对于各种常用类的练习资源

package com.study.srv.demo12; import java.util.Arrays; import java.util.Comparator; /** * @author Wen先森 * @version 1.0 * @date 2022/3/15 15:19 */ public class Demo04 { public static void main(String[] args) { Book[] books=new Book[4]; books[0]=new Book("红楼梦",100); books[1]=new Book("金瓶梅",90); books[2]=new Book("青年文摘",5); books[3]=new Book("Java从入门到精通",300); Arrays.sort(books, new Comparator<Book>() { @Override public int compare(Book o1, Book o2) { Book n1=o1; Book n2=o2; return (int) (n2.getPrice()-n1.getPrice()); } }); comb(books, new Comparator() { @Override public int compare(Object o1, Object o2) { double b1= (double) o1; double b2=(double) o2; return (int) (b2-b1); } }); System.out.println("按照价格排序:"); System.out.println(Arrays.toString(books)); Arrays.sort(books, new Comparator<Book>() { @Override public int compare(Book o1, Book o2) { Book n1=o1; Book n2=o2; return n2.getName().length()-n1.getName().length(); } }); System.out.println("按照名字长度排序:"); System.out.println(Arrays.toString(books)); } public static void comb(Book[] books,Comparator c){ for (int i=0;i<books.length-1;i++){ for (int j = 0; j < books.length - 1; j++) { if (c.compare(books[j].getPrice(),books[j+1].getPrice())<0){ Book temp=books[j]; books[j]=books[j+1]; books[j+1]=temp; } } } } } class Book{ private String name; private double price; public Book(String name, double price) { this.name = name; this.price = price; } public String getName() { return name; } public void setName(String name) { this.name = name; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; } @Override public String toString() { return "Book{" + "name='" + name + '\'' + ", price=" + price + '}'; } }