收集面试题（二十四）（排序自定义类）

// 用户自己开发一个学生类,包括姓名\学号\成绩 三个属性,现在用户希望能使用
// java.util.Arrays.sort()方法来根据学员成绩,排序一个学生类数组,请问要如何实现?
//主要是要想到用Comparator来实现，熟悉api是关键

import java.util.Arrays;
import java.util.Comparator;

/**
 * The Class SortStudent.
 */
public class SortStudent {

	private static Student[] students = null;

	/**
	 * The main method.
	 * 
	 * @param args
	 *            the arguments
	 */
	public static void main(String[] args) {

		initData();

		Arrays.sort(students, new ComparatorStudent());

		for (int i = 0; i < students.length; i++) {
			System.out.println(students[i].toString());
		}
	}

	private static void initData() {
		students = new Student[6];
		students[0] = new Student("张三", 1, 87.0f);
		students[1] = new Student("李四", 3, 23);
		students[2] = new Student("王五", 4, 57.0f);
		students[3] = new Student("赵柳", 2, 187.0f);
		students[4] = new Student("小七", 6, 47.0f);
		students[5] = new Student("八哥", 8, 57.0f);
	}
}

/**
 * The Class ComparatorStudent.
 */
class ComparatorStudent implements Comparator<Student> {

	@Override
	public int compare(Student o1, Student o2) {

		return (int) (o1.getScore() - o2.getScore());
	}

}

/**
 * The Class Student.
 */
class Student {

	/** The name. */
	private String name = null;

	/** The id. */
	private int id = 0;

	/** The score. */
	private double score = 0d;

	/**
	 * Instantiates a new student.
	 */
	public Student() {

	}

	/**
	 * Instantiates a new student.
	 * 
	 * @param name
	 *            the name
	 * @param id
	 *            the id
	 * @param score
	 *            the score
	 */
	public Student(String name, int id, double score) {
		super();
		this.name = name;
		this.id = id;
		this.score = score;
	}

	public String getName() {
		return name;
	}

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

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public double getScore() {
		return score;
	}

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

	@Override
	public String toString() {
		return "name: " + this.name + " id: " + this.id + " score: "
				+ this.score;
	}
}