J250511/01-JavaSE阶段代码/J20250723/Demo07_TreeMap.java

package J20250723;

import java.util.Comparator;
import java.util.Set;
import java.util.TreeMap;

/**
 * @author WanJl
 * @version 1.0
 * @title Demo07_TreeMap
 * @description
 * @create 2025/7/23
 */
public class Demo07_TreeMap {
    public static void main(String[] args) {
        TreeMap<Student,String> map=new TreeMap((Comparator<Student>) (o1, o2) -> {
            int r=o2.getId()-o1.getId();
            r=r==0?o1.getName().compareTo(o2.getName()):r;
            return r;
        });
        Student s1=new Student(1001,"张三1");
        Student s2=new Student(1002,"张三2");
        Student s3=new Student(1003,"张三3");
        Student s4=new Student(1004,"张三4");
        map.put(s1,"北京");
        map.put(s2,"上海");
        map.put(s3,"广州");
        map.put(s4,"深圳");

        //获取key的集合
        Set<Student> students = map.keySet();

        for (Student s:students){
            //get获取值
            String addr = map.get(s);
            System.out.println(s+"->"+addr);
        }
    }
}