java - 填充复杂的 Map 并访问其值

Question

问题1:我想将以下“Class Dog”的“特定”排序值添加到“Ser”类中使用的“Map”中。但我不知道如何实现这一点，

问题2:如果成功填充，如何访问 map 的填充值

以下是我绝望的尝试。

 class Dog implements Comparator<Dog>, Comparable<Dog>{

   private double Price;
 private String Operator;
  Dog(){
   }

  Dog( double p, String o){

   Price= p;
   Operator=o;
  }

  public double getPrice(){
  return Price;
  }
    public String getOperator(){
      return Operator;
   }


  // Overriding the compareTo method
  public int compareTo(Dog d){

   double data= Price - d.Price; 
   if ( data > 0.00001)return 1;
   if (data < 0.00001) return -1;
   return 0;
 }


   // Overriding the compare method to sort the age 
  public int compare(Dog d, Dog d1){

  double data= d.Price - d1.Price; 

   if ( data > 0.00001)return 1;
   if (data < 0.00001) return -1;
   return 0;

      }

}

 public class Ser {                          
   /**                                     
    * @param args
   */
   public static void main(String[] args) {
// Takes a list o Dog objects
ArrayList <Dog> list1 = new ArrayList<Dog>();

Map <Integer, ArrayList<Dog> > map= new HashMap <Integer, ArrayList<Dog> > ();

  list1.add(new Dog(0.99 , "A"));
  list1.add(new Dog(0.91 , "C"));
  list1.add(new Dog(0.92 , "A"));
  list1.add(new Dog(0.97 , "B"));
  list1.add(new Dog( 0.93 , "C"));
  list1.add(new Dog(0.97 , "B"));
  list1.add(new Dog(0.92, "A"));
  list1.add(new Dog(0.97, "C"));
  list1.add(new Dog(0.92, "A"));
  // Sorts the array list using comparator

  Collections.sort(list1, new Dog());

  for(Dog a: list1)//printing the sorted list of ages
      System.out.println( a.getOperator()+"  : "+ a.getPrice());

  map.put(92,  list1);
  map.put(445, list1);
  map.put(966, list1);

 // Collections.sort(list1, new Dog());

 for (ArrayList<Dog> key: map.values() )     
         System.out.println(key);
         }

   }

输出:C:0.91、A:0.92、A:0.92、A:0.92、C:0.93、C:0.97、B:0.97、B:0.97，A:0.99

map 值的输出:[狗@a981ca，狗@8814e9，狗@1503a3，狗@1a1c887，狗@743399，狗@e7b241，狗@167d940，狗@e83912，狗@1fae3c6][狗@a981ca，狗@8814e9，狗@1503a3，狗@1a1c887，狗@743399，狗@e7b241，狗@167d940，狗@e83912，狗@1fae3c6][狗@a981ca，狗@8814e9，狗@1503a3，狗@1a1c887，狗@743399，狗@e7b241，狗@167d940，狗@e83912，狗@1fae3c6]

Answer 1

您看到 Dog 的 Object.toString 表示形式，您需要重写该方法:

@Override
public String toString() {
    return "Dog [Price=" + Price + ", Operator=" + Operator + "]";
}