集合里保存的是對(duì)象，分別按對(duì)象屬性（字符串，整型）的升降排序

 

public class TestSort {
 public static void main(String args[]){
  List list=new ArrayList();
  User u1=new User("2005-10-12",20);
  u1.setB(false);
  list.add(u1);
  
     User u2=new User("2010-03-25",10);
     u2.setB(false);
     list.add(u2);
    
     User u3=new User("2009-06-08",50);
     u3.setB(false);
     list.add(u3);
    
     Collections.sort(list);
    
     for(int i=0;i<list.size();i++){
      User us=(User)list.get(i);
      System.out.println(us);
     }
 }
}

 

//-------------

public class User implements Comparable<User> {
 private String name;
 private int age;
 private boolean b;

 public User() {
  super();
 }
 public User(String name, int age) {
  super();
  this.name = name;
  this.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;
 }
 public boolean isB() {
  return b;
 }
 public void setB(boolean b) {
  this.b = b;
 }
 //排序
 public int compareTo(User o) {
  // TODO Auto-generated method stub
  //按字符屬性升降排序
  if(b){//升
   
   return name.compareTo(o.name)>0? 1 : name.compareTo(o.name)==0 ? 0 : -1;
  }else{//降
      return name.compareTo(o.name)>0? -1 : name.compareTo(o.name)==0 ? 0 : 1;
  }
  //按整型屬性升降排序
  //return this.age>o.age? -1 : this.age == o.age ? 0 : 1;

 }
 //打印
 public String toString(){
  return name+"  "+age;
 }
}