed by the stdin for the command. It will return stdout of the process.

You can use CommandExecutor to connect to the commandserver.

Since:

MMBase-1.8.2

Version:

$Id$

Author:

Michiel Meeuwissen

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CommandServer.Command
static class	CommandServer.Copier

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static ThreadFactory	FACTORY
(package private) static int	number
(package private) static BlockingQueue<Runnable>	threadQueue
(package private) static ThreadPoolExecutor	threads

Constructor Summary

Constructors

Constructor and Description
CommandServer()

Method Summary

Modifier and Type	Method and Description
static void	main(String[] a)
static String	stackTrace(Throwable e, int max)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

number

static int number

FACTORY

static final ThreadFactory FACTORY

threadQueue

static final BlockingQueue<Runnable> threadQueue

threads

static final ThreadPoolExecutor threads

Constructor Detail

CommandServer

public CommandServer()

Method Detail

stackTrace

public static String stackTrace(Throwable e,
                                int max)

main

public static void main(String[] a)
                 throws IOException,
                        InterruptedException

Throws:

IOException

InterruptedException