How to pass system property values to a processBuilder?

Question

Java's Runtime class allows named system property values to be sent as command line arguments when running a jar. Like below:

Runtime.getRuntime().exec("java -jar -DiName=ABC C:\\Test.jar");

I am trying to move from Runtime to ProcessBuilder to achieve the same functionality. Need advice on what the correct way to do this is.

ProcessBuilder pb = new ProcessBuilder("java",  "-jar",  "C:\\Test.jar").start();

In the above code, how can I pass the "iName"?

The reason I am moving from Runtime to ProcessBuilder is, the java program that triggers this Runtime code is not working in a specific production environment which is using 1.8.0_40 JDK.

Answer 1

Just have a look at the Javadoc.

There it is stated clearly that the ProcessBuilder Constructor can be of the form public ProcessBuilder(String... command) (for example, see Timothy Truckle comment) or, equivalently, just a single parameter of type List<String>.

So opposite to Runtime, which tokenizes one single String, here the ProcessBuilder, needs already tokenized parameter list.

Probably, to avoid any future confusion, it would be the best to store the parameters in a variable, for easier modification later. For instance:

List<String> params = java.util.Arrays.asList("java", "-jar", "-DiName=ABC", "C:\\Test.jar");
ProcessBuilder pb = new ProcessBuilder(params).start();

Hope this helps in the long run!

Answer 2

new ProcessBuilder("java",  "-jar", "-DiName=ABC", "C:\\Test.jar");

ProcessBuilder receives array (varargs) of parameters, which will be concatenated and executed.