定义Person抽象类，Student类、Company类，Employee类。
Person类的属性：String name, int age, boolean gender
Person类的方法:
public Person(String name, int age, boolean gender);
public String toString(); //返回"name-age-gender"格式的字符串
public boolean equals(Object obj);//比较name、age、gender,都相同返回true,否则返回false
Student类继承自Person，属性:String stuNo, String clazz
Student类的方法:
//建议使用super复用Person类的相关有参构造函数
public Student(String name, int age, boolean gender, String stuNo, String clazz);
public String toString(); //返回 “Student:person的toString-stuNo-clazz”格式的字符串
public boolean equals(Object obj);//首先调用父类的equals方法,如果返回true，则继续比较stuNo与clazz。
Company类属性：String name
Company类方法:
public Company(String name);
public String toString(); //直接返回name
public boolean equals(Object obj);//name相同返回true
Employee类继承自Person，属性：Company company, double salary
Employee类方法：
//建议使用super复用Person类的相关有参构造函数
public Employee(String name, int age, boolean gender, double salary, Company company);
public String toString(); //返回"Employee:person的toString-company-salary"格式的字符串
public boolean equals(Object obj);//首先调用父类的equals方法,如果返回true。再比较company与salary。
//比较salary属性时，使用DecimalFormat df = new DecimalFormat("#.#");保留1位小数
编写equals方法重要说明：
对Employee的company属性的比较。要考虑传入为null的情况。如果company不为null且传入为null，返回false
对所有String字符类型比较时，也要考虑null情况。
提示：
1.排序可使用Collections.sort
2.equals方法要考虑周全
#main方法说明
创建若干Student对象、Employee对象。
1.输入s，然后依次输入name age gender stuNo clazz创建Student对象。
输入e，然后依次输入name age gender salary company创建Employee对象。
然后将创建好的对象放入List<Person> personList。输入其他字符，则结束创建。
**创建说明:**对于String类型，如果为null则不创建对象，而赋值为null。对于company属性，如果为null则赋值为null，否则创建相应的Company对象。
2.对personList中的元素实现先按照姓名升序排序，姓名相同再按照年龄升序排序。提示：可使用Comparable<Person>或Comparator<Person>
3.接受输入，如果输入为exit则return退出程序，否则继续下面步骤。
4.将personList中的元素按照类型分别放到stuList与empList。注意：不要将两个内容相同的对象放入列表（是否相同是根据equals返回结果进行判定）。
5.输出字符串stuList，然后输出stuList中的每个对象。
6.输出字符串empList，然后输出empList中的每个对象。
1-3为一个测试点 4-6为一个测试点
输入样例：
s zhang 23 false 001 net15
e wang 18 true 3000.51 IBM
s zhang 23 false 001 net15
e bo 25 true 5000.51 IBM
e bo 25 true 5000.52 IBM
e bo 18 true 5000.54 IBM
e tan 25 true 5000.56 IBM
e tan 25 true 5000.51 IBM
s wang 17 false 002 null
s wang 17 false 002 null
e hua 16 false 1000 null
s wang 17 false 002 net16
e hua 16 false 1000 null
e hua 18 false 1234 MicroSoft
!
continue
输出样例：
Employee:bo-18-true-IBM-5000.54
Employee:bo-25-true-IBM-5000.51
Employee:bo-25-true-IBM-5000.52
Employee:hua-16-false-null-1000.0
Employee:hua-16-false-null-1000.0
Employee:hua-18-false-MicroSoft-1234.0
Employee:tan-25-true-IBM-5000.56
Employee:tan-25-true-IBM-5000.51
Student:wang-17-false-002-null
Student:wang-17-false-002-null
Student:wang-17-false-002-net16
Employee:wang-18-true-IBM-3000.51
Student:zhang-23-false-001-net15
Student:zhang-23-false-001-net15
stuList
Student:wang-17-false-002-null
Student:wang-17-false-002-net16
Student:zhang-23-false-001-net15
empList
Employee:bo-18-true-IBM-5000.54
Employee:bo-25-true-IBM-5000.51
Employee:hua-16-false-null-1000.0
Employee:hua-18-false-MicroSoft-1234.0
Employee:tan-25-true-IBM-5000.56
Employee:tan-25-true-IBM-5000.51
Employee:wang-18-true-IBM-3000.51
参考代码：
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);List<Person> personList = new ArrayList<>();while(sc.hasNext()) {
String select = sc.next(); // 输入s或者eif("s".equals(select)) {
Student student = new Student(sc.next(), sc.nextInt(), sc.nextBoolean(), sc.next(), sc.next());personList.add(student);} else if("e".equals(select)) {
String name = sc.next(); // 姓名int age = sc.nextInt(); // 年龄boolean b = sc.nextBoolean(); // 性别double salary = sc.nextDouble(); // 薪资Company company = new Company(sc.next()); // 公司Employee employee = new Employee(name, age, b, company, salary);personList.add(employee);} else {
break;}}// 排序Collections.sort(personList);for (Person person : personList) {
System.out.println(person);}String select = sc.next();if("exit".equals(select)) {
System.exit(0);}// 输出员工，分别放到stuList和empListList<Student> stuList = new ArrayList<>();List<Employee> empList = new ArrayList<>();for (Person person : personList) {
if (person instanceof Student) {
Student stu = (Student) person;if(!stuList.contains(stu))stuList.add(stu);}else if (person instanceof Employee) {
Employee emp = (Employee) person;if(!empList.contains(emp))empList.add(emp);}}System.out.println("stuList");for (Student stu : stuList) {
System.out.println(stu);}System.out.println("empList");for (Employee emp : empList) {
System.out.println(emp);}}
}class Person implements Comparable<Person> {
String name; int age; boolean gender;public Person(String name, int age, boolean gender) {
super();this.name = name;this.age = age;this.gender = gender;}public String toString() {
//返回"name-age-gender"格式的字符串return name + "-" + age + "-" + gender;}@Overridepublic boolean equals(Object obj) {
if (this == obj)return true;if (obj == null)return false;if (getClass() != obj.getClass())return false;Person other = (Person) obj;if (age != other.age)return false;if (gender != other.gender)return false;if (name == null) {
if (other.name != null)return false;} else if (!name.equals(other.name))return false;return true;}@Overridepublic int compareTo(Person o) {
int name = this.name.compareTo(o.name);return name == 0 ? (this.age - o.age) : name;}}class Student extends Person {
String stuNo; String clazz;public Student(String name, int age, boolean gender, String stuNo, String clazz) {
super(name, age, gender);this.stuNo = stuNo;this.clazz = clazz;}//返回 “Student:person的toString-stuNo-clazz”格式的字符串public String toString() {
return "Student:" + super.toString() + "-" + stuNo + "-" + clazz;}// 首先调用父类的equals方法,如果返回true，则继续比较stuNo与clazz。@Overridepublic boolean equals(Object obj) {
if (this == obj)return true;if (!super.equals(obj))return false;if (getClass() != obj.getClass())return false;Student other = (Student) obj;if (clazz == null) {
if (other.clazz != null)return false;} else if (!clazz.equals(other.clazz))return false;if (stuNo == null) {
if (other.stuNo != null)return false;} else if (!stuNo.equals(other.stuNo))return false;return true;}
}class Company {
String name;public Company(String name) {
this.name = name;}//直接返回namepublic String toString() {
return name;}@Overridepublic boolean equals(Object obj) {
if (this == obj)return true;if (obj == null)return false;if (getClass() != obj.getClass())return false;Company other = (Company) obj;if (name == null) {
if (other.name != null)return false;} else if (!name.equals(other.name))return false;return true;}
}class Employee extends Person {
Company company; double salary;public Employee(String name, int age, boolean gender, Company company, double salary) {
super(name, age, gender);this.company = company;this.salary = salary;}//返回"Employee:person的toString-company-salary"格式的字符串public String toString() {
return "Employee:" + super.toString() + "-" + company + "-" + salary;}// 首先调用父类的equals方法,如果返回true。再比较company与salary。@Overridepublic boolean equals(Object obj) {
if (this == obj)return true;if (!super.equals(obj))return false;if (getClass() != obj.getClass())return false;Employee other = (Employee) obj;if (company == null) {
if (other.company != null)return false;} else if (!company.equals(other.company))return false;DecimalFormat df = new DecimalFormat("#.#");if (!df.format(salary).equals(df.format(other.salary)))return false;return true;}}