Java Stream - 如何filter带谓词

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import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
public class Main {
  public static void main(String[] args) throws Exception{
    List<Dish> menu =
        Arrays.asList( new Dish("pork", false, 800, Dish.Type.MEAT),
                       new Dish("beef", false, 700, Dish.Type.MEAT),
                       new Dish("chicken", false, 400, Dish.Type.MEAT),
                       new Dish("rice", true, 350, Dish.Type.OTHER),
                       new Dish("pizza", true, 550, Dish.Type.OTHER),
                       new Dish("prawns", false, 400, Dish.Type.FISH),
                       new Dish("salmon", false, 450, Dish.Type.FISH));
    // Filtering with predicate
    List<Dish> vegetarianMenu =
        menu.stream()
            .filter(Dish::isVegetarian)
            .collect(Collectors.toList());
    vegetarianMenu.forEach(System.out::println);
  }
}
class Dish {
  private final String name;
  private final boolean vegetarian;
  private final int calories;
 
 
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