J260713/授课代码/c260803/src/exericse/exericse02/EmployeeSystem.java

package exericse.exericse02;

import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.TreeSet;

/**
 * @author WanJl
 * @version 1.0
 * @title EmployeeSystem
 * @description
 * @create 2026/8/3
 */
public class EmployeeSystem {
    public static void main(String[] args) {
        // 1. 创建 TreeSet<Employee>（自然排序）
        //    添加 5 名员工（其中两名工号相同，测试去重）：
        //    E001-张三-12000-技术部 / E002-李四-15000-市场部
        //    E003-王五-15000-技术部 / E004-赵六-9000-财务部
        //    E005-刘七-12000-市场部
        TreeSet<Employee> treeSet=new TreeSet<>();
        treeSet.add(new Employee("E001","张三",12000,"技术部"));
        treeSet.add(new Employee("E002","李四",15000,"市场部"));
        treeSet.add(new Employee("E003","王五",15000,"技术部"));
        treeSet.add(new Employee("E004","赵六",9000,"财务部"));
        treeSet.add(new Employee("E005","刘七",12000,"市场部"));

        // 2. 迭代器遍历输出 → 观察：按薪资降序，薪资相同按工号；工号重复的自动去重
        //    输出格式："E001-张三-12000.0-技术部"
        Iterator<Employee> iterator = treeSet.iterator();
        while (iterator.hasNext()){
            Employee employee = iterator.next();
            System.out.println(employee.getId()+"-"+employee.getName()+"-"+employee.getSalary()+"-"+employee.getDept());
        }


        // 3. 临时需求：通讯录按姓名排序 —— 创建 TreeSet<Employee> 传入按姓名排序的 Comparator
        //    匿名内部类：o1.getName().compareTo(o2.getName())
        //    迭代器遍历输出

        treeSet=new TreeSet<>(new Comparator<Employee>() {
            @Override
            public int compare(Employee o1, Employee o2) {
                return o1.getName().compareTo(o2.getName());
            }
        });
        treeSet.add(new Employee("E001","张三",12000,"技术部"));
        treeSet.add(new Employee("E002","李四",15000,"市场部"));
        treeSet.add(new Employee("E003","王五",15000,"技术部"));
        treeSet.add(new Employee("E004","赵六",9000,"财务部"));
        treeSet.add(new Employee("E005","刘七",12000,"市场部"));

        iterator = treeSet.iterator();
        while (iterator.hasNext()){
            Employee employee = iterator.next();
            System.out.println(employee.getId()+"-"+employee.getName()+"-"+employee.getSalary()+"-"+employee.getDept());
        }

        // 4. 思考：E001-张三(12000) 和 E005-刘七(12000) 薪资相同，为何都能存入？
        //    —— compareTo 在薪资相同后继续比较工号，返回值不为 0



    }
}