What is the best way to filter a Java Collection?

Question

I want to filter a java.util.Collection based on a predicate.

Answer 1

The setup:

public interface Predicate {
  public boolean filter(T t);
}

void filterCollection(Collection col, Predicate predicate) {
  for (Iterator i = col.iterator(); i.hasNext();) {
    T obj = i.next();
    if (predicate.filter(obj)) {
      i.remove();
    }
  }
}

The usage:

List myList = ...;
filterCollection(myList, new Predicate() {
  public boolean filter(MyObject obj) {
    return obj.shouldFilter();
  }
});