java - 编译成功但运行时出现错误

Question

我是 Java 初学者，当我尝试运行我的程序时感到困惑......编译后显示编译成功但是当我尝试运行它时，它就会向我显示这条消息。

    Exception in thread "main" java.lang.NoSuchMethodError: employee.<init>(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;D)V
    at academic.<init>(academic.java:19)
    at testEmployee.main(testEmployee.java:16)

Process completed.

我创建了一个父类(super class)和 2 个子类。我仍然不确定我的代码，无法自己找到问题。这是我的代码。

员工.java

 public class employee {
    protected String id;
    protected String name;
    protected String ic;
    protected String tel;
    protected double salary;
    protected boolean showEmployee;
    protected static int count;

    public employee(){
        id ="A00000";
        name = "Michele Wong";
        ic = "920412-14-5443";
        tel = "014-6667733";
        salary = 999.00;
    }

    public employee(String id, String name, String ic, String tel, double salary, boolean showEmployee) {
        this.id = id;
        this.name = name;
        this.ic = ic;
        this.tel = tel;
        this.salary = salary;
        this.showEmployee = showEmployee;
        count++;
    }
      public void setId(String id){
        this.id = id;
      }

      public String getId(){
        return id;
      }

      public void setName(String name){
        this.name = name;
      }

      public String getName(){
        return name;
      }

      public void setIc(String ic){
        this.ic = ic;
      }

      public String getIc(){
        return ic;
      }

      public void setTel(String tel){
        this.tel = tel;
      }

      public String getTel(){
        return tel;
      }

      public void setSalary(double salary){
        this.salary = salary;
      }

      public double getSalary(){
        return salary;
      }

      public void setShowEmployee(boolean showEmployee){
        this.showEmployee = showEmployee;
      }

      public boolean getShowEmployee(){
        return this.showEmployee;
      }

      public String toString(){
        return getId()+ "\t\t\t" +getName()+ "\t\t" +getIc()+ "\t\t" +getTel()+"\t\t";
      }
}

admin.java

    public class admin extends employee{
    private String position;
    private String department;

    public admin() {
        super();
    }

    public admin(String id, String name, String ic, String tel, double salary, String position, String department) {
        super(id, name, ic, tel, salary);
        this.position = position;
        this.department = department;

    }

    public void setPosition(String position){
        this.position = position;
    }

    public String getPosition(){
        return position;
    }

    public void setDepartment(String department){
        this.department = department;
    }

    public String getDepartment(){
        return department;
    }

    public double calculateSalary(){
        return super.getSalary() + 100;
    }

    public void DeleteAdmin(){

    }

    public String toString(){
        return super.toString()+ "\t" +getPosition()+ "\t\t\t" +getDepartment()+ "\t\t\t" +calculateSalary();
    }


}

学术.java

    public class academic extends employee{
    private String subject;
    private String school;

    public academic(){
        super();
    }

    public academic(String id, String name, String ic, String tel, double salary, String subject, String school){
        super(id, name, ic, tel, salary);
        this.subject = subject;
        this.school = school;

    }

    public void setSubject(String subject){
        this.subject = subject;
    }

    public String getSubject(){
        return subject;
    }

    public void setSchool(String school){
        this.school = school;
    }

    public String getSchool(){
        return school;
    }

    public double calculateSalary(){
        return super.getSalary() + 50;
    }

    public String toString(){
        return super.toString()+ "\t" +getSubject()+ "\t\t" +getSchool()+"\t\t\t" +calculateSalary() ;
    }


}

testEmployee.java

        import java.util.*;
    public class testEmployee {
        private static int totalEmployee = 8;
        private static int employeeID = 1000;

        public static void main(String[]args){

            academic[] aca = new academic[4];
            aca[0] = new academic("A10001", "Jennifer Lee", "930307-14-5556", "012-3456712", 990.00, "Programming", "SAS");
            aca[1] = new academic("A10002", "Harry Tan", "950402-12-2233", "012-1234598", 980.00, "Accounting", "SSH");
            aca[2] = new academic("A10003", "Kelvin Woo", "981225-13-1456", "016-5803157", 990.00, "English for Science", "SBS");
            aca[3] = new academic("A10004", "Terry Yap", "911030-14-5678", "014-9126534", 990.00, "Java", "SAS");

            admin[] admin = new admin[4];
            admin[0] = new admin("A10005", "David Foo", "910922-14-9008", "014-1489763", 1000.00, "Head of Division", "SAS");
            admin[1] = new admin("A10006", "Danny Choo", "930302-15-4443", "012-0987634", 990.00, "Head of Division", "SAD");
            admin[2] = new admin("A10007", "Kelly Tan", "900828-13-3213", "016-8903245", 1100.00,"Head of Division","SOT");
            admin[3] = new admin("A10008", "Donald Heng", "900730-12-6789", "016-9823081", 990.00,"Head of Division","SSH");
            MainMenu(aca, admin);
        }

        //Main Menu
        public static void MainMenu(employee[] aca,employee[] admin){
            Scanner input = new Scanner(System.in);

            System.out.println("********************\n");
            System.out.println("*   MAIN MENU   *\n");
            System.out.println("********************\n");
            System.out.println("1. Display Records \n");
            System.out.println("2. Search Employee\n");
            System.out.println("3. Add Employee\n");
            System.out.println("4. Edit Employee\n");
            System.out.println("5. Delete Employee\n");
            System.out.println("6. Exit \n");
            System.out.print("Please enter your selection: ");
            int selection = input.nextInt();

            switch(selection){
            case 1: Display(aca, admin);
            break;

            case 2: Search(aca, admin);
            break;

            case 3: Add(aca, admin);
            break;

            case 4: Edit(aca, admin);
            break;

            case 5: Delete(aca, admin);
            break;

            case 6:
            System.out.println("Exiting Menu. \nThank you for using the system.");
            System.exit(3);
            break;

            default:
            System.out.println(" Wrong input!\n");
            System.out.println(" Please re-enter \n");
            System.out.println("Press Any Key To Continue...");
            input.nextLine();
            input.nextLine();
            MainMenu(aca, admin);
            break;
          }
        }

        //Display Menu
        public static void Display(employee[] aca,employee[] admin){
            Scanner input = new Scanner(System.in);
            System.out.println("********************\n");
            System.out.println("*   DISPLAY MENU   *\n");
            System.out.println("********************\n");
            System.out.println("1. ACADEMIC \n");
            System.out.println("2. ADMINISTRATIVE \n");
            System.out.println("3. EXIT \n");
            System.out.print("Please enter your selection: ");
            int selection = input.nextInt();

            switch(selection){
            case 1: AcaDisplay(aca, admin);
            break;

            case 2: AdminDisplay(aca, admin);
            break;

            default:
            System.out.println(" Wrong input!\n");
            System.out.println(" Please re-enter \n");
            System.out.println("Press Any Key To Continue...");
            input.nextLine();
            input.nextLine();
            MainMenu(aca, admin);
            break;
            }
        }

        //Display Academic Employee Details
        public static void AcaDisplay(employee[] aca,employee[] admin){
            Scanner input = new Scanner(System.in);
            System.out.println("Employee ID \t Employee Name \t\t Employee IC \t Employee Phone Number \t Subject \t\t School \t Salary ");
            for(int i=0; i <totalEmployee; i++){
                System.out.println(aca[i].toString());
            }

            System.out.print("Continue?(Y/N) ");
            char choice = input.next().charAt(0);

            if(choice == 'y' || choice == 'Y'){
                 MainMenu(aca, admin);
              }
              else if(choice == 'n' || choice == 'N'){
                System.out.println("Exiting Menu. \nThank you for using the system.");
                System.exit(3);
              }
              else {
                System.out.print("\nWrong input. \n Please re-type.");
                AcaDisplay(aca,admin);
              }
        }

        //Display Admin Employee Details
        public static void AdminDisplay(employee[] aca,employee[] admin){
            Scanner input = new Scanner(System.in);
            System.out.println("Employee ID \t Employee Name \t Employee IC \t Employee Phone Number \tEmployee Position \t\t Department \tSalary ");
            for(int i=0; i <totalEmployee; i++){
                System.out.println(admin[i].toString());
            }
            System.out.print("Continue?(Y/N) ");
            char choice = input.next().charAt(0);

            if(choice == 'y' || choice == 'Y'){
                 MainMenu(aca, admin);
              }
              else if(choice == 'n' || choice == 'N'){
                System.out.println("Exiting Menu. \nThank you for using the system.");
                System.exit(3);
              }
              else {
                System.out.print("\nWrong input. \n Please re-type.");
                AdminDisplay(aca,admin);
              }
        }

        //Search Employee
        public static void Search(employee[] aca,employee[] admin){
            Scanner input = new Scanner(System.in);
            System.out.print("Enter Employee ID: ");
            String search = input.nextLine();
            for(int i=0; i<totalEmployee; i++){
                if(aca[i].getId() == search){
                    System.out.println("Employee ID \t Employee Name \t\t Employee IC \t Employee Phone Number \t Subject \t\t School \t Salary ");
                    System.out.println(aca[i].toString());
                    }

                else if(admin[i].getId() == search){
                    System.out.println("Employee ID \t Employee Name \t Employee IC \t Employee Phone Number \tEmployee Position \t\t Department \tSalary ");
                    System.out.println(admin[i].toString());
                    }
                else {
                    System.out.print("\nWrong input. \n Please re-type.");
                    Search(aca,admin);
                     }

                }

        }

        //Add Employee
        public static void Add(employee[] aca,employee[] admin){
            Scanner input = new Scanner(System.in);
            System.out.println("********************\n");
            System.out.println("*   DISPLAY MENU   *\n");
            System.out.println("********************\n");
            System.out.println("1. ACADEMIC \n");
            System.out.println("2. ADMINISTRATIVE \n");
            System.out.println("3. EXIT \n");
            System.out.print("Please enter your selection: ");
            int selection = input.nextInt();

            if(selection == 1)
                System.out.println("Academic");
            else
                System.out.println("Administrative");

            Scanner add = new Scanner(System.in);
            char choice;

            do{
                System.out.print("\nEnter New Employee ID :");
                String newID = add.nextLine();
                System.out.print("Enter New Employee Name :");
                String newName = add.nextLine();
                System.out.print("Enter New Employee IC :");
                String newIC = add.nextLine();
                System.out.print("Enter New Employee Phone Number :");
                String newPhoneNumber = add.nextLine();
                System.out.print("Enter New Employee Salary :");
                double newSalary = add.nextDouble();

                if(selection == 1){
                    System.out.print("Enter New Employee Subject :");
                    String newSubject = add.nextLine();
                    add.nextLine();
                    System.out.print("Enter New Employee School :");
                    String newSchool = add.nextLine();
                    aca[totalEmployee] = new academic(newID,newName,newIC,newPhoneNumber,newSalary,newSubject,newSchool);
                    System.out.print(aca[totalEmployee].toString());
                    }
                else{
                    System.out.print("Enter New Employee Position :");
                    String newPosition = add.nextLine();
                    add.nextLine();
                    System.out.print("Enter New Employee Department :");
                    String newDepartment = add.nextLine();
                    admin[totalEmployee] = new academic(newID,newName,newIC,newPhoneNumber,newSalary,newPosition,newDepartment);
                    System.out.print(admin[totalEmployee].toString());
                    }

                System.out.print("\nDo you want to add more ? (Y/N)");
                choice = add.next().charAt(0);

        }while(choice == 'Y' || choice == 'y');
        MainMenu(aca, admin);
        }

        //Edit Employee
        public static void Edit(employee[] aca,employee[] admin){
            Scanner input = new Scanner(System.in);
            System.out.print("Enter the employee's ID");
            String id = input.nextLine();
            for(int i=0; i<totalEmployee; i++){
                if(aca[i].getId() == id){
                    String AcaID = aca[i].getId();
                    System.out.print("Enter employee's name: ");
                    String name = input.nextLine();
                    System.out.print("Enter employee's IC number(eg.930302-14-5434): ");
                    String IC = input.nextLine();
                    System.out.print("Enter employee's Phone Number: ");
                    String tel = input.nextLine();
                    System.out.print("Enter the Salary: ");
                    double salary = input.nextDouble();
                    System.out.print("Enter the Subject: ");
                    String subject = input.nextLine();
                    System.out.print("Enter the School: ");
                    String school = input.nextLine();
                    admin[i] = new academic(id,name,IC, tel, salary, subject, school);
                    }
                    else if(admin[i].getId() == id){
                        String AdminID = admin[i].getId();
                        System.out.print("Enter employee's name: ");
                        String name = input.nextLine();
                        System.out.print("Enter employee's IC number(eg.92030-10-55588): ");
                        String IC = input.nextLine();
                        System.out.print("Enter employee's Phone Number: ");
                        String tel = input.nextLine();
                        System.out.print("Enter the Salary: ");
                        double salary = input.nextDouble();
                        System.out.print("Enter employee's position: ");
                        String position = input.nextLine();
                        System.out.print("Enter employee's department: ");
                        String department = input.nextLine();
                        admin[i] = new academic(id,name,IC, tel, salary, position, department);
                    }
                    else {
                        System.out.print("\nThis ID does not exist. \n Please re-type.");
                        Edit(aca,admin);
                    }
            }
        }

        //Delete Employee
        public static void Delete(employee[] aca,employee[] admin){
            Scanner input = new Scanner(System.in);
            System.out.print("Enter the employee's ID");
            String delete = input.nextLine();
            //int deleteEMP = Integer.parseInt(input);
            for(int i=0; i<totalEmployee; i++){
                if(aca[i].getId() == delete){
                    aca[i].setShowEmployee(false);
                }
                else if(admin[i].getId() == delete){
                    admin[i].setShowEmployee(false);
                }
                else {
                System.out.print("\nWrong input. \n Please re-type.");
                Delete(aca,admin);
              }
            }
        }
}

Answer 1

Employee 有两个构造函数:一个不带参数，另一个带 4 个字符串、一个 double 值和一个 boolean 值。

在academic的第19行中，您尝试使用4个字符串和一个 double 值但没有 boolean 值来调用super(即employee)。由于 employee 中没有这样的构造函数，因此您会收到错误。

这段代码不应该编译。事实上，它确实表明您在编译过程中做了一些奇怪的事情。尝试从头开始编译所有内容，看看是否出现编译错误。