如何基于Java實現(xiàn)對象List排序

更新時間：2020年01月14日 10:29:02 作者：龍凌云端

這篇文章主要介紹了如何基于Java實現(xiàn)對象List排序,文中通過示例代碼介紹的非常詳細(xì)，對大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價值,需要的朋友可以參考下

按照對象中的某個屬性，對對象List進(jìn)行排序。

以初唐四杰的成績排名為例，對詩人進(jìn)行排序。

Java實現(xiàn)如下：

1、詩人（Poet）類結(jié)構(gòu)，定義如下：

/**
 * Created by Miracle Luna on 2020/1/11
 */
public class Poet {
  private String name;
  private Double score;

  public Poet(String name, Double score) {
    this.name = name;
    this.score = score;
  }

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public Double getScore() {
    return score;
  }

  public void setScore(Double score) {
    this.score = score;
  }

  @Override
  public String toString() {
    return "Poet{" +
        "name='" + name + '\'' +
        ", score=" + score +
        '}';
  }
}

2、詩人按照成績排名，代碼如下：

import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;

/**
 * Created by Miracle Luna on 2020/1/11
 */
public class PoetSort {

  public static void main(String[] args) {
    List<Poet> poetList = new ArrayList<Poet>();
    Poet poet1 = new Poet("楊炯", 94.0);
    poetList.add(poet1);
    Poet poet2 = new Poet("盧照鄰", 92.5);
    poetList.add(poet2);
    Poet poet3 = new Poet("駱賓王", 95.0);
    poetList.add(poet3);
    Poet poet4 = new Poet("王勃", 99.5);
    poetList.add(poet4);


    // 初始順序
    System.out.println("==> 初始順序如下：");
    poetList.forEach(poet -> System.out.println(poet.toString()));

    // 按照分?jǐn)?shù)排名(從高到低)
    poetList.sort(new Comparator<Poet>() {
      @Override
      public int compare(Poet poet1, Poet poet2) {
        Double score1 = poet1.getScore();
        Double score2 = poet2.getScore();
        return score2.compareTo(score1);
      }
    });
    System.out.println("\n==> 按照分?jǐn)?shù)排名(從高到低)如下：");
    poetList.forEach(poet -> System.out.println(poet.toString()));

    // 按照分?jǐn)?shù)排名(從低到高)
    poetList.sort(new Comparator<Poet>() {
      @Override
      public int compare(Poet poet1, Poet poet2) {
        Double score1 = poet1.getScore();
        Double score2 = poet2.getScore();
        return score1.compareTo(score2);
      }
    });
    System.out.println("\n==> 按照分?jǐn)?shù)排名(從低到高)如下：");
    poetList.forEach(poet -> System.out.println(poet.toString()));
  }
}

3、運行結(jié)果如下：

==> 初始順序如下：
Poet{name='楊炯', score=94.0}
Poet{name='盧照鄰', score=92.5}
Poet{name='駱賓王', score=95.0}
Poet{name='王勃', score=99.5}

==> 按照分?jǐn)?shù)排名(從高到低)如下：
Poet{name='王勃', score=99.5}
Poet{name='駱賓王', score=95.0}
Poet{name='楊炯', score=94.0}
Poet{name='盧照鄰', score=92.5}

==> 按照分?jǐn)?shù)排名(從低到高)如下：
Poet{name='盧照鄰', score=92.5}
Poet{name='楊炯', score=94.0}
Poet{name='駱賓王', score=95.0}
Poet{name='王勃', score=99.5}

以上就是本文的全部內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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