問(wèn)題描述

我有那個(gè)結(jié)構(gòu)的集合.我沒(méi)有重復(fù)，但是當(dāng)我打電話時(shí):set.add(element) -> 并且已經(jīng)有確切的元素我想替換舊的.

I have Set of that structure. I do not have duplicates but when I call: set.add(element) -> and there is already exact element I would like the old to be replaced.

import java.io.*;

public class WordInfo implements Serializable {
    File plik;
    Integer wystapienia;

    public WordInfo(File plik, Integer wystapienia) {
        this.plik = plik;
        this.wystapienia = wystapienia;
    }

    public String toString() {
    //  if (plik.getAbsolutePath().contains("src") && wystapienia != 0)
            return plik.getAbsolutePath() + "	WYSTAPIEN " + wystapienia;
    //  return "";
    }
    @Override
    public boolean equals(Object obj) {
        if(this == obj) return true;
        if(!(obj instanceof WordInfo)) return false;
        return this.plik.equals(((WordInfo) obj).plik);
    }

    @Override
    public int hashCode() {        
        return this.plik.hashCode();
    }
}

推薦答案

每次添加前做一個(gè)remove:

Do a remove before each add:

 someSet.remove(myObject);
 someSet.add(myObject);

remove 將刪除任何等于 myObject 的對(duì)象.或者，您可以檢查添加結(jié)果:

The remove will remove any object that is equal to myObject. Alternatively, you can check the add result:

 if(!someSet.add(myObject)) {
     someSet.remove(myObject);
     someSet.add(myObject);
 }

哪種方式更有效取決于您發(fā)生碰撞的頻率.如果它們很少見，第二種形式通常只做一次操作，但當(dāng)發(fā)生碰撞時(shí)，它會(huì)做三次.第一種形式總是做兩個(gè).

Which would be more efficient depends on how often you have collisions. If they are rare, the second form will usually do only one operation, but when there is a collision it does three. The first form always does two.

這篇關(guān)于替換 HashSet Java 成員的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！