JAVA Queue隊列

Person類

public class Person {   
  
    @Override
    public String toString() {
         return this.getName()+" "+this.getAge();
    }

    private String name;   
    private int age;   
  
    public Person(String name, int age) {   
        this.age = age;   
        this.name = name;   
    }   
  
    public String getName() {   
        return name;   
    }   
  
    public void setName(String name) {   
        this.name = name;   
    }   
  
    public int getAge() {   
        return age;   
    }   
  
    public void setAge(int age) {   
        this.age = age;   
    }   

}

 

比較器類

import java.util.Comparator;


public class Comparator1 implements Comparator{
 
 private int compare(String name1, String name2){
  return name1.compareTo(name2);
 }
 
 private int compare(int age1, int age2){
  if(age1 > age2)
   return 1;
  else if(age1 == age2)
   return 0;
  else
   return -1;
 }
 
 public int compare(Person p1, Person p2) {//接口的方法
  String name1 = p1.getName();
  String name2 = p2.getName();
  
  int age1 = p1.getAge();
  int age2 = p2.getAge();
  
  return (compare(name1, name2) == 0 ? compare(age1, age2) : compare(name1, name2));
 }
 
}

 

測試類

import java.util.Iterator;
import java.util.PriorityQueue;


public class Tester {
 
 public static void main(String[] args) {   
        Person p1 = new Person("a", 4);   
        Person p2 = new Person("b", 2);   
        Person p3 = new Person("c", 1);   
        Person p4 = new Person("a", 1);   
        Person p5 = new Person("a", 6);   
        Person p6 = new Person("a", -1);   
         
        PriorityQueue pq = new PriorityQueue(20 ,new Comparator1());
        pq.add(p1);   
        pq.add(p2);   
        pq.add(p3);   
        pq.add(p4);   
        pq.add(p5);   
        pq.add(p6);   
        
        Iterator it = pq.iterator();
        while(it.hasNext()){
         System.out.println(it.next());
        }
        
        while(!pq.isEmpty()){
         System.out.println(pq.poll());//前面對toString()進行了重載
         System.out.println("sdfsd");
        }//這裏要注意，對優先隊列用迭代器遍歷，順序不是按照優先隊列的順序輸出
    }  

}