jmu-Java-03面向对象-06-继承覆盖综合练习-Person、Student、Employee、Company (20 分) ///答案，不包括解析

 

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：

  1. 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
  2. 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

  1. 创建若干Student对象、Employee对象。
    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
答案

import java.awt.List;
import java.awt.TexturePaint;
import java.lang.reflect.Array;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Scanner;

import javax.naming.BinaryRefAddr;
import javax.security.auth.SubjectDomainCombiner;
import javax.sound.sampled.Line;

class Person{
	private String name;
	private int avg;
	private boolean gender;
	private String str;
	public Person(String name, int avg, boolean gender,String str) {
		this.name = name;
		this.avg = avg;
		this.gender = gender;
		this.str = str;
	}
	public String toString() {
		return name+"-"+avg+"-"+gender;
	}
	public boolean equals(Object obj) {
		Person aPerson = (Person)obj;
		if(aPerson.name==null||this.name==null) {
			return false;
		}
		if(aPerson.name.compareTo(this.name)==0&&aPerson.avg==this.avg&&aPerson.gender==this.gender) {
			return true;
		}
		return false;
	}
	public String getName() {
		return name;
	}
	public int getAvg() {
		return avg;
	}
	public String getStr() {
		return str;
	}
	public boolean getGender() {
		return gender;
	}
}

class Student extends Person {
	private String stuNo;
	private String clazz;
	
	public Student(String name, int avg, boolean gender, String str, String stuNo, String clazz) {
		super(name, avg, 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)==true) {
			if(this.stuNo==null|this.clazz==null||a.clazz==null||a.stuNo==null) {
				return false;
			}
			if(this.clazz.compareTo(a.clazz)==0&&this.stuNo.compareTo(a.stuNo)==0)
				return true;
		}
		return false;
	}
	public String getStuNo() {
		return stuNo;
	}
	public String getClazz() {
		return clazz;
	}
}

class Company{
	private String name;
	public 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) {
			if (other.name != null)
				return false;
		} else if (!name.equals(other.name))
			return false;
		return true;
	}
}

class Employee extends Person{
	private Company company;
	private double salary;
	public Employee(String name, int avg, boolean gender, String str, Company company, double salary) {
	    super(name, avg, 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)==true) {
			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);
			if(this.company.toString().compareTo(other.company.toString())==0&&df1.compareTo(df2)==0) {
				return true;
			}
		}
		return false;
	}
	public Company getCompany() {
		return company;
	}
	public double getSalary() {
		return salary;
	}
	
}
public class Main {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		String c;
		String nameString;
		int avg;
		boolean gender;
		ArrayList<Person> persons = new ArrayList<Person>();
		ArrayList<Student> students = new ArrayList<Student>();
		ArrayList<Employee> employees = new ArrayList<Employee>();
		String tempString;
		String stuNoString;
		String company;
		String clazzString;
		double salary;
		while(true) {
			c = sc.next();
			if(c.compareTo("s")==0) {
				nameString = sc.next();
				avg = sc.nextInt();
				gender = sc.nextBoolean();
				stuNoString = sc.next();
				clazzString = sc.next();
				Student tempStudent = new Student(nameString, avg, gender, c, stuNoString, clazzString);
				persons.add(tempStudent);
			}else if(c.compareTo("e")==0) {
				nameString = sc.next();
				avg = sc.nextInt();
				gender = sc.nextBoolean();
				salary = sc.nextDouble();
				company = sc.next();
				Company company2 = new Company(company);
				Employee tempEmployee = new Employee(nameString, avg, gender, c, company2, salary);
				persons.add(tempEmployee);
			}else {
				persons.sort(Comparator.comparing(Person::getName).thenComparingInt(Person::getAvg));
				for(int i=0;i<persons.size();i++) {
					if(persons.get(i).getStr().compareTo("s")==0) {
						System.out.println("Student:"+persons.get(i).toString());
						int flag = 0;
						for(int j=0;j<students.size();j++) {
							if(students.get(j).equals(persons.get(i))) {
								flag=1;
								break;
							}
						}
						if(flag == 0) {
							students.add((Student) persons.get(i));
						}
						
					}else {
						System.out.println("Employee:"+persons.get(i).toString());
						int flag = 0;
						for(int j=0;j<employees.size();j++) {
							if(employees.get(j).equals(persons.get(i))) {
								flag = 1;
								break;
							}
						}
						if(flag == 0) {
							employees.add((Employee)persons.get(i));
						}
						
					}
				}
				tempString = sc.next();
				if(tempString.compareTo("exit")==0||tempString.compareTo("return")==0) {
					return;
				}
				System.out.println("stuList");
				for(int i=0;i<students.size();i++) {
					System.out.println("Student:"+students.get(i).toString());
				}
				System.out.println("empList");
				for(int i=0;i<employees.size();i++) {
					System.out.println("Employee:"+employees.get(i).toString());
				}
				
			}
		}
	}
}

　　

 
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原文地址：https://www.cnblogs.com/haijie-wrangler/p/11345661.html