ArrayList 排序

简单说明：

ArrayList是TestBean的集合，根据TestBean类中的属性对ArrayList中TestBean 排序。

 

方法：使用Comparator比较器接口和Collections类进行排序。

 

package audition;
 
public
class TestBean {
 
    public String
key1;
    public String
key2;
    public String
key3;
    public
int value1;
    public
int value2;
   
    public
String toString(){
       return
key1+" "+key2+" "+key3+" "+value1+"
"+value2;
    }
}

 

 

import java.util.Comparator;
import audition.TestBean;
 
public
class ComparatorTest implements
Comparator<TestBean> {
 
    @Override
    public
int compare(TestBeano1, TestBean o2) {
       if(o2.key1.equals(o1.key1)==false)
           return o2.key1.compareTo(o1.key1);
       else
if(o2.key2.equals(o1.key2)==false)
           return o2.key2.compareTo(o1.key2);
       else
if(o2.key3.equals(o1.key3)==false)
           return o2.key3.compareTo(o1.key3);
       return 0;
    }
}

 

 

 

package audition;
 
import java.util.ArrayList;
import audition.TestBean;
import java.util.Collections;
 
public
class TestMain {
 
    public ArrayList<TestBean> init(){
       ArrayList<TestBean> al = new ArrayList<TestBean>();
       for(int i = 0;i<5;i++){
           TestBean tb = new TestBean();
           tb.key1 =
"1"+i;
           tb.key2 =
"2"+i;
           tb.key3 =
"3"+i;
           al.add(tb);
       }
       return al;
    }
   
    //ArrayList中的bean，根据key1,key2,key3进行排序，key1>key2>key3
    public
void sort(ArrayList<TestBean> al_tb){
       ComparatorTest com = new ComparatorTest();
       Collections.sort(al_tb, com);
    }
   
    public
void display(ArrayList<TestBean> al_tb){
       for(TestBean tb : al_tb){
           System.out.println(tb);
       }
    }
   
   
    public
static void main(String[] str){
       TestMain tm = new TestMain();
       ArrayList<TestBean> al_tb = tm.init();
       tm.sort(al_tb);
       tm.display(al_tb);
    }
}