137. Implementing a custom method ObjectInputFilter

Let’s assume that we already have the Melon class and the helper methods for serializing/deserializing objects to/from byte arrays from Problem 131.

An ObjectInputFilter can be written via a dedicated method as in the following example:

public final class Filters {
 private Filters() {
  throw new AssertionError("Cannot be instantiated");
 }
 public static ObjectInputFilter.Status melonFilter(
               FilterInfo info) {
  Class<?> clazz = info.serialClass();
  if (clazz != null) {
   // or, clazz.getName().equals("modern.challenge.Melon")
   return 
    !(clazz.getPackage().getName().equals("modern.challenge")
      && clazz.getSimpleName().equals("Melon"))
      ? Status.ALLOWED :Status.REJECTED;
  }
  return Status.UNDECIDED;
 }
}

Of course, you can add more filters in this class.

We can set this filter as a stream-global filter as follows:

...