7-2 jmu-Java-03面向對象-06-繼承覆蓋綜合練習-Person、Student、Employee、Company (20 分)
定義Person抽象類，Student類、Company類，Employee類。
Person類的屬性：String name, int age, boolean gender
Person類的方法:
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);//比較name、age、gender,都相同返回true,否則返回false
Student類繼承自Person，屬性:String stuNo, String clazz
Student類的方法:
//建議使用super複用Person類的相關有參構造函數
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);//首先調用父類的equals方法,如果返回true，則繼續比較stuNo與clazz。
Company類屬性：String name
Company類方法:
public Company(String name);
public String toString(); //直接返回name
public boolean equals(Object obj);//name相同返回true
Employee類繼承自Person，屬性：Company company, double salary
Employee類方法：
//建議使用super複用Person類的相關有參構造函數
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);//首先調用父類的equals方法,如果返回true。再比較company與salary。
//比較salary屬性時，使用DecimalFormat df = new DecimalFormat("#.#");保留1位小數
編寫equals方法重要說明：
- 對Employee的company屬性的比較。要考慮傳入爲
null的情況。如果company不爲null且傳入爲null，返回false - 對所有String字符類型比較時，也要考慮
null情況。
提示
- 排序可使用Collections.sort
- equals方法要考慮周全
main方法說明
- 創建若干Student對象、Employee對象。
輸入s，然後依次輸入name age gender stuNo clazz創建Student對象。
輸入e，然後依次輸入name age gender salary company創建Employee對象。
然後將創建好的對象放入List personList。輸入其他字符，則結束創建。
創建說明: 對於String類型，如果爲null則不創建對象，而賦值爲null。對於company屬性，如果爲null則賦值爲null，否則創建相應的Company對象。 - 對personList中的元素實現先按照姓名升序排序，姓名相同再按照年齡升序排序。提示：可使用
Comparable或Comparator - 接受輸入，如果輸入爲
exit則return退出程序，否則繼續下面步驟。 - 將personList中的元素按照類型分別放到stuList與empList。注意：不要將兩個內容相同的對象放入列表（是否相同是根據equals返回結果進行判定）。
- 輸出字符串
stuList，然後輸出stuList中的每個對象。 - 輸出字符串
empList，然後輸出empList中的每個對象。
1-3爲一個測試點 4-6爲一個測試點
輸入樣例：
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
輸出樣例：
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
參考答案
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.Scanner;
class Person {
private String name;
private int age;
private boolean gender;
private String str;
Person(String name, int age, boolean gender, String str) {
this.name = name;
this.age = age;
this.gender = gender;
this.str = str;
}
public String toString() {
return name + "-" + age + "-" + gender;
}
@Override
public boolean equals(Object obj) {
Person aPerson = (Person) obj;
if (aPerson.name == null || this.name == null) {
return false;
}
return aPerson.name.compareTo(this.name) == 0 && aPerson.age == this.age && aPerson.gender == this.gender;
}
String getName() {
return name;
}
int getAge() {
return age;
}
String getStr() {
return str;
}
}
class Student extends Person {
private String stuNo;
private String clazz;
Student(String name, int age, boolean gender, String str, String stuNo, String clazz) {
super(name, age, gender, str);
this.stuNo = stuNo;
this.clazz = clazz;
}
public String toString() {
return super.toString() + "-" + stuNo + "-" + clazz;
}
public boolean equals(Object obj) {
Student a = (Student) obj;
if (super.equals(obj)) {
if (this.stuNo == null | this.clazz == null || a.clazz == null || a.stuNo == null) {
return false;
}
return this.clazz.compareTo(a.clazz) == 0 && this.stuNo.compareTo(a.stuNo) == 0;
}
return false;
}
}
class Company {
private String name;
Company(String name) {
this.name = name;
}
@Override
public String toString() {
return name;
}
@Override
public 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) {
return other.name == null;
} else return name.equals(other.name);
}
}
class Employee extends Person {
private Company company;
private double salary;
Employee(String name, int age, boolean gender, String str, Company company, double salary) {
super(name, age, gender, str);
this.company = company;
this.salary = salary;
}
@Override
public String toString() {
return super.toString() + "-" + company.toString() + "-" + salary;
}
@Override
public boolean equals(Object obj) {
if (super.equals(obj)) {
Employee other = (Employee) obj;
if (this.company.toString() == null || other.company.toString() == null) {
return false;
}
String df1 = new DecimalFormat("#.#").format(this.salary);
String df2 = new DecimalFormat("#.#").format(other.salary);
return this.company.toString().compareTo(other.company.toString()) == 0 && df1.compareTo(df2) == 0;
}
return false;
}
}
public class Main {
/**
* @param args null
* @author 徐亮亮
*/
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String c;
String nameString;
int age;
boolean gender;
ArrayList<Person> persons = new ArrayList<>();
ArrayList<Student> students = new ArrayList<>();
ArrayList<Employee> employees = new ArrayList<>();
String tempString;
String stuNoString;
String company;
String clazzString;
double salary;
while (true) {
c = sc.next();
if (c.compareTo("s") == 0) {
nameString = sc.next();
age = sc.nextInt();
gender = sc.nextBoolean();
stuNoString = sc.next();
clazzString = sc.next();
Student tempStudent = new Student(nameString, age, gender, c, stuNoString, clazzString);
persons.add(tempStudent);
} else if (c.compareTo("e") == 0) {
nameString = sc.next();
age = sc.nextInt();
gender = sc.nextBoolean();
salary = sc.nextDouble();
company = sc.next();
Company company2 = new Company(company);
Employee tempEmployee = new Employee(nameString, age, gender, c, company2, salary);
persons.add(tempEmployee);
} else {
persons.sort(Comparator.comparing(Person::getName).thenComparingInt(Person::getAge));
for (Person person : persons) {
if (person.getStr().compareTo("s") == 0) {
System.out.println("Student:" + person.toString());
int flag = 0;
for (Student student : students) {
if (student.equals(person)) {
flag = 1;
break;
}
}
if (flag == 0) {
students.add((Student) person);
}
} else {
System.out.println("Employee:" + person.toString());
int flag = 0;
for (Employee employee : employees) {
if (employee.equals(person)) {
flag = 1;
break;
}
}
if (flag == 0) {
employees.add((Employee) person);
}
}
}
tempString = sc.next();
if (tempString.compareTo("exit") == 0 || tempString.compareTo("return") == 0) {
return;
}
System.out.println("stuList");
for (Student student : students) {
System.out.println("Student:" + student.toString());
}
System.out.println("empList");
for (Employee employee : employees) {
System.out.println("Employee:" + employee.toString());
}
}
}
}
}