java ArrayList根据存储对象排序 java实现ArrayList根据存储对象排序功能示例

package demo;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
class Stu{
  public int age;
  private String name;
  public Stu(String name,int age){
    this.age=age;
    this.name=name;
  }
  public String toString(){
    String str=name+"is "+age;
    return str;
  }
}
public class Sort{
  @SuppressWarnings({ "unchecked", "rawtypes" })
 public static void main(String[] args){
    ArrayList<Stu> s=new ArrayList<Stu>();
    s.add(new Stu("cjc",25));
    s.add(new Stu("jake",17));
    s.add(new Stu("john",30));
    s.add(new Stu("Alice",23));
    System.out.println("测试结果：");
    System.out.println("The order before sorting!");
    System.out.println(s);
    //对集合中的元素更具年龄进行排序
    Collections.sort(s,new Comparator(){
      @Override
      public int compare(Object o1, Object o2) {
        // TODO Auto-generated method stub
        Stu stu1=(Stu)o1;
        Stu stu2=(Stu)o2;
        return stu2.age-stu1.age;
      }
    });
    System.out.println("The order after sorting!");
    System.out.println(s);
  }
}