需求

  • 学校cac有两个考场
  • 每个考场有相应的座位号分别对应相应的学生
  • 打印出相应信息
  • 从中展现Map自定义排序的功能

基本思路

1，假设有两个考场，每个考场的学生有对应的座位号
2，利用两个映射关系完成： (1)考场名字-->考场座位号表 (2)学生映射相应的座位号
PS:其实应该座位号映射到学生才符合我们日常逻辑，不过这里为了体现排序取反了

代码

package 集合框架;

import java.util.*;

/* * 学校cac有两个考场 * 每个考场有相应的座位号分别对应相应的学生 * 打印出相应信息 * */

class Map集合_Test01 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        TreeMap<String,TreeMap<Student,String>> Tab = new TreeMap<String,TreeMap<Student,String>>();  //默认字典序

        TreeMap<Student,String> room1 = new TreeMap<Student,String>(new _MyComparator());  //分数升序

        TreeMap<Student,String> room2 = new TreeMap<Student,String>(); //分数降序

        Tab.put("number_1", room1);
        Tab.put("number_2", room2);

        room1.put(new Student("lili" ,80),"03");
        room1.put(new Student("lilei",80), "02");
        room1.put(new Student("Kruskal",98), "11");
        room1.put(new Student("prime",99), "01");

        room2.put(new Student("liming" ,80),"03");
        room2.put(new Student("huahua",80), "02");
        room2.put(new Student("Kruskal",98), "11");
        room2.put(new Student("prime",99), "01");
        room2.put(new Student("A_prime",99), "04");

        System.out.println("考场数:"+Tab.size());

        Set< Map.Entry<String ,TreeMap<Student,String>> > set = Tab.entrySet();

        Iterator< Map.Entry<String ,TreeMap<Student,String>> > it = set.iterator();

        while(it.hasNext()) {
            Map.Entry<String, TreeMap<Student,String>> ot = it.next();
            Set<Map.Entry<Student,String>> s = ot.getValue().entrySet();

            String test_room = ot.getKey();

            System.out.println("考场:"+test_room);
            System.out.println("姓名\t\t分数\t\t座位号");
            Map_show(s.iterator());

        }

    }

    public static void Map_show(Iterator<Map.Entry<Student,String>> it) {

        while(it.hasNext()) {
            Map.Entry<Student,String> ot = it.next();
            Student stu = ot.getKey();
            String num = ot.getValue();
            System.out.println(stu.getName()+"\t\t"+stu.getScore()+"\t\t"+num);
        }
        System.out.println();
    }

}

class _MyComparator implements Comparator<Student> {  //按照成绩优先其次姓名字典序的方式排序
    public int compare(Student o1, Student o2) {
        int num = new Integer(o2.getScore()).compareTo(new Integer(o1.getScore()));

        if(num == 0) {
            return o1.getName().compareTo(o2.getName());
        }

        return num;
    }

}

class Student implements Comparable<Student> {  //学生信息
    private String name;
    private int score;
    public Student(String name,int score) {
        this.name=name;
        this.score=score;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getScore() {
        return score;
    }
    public void setScore(int score) {
        this.score = score;
    }

    public int compareTo(Student x) {  //按成绩升序、姓名字典序排序

        int num = new Integer(this.score).compareTo(new Integer(x.getScore()));

        if(num == 0) {
            return this.name.compareTo(x.getName());
        }

        return num;     
    }
}