Pass the optional (second) argument to Guaw Predicate

Question

I have a Predicate that filters my Task objects based on date:

 Predicate<Task> startDateFiltering = new Predicate<Task>() { @Override public boolean apply(Task input) { return input.getStartDate() != null && input.getStartDate().after(date); } }; 

It makes no sense to use it as long as the date variable is available in context. However, I would like to make it reusable and embed it in the Task class by doing something like this:

 public static final Predicate<Task> startDateFiltering = new Predicate<Task>() { @Override public boolean apply(Task input) { return input.getStartDate() != null && input.getStartDate().after(date); } }; 

To access it as Task.startDateFiltering every time I need it. But how do you pass the date argument to it?

Answer 1

I would create a static factory method (or just immediately a new instance every time)

 public static Predicate<Task> startDateFilteringWithDate(final Date date) { return new Predicate<Task>() { @Override public boolean apply(Task input) { return input.getStartDate() != null && input.getStartDate().after(date); } }; } 

Answer 2

Wrap it in a method ( Factory pattern view).

 public static Predicate<Task> startDateFiltering(Date date) { return new Predicate<Task>() { public boolean apply(Task input) { return input.getStartDate() != null && input.getStartDate().after(date); } } }