Is ProcessBuilder aware of environment variable?

Question

https://docs.oracle.com/javase/7/docs/api/java/lang/ProcessBuilder.html

Suppose that a java program (say, my.jar) uses ProcessBuilder to start subprocess.

If I start the program with VAR=xxx java -jar my.jar , will the subprocess be aware of the environment variable VAR is set to xxx?

Answer 1

Variables will be passed on if they are exported correctly - and that very much depends on your OS and command shell.

Before launching your Java app, try set VAR=xyz (Windows) or export VAR=xyz (GNU/Linux depending on your shell), and these should be passed onto java process and any sub-process called with ProcessBuilder - except where your code passes in environment() which may change the environment settings of the sub-process.

However on GNU/Linux with bash a local variable declaration such as NOTEXPORTED=XYZ isn't passed on to the java process, therefore isn't passed on sub-process. For the following example, VAR2 is passed to the java application but not VAR1 - unless changed to export VAR1=123 .

VAR1=123
VAR2=456 java -jar xyz.jar