我是java的初学者，当我尝试运行我的程序时被迷惑了...... 编译后，它显示编译成功 但是一旦我尝试运行它，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.
我创建了一个超类和2个子类。我仍然不确定我的代码，也无法自己找到问题。 这是我的代码。
employee.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();
}
}
academic.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);
}
}
}
}
答案 0 :(得分：3)
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和一个布尔值。
在academic的第19行中，您尝试使用4个字符串调用super（employee）并使用double但不使用布尔值。由于employee中没有这样的构造函数，因此会出现错误。
这段代码不应该编译。它确实表明你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，看看是否收到编译错误。
答案 1 :(得分：1)
我很惊讶这个编译。
在管理构造函数中调用
super(id, name, ic, tel, salary);
但员工没有这样的构造函数。你错过了所需的最后一个参数，它是一个布尔值。
另外：您应该将employee类中的count初始化为0以避免NullPointer
答案 2 :(得分：0)
编译后显示编译成功但是一旦我尝试运行它，就会显示这条消息：
java.lang.NoSuchMethodError: employee.<init>(...
这意味着您需要重新编译依赖于employee类构造函数的类。当你这样做时，你很可能会发现你的academic类没有编译。
如果您手动编译（即没有构建工具），每当您进行更改时，最好重新编译所有类。否则，您将错过发生的问题，因为（例如）您删除或更改了方法构造函数或字段的签名。
不是手工编译，而是使用构建工具或IDE。我希望他们能尽快教你这个......
虽然我引起了你的注意，但是你的类名违反了基本的Java风格规则。所有类名都应以大写字母开头。更改类名，并重命名源文件以匹配。
答案 3 :(得分：0)