Java中List的排序

package com.sun;

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

public class Demo {

	public Demo() {
		// TODO Auto-generated constructor stub
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub

		int a= 0;
		Dob db  = new Dob();
		Dob db1  = new Dob();
		Dob db2  = new Dob();
		db.setName("sun");
		db.setAge(20);
		db.setSex(3);
		
		db1.setName("zhi");
		db1.setAge(22);
		db1.setSex(1);
		
		db2.setName("yan");
		db2.setAge(21);
		db2.setSex(2);
		List<Dob> as = new ArrayList<Dob>();
		System.out.println("as="+as.size());
		as.add(db);
		as.add(db1);
		as.add(db2);
		
		 Collections.sort(as, new Comparator<Dob>() {
//比较。如果年龄不同先比较年龄 ，相同就比较性别
	            public int compare(Dob arg0, Dob arg1) {
	            	int flg = arg0.getAge().compareTo(arg1.getAge());
	            	if(flg==0){
	            		 return arg0.getSex().compareTo(arg1.getSex());
	            	}else{
	            		 return arg0.getAge().compareTo(arg1.getAge());
	            	}
	               
	            }

	        });
		
		
		for (Dob p : as) {
            System.out.println(p.getName());
            System.out.println(p.getAge());
        }
		
System.out.println("as="+as.size());

	}


}
	class Dob {
		public String  name;

		public Integer age;

		public Integer sex;



		public String getName() {
			return name;
		}
		public void setName(String name) {
			this.name = name;
		}
		public Integer getAge() {
			return age;
		}
		public void setAge(Integer age) {
			this.age = age;
		}
		public Integer getSex() {
			return sex;
		}
		public void setSex(Integer sex) {
			this.sex = sex;
		}

}