How to optimize launch times of small Java command line programs? [duplicate]

Question

Possible Duplicate:
How to speed up Java VM (JVM) startup time?

Over the course of the day, I have to execute a series of small & quick Java command line programs. On Windows, to run a simple Java program from a the command line (like Hello World), sometimes it takes around 5 seconds due to the overhead of launching the java.exe process. The programs take a second to execute but the overhead of starting the programs is dominates the total execution time. Is there a way to optimize this?

Is there something like a Java shell that I can use to execute programs in-process? Similar to the Python shell?

Answer 1

This may be overkill, but you could set up an application server like Tomcat or Glassfish and run your programs within the server. From what I understand, one of the original purposes of Java Servlets was to eliminate the startup dely associated with traditional CGI programs.

I don't know much about Java, so I don't know if there are simpler solutions available. But Tomcat et al are already available, so you wouldn't need to write your own server program.

Edit: someone else pointed out a similar question, How to speed up Java VM (JVM) startup time? One of the answers to that question mentions Nailgun, which looks like a near-perfect solution to your problem.

Answer 2

You might write your own shell. You can write a single command line program that embeds all the functionality of those "utilities". You launch it, you keep it running and then you make your queries via some syntax you decide.