怎么根据对象里面的的某1个字段对List排序

如何根据对象里面的的某1个字段对List排序
对象类型List<User>,想根据里面的percent字段排序，percent是字符串类型百分比形如"25.12%"，想根据这个字段由高到低排序！

[解决办法]
我这里有个sample
People.java

Java code

package com.zhoujl.test;/** * @author zhoujl * 2011/12/28 10:11:04 */public class People implements Comparable {    private int age;    private String name;        public People(int age,String name) {        this.age = age;        this.name = name;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    /*      * 在这里写比较的逻辑return 1就是大于  return 0就是小于     */    @Override    public int compareTo(Object people) {                if(this.age>((People)people).age) {            return 1;        }else {             return 0;        }    }    @Override    public String toString() {        return "Name:" +name+"\n"+"Age:"+age+"\n";    }                }