Java Comparator接口

Java Comparator接口 代码演示
演示1.

package Practice;

import java.util.ArrayList;

import java.util.Collections;
import java.util.List;


public class Comparator {
    public static void main(String[] args) {
         List nums=new ArrayList();
         nums.add(1);
         nums.add(3);
          nums.add(2);
    Collections.sort(nums, new java.util.Comparator() {  
        @Override
        public int compare(Integer o1, Integer o2) {
            return o1-o2;
        }
    });
        System.out.println(nums);



    }

}

演示2

package Practice;

import java.util.ArrayList;

import java.util.Collections;
import java.util.List;


public class Comparator {
    public static void main(String[] args) {
         List names=new ArrayList();
         names.add("james");
          names.add("Tom");
           names.add("Mike");
        names.add("Peter");
        names.add("LinDan");
        names.add("admin");
        names.add("aamin");
        Collections.sort(names,new MyComparator());
        System.out.println(names);



    }

}
class  MyComparator implements java.util.Comparator{
    @Override
    public int compare(String o1, String o2) {
        if (o1.length()!=o2.length())
            return  o1.length()-o2.length();
        return  o1.compareTo(o2);
    }
}