Get interface constant name using its value

Have converted this to a generic method, for improved reusability (eg. for switch & default):

/**
 * @param cls The *.class which to traverse
 * @param value The constant value to look for
 */
@Nullable
private String getConstantName(Class<?> cls, int value) {
    for (Field f : cls.getDeclaredFields()) {
        int mod = f.getModifiers();
        if (Modifier.isStatic(mod) && Modifier.isPublic(mod) && Modifier.isFinal(mod)) {
            try {
                // Log.d(LOG_TAG, String.format("%s = %d%n", f.getName(), (int) f.get(null)));
                if((int) f.get(null) == value) {return f.getName();}
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        }
    }
    return null;
}

I can think of two better solutions to this than using reflection.

1. Any decent IDE will auto-fill in switch statements for you. I use IntelliJ and it does this (you just press ctrl-enter). I'm sure Eclipse/Netbeans have something similar; and

2. Enums make a far better choice for constants than public static primitives. The added advantage is they will relieve you of this problem.

But to find out what you want via reflection, assuming:

interface Foo {
  public static final int CONST_1 = 1;
  public static final int CONST_2 = 3;
  public static final int CONST_3 = 5;
}

Run:

public static void main(String args[]) {
  Class<Foo> c = Foo.class;
  for (Field f : c.getDeclaredFields()) {
    int mod = f.getModifiers();
    if (Modifier.isStatic(mod) && Modifier.isPublic(mod) && Modifier.isFinal(mod)) {
      try {
        System.out.printf("%s = %d%n", f.getName(), f.get(null));
      } catch (IllegalAccessException e) {
        e.printStackTrace();
      }
    }
  }
}

Output:

CONST_1 = 1
CONST_2 = 3
CONST_3 = 5