如何使用集合从 arrayList 调用第二大数字 [英] How can I call second largest number from arrayList using collections

问题描述

我需要 ArrayList 中的最高、第二高和第三高的数字.我通过调用 Collections.max() 获得最大值(即最高数字)，​​但我还需要第二大和第三大的值.
我的代码:

I need highest, second highest and third highest numbers from my ArrayList. I am getting max value (i.e. highest number) by calling Collections.max() but I also need the second largest and the third largest values.
My Code:

maxPartyid = 
Collections.max(electionresdashlist.get(k).getPartyNamesDTO());  //1st Highest
                         
System.out.println( "maxPartyid:::"+maxPartyid);
             
in DTO :
public class PartyNamesDTO implements Comparable<PartyNamesDTO>{

    private String partyId;
    public String getPartyId() {
        return partyId;
    }
    public void setPartyId(String partyId) {
        this.partyId = partyId;
    }
    private Integer votes;
    
    
    public Integer getVotes() {
        return votes;
    }
    public void setVotes(Integer votes) {
        this.votes = votes;
    }
    
    @Override
        public int compareTo(PartyNamesDTO emp) {
            return this.votes.compareTo(emp.getVotes());
        }
    
        public String toString(){
            return partyId;
        }
}        
             
             

推荐答案

你可以使用java 8流来排序和跳过不必要的元素

You can use java 8 streams to sort and skip unnecessary elements

list.stream().sorted(Comparator.reverseOrder()).limit(2).skip(1).findFirst()

findFirst() 返回对象的 Optional.

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