Question

Having this class

Class Test
{ 
  static int version=1;
  String A;
  String B;

  //constructor
  //setters, getters, etc...      
  public void printAll(void)
  {
     System.out.println(A);
     System.out.println(B);
  }    
}

After a while, we modify the Class to add a String C :

Class Test
{ 
  static int version=2;
  String A;
  String B;
  String C;

  //constructor
  //setters, getters, etc...      
  public void printAll(void)
  {
     System.out.println(A);
     System.out.println(B);
     //it seems somebody has forgotten to print C!!!!!!!!!

  }    
}

Is here some known approach to avoid this kind of bug?

Thanks

Answer 1

You can use annotations to have a more structured way to use reflection, where you better control which fields will be printable:

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD})
@interface Printable { }

class Test {

  @Printable String A;
  @Printable String B;
  @Printable String C;

  public void printAll() {
    for (Field field : getClass().getDeclaredFields()) {
      if (field.isAnnotationPresent(Printable.class)) {
        try {
          System.out.println(field.get(this));
        } catch (Exception e) {
          throw new RuntimeException(e);
        }       
      }
    }
  }

}