简单的Collections.sort 方法。 大伙看下，帮忙补充一下 这个方法好么。。

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

public class StringSorting {
public static void main(String[] args) {
ArrayList persons = new ArrayList();
persons.add(new Person("Sam"));
persons.add(new Person("Jerry"));
persons.add(new Person("Abel"));
persons.add(new Person("Sara"));
persons.add(new Person("Tom"));
persons.add(new Person("Matt"));
persons.add(new Person("Chris"));
persons.add(new Person("Nancy"));
persons.add(new Person("Sandra"));
Collections.shuffle(persons);

    reorderEveryone(persons);

    String result = persons.toString();
    String expected = "[Jerry, Sam, Nancu, Sandra, Abel, Matt, Chris, Tom, Sara]";

    println("It is now   : "+result);
    println("It should be: " + expected);

    if(result.equals(expected)){
        println("It works!");
    } else {
        println("Keep trying!");
    }
}

private static void println(Object s) {
    System.out.println(s);
}


private static class Person {
    String name;

    public Person(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return name;
    }
}

/// DO NOT CHANGE CODE BEFORE THIS LINE

private static void reorderEveryone(ArrayList<Person> persons) {
    补充这里 让 这个打印出working
}

}

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

可以参考一下这个，效率比较高

java中Collections.sort() 排序函数的用法
http://www.blogjava.net/landor2004/articles/sort.html