用Java集合中的Collections.sort方法对list排序

根据Collections.sort重载方法来实现 按照list中的bean的某一个属性进行排序;

//******实体Bean**
package com.iqb.william.test;

public class User {

private String userName; //姓名

private Integer age; //年龄 目的：想要根据年龄来进行排序

private Integer sex; //性别

public String getUserName() {
return userName;
    }

public void setUserName(String userName) {
this.userName = userName;
    }

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;
    }

}

具体的实现可以看如下代码：

//****具体的排序方法：灵活 可根据某一个属性来进行排序******
package com.iqb.william.test;

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

public class CollectionSortService {

@SuppressWarnings({ "unchecked", "rawtypes" })
public static void main(String[] args) {
//******定义一个List
        List<User> userList=new ArrayList<User>();

        User user1=new User();
        User user2=new User();
        User user3=new User();

        user1.setUserName("lily");
        user1.setAge(11);
        user2.setUserName("rose");
        user2.setAge(12);
        user3.setUserName("jack");
        user3.setAge(13);

        userList.add(user1);
        userList.add(user2);
        userList.add(user3);
//******************将假设的用户信息放入到list中*********

//利用重载Collections.sort()方法进行比较list中元素的顺序；
        Collections.sort(userList, new Comparator() {
@Override
public int compare(Object arg0, Object arg1) {
                User user1=(User) arg0;
                User user2=(User) arg1;
return user1.getAge().compareTo(user2.getAge());
            }
        });

for(User user : userList){
            System.out.println("Name:"+user.getUserName()+" Age:"+user.getAge());
        }
    }
}

上面的compareTo()方法是调用的Integer.class中的compareTo（xx） 方法，
     前者大于后者那么返回 1；
     前者等于后者那么返回 0；
     前者小于后者那么返回 -1；

    /**
 * Compares two {@code Integer} objects numerically.
 *
 * @param anotherInteger the {@code Integer} to be compared.
 * @return the value {@code 0} if this {@code Integer} is
 * equal to the argument {@code Integer}; a value less than
 * {@code 0} if this {@code Integer} is numerically less
 * than the argument {@code Integer}; and a value greater
 * than {@code 0} if this {@code Integer} is numerically
 * greater than the argument {@code Integer} (signed
 * comparison).
 * @since 1.2
 */
    public int compareTo(Integer anotherInteger) {
return compare(this.value, anotherInteger.value);
    }

/**
 * Compares two {@code int} values numerically.
 * The value returned is identical to what would be returned by:
 * <pre>
 * Integer.valueOf(x).compareTo(Integer.valueOf(y))
 * </pre>
 *
 * @param x the first {@code int} to compare
 * @param y the second {@code int} to compare
 * @return the value {@code 0} if {@code x == y};
 * a value less than {@code 0} if {@code x < y}; and
 * a value greater than {@code 0} if {@code x > y}
 * @since 1.7
 */
    public static int compare(int x, int y) {
return (x < y) ? -1 : ((x == y) ? 0 : 1);
    }

以上仅仅是当前遇到的需要根据某个属性进行排序的例子，如果有不对的地方，请指教，谢谢。