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Java List 排序

2023-09-11 14:16:16 时间

  

 

package ersatz;

import java.util.Comparator;
import java.util.LinkedList;
import java.util.List;

public class Ersatz {
  public static void main(String[] args) {
    List list = new LinkedList();
    list.add(new Book("a", "aa", 100));
    list.add(new Book("b", "bb", 10));
    list.add(new Book("c", "cc", 19));
    list.add(new Book("d", "dd", 80));

    sort(list, new Comparator() {
      @Override
      public int compare(Object o1, Object o2) {
        Book b1 = (Book) o1;
        Book b2 = (Book) o2;
        if (b1.getPrice() > b2.getPrice()) {
          return 1;
        } else if (b1.getPrice() < b2.getPrice()) {
          return -1;
        } else {
          return 0;
        }
      }
    });

    for (Object value : list) {
      System.out.println(value);
    }

    sort(list, new Comparator() {
      @Override
      public int compare(Object b, Object p) {
        Book b1 = (Book) b;
        Book b2 = (Book) p;
        if (b1.getPrice() > b2.getPrice()) {
          return -1;
        } else if (b1.getPrice() < b2.getPrice()) {
          return 1;
        } else {
          return 0;
        }
      }
    });

    for (Object value : list) {
      System.out.println(value);
    }
  }

  public static void sort(List list, Comparator comparator) {
    int size = list.size();
    for (int i = 0; i < size - 1; ++i) {
      for (int j = 0; j < size - 1 - i; ++j) {
        Book b1 = (Book) list.get(j);
        Book b2 = (Book) list.get(j + 1);
        if (comparator.compare(b1, b2) > 0) {
          list.set(j, b2);
          list.set(j + 1, b1);
        }
      }
    }
  }
}

class Book {
  private String name;
  private String author;
  private double price;

  @Override
  public String toString() {
    return "名称:" + name + "\t\t价格:" + price + "\t\t作者:" + author;
  }

  public String getName() {
    return name;
  }

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

  public String getAuthor() {
    return author;
  }

  public void setAuthor(String author) {
    this.author = author;
  }

  public double getPrice() {
    return price;
  }

  public void setPrice(double price) {
    this.price = price;
  }

  public Book(String name, String author, double price) {
    this.name = name;
    this.author = author;
    this.price = price;
  }
}