Set private field value

 
import java.lang.reflect.Field;

public class FieldTroubleToo {
  public final boolean b = true;

  public static void main(String... args) {
    FieldTroubleToo ft = new FieldTroubleToo();
    try {
      Class<?> c = ft.getClass();
      Field f = c.getDeclaredField("b");
      // f.setAccessible(true); // solution
      f.setBoolean(ft, Boolean.FALSE); // IllegalAccessException

      // production code should handle these exceptions more gracefully
    } catch (NoSuchFieldException x) {
      x.printStackTrace();
    } catch (IllegalArgumentException x) {
      x.printStackTrace();
    } catch (IllegalAccessException x) {
      x.printStackTrace();
    }
  }
}