JAva 8はストリームのfilterを使用してデータをフィルタします

package chapter1;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static java.util.stream.Collectors.groupingBy;

public class stream {
    //                       150   ，        
    //                     

    public static void main(String[] args) {
        List appleList = new ArrayList<>();

        //    
        Map> AppMap = new HashMap<>();
        for (Apple apple : appleList) {
            if (apple.getWeight() > 150) { //      150
                if (AppMap.get(apple.getColor()) == null) { //       
                    List list = new ArrayList<>(); //        
                    list.add(apple);//        
                    AppMap.put(apple.getColor(),list);//     map 
                }else { //        
                    AppMap.get(apple.getColor()).add(apple);//        ，        
                }
            }
        }

        //               150        ，      



        //      java8    api          
        Map> AppMap2=appleList.stream().filter((Apple a)->a.getWeight()>150) //     150 
                .collect(groupingBy(Apple::getColor)); //           map
        

    }


    class Apple {

        private String color;//  
        private Integer weight; //  

        public String getColor() {
            return color;
        }

        public void setColor(String color) {
            this.color = color;
        }

        public Integer getWeight() {
            return weight;
        }

        public void setWeight(Integer weight) {
            this.weight = weight;
        }


    }
}