setcomparator.java

大学java作业源程序

package problem_10;
//SetComparator.java
import java.util.Comparator;

//比较器类，实现Comparator接口，用于TreeSet中的排序
public class SetComparator implements Comparator<Book> {
	//实现compare()函数，确定bookA和bookB的先后顺序，出版日期早者在前，出版日期相同时书名字母表序在前者在前
	public int compare(Book bookA, Book bookB) {
		if(bookA.getDate().compareTo(bookB.getDate()) > 0)
			return 1;
		else if(bookA.getDate().compareTo(bookB.getDate()) < 0)
			return -1;
		else if(bookA.getTitle().compareTo(bookB.getTitle()) > 0)
			return 1;
		else if(bookA.getTitle().compareTo(bookB.getTitle()) < 0)
			return -1;
		else
			return 0;
	}
}