写法一：
    要写的类作为public calss，添加main方法用于测试

    1. import java.time.LocalDate;
    3. public class Employee {
    4.     private String name;
    5.     private double salary;
    6.     private LocalDate hireDay;
    8.     public Employee(String n, double s, int year, int month, int day) {
    9.         name = n;
    10.         salary = s;
    11.         hireDay = LocalDate.of(year, month, day);
    12.     }
    14.     public String getName() {
    15.         return name;
    16.     }
    18.     public double getSalary() {
    19.         return salary;
    20.     }
    22.     public LocalDate getHireDay() {
    23.         return hireDay;
    24.     }
    26.     public void raiseSalary(double byPercent) {
    27.         double raise = salary * byPercent / 100;
    28.         salary += raise;
    29.     }
    31. /*    
    32.     public static void main(String[] args){
    33.         // to do some tests
    34.     }
    35. */
    37. }

    写法二：
    要写的类作为public class，再写一个测试类
    捕获.PNG

    写法三：
    要写的类作为public calss，测试类单独存放

    写法四：
    要写的类作为class，测试类作为public class

    1. import java.time.*;
    3. /*
    4.  * This program tests the Employee class
    5.  * @version 1.0 2020-05-07
    6.  * @author Java Core Volume 1 page 104
    7.  */
    9. public class EmployeeTest {
    11.     public static void main(String[] args) {
    13.         Employee[] staff = new Employee[3];
    15.         staff[0] = new Employee("Alice", 7500, 1987, 12, 15);
    16.         staff[1] = new Employee("Bob", 5000, 1989, 10, 1);
    17.         staff[2] = new Employee("Carl", 4000, 1990, 3, 15);
    19.         // raise everyone's salary by 5%
    20.         for(Employee e : staff) {
    21.             e.raiseSalary(5);
    22.         }
    24.         // print out info about all employees
    25.         for(Employee e : staff) {
    26.             System.out.println("name=" + e.getName() + ", salary=" + e.getSalary() 
    27.                                 + ", hireDay=" + e.getHireDay());    
    28.         }
    29.     }
    31. }
    33. class Employee{
    34.     private String name;
    35.     private double salary;
    36.     private LocalDate hireDay;
    38.     public Employee(String n, double s, int year, int month, int day) {
    39.         name = n;
    40.         salary = s;
    41.         hireDay = LocalDate.of(year, month, day);
    42.     }
    44.     public String getName() {
    45.         return name;
    46.     }
    48.     public double getSalary() {
    49.         return salary;
    50.     }
    52.     public LocalDate getHireDay() {
    53.         return hireDay;
    54.     }
    56.     public void raiseSalary(double byPercent) {
    57.         double raise = salary * byPercent / 100;
    58.         salary += raise;
    59.     }
    60. }