java 排序

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;

public class ArrayListSort {

	public static void main(String[] args) {
		ArrayList<Person> persons = new ArrayList<Person>();
		Person zhangsan = new Person("zhangsan", 20, true,3.55f);
		Person lisi = new Person("lisi", 21, true,2.25f);
		Person wangwu = new Person("wangwu", 18, false,5.5656f);
		Person liufeng = new Person("liufeng",15,false,1.3512f);
		persons.add(zhangsan);
		persons.add(lisi);
		persons.add(wangwu);
		persons.add(liufeng);

		Collections.sort(persons, new Comparator<Person>() {
			@Override
			public int compare(Person o1, Person o2) {
				if (o1 != null && o2 != null) {
					if (o1.getScore() > o2.getScore()) {
						return 1;
					} else if (o1.getScore() < o2.getScore()) {
						return -1;
					}
				}
				return 0;
			}
		});

		for (Person p : persons) {
			System.out.println(p);
		}
	}

}
class Person {

	private String name;
	private int age;
	private boolean sex;
	private float score;

	public Person() {
	}

	public Person(String name, int age, boolean sex,float score) {
		this.name = name;
		this.age = age;
		this.sex = sex;
		this.score = score;
	}

	public String getName() {
		return name;
	}

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

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public boolean isSex() {
		return sex;
	}

	public void setSex(boolean sex) {
		this.sex = sex;
	}
	
	public float getScore() {
		return score;
	}

	public void setSocre(float score) {
		this.score = score;
	}

	@Override
	public String toString() {
		return "name=" + name + "\tage=" + age + "\tsex=" + sex+"\tscore="+score;
	}

}