java8 把List 根据某字段去重

 

 

import java.util.ArrayList;
import java.util.List;
import org.apache.shiro.SecurityUtils;
import org.apache.shiro.subject.Subject;
import java.util.*;
import java.util.stream.Collectors;

import static java.util.Comparator.comparing;
import static java.util.Comparator.comparingLong;
import static java.util.stream.Collectors.collectingAndThen;
import static java.util.stream.Collectors.toCollection;

 1   public static void main(String[] args) {
 2     Milk milk0=new Milk(0,"123456");
 3     Milk milk1=new Milk(1,"123476");
 4     Milk milk2=new Milk(0,"876433");
 5     List list=new ArrayList<>();
 6     list.add(milk0);
 7     list.add(milk1);
 8     list.add(milk2);
 9     //去重
10     List uniqueMilk = list.stream().collect(
11         collectingAndThen(
12             toCollection(() -> new TreeSet<>(comparing(n->n.getKey()))),ArrayList::new)
13     );
14 
15     for (Milk m:uniqueMilk) {
16       System.out.println(m.toString());
17     }
18 
19   }

 

public class Milk {
  private Integer key;
  private String value;

  public Milk(Integer key, String value) {
    this.key = key;
    this.value = value;
  }

  public Integer getKey() {
    return key;
  }

  public void setKey(Integer key) {
    this.key = key;
  }

  public String getValue() {
    return value;
  }

  public void setValue(String value) {
    this.value = value;
  }

  @Override
  public String toString() {
    return "Milk{" + "key=" + key + ", value='" + value + '\'' + '}';
  }
}

 

转载于:https://www.cnblogs.com/qq1141100952com/p/11197120.html