Proper usage of Java -D command-line parameters

Question

When passing a -D parameter in Java, what is the proper way of writing the command-line and then accessing it from code?

For example, I have tried writing something

Answer 1

That should be:

java -Dtest="true" -jar myApplication.jar

Then the following will return the value:

System.getProperty("test");

The value could be null, though, so guard against an exception using a Boolean:

boolean b = Boolean.parseBoolean( System.getProperty( "test" ) );

Note that the getBoolean method delegates the system property value, simplifying the code to:

if( Boolean.getBoolean( "test" ) ) {
   // ...
}