Decimal Separator

gistfile1.txt

$ cat Printf.java
public class Printf {
    public static void main(String[] args) {
        System.out.println("Locale.getDefault()=" + java.util.Locale.getDefault());
	    System.out.printf("%.3f%n", 123.45);
    }
}
$ javac Printf.java

$ java -version
java version "1.8.0_77"
Java(TM) SE Runtime Environment (build 1.8.0_77-b03)
Java HotSpot(TM) 64-Bit Server VM (build 25.77-b03, mixed mode)
$ java Printf
Locale.getDefault()=en_US
123.450
$ java -Duser.country=DE -Duser.language=de Printf
Locale.getDefault()=de_DE
123,450


[switch JDK versions]


$ java -version
java version "9-ea"
Java(TM) SE Runtime Environment (build 9-ea+127)
Java HotSpot(TM) 64-Bit Server VM (build 9-ea+127, mixed mode)
$ java Printf
Locale.getDefault()=en_US
123.450
$ java -Duser.country=DE -Duser.language=de Printf
Locale.getDefault()=de_DE
123,450