定义一个Person的类,存入ArrayList集合中,去除重复元素,定义:名字相同的和年龄都相同的为重复元素。

取重

public class Qu {
 
 public static void main(String[] args) {
 
   Sa2 a = new Sa2("张三",20);
   Sa2 a1 = new Sa2("张三",30);
   Sa2 a3 = new Sa2("张三",20);
   ArrayList<Sa2> list = new ArrayList<Sa2>();
   list.add(a);
   list.add(a1);
   list.add(a3);
 
   ArrayList<Sa2> list1 = quCong(list);
   System.out.println(list1);
       }
   public static ArrayList<Sa2> quCong(ArrayList<Sa2>list){
   ArrayList<Sa2> list1=new ArrayList<Sa2>();
   ListIterator<Sa2> it = list.listIterator();
   while(it.hasNext()){
   Sa2 str = it.next();
   if(!list1.contains(str)){
   list1.add(str);
 
       }
     }
     return list1;
  
     }
 
  }
 ————————————————————————————————————————————————————
  public class Sa2 {
   String name;
   int age;
   public  Sa2(String name,int age){
   this.name=name;
   this.age=age;
   }
   public int HashCode(){//重写,把底层改变。
 
   return 1;
   }
 
 
 
   public boolean equals(Object obj){
 
 
   if(obj instanceof Sa2){
   Sa2 p = (Sa2)obj;
   return this.name.equals(p.name) && this.age == p.age;
   }
 
   return false;
 
   }
 
   public String toString(){
   return "Sa2[name"+ name+",age="+age+"]";
   }
  
 }