OnJava8-Examples/exceptions/Switch.java

// exceptions/Switch.java

public class Switch {
  private boolean state = false;
  public boolean read() { return state; }
  public void on() { state = true; System.out.println(this); }
  public void off() { state = false; System.out.println(this); }
  @Override
  public String toString() { return state ? "on" : "off"; }
}