Setting Environment variables From a Java Programme

[abinash parija]

Hi,


Is there any way by which i can set the environment variables.
Actually i need to rub an exe for which environment variable set up is required.


Thanks in advance

[Campbell Ritchie]

Please explain more. You can try passing "set CLASSPATH=foo/bar/something" as an argument via Runtime.getRuntime.exec(), but I am not sure whether that is what you need. Don't use Runtime.exec() until you read the classic paper by Michael Daconta which you should find here: When Runtime.exec() won't.

[Rob Spoor]

Using ProcessBuilder you can specify the environment variables you pass to it:

ProcessBuilder builder = new ProcessBuilder(...);
builder.environment().put("CLASSPATH", "foo/bar/something");

By default. environment() returns a Map with all current environment variables.

[Samuel Behrman]

I think you've hit the nail on the head.

A possible way to ease the burden would be to factor out a method

void setUpEnvironment(ProcessBuilder builder) {
Map<String, String> env = builder.environment();
// blah blah
}
and pass any ProcessBuilders through it before starting them.

Also, you probably already know this, but you can start more than one process with the same ProcessBuilder. So if your subprocesses are the same, you don't need to do this setup over and over.