ResourceBundle.keySet() has the following syntax.
public Set < String > keySet()
In the following code shows how to use ResourceBundle.keySet() method.
import java.util.Locale; import java.util.ResourceBundle; /* w ww . jav a2s . c o m*/ public class Main { public static void main(String[] args) { ResourceBundle bundle = ResourceBundle.getBundle("hello", Locale.US); System.out.println(bundle.getString("hello")); System.out.println(bundle.keySet()); } }