public static <T> void sort(List<T> list, Comparator<? super T> c) { 
  Object[] a = list.toArray(); 
  Arrays.sort(a, (Comparator)c); 
  ListIterator i = list.listIterator(); 
  for (int j=0; j<a.length; j++) { 
    i.next(); 
    i.set(a[j]); 
  } 
  } 

package com.fox; 
 
/** 
 * @author huangfox 
 * @desc 
 */
public class User implements Comparable<User> { 
 
  private String name; 
  private int age; 
 
  public User() { 
  } 
 
  public User(String name, int age) { 
    super(); 
    this.name = name; 
    this.age = age; 
  } 
 
  @Override
  public String toString() { 
    return "name:" + name + ",age:" + age; 
  } 
 
  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; 
  } 
 
  @Override
  public int compareTo(User o) { 
    if (o.age < this.age) 
      return 1; 
    else if (o.age > this.age) 
      return -1; 
    else
      return 0; 
  } 
 
  /** 
   * @param args 
   */
  public static void main(String[] args) { 
    User u1 = new User("fox", 11); 
    User u2 = new User("fox2", 21); 
    System.out.println(u2.compareTo(u1)); 
  } 
 
}

// List<User> us = new ArrayList<User>(); 
    List<User> us = new LinkedList<User>(); 
    us.add(new User("f5", 12)); 
    us.add(new User("f2", 22)); 
    us.add(new User("f3", 2)); 
    us.add(new User("f4", 14)); 
    us.add(new User("f5", 32)); 
    us.add(new User("f4", 12)); 
    us.add(new User("f7", 17)); 
    us.add(new User("f8", 52)); 
    System.out.println(us.toString()); 
    long bt = System.nanoTime(); 
    Collections.sort(us, new Comparator<User>() { 
 
      @Override
      public int compare(User o1, User o2) { 
        if (o1.getAge() < o2.getAge()) 
          return -1; 
        else if (o1.getAge() > o2.getAge()) 
          return 1; 
        else
          return o1.getName().compareTo(o2.getName()); 
      } 
    }); 
    long et = System.nanoTime(); 
    System.out.println(et - bt); 
    System.out.println(us.toString());

Set<User> us = new HashSet<User>(); 
    // Set<User> us = new TreeSet<User>(); 
    // Set<User> us = new TreeSet<User>(new Comparator<User>() { 
    // 
    // @Override 
    // public int compare(User o1, User o2) { 
    // if (o1.getAge() < o2.getAge()) 
    // return -1; 
    // else if (o1.getAge() > o2.getAge()) 
    // return 1; 
    // else 
    // return o1.getName().compareTo(o2.getName()); 
    // } 
    // }); 
    us.add(new User("f5", 12)); 
    us.add(new User("f2", 22)); 
    us.add(new User("f3", 2)); 
    us.add(new User("f4", 14)); 
    us.add(new User("f5", 32)); 
    us.add(new User("f4", 12)); 
    us.add(new User("f7", 17)); 
    us.add(new User("f8", 52)); 
    // set -> array 
    List<User> list = new ArrayList<User>(us); 
    System.out.println(list); 
    Collections.sort(list); 
    System.out.println(list);

Map<String, Integer> us = new HashMap<String, Integer>(); 
    // Map<String, Integer> us = new TreeMap<String, Integer>(); 
    us.put("f1", 12); 
    us.put("f2", 13); 
    us.put("f5", 22); 
    us.put("f4", 42); 
    us.put("f3", 15); 
    us.put("f8", 21); 
    us.put("f6", 123); 
    us.put("f7", 1); 
    us.put("f9", 19); 
    System.out.println(us.toString()); 
    System.out.println(new TreeMap<String, Integer>(us));

// 按照value排序 
    Set<Entry<String, Integer>> ks = us.entrySet(); 
    List<Entry<String, Integer>> list = new ArrayList<Map.Entry<String, Integer>>( 
        ks); 
    Collections.sort(list, new Comparator<Entry<String, Integer>>() { 
 
      @Override
      public int compare(Entry<String, Integer> o1, 
          Entry<String, Integer> o2) { 
        if (o1.getValue() < o2.getValue()) 
          return -1; 
        else if (o1.getValue() > o2.getValue()) 
          return 1; 
        return 0; 
      } 
    }); 
    System.out.println(list);